JP3625305B2 - Ultrasonic diagnostic equipment - Google Patents

Description

となることが考えられるから、適当なしきい値Ｋを導入し、
【数１】
（Ｐ１／Ｐ２）＜Ｋ
となるピクセル領域を心腔領域（又は非心筋領域）と定義することができる。
【０１１３】
そこで、前記心腔域同定回路８０は、ピクセル毎に、レシーバ回路３３の出力信号のレベルＰ１、Ｐ２を比較して、「Ｐ１／Ｐ２」がしきい値Ｋよりも小さい領域を心腔領域のピクセルとして自動的に同定する。この同定結果（すなわち、“（Ｐ１／Ｐ２）＜Ｋ”か否か）に基づいて心腔域表示制御回路８１はＤＳＣ３５に画像データの各ピクセルの表示／非表示情報を送る。ＤＳＣ３５は、その表示／非表示情報に応じてフレーム画像データの各ピクセルをマスク（非表示）する。この結果、第６実施例の場合と同様に、心腔領域を表示しない心筋分布像が得られ、心筋の造影剤による輝度増強の変化を容易に且つ精度良く画像上で同定できる。
【０１１４】
なお、上記心腔域同定回路８０で用いられる論理式は上述したものに限定されることなく、診断対象の状態に応じて変更できる。当然にしきい値Ｋも適宜選択するようにしてよい。
【０１１５】
なおまた、上記第６及び第７実施例では診断対象を心筋とする場合について説明したが、これ以外にも、例えば大血管系であってもよく、その血管壁と血管内部との間の同様の表示／非表示制御に適用してもよい。
【０１１６】
（第８実施例）
第８実施例を図２２及び図２３を参照して説明する。この実施例は、異なる周波数の複数の超音波ビームを同時に生体内に送信し、これに基づくコントラストエコー法を実施する超音波診断装置に関する。すなわち、異なる周波数（基本波成分ｆ１、ｆ２、ｆ３・・・）の複数の超音波ビームを同時に生体内に送信する送信系と、生体内にて生成される、それらの基本周波数間並びにそれらの基本周波数の高調波成分間の和の周波数成分（ｆ１＋ｆ２、ｆ２＋ｆ３、……、Ｎｆ１＋Ｍｆ３、……；Ｍ、Ｎは整数）及び差の周波数成分（ｆ１−ｆ２、ｆ２−ｆ３、・・・、Ｎｆ１−Ｍｆ３、・・・；Ｍ、Ｎは整数）の内の少なくとも１成分以上を含む周波数帯域のエコー信号を受信し信号処理できる受信・処理系と、基本波成分及び非基本波成分のコントラスト像を表示できる表示系とを備えたものであり、生体内の造影剤の非線形散乱に拠る送信周波数成分の和又は差周波数を検出し、これに基づいて生体内に超音波造影剤の分布を映像化するものである。
【０１１７】
これの具体例を示す図２２の超音波診断装置は、２周波数成分（ｆ１、ｆ２）の同時駆動を行い、その差周波数成分（ｆ１−ｆ２）を映像化しようとするものである。
【０１１８】
この超音波診断装置に備えたプローブ１０は前述と同様に振動子グループＡ及びＢに機能上振り分けられ、この内、振動子グループＡの振動子群を第１基本波成分ｆ１の送信用に、また振動子グループＢの振動子群を第２基本波成分ｆ２の送信用に各々当てている。プローブ１０の全振動子は、基本波帯域（ｆ１、ｆ２）とその差周波数帯域（ｆ１−ｆ２）の両方に十分な送受信感度を持たせている。
【０１１９】
送信系としては図示の如く、クロック発生回路２０及び送信フォーカス用の送信遅延回路２１が設けられ、この送信遅延回路２１の出力側に、第１のパルサ回路２２ａ及び第１の送信共振回路２３ａの直列回路と第２のパルサ回路２２ｂ及び第２の送信共振回路２３ｂの直列回路とが併設されている。この内、第１のパルサ回路２２ａの各パルサは第１基本波成分ｆ１を中心周波数にもつ駆動パルスを発生し、第２のパルサ回路２２ｂの各パルサは第２基本波成分ｆ２を中心周波数にもつ駆動パルスを発生する。そして、第１の送信共振回路２３ａは第１基本波成分ｆ１を中心周波数とする設定帯域に共振可能で、振動子グループＡの各振動子に接続されている。第２の送信共振回路２３ｂは第２基本波成分ｆ２を中心周波数とする設定帯域に共振可能で、振動子グループＢの各振動子に接続されている。これらの送信共振回路２３ａ、２３ｂは、各々、前述したと同様に機能するので、パルサが完全なＳｉｎ波駆動ではなくて駆動パルスの高調波成分が含まれていたとしても、それらの高調波成分は除去され、第１、第２基本波成分ｆ１、ｆ２からなる駆動パルスが各々、振動子グループＡ、Ｂに供給される。
【０１２０】
上記第１，第２の送信共振回路２３ａ、２３ｂのパルサ側端は、全チャンネル分のプリアンプを搭載したプリアンプ回路３０を介して受信遅延・加算回路３１に接続されている。この回路３１の出力端は、第１基本波成分ｆ１を抽出する基本波用ＢＰＦ３２ａと差周波数成分「ｆ１−ｆ２」を抽出する差周波用のＢＰＦ３２ｂとを並列に介して、レシーバ回路３３に接続されている。このレシーバ回路３３の出力側にはＤＳＣ３５、モニタ３６が順次設けられている。
【０１２１】
このため、プローブ１０により受信された基本波成分（ｆ１、ｆ２）および差周波数成分「ｆ１−ｆ２」を含むエコー信号は、非共振状態の送信共振回路２３ａ、２３ｂを経てプリアンプ回路３０に送られる。このプリアンプ回路３０でチャンネル毎に増幅されたエコー信号は、受信遅延・加算回路３１で受信フォーカスが掛けられる。この受信処理がなされたエコー信号の中から、基本波用ＢＰＦ３２ａにより一方の基本波成分ｆ１のエコー信号Ｓｆ１が抽出され、差周波数用ＢＰＦ３２ｂにより差周波数成分「ｆ１−ｆ２」のエコー信号Ｓｆ１−ｆ２が抽出され、各々がレシーバ回路３３に送られ、包絡線検波や対数圧縮の処理に付される。この結果、一方の基本波成分ｆ１及び差周波数成分「ｆ１−ｆ２」のエコー信号Ｓｆ１、Ｓｆ１−ｆ２に基づくＢモード像の画像データが個別につくられ、これらがＤＳＣ３５を介してモニタ３６に送られて分割像或いは重畳像として表示される。
【０１２２】
したがって、本実施例によっても第１〜第４実施例と同等の効果が得られるほか、差周波数成分に基づくＢモード像を映像化するため、２次高調波は、送信時に発生し易いが、差周波数成分が発生することはない。したがって、２次高調波を利用するよりＳ／Ｎ比良く検出できる可能性があるという特別の利点もある。
【０１２３】
なお、この第８実施例では超音波ビームの同時駆動数を「２周波」としたが、「３周波」以上であってもよい。また、基本波像を形成する基本波成分としては上述していないもう一方の第２基本波成分ｆ２を用いるようにしてもよい。さらに、基本波像とペアを成す、造影剤の散乱に基づく画像は和周波数成分を使って生成するようにしてもよい。さらに、この実施例において、第１実施例同様に送受信系に対して種々の変形が可能である。
【０１２４】
さらに、複数の周波数の超音波ビームを同時に送信する構成に対しては、複数の周波数成分が線形加算された時間波形を送信できる送信器、シンセサイザー等を備えることもできる。
【０１２５】
（第９実施例）
第９実施例を図２４に基づいて説明する。この実施例に係る超音波診断装置も第８実施例と同様に、生体内で発生した、送信ビーム信号の周波数成分間の和または差の周波数成分を検出・表示することにより、生体内の造影剤の分布の映像化を目的にしている。
【０１２６】
この超音波診断装置に用いるプローブ１０は複合型プローブであって、フェーズド・アレイ・プローブ１０ａとシングルプローブ１０ｂとを備えている。フェーズド・アレイ・プローブ１０ａは、２つの基本波成分ｆ１、ｆ２の内の一方ｆ１の送受信及びそれらの差周波数成分「ｆ１−ｆ２」の受信を担っており、「ｆ１−ｆ２」〜ｆ１の周波数帯域に十分な超音波送受信感度を有している（図２３（ａ）または（ｂ）参照）。これに対し、シングルプローブ１０ｂはもう一方の基本波成分ｆ２の送信専用であり、その基本波成分ｆ２の帯域に十分な送信感度を持たせている。
【０１２７】
また、第８実施例と同様に、送信系には第１、第２のパルサ回路２２ａ、２２ｂが設けられ、第１基本波成分ｆ１の駆動パルスを出力する第１のパルサ回路２２ａがフェーズド・アレイ・プローブ１０ａにチャンネル毎に接続されるとともに、第２基本波成分ｆ２の駆動パルスを出力する第２のパルサ回路２２ｂがシングルプローブ１０ｂに接続されている。また、フェーズド・アレイ・プローブ１０ａには受信・処理系のプリアンプ回路３０が接続され、これ以降は、第８実施例と同一に信号処理される。フェーズド・アレイ・プローブ１０ａとシングルプローブ１０ｂから個々に放射される２つの超音波ビーム信号は、所望の診断部位の位置で交差するようにビーム方向、位置が設定されるとともに、その交差領域を示す画像がモニタ３６に表示されるようになっている。
【０１２８】
この結果、上記交差領域、すなわち診断部位に受信フォーカスされるように受信遅延・加算回路３１により遅延加算処理することで、第８実施例と同様に、第１基本波成分ｆ１及び差周波数成分「ｆ１−ｆ２」のエコー信号に基づくＢモード像が得られる。この実施例では、２つの基本波成分ｆ１、ｆ２の内、第２基本波成分ｆ２をシングルプローブ１０ｂで送信するので、フェーズド・アレイ・プローブは従来用いられているプローブを流用して構成できるという独特の効果がある。
【０１２９】
なお、上記シングルプローブはビーム方向を機械的に偏向可能な構成であってもよい。また、送信共振回路を第１のパルサ回路及びシングルプローブ間と第２のパルサ回路及びフェーズド・アレイ・プローブ間とに各々介挿させる構成も可能である。
【０１３０】
（第１０実施例）
本発明の第１０実施例を、図２５を参照して説明する。
【０１３１】
この第１０実施例は受信可能な非線形波成分（高周波，分調波，超音波または和／差周波数）を発する反射エコー源の移動速度の演算および表示に関する。
【０１３２】
同図に示す超音波診断装置は、第１実施例、すなわち図１と同一の構成に加えて、速度演算部９０を受信・処理系に備えている。具体的には、２次高調波成分を抽出する非線形波用ＢＰＦ３２ｂの出力側が速度演算部９０を介してＤＳＣ３５に至るとともに、基本波用ＢＰＦ３２ａの出力側がレシーバ回路３３を介してＤＳＣ３５に至る。速度演算部９０は、従来周知のドプラ法または相互相関法などの手法を用いて２次元の運動速度データを演算するようになっている。
【０１３３】
このため、受信遅延・加算回路３１により受信フォーカスが掛けられた基本波成分および非基本波成分を含むエコー信号は、基本波用ＢＰＦ３２ａから基本波成分のみのエコー信号Ｓｆとしてレシーバ回路３３に送られる。このため、レシーバ回路３３から、組織の形態情報としてのＢモード像（基本波像）データがＤＳＣ３５に供給される。これに対して、非基本波用ＢＰＦ３２ｂからは、全エコー信号の内の２次高調波成分から成るエコー信号Ｓ２ｆが抽出されて速度演算部９０に送られる。速度演算部９０は例えば特開平６−１１４０５９号に示す如く構成されており、特に、対象部位の先験的に知られている速度範囲に対応する周波数帯域のみのドプラ信号を抽出するフィルタを備えている。この速度演算部９０により、このエコー信号Ｓ２ｆに基づいて、２次高調波成分を発生させるエコー反射源、例えばコントラストエコー法施行時の超音波造影剤（すなわち静脈血流）を含む２次元分布の運動速度データが演算される。この運動速度データはＤＳＣ３５を介して、前述のＢモード像データと共にモニタ３６に送られ、例えばＢモード像を背景とした速度分布像が表示される。これにより、組織内（例えば心筋内）の血流速度が評価できるという利点がある。
【０１３４】
なお、スキャン面のＢモード像上に設定した関心領域のエコー源の運動速度を同時に演算させ、その時間変化を表示させるようにしてもよい。
【０１３５】
（第１１実施例）
本発明の第１１実施例を、図２６を参照して説明する。この実施例に係る超音波診断装置は、超音波造影剤によるコントラストエコー法適用時に、基本波成分のエコーレベルに基づく心筋のような組織の形態情報と、非基本波成分のエコーレベルに基づく組織内血流情報とに加え、基本波成分のエコーレベルに基づいて組織（例えば心筋）の運動速度を演算できるようにし、それら三者、すなわち「組織形態情報」，「組織内血流情報」，及び「組織運動速度」を同時に表示できるようにしたものである。
【０１３６】
これを具体的に説明すると、この超音波診断装置は図１（第１実施例）と同等の構成に加えて、クラッタ除去フィルタ９１，血流用速度演算部９２，及び組織用速度演算部９３を図示の如く備えている。すなわち、基本波用ＢＰＦ３２ａの出力端とＤＳＣ３５の間に、一方のレシーバ回路３２ａ、不要なクラッタ成分を除するクラッタ除去フィルタ９１及び血流の運動速度を演算する血流用速度演算部９２の直列構成、ならびに心筋などの組織の運動速度を演算する組織用速度演算部９３が並設されている。
【０１３７】
非基本波用ＢＰＦ３２ｂは、もう一方のレシーバ回路３２ｂを介してＤＳＣ３５に至る。
【０１３８】
この内、組織用速度演算部９３としては例えば特開平５−８４２４６号で開示された構成のものが知られている。すなわち、受信フォーカスが掛けられたエコー信号を位相検波部でドプラ周波数について位相検波し、この位相検波信号からフィルタ部のＬＰＦにより血流や心臓の弁などに因るドプラ信号を除去し、このフィルタリングされたエコー信号を使って、周波数解析部により、自己相関法やＦＦＴ法の手法に基づいて組織のドプラ偏移周波数の２次元分布のデータを算出するようにしたものである。したがって、この血流用組織演算部９２では、上記ドプラ偏向移周波数の２次元分布データを使って組織の運動速度の最大値や平均値が求められる。なお、上記周波数解析部の解析手法としては、相互相関法であってもよい。
【０１３９】
このために、受信遅延・加算回路３１により受信フォーカスを掛けられた、基本波成分及び非基本波成分を含むエコー信号の中から、基本波用ＢＰＦ３２ａで基本波成分Ｓｆが抽出され且つ非基本波用ＢＰＦ３２ｂで２次高周波成分Ｓ２ｆが抽出される。この内、基本波成分Ｓｆのエコー信号は、レシーバ回路３２ａによりＢモード像の画像データに生成される一方で、クラッタ除去フィルタ９１及び血流用速度演算部９２により血流の速度分布像（例えばカラードプラ（ＣＦＭ）像）の画像データに生成され、且つ、組織用速度演算部９３により組織（例えば心筋）の運動速度分布像の画像データに生成される。一方、２次高調波成分Ｓ２ｆのエコー信号は、もう一方のレシーバ回路３３ｂにより２次高調波成分のＢモード像の画像データに生成される。これら４通りの画像データはＤＳＣ３５に各々送られた後、その時点で指令されている表示態様のフレーム画像データに変換され（各画像データの取捨選択及び合成を含む）、モニタ３６で表示される。
【０１４０】
この表示例を、静脈注入による超音波造影剤に係るコントラストエコー法を心臓に適用した場合について図２７で説明する。同図に示すように、受信・処理系の基本波系のレシーバ回路３３ａを通過したエコー信号が心臓のＢモード像ＩＭｆの画像データを成し、これにより心筋の形態情報や心筋の動きの視覚情報を提供する。また、受信・処理系の２次高調波系を通過したエコー信号が心筋内血流の分布像（ｐｅｒｆｕｓｉｏｎ）ＩＭ２ｆの画像データを提供する。表示の一態様として、ＤＳＣ３５にて、両者ＩＭｆ及びＩＭ２ｆの画像データを重畳することで、複合画像ＩＭｆ＋２ｆがモニタ３６に表示され、この心筋内の血流灌流領域ＲＢ （画像ＩＭｆ＋２ｆ中の黒塗りの部分）がリアルタイムに可視化される。
【０１４１】
また上記基本波系の組織用速度演算部９３を通過したエコー信号が心筋の運動速度の２次元分布像の画像データを成す。そこで、この運動速度の２次元分布像（図示せず）をそのまま表示させるようにしてもよいし、また例えばＤＳＣ３５にてピクセル毎に速度Ｖ＞Ｖｔ（Ｖｔ：与えられた閾値）か否かを判定し、この判定条件に合致した、閾値Ｖｔ以上の運動速度の２次元分布像ＩＭｖの画像データが形成される。この２次元分布像ＩＭｖを表示させることにより、心筋の壁運動異常領域Ｒｗ（画像ＩＭｖ中の白抜きの部分）が可視化される。さらに別の表示態様として、上述の如く閾値処理された心筋運動速度の２次元分布像ＩＭｖと心筋Ｂモード像ＩＭｆ及び心筋内血流分布像ＩＭ２ｆとの三者をＤＳＣ３５にて重畳演算する（壁運動異常領域Ｒｗと血流灌流領域ＲＢとの論理積を演算する）。これにより、モニタ３６には、複合画像ＩＭｆ＋２ｆ＋ｖが表示され、心筋Ｂモード像を背景にして、心筋壁の運動は止まっている（詳細には、壁運動速度がある閾値以下）が、血流は灌流しているという、診断上興味深い領域ＲＷ＋Ｂがリアルタイムに可視化される。
【０１４２】
このように、本実施例によれば、例えば心筋を形態・運動・血液灌流の各観点から個別にリアルタイムに診断できる一方で、それらを総合的にリアルタイムに診断でき、いわゆる心筋のバイアビリティ評価が可能になる。これにより、従来に無い有用な情報を提供することができる。
【０１４３】
（第１２実施例）
本発明の第１２実施例を図２８〜図３０に基づいて説明する。この実施例の超音波診断装置は超音波造影剤に係る非基本波成分による画像データを一定時間間隔で収集し、この収集データから輝度変化曲線（ＴＤＣ：Ｔｉｍｅ Ｄｅｎｓｉｔｙ Ｃｕｒｖｅ）を演算するとともに、この変化曲線の特徴量（パラメータ）を演算するようにしたものである。
【０１４４】
図２８に示すこの実施例の超音波診断装置は、前述した図１（第１実施例）の構成に加えて、上述の一定時間間隔の画像データ収集を行うために、ＥＣＧ（心電計）９５，ＥＣＧ用アンプ９６，及びトリガ信号発生器９７を備えている。ＥＣＧ９５は被検者の各心時相の心電図情報（ＥＣＧ信号）を、ＥＣＧ用アンプ９６を介してトリガ信号発生器９７に送ってくる。このトリガ信号発生器９７は、ＥＣＧ信号の内の例えばＲ波の立ち上がりに応答したトリガパルスを生成してクロック発生回路２０の送受タイミング決定部及びＤＳＣ３５に送る。このため、クロック発生回路２０の送受タイミング決定部は、トリガパルス到来からの一定時間のカウントによって、ＥＣＧ信号の各周期における最適なデータ収集タイングＴｎを決め、このタイミングＴｎに合致した送受信タイミングを含む一連の送受信を送信系及び受信・処理系に行なわせる。このデータ収集タイミングＴｎは、例えば図２９（ａ）に示す如く左心室拡張末期（例えばＲ波から一定時間後）に設定される。したがって、このようにＥＣＧ同期されたデータ収集タイミングＴｎの到来毎に画像データが収集されることになる。
【０１４５】
さらに、この超音波診断装置はその受信・処理系の一部として、ＤＳＣ３５に接続されたイメージメモリ回路９８，輝度変化曲線演算部９９，及びパラメータ演算部１００を備えている。イメージメモリ回路９８はＤＳＣ３５に送られてきた非基本波成分としての２次高調波成分の画像データをデータ収集タイミングＴｎ毎に逐一記憶する。輝度変化曲線演算部９９はＣＰＵ機能を有し、イメージメモリ回路９８に記憶した画像データの内、心筋の一部に設定されたＲＯＩ（このＲＯＩは事前に、又は画像収集後に設置される）の位置に対応した画像データを読み出して輝度変化曲線ＴＤＣのデータを演算する。
【０１４６】
これにより、各心周期におけるＥＣＧ同期されたデータ収集タイミングＴｎ毎に（図２９（ａ）参照）、例えば左室短軸像（同図（ｂ）参照）の画像データが収集され、これらの画像データがイメージメモリ回路９８に格納される。そこで、輝度変化曲線演算部９９により全画像データ収集後に、各画像データのＲＯＩ位置相当のデータが読み込まれ、ＲＯＩ内データを平均するなどの演算を行なって、造影剤注入時刻ｔ０からの経過時間ｔに対する輝度の変化データ（図２９（ｃ）参照）が演算される。なお、この演算は画像データ収集中に一定タイミング毎に行なうことも可能で、これによりイメージメモリ回路９８のメモリ容量を減らすことができる。
【０１４７】
さらに輝度変化曲線演算部９９とＤＳＣ３５の間にはパラメータ演算部１００を設けている。このパラメータ演算部１００はＣＰＵ機能を有し、図３０の処理を順次行なうようになっている。すなわち、輝度変化曲線演算部９９における輝度変化曲線のデータ演算が完了したか否かを判断し（図３０ステップ１００ａ）、完了した場合、その曲線データのフィッティング処理を行なう（同図ステップ１００ｂ）。このフィッティング処理は、得られた輝度変化曲線のデータに対して適当な関数（ガンマ関数，ガウス関数，指数関数など）でフィッティングするもので、これによりノイズや測定誤差の影響を低減させ、本質的な輝度変化が抽出される。なお、このフィッティング処理は輝度変化曲線演算部９９で行なう構成にすることもできるし、必要ある場合のみ行なうようにすることもできる。
【０１４８】
パラメータ演算部１００ではさらに、フィッティング処理した輝度変化曲線データを使って、輝度変化曲線の特徴量を表わす各種のパラメータ、例えば最大輝度レベルＬＭＡＸ，最大輝度時刻ｔＭＡＸ，輝度半減レベルＬＨＦ，輝度半減時刻ｔＨＦ輝度半減時間（＝最大輝度時刻ｔＭＡＸ−輝度半減時刻ｔＨＦ），最大輝度到達時間（注入時刻ｔ０−最大輝度時刻ｔＭＡＸ），コントラスト持続時間（閾値以上の輝度レベルの持続時間）などが演算される（同図ステップ１００ｃ参照）。
【０１４９】
このように演算されたパラメータのデータは、輝度変化曲線のデータと共にＤＳＣ３５に送られ（同図ステップ１００ｄ参照）、例えば基本波像ＩＭｆ及び２次高調波像ＩＭ２ｆの重畳画像ＩＭｆ＋２ｆとの分割表示の態様にて、モニタ３６に表示される。
【０１５０】
これにより、前述した第１実施例と同等な利点のほか、超音波造影剤を用いたコントラストエコー法の実施時に、造影剤、すなわち組織内血流分布像のみの輝度変化及びその特徴量を心周期に影響されない状態で自動的に把握することができ、診断上有益な情報を得ることができる。
【０１５１】
なお、この実施例で設定するＲＯＩ数は複数であってもよい。また画像の収集タイミングはＥＣＧ同期タイミングに限らず、単に定時間間隔やフレーム毎のタイミングであってもよい。さらに収集した画像データの記憶手段も自己の装置内のイメージメモリ回路に限定されず、装置に接続されたＭＯ（光磁気ディスク）やワークステーションであってもよい。
【０１５２】
なお、上記第１２実施例において、周知の如く、輝度変化曲線は組織の同一部位を対象とした場合でないとその意味をなさない可能性が大きい。このため、輝度変化曲線のデータは通常、（１）動かない組織（腹部臓器など）、（２）ＥＣＧ同期された心筋像、などを対象としている。しかし、これでも組織がわずかに動く場合、フレーム毎にＲＯＩの位置を微調整する手段を付加するようにしてもよい。ＲＯＩの微調整は、簡便的には、マウス等でＲＯＩの位置を微調整するマニュアル微調機構で行うようにしてもよい。
【０１５３】
さらに、上述した第１２実施例の処理を拡大して、収集された各画像の全ピクセルまたは全ての複数ピクセルの組に対して同様の演算を、輝度変化曲線演算部及びパラメータ演算部に実行させるように構成し、これにより例えば最大輝度レベルなどのパラメータを２次元表示させることもできる。この結果、最大輝度レベルの２次元分布を一目で観察できるようになり、診断上有益な手立てとなる。
【０１５４】
なお、本発明によれば非基本波成分を意図的（又は積極的）に抑圧する抑圧手段としては、基本波成分のみを通す送信系フィルタを用いることもできる。
【０１５５】
また本発明における抑圧手段としてフィルタや直列共振による送信共振回路を用いる場合、図３１（ａ），（ｂ）のような配置構成を採ることもできる。すなわち同図（ａ）では、プローブ１０とパルサ回路２２及びプリアンプ回路３０との間にフィルタ１１０を挿入するとともに、送信時にこのフィルタ１１０のみを作動させ、且つ受信時にこのフィルタ１１０を回路から切り離して受信用のバイパス路を形成する切換スイッチ１１１を設けたものである。また同図（ｂ）では、同じくプローブ１０とパルサ回路２２及びプリアンプ回路３０との間に送信共振回路としての直列共振用インダクタンス１１２を挿入し、このインダクタンス１１２と並列に送信時オフ、受信時オンとする切換スイッチ１１３を設けたものである。これらの回路構成によっても前述のものと同等の作用効果が得られる。
【０１５６】
【発明の効果】
本発明の超音波診断装置は、超音波パルス信号と電気量の信号との間で互いに双方向に変換可能なプローブと、所望の励振周波数を中心周波数とする基本波成分に対する非基本波成分の信号のレベルを積極的に抑圧して実質的にその基本波成分の励振周波数から成る電気量の駆動パルス信号を前記プローブに与える送信手段と、前記プローブが前記駆動パルス信号に応じて前記超音波信号を放射するとともに該超音波信号の反射信号を受信したことに応じて該プローブから出力される電気量のエコー信号を入力して該エコー信号から前記基本波成分と該エコー信号に含まれる該基本波成分に対する非基本波成分とに関する画像データを生成する受信処理手段と、その画像データを表示する表示手段と、を備えたことを要部とするので、周囲からの組織エコーの影響が大きい部位（心筋、臓器実質など）でも、静脈注入によるコントラストエコー法を実施して、造影剤による輝度増強の像を的確に得ることができる。
【０１５７】
特に、心筋分布像による心筋内血流の灌流域の評価を静脈注入によるコントラストエコー法により可能にする。
【０１５８】
さらに、心壁の運動情報と心筋血流の灌流情報を同時に収集・評価できるとともに、狭心症の診断に使われるストレスエコー法において、それぞれの負荷状態での心壁の運動情報と心筋血流の灌流情報を同時に収集・評価できるなど、より総合的な診断が可能になる。
【図面の簡単な説明】
【図１】本発明の第１実施例に係る超音波診断装置のブロック図。
【図２】送信共振回路の一例を示す回路図。
【図３】第１実施例で得られる画像の例を示す図。
【図４】送信共振回路の他の例を示す回路図。
【図５】第１実施例の変形例に係る超音波診断装置の部分ブロック図。
【図６】第１実施例の別の変形例に係る超音波診断装置の部分ブロック図。
【図７】第１実施例のさらに別の変形例に係る超音波診断装置のブロック図。
【図８】第１実施例のさらに別の変形例に係る超音波診断装置のブロック図。
【図９】本発明の第２実施例に係る超音波診断装置のブロック図。
【図１０】本発明の第２実施例の変形例に係る超音波診断装置のブロック図。
【図１１】（ａ），（ｂ）は各々、振動子の周波数特性を示す図。
【図１２】本発明の第３実施例に係る超音波診断装置のブロック図。
【図１３】本発明の第３実施例の変形例に係る超音波診断装置のブロック図。
【図１４】（ａ）〜（ｃ）は各々、振動子の周波数特性を示す図。
【図１５】本発明の第４実施例に係る超音波診断装置のブロック図。
【図１６】本発明の第５および第６実施例に係る超音波診断装置のブロック図。
【図１７】（ａ），（ｂ）は各々、マネージャの処理例を示す概略フローチャート。
【図１８】本発明の第６実施例に係る超音波診断装置のマネージャの処理例を示す概略フローチャート。
【図１９】本発明の第６実施例に係る超音波診断装置のＤＳＣの処理例を示す概略フローチャート。
【図２０】造影剤の注入に伴う輝度変化曲線と心筋の２次高調波像の変化を示す説明図。
【図２１】本発明の第７実施例に係る超音波診断装置のブロック図。
【図２２】本発明の第８実施例に係る超音波診断装置のブロック図。
【図２３】（ａ），（ｂ）は振動子の周波数特性を示す図。
【図２４】本発明の第９実施例に係る超音波診断装置のブロック図。
【図２５】本発明の第１０実施例に係る超音波診断装置のブロック図。
【図２６】本発明の第１１実施例に係る超音波診断装置のブロック図。
【図２７】第１１実施例における各種画像の組合せ例を示す図。
【図２８】本発明の第１２実施例に係る超音波診断装置のブロック図。
【図２９】ＥＣＧ信号，画像収集タイミング，および輝度変化曲線（ＴＤＣ）の関係を説明する図。
【図３０】輝度変化曲線の特徴量のパラメータを演算するためのフローチャートの概略図。
【図３１】（ａ），（ｂ）は抑圧手段及びその配置の変形例を示す図。
【符号の説明】
１０，１０ａ，１０ｂ プローブ
１１ 装置本体
２０ クロック発生回路（送信手段）
２１ 送信遅延回路（送信手段）
２２，２２ａ，２２ｂ パルサ回路（送信手段）
２３，２３ａ，２３ｂ 送信共振回路（送信手段／抑圧手段）
３０，３０ａ，３０ｂ プリアンプ回路（受信手段）
３１，３１ａ，３１ｂ 受信遅延・加算回路（受信手段）
３２ａ，３２ｂ ＢＰＦ（受信手段）
３３，３３ａ，３３ｂ レシーバ回路（受信手段）
３５ ＤＳＣ（表示手段）
３６ モニタ（表示手段）
５０ 入力器
５１ マネージャ
５２ イメージメモリ回路
５３ スピーカ
５４ 制御回路
５５ 演算回路
８０ 心腔同定回路
８１ 心腔表示制御回路
９０ 速度演算部
９３ 組織用速度演算部
９５ ＥＣＧ
９６ ＥＣＧ用アンプ
９７ トリガ信号発生器
９８ イメージメモリ回路
９９ 輝度変化曲線演算部
１００ パラメータ演算部[0001]
[Industrial application fields]
The present invention relates to an ultrasonic diagnostic apparatus in which an ultrasound contrast agent is injected into a subject and a contrast image is obtained by utilizing the property that echo is enhanced by the strong scattering characteristic of the contrast agent with respect to ultrasound.
[0002]
[Prior art]
In recent years, a contrast echo method using an ultrasonic contrast agent has attracted attention in the field of myocardial image analysis.
[0003]
As one of the contrast echo methods, a myocardial contrast echo method based on arterial injection in which an ultrasound contrast agent is injected from an artery has been studied, and evaluation of a perfusion region of intramyocardial blood flow based on a myocardial distribution image (perfu-sion). It's being used. In this myocardial contrast echo method, an ultrasound contrast agent (for example, 5% human albumin in which bubbles are generated manually or by a sonicator) is injected from a catheter placed in the aorta. The perfusion region of the intramyocardial blood flow due to the contrast agent is displayed as a luminance enhancement region on the B mode. Similarly, in order to evaluate the perfusion zone of the blood flow or the dominant vasculature of the tumor, a contrast echo method using arterial injection has also been studied in the abdominal region. As a diagnostic apparatus for performing these contrast echo methods, an ultrasonic diagnostic apparatus for general examination or a workstation is used. As a result, the luminance enhancement of the B-mode image is visually evaluated. Or Or, after the image data stored in the memory is appropriately processed on the workstation, the change in the brightness level is quantitatively evaluated. Or It is supposed to be.
[0004]
In recent years, an ultrasound contrast agent capable of evaluating the left heart system by injecting an ultrasound contrast agent from a vein has been developed, and an ultrasonic contrast echo method using the same has been attempted.
[0005]
This ultrasound contrast agent is imported and sold by Shionogi Pharmaceutical Co., Ltd. “The average particle diameter of about 4 μm in which air is contained in an albumin film produced when ultrasonically treating 5% human serum albumin. No air spherules "(Brand name: Albunex Note 5ml).
[0006]
The contrast echo method using intravenous injection is currently in the testing and research stages, and in the future, its usefulness is expected to increase in the diagnosis of the head, heart chamber, abdomen, and the like.
[0007]
[Problems to be solved by the invention]
Among the conventional contrast echo methods described above, the contrast echo method by arterial injection requires that the catheter be placed in the aorta, so that the facility (operating room) where it can be performed is limited to a relatively large hospital, and is invasive. It is assumed that it will not be easily spread to general clinics in the future due to the large burden on patients due to the diagnosis accompanied by sex.
[0008]
On the other hand, contrast echo by intravenous injection is extremely invasive and requires less burden on the patient, but the contrast agent reaches the myocardium and other target sites through the lungs, so contrast by arterial injection Compared with the echo method, the contrast agent concentration is reduced, and the degree of brightness enhancement is reduced. For this reason, it is extremely difficult to observe brightness enhancement by contrast agents in areas where the influence of tissue echoes from the surroundings such as the myocardium and the peripheral part of the abdomen is large. It cannot be applied to the evaluation of
[0009]
The present invention has been made in view of the current state of contrast echo method using such a conventional ultrasonic contrast agent. Even in a site (myocardium, organ parenchyma, etc.) where the influence of tissue echo from the surrounding area is large, intravenous injection is performed. An object of the present invention is to provide an ultrasonic diagnostic apparatus that can accurately obtain an image of brightness enhancement by a contrast agent by performing the contrast echo method according to the above.
[0010]
In particular, another object is to provide an ultrasonic diagnostic apparatus that enables evaluation of a perfusion region of intramyocardial blood flow using a myocardial distribution image by a contrast echo method using intravenous injection.
[0011]
Another object of the present invention is to provide an ultrasonic diagnostic apparatus capable of simultaneously collecting and evaluating cardiac wall motion information and myocardial perfusion information because the ultrasonic diagnostic apparatus can evaluate cardiac wall motion. And
[0012]
In addition, in the stress echo method used to diagnose angina pectoris, to provide an ultrasound diagnostic apparatus capable of simultaneously collecting and evaluating heart wall motion information and myocardial perfusion information in each load state, Another purpose.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, an ultrasonic diagnostic apparatus according to the present invention is configured as follows.
[0014]
The ultrasonic diagnostic apparatus according to the present invention includes an ultrasonic pulse A probe capable of bi-directional conversion between a signal and an electric quantity signal, and a signal level of a non-fundamental wave component with respect to a fundamental wave component centered on a desired excitation frequency Repress Transmitting means for supplying the probe with a drive pulse signal of an electric quantity substantially consisting of an excitation frequency of the fundamental wave component; and the probe converts the drive pulse signal into the drive pulse signal. pls respond Ultrasound pulse Radiate signal and ultrasonic pulse An echo signal of an electric quantity output from the probe in response to reception of a reflected signal of the signal is input, and the fundamental wave component and the fundamental wave component included in the echo signal are input from the echo signal. Said The main part includes reception processing means for generating image data related to the non-fundamental wave component and display means for displaying the image data.
[0015]
In particular, the fundamental wave component is composed of one fundamental frequency, and the non-fundamental wave component is composed of at least one of a harmonic component, a subharmonic component, and a superharmonic component of the fundamental component. The non-fundamental wave component is preferably a second harmonic component of the fundamental wave component.
[0016]
In particular, the transmission means is configured to output the non-fundamental wave component. Actively Suppression means for suppressing is provided. This suppression means is, for example, a transmission resonance circuit that is in a resonance state only at the time of transmission and allows only the fundamental wave component of the drive pulse signal to pass. The transmission resonance circuit is a part of the transmission means, and a pulsar circuit and the probe. A configuration interposed between the two is preferable.
[0017]
Further, the fundamental wave component is composed of a plurality of different fundamental frequencies, and the non-fundamental wave component is composed of at least one of the frequency components of the fundamental frequency or the sum or difference of harmonic components of the fundamental frequency. A configuration is preferred. For example, the number of the plurality of different fundamental frequencies is two, and the non-fundamental wave component is a difference between the harmonic components.
[0018]
Further, the ultrasonic diagnostic apparatus applies an ultrasonic contrast echo method for injecting an ultrasonic contrast agent into a subject from a vein to obtain an ultrasonic echo image, and notifies the injection timing of the ultrasonic contrast agent. A notification unit; and a superimposing unit that superimposes elapsed time data after the injection of the ultrasound contrast agent on image data of at least the non-fundamental wave component obtained after the injection of the ultrasound contrast agent.
[0019]
Furthermore, the ultrasonic diagnostic apparatus is an apparatus that applies an ultrasonic contrast echo method for obtaining an ultrasonic echo image by injecting an ultrasonic contrast agent into a subject from a vein, and echoing a tissue such as a myocardium or a blood vessel wall. It further comprises region distinguishing means for distinguishing the level enhancement region from regions outside the tissue such as heart chambers and blood vessels, and region display means for selectively displaying only the echo level enhancement region of the tissue.
[0020]
In particular, the reception processing means comprises: an extraction means for extracting the non-fundamental wave component from the echo signal; and a two-dimensional distribution of motion velocity of a reflected echo source that generates the non-fundamental wave component based on the non-fundamental wave component. Speed calculation means for calculating data, and the display means includes speed display means for displaying the two-dimensional distribution data of the motion speed.
[0021]
In particular, the reception processing means obtains first and second extraction means for extracting the fundamental wave component and the non-fundamental wave component from the echo signal, and obtains image data of tissue morphology information based on the fundamental wave component. Blood in the tissue that generates the non-fundamental wave component based on the non-fundamental wave component; and a first operation means that obtains image data of tissue motion information based on the fundamental wave component. Third computing means for obtaining flow information image data; and image data output means for outputting at least one image data of the tissue morphology information, tissue motion information, and blood flow information in the tissue to the display means; Is provided.
[0022]
Furthermore, the reception processing means generates image data based on the extraction means for extracting the non-fundamental wave component from the echo signal, the extraction means for extracting the non-fundamental wave component, and the non-fundamental wave component. Generation means, storage means for storing image data of the non-fundamental component for a plurality of frames over a predetermined period, and data of luminance change curves of the same part of a tissue (myocardium, etc.) based on the image data for the plurality of frames Time series data calculating means and feature quantity calculating means for calculating the feature quantity of the curve from the brightness change curve data, and the display means displays the brightness change curve together with the feature quantity. Means.
[0023]
[Action]
The drive pulse signal given to the probe from the transmission means has a level of non-fundamental wave component (second harmonic component etc.) substantially and Actively Most of them are reduced to the fundamental wave component and given to the probe. Of this non-fundamental wave component Aggressive Repression is For example, This is preferably implemented by a transmission resonance circuit that resonates only during transmission and passes only the fundamental wave component.
[0024]
For this reason, when the ultrasonic contrast echo method of injecting an ultrasonic contrast agent from a vein is performed, the nonlinear ultrasonic beam scattering of the ultrasonic contrast agent is directly reflected in the non-fundamental wave component of the echo signal. That is, since the ultrasonic beam incident on the subject is substantially only the fundamental wave component, the non-fundamental wave component included in the echo signal depends on the nonlinear scattering of the contrast agent. Therefore, the flow of the contrast agent can be grasped by imaging the non-fundamental wave component. In this way, only the fundamental wave component in advance Substantially Since the processed ultrasonic beam signal is made incident, the contrast echo method of venous injection is applied even to the part where the influence of the tissue echo is large, for example, in the perfusion region of the intramyocardial blood flow by the myocardial distribution image. Evaluation can be suitably performed.
[0025]
It is especially effective for intramyocardial diagnosis, and heart wall motion information is collected at the same time or combined with stress echo method. Or By doing so, it is possible to comprehensively evaluate the function of the heart in relation to the myocardial blood flow.
[0026]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0027]
(First embodiment)
A first embodiment will be described with reference to FIGS. The ultrasonic diagnostic apparatus according to the first embodiment uses a contrast echo method for efficiently detecting a second harmonic component generated by nonlinear scattering of bubbles contained in an ultrasonic contrast agent and displaying the distribution image two-dimensionally. To implement.
[0028]
As shown in FIG. 1, this ultrasonic diagnostic apparatus drives an ultrasonic probe 10 that transmits and receives an ultrasonic signal to and from a subject, and drives the ultrasonic probe 10, and receives a reception signal of the ultrasonic probe 10. It comprises an apparatus body 11 for processing.
[0029]
The ultrasonic probe (hereinafter referred to as “probe”) 10 is configured in a phased array type in which a plurality of transducers are arranged in the scanning direction. Each transducer has the same reception characteristic, and has a sufficiently wide signal passband that can detect the fundamental wave component that drives the transducer and the second-order harmonic component generated in the living body.
[0030]
The apparatus main body 11 includes circuits of a transmission system that drives the probe 10, a reception / processing system that receives and processes signals from the probe 10, and a display system that displays processed images. In addition, there are an input system such as an operation panel and a biological signal detection system such as an ECG, which are omitted in the drawing.
[0031]
The transmission system includes a clock generation circuit 20, a transmission delay circuit 21, a pulsar circuit 22, and a transmission resonance circuit 23. The clock generation circuit 20 is a circuit that generates a clock signal that determines the transmission timing and transmission frequency of the ultrasonic signal, and the transmission delay circuit 21 is a circuit that performs transmission focus by delaying at the time of transmission. The pulsar circuit 22 includes pulsars corresponding to the number of individual paths (hereinafter referred to as “channels”) corresponding to each transducer, generates drive pulses at a transmission timing multiplied by a delay, and transmits to each transducer of the probe 10. It comes to supply.
[0032]
The transmission resonance circuit 23 is a circuit corresponding to one of the features of the present invention, and is equipped to efficiently detect the second harmonic component of the echo signal generated by the ultrasound contrast agent in the living body. . In other words, unless the pulser is completely sine wave driven at the time of transmission, it has a function of removing harmonic components that are always generated. Specifically, as shown in FIG. 2, the transmission resonance circuit 23 includes a limiter 24 composed of a diode antiparallel circuit, and a coil portion that resonates with a capacitive impedance such as a probe or a cable and has a pass band only in the vicinity of the fundamental wave. 25. Since the limiter 24 is turned on when the applied signal value exceeds a certain level, the transmission resonance circuit 23 is in a resonance state only at the time of transmission with a high signal level, and remains in a non-resonance state at the time of reception. A series circuit of the limiter 24 and the coil unit 25 is actually provided for each channel.
[0033]
Further, the reception / processing system includes a preamplifier circuit 30, a reception delay / adder circuit 31, band-pass filters (BPF) 32a and 32b, and a receiver circuit 33 on the output side of the probe 10, for example, in this order. The preamplifier circuit 30 amplifies the power of the reception echo for each reception channel and sends it to the reception delay / adder circuit 31. The reception delay / adder circuit 31 includes a delay unit for each reception channel and an addition unit that adds the delay results, and performs reception focus on the reception echo signal. On the output side of the reception delay / adder circuit 31, the fundamental wave and nonlinear wave bandpass filters 32a and 32b are connected in parallel. The passband of the fundamental wave bandpass filter 32a matches the fundamental wave component of the echo signal, while that of the nonlinear wave bandpass filter 32b matches the second harmonic component of the echo signal. Further, the receiver circuit 33 is a reception processing circuit that obtains an image signal of a B-mode image by performing processing such as envelope detection and log compression for each fundamental wave component and second harmonic component.
[0034]
Furthermore, the reception / processing system includes a DSC (digital scan converter) 35 and a monitor 36. The DSC 35 includes an A / D converter, a multiplexer, a frame memory, a writing / reading circuit, a D / A converter, etc., and forms an image signal of one frame corresponding to the commanded display mode, The standard TV system can be read out. The image signal read from the DSC 35 is output to the monitor 36 and displayed.
[0035]
Then, the effect of 1st Example is demonstrated.
[0036]
At the time of transmission, with the transmission focus applied by the transmission delay circuit 21, Per channel In addition, a drive voltage signal is supplied from the pulsar circuit 22 to each transducer of the probe 10 via the transmission resonance circuit 23. At this time, the limiter 24 of the transmission resonance circuit 23 is kicked on because the drive voltage signal is higher than a predetermined level, and the resonance unit 24 resonates. Due to this resonance, only the fundamental wave component of the drive voltage signal passes through the transmission resonance circuit 23 and is supplied to each transducer of the probe 10.
[0037]
It is practically difficult to drive the pulsar circuit 22 with a sine wave. Normally, the generated drive voltage signal includes a harmonic component. However, the transmission resonance circuit 23 described above causes such a harmonic component to be intentional. Each vibrator is excited by a drive voltage signal of only the fundamental wave component.
[0038]
When each transducer of the probe 10 is excited in this way, an ultrasonic beam signal that is focused on the transmission is transmitted from the probe 10 toward a diagnostic site such as the myocardium of the subject. This ultrasonic beam signal becomes an ultrasonic echo signal reflected and scattered by each tissue of the diagnostic site and an injected ultrasonic contrast agent (for example, “Albnex Note 5 ml” described above: trade name). In particular, the ultrasound contrast agent is composed of minute bubbles, and the echo signal is enhanced by the strong scattering characteristics of the bubbles. This scattering has nonlinear characteristics, and harmonic components are also generated by the scattering of the nonlinear characteristics. As a result, the ultrasonic echo signal includes an echo component (fundamental wave component) from biological tissue other than the contrast agent (bubble) and an echo component (fundamental wave component and its harmonic component) from the contrast agent.
[0039]
This ultrasonic echo signal is received by each transducer of the probe 10 and converted into a corresponding electrical signal. Since the power of the electrical echo signal is weak, each limiter 24 of the transmission resonance circuit 23 is not kicked on, and the transmission resonance circuit 23 remains in a non-resonance state. As a result, the echo signal including the fundamental wave component and the harmonic component reaches the preamplifier circuit 30 without being involved in the transmission resonance circuit 23 and is amplified in power, and then received by the reception delay / adder circuit 30 for each channel. And added. As a result, reception focus is set. The received echo signal is sent in parallel to the fundamental wave BPF 32a and the nonlinear wave BPF 32b. In the fundamental wave BPF 32a, the fundamental wave component Sf of the echo signal is extracted and sent to the subsequent receiver circuit 33, and in the nonlinear wave BPF 32a, only the second harmonic component S2f of the echo signal is extracted. Similarly, it is sent to the receiver 33.
[0040]
The echo signal of the fundamental wave component Sf sent to the receiver circuit 33 is subjected to processing such as envelope detection and logarithmic compression, and image data of a B-mode image (amplitude luminance modulation image) of the fundamental wave component is generated. On the other hand, the echo signal of the second harmonic component S2f sent to the receiver circuit 33 is also subjected to similar processing, and image data of a B mode image of the second harmonic component is generated.
[0041]
The image data of each B-mode image of these fundamental wave components and second-order harmonic components is then converted into image data of the commanded display mode in the DSC 35. There are various display modes of the B mode image IMf (hereinafter simply referred to as “fundamental wave image”) based on the fundamental wave component and the B mode image IM2f (hereinafter simply referred to as “second harmonic image”) based on the second harmonic component. For example, when the contrast echo method is performed, a display mode command for superimposing and displaying the second harmonic image IM2f on the fundamental wave image IMf is issued. In response to this, the DSC 35 also synthesizes both image data and supplies them to the monitor 36. Therefore, as shown in FIG. 3, the monitor 36 displays an image “IMf + 2f” in which the second harmonic image IM2f is superimposed on the fundamental wave image IMf. Is displayed, and the morphology of the living tissue and the distribution of the ultrasound contrast agent therein can be observed.
[0042]
Thus, in this embodiment, the transmission resonance circuit 23 intentionally (positively) cuts harmonic components other than the fundamental component. Substantially Since the ultrasonic beam is transmitted with only the fundamental wave component, most of the second-order harmonic components included in the echo signal are due to the nonlinear scattering characteristics of the ultrasonic contrast agent. In other words, only the second harmonic component resulting from the contrast agent scattering can be selectively processed and imaged with respect to the transmitted fundamental wave component ultrasonic signal. Considering this, the use of an excellent second harmonic component is achieved.
[0043]
In the above embodiment, the second harmonic component is exemplified as the nonlinear wave component to be extracted, but the present invention is not necessarily limited thereto. For example, as other nonlinear wave components, N-order harmonic components (N × f: f is a fundamental frequency, N is a positive integer), N-order subharmonic components (f / N: f is a fundamental frequency, and N is a positive integer) ) And super harmonics (M × f / N: f is a fundamental frequency, and M and N are positive integers other than 1), and their frequency components are selectively selected by the nonlinear wave BPF as described above. May be extracted. In addition, in order to target multiple harmonic components at the same time, a signal extraction / processing system is provided for each of the multiple harmonic components, or a plurality of nonlinear wave components are passed through one system without being separated. Do It is good also as a structure of.
[0044]
In the above embodiment, the signal processing of the fundamental wave component and the nonlinear wave component is performed by separate systems. However, after reception by the preamplifier circuit, the signal processing system is digitized and only one system is used thereafter. The signal processing of the fundamental wave component and the nonlinear wave component may be performed by time division. Further, a memory can be provided to perform signal processing on a desired component.
[0045]
Furthermore, in the above-described embodiment, two BPFs for extracting the fundamental wave component and the nonlinear wave component are inserted in the subsequent stage of the reception delay / adder circuit. May be provided. However, as in the above embodiment, it is advantageous to provide a BPF on the output side of the reception delay / adder circuit because the number of filters can be reduced, so that an increase in device size and an increase in manufacturing cost can be avoided. is there.
[0046]
Furthermore, the probe according to the ultrasonic diagnostic apparatus is not limited to the electronic array probe, but may be a mechanical scanning probe.
[0047]
Furthermore, various modifications can be made to the ultrasonic diagnostic apparatus according to the first embodiment.
[0048]
First, FIG. 4 shows a modification of the transmission resonance circuit 23. In this transmission resonance circuit 23, an on / off electronic switch SW is inserted between the limiter 24 and the transmission / reception line, and in the diagnostic mode for the non-linear scattering component of the contrast agent, the electronic switch SW is turned on. In the normal diagnosis mode for linear scattering components (fundamental wave components), the electronic switch SW is switched off and non-resonant at the time of transmission / reception. The state is obtained. The electronic switch SW is turned on and off by energizing a control signal from a controller (not shown), for example. By configuring and functioning in this manner, the transmission resonance circuit 23 can be disconnected from the circuit in the normal mode, and the functions can be enhanced.
[0049]
Furthermore, in the first embodiment, the beam forming (phased addition) is performed with the RF (high frequency) signal as it is, but a receiving system that performs beam forming after shifting the signal band to the intermediate frequency is also possible. FIG. 5 and FIG. 6 show the modification examples. 5 includes a mixer circuit 41 to which a reference signal of a reference frequency fr is supplied from a reference signal generator 40 between a preamplifier circuit 30 and a reception delay / adder circuit 31, and a signal shifted to an intermediate frequency. It consists of BPFs 32a and 32b that extract fundamental wave components and nonlinear components. The receiving system according to the modification shown in FIG. 6 has a function equivalent to that shown in FIG. 5, and the reference signal generator 40 * sets the reference frequency fr of the reference signal to a fundamental frequency fr = fr (1) nonlinearly. It can be changed to wave fr = fr (2). As a result, the frequency of the reference signal applied to the mixer circuit 41 can be changed between when the fundamental wave component is detected and when the nonlinear wave component is detected, and both components can be detected by a single receiving circuit. . The change of the reference frequency fr may be performed on the same channel by time division, or may be performed for each channel in which the reception channel group is grouped for detecting the fundamental wave component and detecting the nonlinear wave component. .
[0050]
Furthermore, in the first embodiment, the harmonic component generated in the transmission pulsar circuit 22 is reduced. Modifications corresponding to this are shown in FIGS. In the modification according to FIG. 7, a sine wave drive pulsar circuit 43 capable of sine wave drive is provided instead of the pulsar circuit 22 of the first embodiment. Specifically, the pulsar circuit 43 is realized by a circuit configuration including, for example, a pulsar capable of driving a rectangular wave with a duty ratio of 50% and a pulsar capable of class A operation for reducing the second harmonic component. As a result, harmonic components can be reduced without using the transmission resonance circuit as described above, which contributes to simplification and miniaturization of the apparatus.
[0051]
On the other hand, the ultrasonic diagnostic apparatus according to the modification shown in FIG. 8 is a transmission system that removes harmonic components other than the fundamental wave component, subharmonic components, and the like in the transmission circuit between the pulser circuit 22 and the probe 10. The filter circuit 44 is inserted and the transmission resonance circuit is removed. This also increases the circuit size to some extent compared with the case where a transmission resonance circuit is equipped, Harmonic component Can be reduced to a desired level.
[0052]
(Second embodiment)
Next, a second embodiment will be described with reference to FIG. In the second and subsequent embodiments, the same reference numerals are used for the same or equivalent components as those in the first embodiment, and the description thereof is omitted or simplified.
[0053]
The ultrasonic diagnostic apparatus shown in FIG. 9 includes a phased array type probe 10 in which a plurality of transducers 101... 10 n (n is a positive even number) are arranged, and each of the transducers 101. Has sufficient transmission / reception sensitivity in both the frequency band of the fundamental wave component of the signal to be handled and the frequency band of the second harmonic component thereof. The transducer group of the probe 10 is divided into a transducer group A for transmitting / receiving a fundamental wave component and a transducer group B for receiving a second harmonic component in terms of function. As an example of this division, odd-numbered transducers are allocated to transducer group A and even-numbered transducers are allocated to transducer group B as shown in the figure.
[0054]
.., 10n-1 of the transducer group A is connected to a transmission resonance circuit 23 that is formed and functions in the same manner as in the first embodiment. The transmission resonance circuit 23 forms a transmission system together with the clock generation circuit 20, the transmission delay circuit 21, and the pulsar circuit 22.
[0055]
Furthermore, a preamplifier circuit 30a, a reception delay / adder circuit 31a, a fundamental wave BPF 32a, and a receiver 33 circuit that form a reception / processing system for the fundamental wave component are connected to the transmission resonance circuit 23 in parallel with the pulsar circuit 22. ing. On the other hand, the transducers 102, 104,... 10n of the transducer group B include a preamplifier 30b, a reception delay / adder circuit 31b, a nonlinear wave component BPF 32b, and a receiver circuit that form a reception / processing system for nonlinear wave components. 33 is connected. The output side of the receiver circuit 33 is connected to a DSC 35 and a monitor 36 constituting a display system.
[0056]
The effect of this 2nd Example is demonstrated. The transducers 101, 103,... 10n-1 of the transducer group A are excited by each circuit of the transmission system, and an ultrasonic beam signal is transmitted into the subject. At this time, even when each pulsar of the pulsar circuit 22 outputs a vibration signal including a harmonic component due to the fact that the pulsator is not completely sine wave driven, the harmonic component is accurately removed by the transmission resonance circuit 23, and most of them. Since the drive signal composed of the fundamental wave component is supplied to each transducer of the transducer group A for each channel, most of the ultrasonic beam signal transmitted into the subject consists of the fundamental wave component. This ultrasonic beam signal is reflected and scattered by the tissue in the subject and the ultrasonic contrast agent, and is received by all the transducers of the probe 10 as in the first embodiment, and converted into an echo signal of the corresponding electric quantity. Is done.
[0057]
Among these, echo signals including fundamental wave components and second harmonic components output from the vibrators 101, 103,..., 10n-1 of the vibrator group A pass through the transmission resonance circuit 23 in a non-resonant state. , The signal is amplified by the preamplifier for each odd channel of the one preamplifier circuit 30a. The amplified echo signals are subjected to reception delay for each channel by the reception delay / adder circuit 31a and then added to give a reception focus. From this delayed / added echo signal, only the fundamental wave component Sf is extracted by the BPF 32 a for the fundamental wave component, and sent to the receiver circuit 33.
[0058]
On the other hand, echo signals including fundamental wave components and second harmonic components output from the vibrators 102, 104,... 10n of the vibrator group B are amplified by the other preamplifier circuit 30b. The reception focus is similarly applied by the other reception delay / adder circuit 31b. This echo signal is further sent to the band-pass filter 32b for the nonlinear wave component, the second harmonic component S2f is extracted, and this component S2f is also output to the receiver circuit 33.
[0059]
The echo signal of the fundamental wave component Sf and the echo signal of the second harmonic component S2f sent to the receiver circuit 33 are each subjected to envelope detection and logarithmic compression processing, converted into an image signal of a B-mode image, Sent to the DSC 35. For this reason, as in the case of the first embodiment, the monitor 36 displays the fundamental wave image IMf and the second harmonic image IM2f (for example, their weight images) according to a desired display mode.
[0060]
Therefore, the second embodiment can obtain the same effect as that of the first embodiment. In particular, the transducer group of the probe 10 is divided into a transducer group A for transmission and reception and a transducer group B for reception. As a result, the transmission resonance circuit or the like does not require a circuit configuration that is turned ON only during transmission. Therefore, there is an advantage that a mechanism such as series resonance can be easily realized. An example of this “circuit configuration that is turned ON only during transmission” will be described with reference to FIG.
[0061]
Note that the bandpass filters 32a and 32b for extracting the fundamental wave component and the second harmonic component are not limited to the insertion positions described above, but at other positions such as output stages of the preamplifier circuits 30a and 30b. There may be. Similarly to the case of FIG. 8 described above, a transmission resonance filter circuit (see reference numeral 44 in FIG. 8) is provided in place of the transmission resonance circuit 23, and this filter circuit 23 is kept in an operating state at the time of reception. It may be.
[0062]
Furthermore, a modification according to the second embodiment is shown in FIGS. The phased aire type probe 10 of the ultrasonic diagnostic apparatus shown in FIG. 10 is divided into transducer groups A and B as in the second embodiment (FIG. 9). Each of the transducers 101, 103,..., 10n-1 of the transducer group A has a frequency band set so as to respond only to the fundamental wave component f (see FIG. 11A). . Each of the vibrators 102, 104,... 10n of the vibrator group B has a frequency band set so as to respond only to the second harmonic component “2 · f” (FIG. 11B). reference). These frequency bands are set, for example, by changing the resonance frequency of the vibrator for each group.
[0063]
By forming the probe 10 in this way, the ultrasonic signal of only the fundamental wave component is transmitted / received through the transducer group A, and the preamplifier circuit 30a and the reception delay / adder circuit connected to the transducer group A are transmitted. An echo signal of only the fundamental wave component Sf is obtained directly from 31a. Similarly, an echo signal of only the second harmonic component S2f out of the nonlinear wave component generated by nonlinear scattering of the ultrasound contrast agent is received via the transducer group B, and the preamplifier connected to the transducer group B An echo signal of the second harmonic component S2f is obtained directly from the circuit 30b and the reception delay / adder circuit 31b. Therefore, it is not necessary to provide the transmission resonance circuit 23 used in the second embodiment and the band-pass filters 32a and 32b at the time of reception, and the circuit configuration is simplified. This also has the same effect as that of the second embodiment. Is obtained. Further, when a band pass filter is also installed, it is possible to detect a second harmonic with a higher S / N ratio.
[0064]
Further, various circuit configurations are added to the modification shown in FIG.
[0065]
The first is that the signal intensity of the non-fundamental wave component is smaller than that of the fundamental wave component. The preamplifier circuits 30a and 30b of the fundamental wave component system and the non-fundamental wave component system have variable preamplifier gains, and a signal for gain setting is supplied from the gain setting unit 30S. The gain setting unit 30S sets the gain of the non-fundamental component preamplifier circuit 30b higher than that of the fundamental wave component preamplifier circuit 30a. Thereby, the signal strengths of the fundamental wave component and the non-fundamental wave component can be adjusted to be the same or substantially the same, and the S / N ratio imbalance between them can be eliminated.
[0066]
Secondly, when the ultrasonic beam signal is incident on the subject, the attenuation of the ultrasonic signal changes according to the depth in the subject. Specifically, the drive voltage control circuit 22S is connected to the pulsar circuit 22. The drive voltage control circuit 22S receives transmission focus position information from a controller (not shown), and raises the drive voltage of the pulsar circuit 22 in, for example, multiple steps as the transmission focus position becomes deeper from the subject surface.
[0067]
As a result, the transmission sound pressure is kept substantially constant even when the focus position is deepened, so that a tissue image having substantially the same luminance can be obtained in the same blood flow state regardless of the depth position.
[0068]
Thirdly, the reception processing side deals with non-uniformity of various conditions depending on the position in the image (tomogram). In order to do this, a data table 35S is connected to the DSC 35 of the reception processing system. In this data table 35S, correspondence data of “position-correction coefficient” for various conditions such as transmission sound pressure in the tomography, ultrasonic beam width, scan mode, target tissue specificity, and the like that vary depending on the position in the image is stored in advance. Stored. Therefore, when the DSC 35 generates an image based on the non-fundamental wave component, the correction coefficient is read with reference to the data table 35S for each position in the tomography, and the echo level of the non-fundamental wave component is read out. Image data is generated while correcting. As a result, it is possible to accurately avoid a situation in which the image quality changes depending on the position in the tomographic plane.
[0069]
That is, with the control or correction related to the second and third circuit configurations, if the contrast agent distribution is uniform in the tomographic image when applying the ultrasonic contrast echo method by intravenous injection of the ultrasonic contrast agent, the same luminance or Images with the same color can be obtained.
[0070]
The correction using the data table 35S is not necessarily limited to the circuit configuration performed by the DSC 35. For example, the gain of the preamplifier circuit 30b may be adjusted for each channel with the read correction coefficient, or the gain of the receiver circuit 33 may be changed. Like May be.
[0071]
Further, the correction on the reception processing side by the data table 35S and the correction of the transmission sound pressure by the drive voltage control circuit 22S described above may be used in combination.
[0072]
On the other hand, the same various modifications as described in the first embodiment can be made to the second embodiment and its modifications (see, for example, FIGS. 4 to 8). Further, although the second harmonic component is exemplified as the nonlinear wave component, other harmonic components, subharmonic components, and superharmonic components may be imaged.
[0073]
(Third embodiment)
Next, a third embodiment will be described with reference to FIG. The ultrasonic diagnostic apparatus shown in the figure includes a probe 10 formed in the same manner as in FIG. 9 (second embodiment) described above. That is, each transducer of the probe 10 has sufficient sensitivity in both the fundamental wave band and the second harmonic band, and is functionally divided into transducer groups A and B. In this embodiment, the transducer group A Are assigned for transmission and transducer group B is assigned for reception.
[0074]
As shown in the figure, a clock generation circuit 20, a transmission delay circuit 21, a pulser circuit 22, and a transmission resonance circuit 23 are connected in series in this order to the transducers 101, 103,. Yes. On the other hand, the vibrators 102, 104,... 10n of the vibrator group B are connected to the reception delay / adder circuit 31 through the preamplifier circuit 30, and the output side of the circuit 31 is for the fundamental wave and the nonlinear wave. To the receiver circuit 33, DSC 35, and monitor 36 through the band-pass filters 32 a and 32 b in parallel.
[0075]
Subsequently, the function and effect of the third embodiment will be described. Each transducer of the transducer group A passes the drive signal for each odd-numbered channel from the pulsar circuit 22 through the transmission resonance circuit 23, so that the harmonic component is almost removed and the drive signal mainly composed of the fundamental component is used. Excited. As a result, an ultrasonic beam signal consisting mostly of the fundamental wave is transmitted into the subject.
[0076]
On the other hand, an echo signal including a fundamental wave component and a second harmonic component is output from each transducer of the transducer group B corresponding to the ultrasonic signal reflected / scattered in the subject. This echo signal is amplified by the preamplifier circuit 30, subjected to reception focus processing by the reception delay / adder circuit 31, and then supplied to both BPFs 32a and 32b. As a result, the fundamental wave component Sf is extracted by the BPF 32a for one fundamental wave, and the second harmonic component S2f is extracted by the BPF 32b for the other nonlinear wave. Both components are subjected to signal processing in the receiver circuit 33 in the same manner as described above, and converted into respective B-mode image signals. A B mode fundamental wave image and a second harmonic image are displayed on the monitor 36 based on the fundamental wave and second harmonic image signals.
[0077]
As a result, the same effects as those of the above-described embodiments can be obtained, and the set of the preamplifier circuit and the reception delay / adder circuit can be reduced to one set as compared with the configuration of FIG. 9 (second embodiment).
[0078]
A modification of the third embodiment is shown in FIGS. The ultrasonic diagnostic apparatus shown in FIG. 13 includes a phased array type probe 10, and the transducer group of this probe 10 is functionally divided into transducer groups A and B as in the third embodiment. . Among these, the transducers 101, 103,..., 10n-1 of the transducer group A respond to only the fundamental wave component f by using a method such as changing the transducer thickness (FIG. 14A). The frequency band is set, whereas the transducers 102, 104,... 10n of the transducer group B respond to the fundamental wave component f and the second harmonic component “2 · f”. The frequency band is set (see FIG. 14B or FIG. 14C). As shown in the figure, a clock generation circuit 20, a transmission delay circuit 21, and a pulsar circuit 22 are connected to each transducer of the transducer group A. On the output side of each transducer of the transducer group B, a preamplifier circuit 30, A reception delay / addition circuit 31, BPFs 32a and 32b for fundamental waves and nonlinear waves, a receiver circuit 33, a DSC 35, and a monitor 36 are provided. As a result, the same operational effects as those of the third embodiment (FIG. 12) can be obtained, and the transmission resonance circuit 23 becomes unnecessary as compared with that of FIG.
[0079]
Note that the third embodiment and its modifications can be further modified in the same manner as in the first embodiment (see, for example, FIGS. 4 to 8). Further, although the second harmonic component is exemplified as the nonlinear wave component, other harmonic components, subharmonic components, and superharmonic components may be imaged.
[0080]
(Fourth embodiment)
Fourth embodiment The figure Explanation will be made with reference to FIG. The ultrasonic diagnostic apparatus shown in the figure includes a probe 10 formed in the same manner as in FIG. 9 (second embodiment) described above. That is, each transducer of the probe 10 has sufficient sensitivity in both the fundamental wave band and the second harmonic band, and is functionally divided into transducer groups A and B. In this embodiment, the transducer group A Are assigned for transmission and reception, and transducer groups A and B are assigned for reception.
[0081]
As shown in the figure, a clock generation circuit 20, a transmission delay circuit 21, a pulser circuit 22, and a transmission resonance circuit 23 are connected in series in this order to the vibrators 101, 103,. Yes. On the other hand, each channel corresponding to the transducer of the transducer group B and the transducer group A between the transmission resonance circuit 23 and the pulsar circuit 22 is individually delayed by the delay of the reception delay / addition circuit 31 via the preamplifier of the preamplifier circuit 30. And the output side of the circuit 31 reaches the receiver circuit 33, the DSC 35, and the monitor 36 through the band pass filters 32a and 32b for the fundamental wave and the nonlinear wave in parallel.
[0082]
Then, the effect of this 4th Example is demonstrated. Each transducer of the transducer group A receives a drive signal for each channel from the pulser circuit 22 Issue By passing through the signal resonance circuit 23, most of the harmonic components are removed and excited by a drive signal mainly composed of the fundamental wave components. As a result, an ultrasonic beam signal mostly consisting only of the fundamental wave is transmitted in the subject.
[0083]
On the other hand, an echo signal including a fundamental wave component and a second harmonic component is output from each transducer of the transducer groups A and B corresponding to the ultrasonic signal reflected and scattered in the subject. Both echo groups A and B are amplified by the preamplifier circuit 30, subjected to reception focus processing by the reception delay / adder circuit 31, and then supplied to both BPFs 32a and 32b. As a result, the fundamental wave component Sf is extracted by the BPF 32a for one fundamental wave, and the second harmonic component S2f is extracted by the BPF 32b for the other nonlinear wave. Both components are subjected to signal processing in the receiver circuit 33 in the same manner as described above, and converted into respective B-mode image signals. Based on the image signals for the fundamental wave and the second harmonic, the B mode fundamental wave image IMf and the second harmonic image IM2f are displayed on the monitor 36.
[0084]
As a result, the same effects as those of the above-described embodiments can be obtained, and the number of transducers to be received is larger than that of the configurations of FIGS. 12 and 13 (third embodiment and its modifications) (the transducer groups A and Since both B are involved in reception), a higher level echo signal is obtained, which is advantageous in terms of the S / N ratio.
[0085]
(5th Example)
Example 5 The figure A description will be given with reference to FIGS. The fifth embodiment is intended to improve the workability of contrast medium injection and the convenience of image recognition after injection when performing a contrast echo method using an ultrasonic contrast medium.
[0086]
The ultrasonic diagnostic apparatus shown in FIG. 16 has the same probe 10 and apparatus main body 11 as described in the first embodiment (see FIG. 1), while the input device 50 operated by the operator, the procedure stored in advance. A manager 51 that performs processing according to (see FIG. 17), and an image memory circuit 52 and a speaker 53 that operate in response to a command from the manager 51 are included. Among these, the input device 50 is composed of one or more of a keyboard, a trackball, a mouse, and a voice input device, and a schedule for performing contrast echo method (for example, contrast agent injection time, etc.) using the input device 50. Is input to the manager 51. As the input device 50, other storage media such as a floppy disk, a hard disk, a magneto-optical disk, a CD-ROM, a DAT (dat tape), and an MT (magnetic tape) can be used. Further, the image memory circuit 52 sequentially stores, for example, image data of a superimposed image of the fundamental wave image and the second harmonic image converted by the DSC 35. The DSC 35 converts the image data for display, synthesizes the character data instructed by the manager 51, and outputs it to the monitor 36.
[0087]
Further, the manager 51 has a computer configuration such as a dedicated CPU and an internal memory input / output interface, and performs the processing of FIG.
[0088]
That is, first, contrast echo method trial conditions (image quality conditions, TDC (Time-Density-Curve) measurement conditions (ROI, measurement time interval), ECG synchronization conditions, etc.) and contrast echo method trial schedule (contrast agent injection) (Schedule) Time, and when using other drugs together, the amount and timing data) are input from a floppy disk or the like (step 60).
[0089]
Next, the time measurement is started and the display of the time measurement is started on the screen of the monitor 36 (step 61). When this is done, the collection of necessary data is started before injection of the contrast agent (step 62). This data includes an image and luminance data before injection of contrast medium, image data at a desired timing and time interval, ROI luminance data at a desired timing and time interval, and the like. These data are transferred to the MO and workstation.
[0090]
Then, when the scheduled injection time is reached, the contrast agent injection timing is instructed by voice through the speaker 53 (step 63).
[0091]
After that, while collecting the data after injection in the same manner as described above (step 64), when a predetermined time is reached, the injection of another drug is instructed by voice or the like (step 65), and the data after drug injection is collected (step 65). Step 66). When the end time of the predetermined schedule is reached, the collection of image data, the collection of ROI luminance data, the data transfer to the MO or workstation, and the timing are terminated (step 67).
[0092]
Note that the process executed by the manager 51 can be configured as shown in FIG. This allows the operator to instruct the timing of contrast medium injection by voice. For the same processing as in FIG. Is attached.
[0093]
First, data is input in the same manner as in step 60 of FIG. 17A (step 60a), but “contrast agent injection (scheduled) time” is not included in this data. When data input at this step is completed, data before injection (image before injection, luminance data of ROI) is started and data transfer to the MO or workstation is started (step 60b).
[0094]
Next, the operator commands the injection (timing) of the contrast medium from the microphone of the input device 50 at any appropriate time (step 60c). Along with this, timing is also started.
[0095]
Then, after the injection of the contrast agent, collection of images is started at a desired timing and time interval, and luminance data of ROI is started to be collected at a desired timing and time interval.
[0096]
Thereafter, the same processing as in FIG. 17A is performed (steps 65 to 67).
[0097]
By configuring and functioning as described above, when the contrast echo method using the ultrasonic contrast agent is performed, the operator or doctor can accurately perceive the injection timing of the contrast agent and synchronized with the injection timing. In addition, image data including the elapsed time thereafter can be automatically obtained, and later image processing and image interpretation are facilitated.
[0098]
In the fifth embodiment, control may be performed so that ECG data is acquired and an image of a desired cardiac phase at a desired time after injection of a contrast agent is automatically collected. Further, the manager is not necessarily limited to the configuration in which the dedicated CPU is mounted, and the manager may also be used as a CPU unique to the diagnostic apparatus.
[0099]
Furthermore, as a modification of the present embodiment, there is an apparatus having a configuration in which a control circuit 54 and an arithmetic circuit 55 are added as shown in FIG. The control circuit 54 receives the ECG signal and outputs a synchronization signal for instructing the collection timing to the transmission system and the reception / processing example in order to collect data in synchronization with the ECG signal. On the other hand, the control circuit 54 inputs a signal output from an operator or the like, and outputs an image processing start command signal to the arithmetic circuit 55. Upon receiving the command signal, the arithmetic circuit 55 performs subtraction and maximum value hold operations between the images for the plurality of frames of tomographic image data stored in the image memory circuit 52 by ECG synchronization, An image showing a change between images is displayed on the monitor 36 via the DSC 35. Thereby, for example, it is possible to easily grasp the state of the change between the images of the second harmonic image visually.
[0100]
Note that when subtraction is calculated, it is particularly desirable to perform subtraction on the reference image IMref (see FIG. 20) before the contrast agent is injected.
[0101]
Furthermore, the ultrasonic diagnostic apparatus according to the configuration of FIG. 16 can be used in combination with the ultrasonic stress echo method. That is, an ultrasonic contrast echo method by intravenously injecting an ultrasonic contrast agent is performed before and after drug loading. For this purpose, the control circuit 54 causes the image memory circuit 52 to store tomographic image data relating to the non-fundamental wave component S2f of the same time phase and cross section before and after the drug loading. Then, the arithmetic circuit 55 performs a desired calculation such as subtraction between pixels before and after the load, and displays an image of the calculation result on the monitor 36 via the DSC 35. This makes it possible to clearly observe the myocardial region where there is no blood circulation before and after the load.
[0102]
(Sixth embodiment)
A sixth embodiment will be described with reference to FIG. 16 (also used as the fifth embodiment) and FIGS. The sixth embodiment relates to an ultrasound diagnostic apparatus suitable for applying a contrast echo method to the myocardium, and particularly suitable for obtaining a myocardial distribution image. Specifically, when obtaining a myocardial distribution image, the brightness enhancement by the contrast medium in the heart chamber is significantly larger than that of the myocardium, which may prevent identification of the brightness enhancement by the myocardial contrast medium. When this happens, there is a possibility that the brightness of the distribution image of the myocardium cannot be accurately identified.
[0103]
In order to prevent such a situation, the ultrasonic diagnostic apparatus of this embodiment has the configuration shown in FIG. 16, while the manager 51 executes the process shown in FIG. 18 and the DSC 35 executes the process shown in FIG. I try to let them.
[0104]
Referring to FIG. 18, in the case of displaying a myocardial distribution image by the contrast echo method, the manager 51 firstly controls the controller of an apparatus (not shown) at an appropriate timing t0-1 before the time t0 when the contrast agent is injected (see FIG. 20). And so on (steps 70 and 71). A reference image IMref is obtained by this photographing as shown in FIG. 20, and this image IMref is displayed on the monitor 36 and the image data is stored in the image memory of the image memory circuit 52.
[0105]
Next, the cardiac chamber region is identified manually or automatically using the reference image IMref (step 72). In the case of manual operation, the operator identifies the contour of the heart chamber region on the reference image IMref displayed on the monitor 36 by operating the input device 50 and tracing it. In the case of automatic, it can be identified, for example, by discriminating the luminance level of the B-mode image (reference image IMref) with a desired threshold value. As a result, the heart chamber region HSP is determined as shown in FIG. 20, for example (see heart chamber region image IMHSP).
[0106]
Therefore, a mask image is created from the cardiac cavity region image IMHSP, and the data is stored in the image memory circuit 52 (step 73).
[0107]
Further, the processing of FIG. 19 is performed for each frame by the DSC 35 after the contrast agent injection time t0. First, when one frame of image data (for example, superimposed image data of a fundamental wave image and a second harmonic image) is generated, for each pixel, the corresponding pixel of the mask image (heart chamber region image IMHSP) is generated. The pixel value is referred to (step 75). When the pixel value of the corresponding pixel of this mask image is zero, it is recognized as a display pixel, and the process proceeds to the next pixel check without doing anything (steps 76 and 78). However, when the pixel value of the corresponding pixel of the mask image is not zero, the pixel is recognized as a non-display pixel, and its pixel data is set to zero (step 77).
[0108]
As a result, after injection of the contrast agent, the spread of the contrast agent and its intensity (luminance) change with the passage of time thereafter, and an image of the myocardium HM in which the cardiac chamber HSP is masked (for example, IM1 to IM1 in FIG. 20). IM3) is formed and displayed every moment. Therefore, when a myocardial distribution image is obtained, the heart cavity region is not displayed, only the luminance change of the myocardial region is displayed in real time, and the luminance enhancement by the myocardial contrast agent can be accurately performed.
[0109]
Note that the luminance curve in FIG. 20 shows how the average luminance value of a part of the myocardium changes as a representative value of the whole image in order to easily show the luminance enhancement by the contrast agent.
[0110]
(Seventh embodiment)
Example 7 The figure This will be described with reference to FIG. Similarly to the sixth embodiment, in the seventh embodiment, when the contrast echo method is performed on the myocardium, the influence on the display due to the brightness enhancement by the contrast medium in the heart chamber being significantly stronger than that of the myocardium will be improved. Thus, as in the sixth embodiment, the heart chamber region is set as a non-display region, and only the luminance change of the myocardial region is displayed. What is different from the sixth embodiment is a method for identifying a heart chamber region, and pays attention to a level difference or level ratio between a fundamental wave component and a nonlinear wave component.
[0111]
As shown in FIG. 21, the ultrasonic diagnostic apparatus according to this embodiment includes the same configuration as that of FIG. 1 according to the first embodiment, and includes a cardiac chamber identification circuit 80 and a heart between the receiver circuit 33 and the DSC 35. A cavity area display control circuit 81 is provided.
[0112]
Here, the echo level of the fundamental wave component Sf obtained from the receiver circuit 33 is P1, and the echo level of the nonlinear wave component SNL is P2. In contrast echo method using venous injection, both fundamental wave component and nonlinear wave component occur in the heart chamber region due to the contrast medium in the heart chamber, whereas in the myocardial region, the fundamental wave component mainly originates from the myocardial tissue. The nonlinear wave component is generated due to the contrast agent in the myocardium. When this happens,
[Outside 1]

Since an appropriate threshold value K is introduced,
[Expression 1]
(P1 / P2) <K
Can be defined as a cardiac chamber region (or non-myocardial region).
[0113]
Therefore, the heart chamber identification circuit 80 compares the levels P1 and P2 of the output signal of the receiver circuit 33 for each pixel, and determines that the region where “P1 / P2” is smaller than the threshold value K is the heart chamber region. Automatically identify as a pixel. Based on this identification result (that is, whether “(P1 / P2) <K”), the heart chamber display control circuit 81 sends display / non-display information of each pixel of the image data to the DSC 35. The DSC 35 masks (non-displays) each pixel of the frame image data according to the display / non-display information. As a result, as in the case of the sixth embodiment, a myocardial distribution image without displaying the heart chamber region is obtained, and the change in luminance enhancement due to the myocardial contrast medium can be easily and accurately identified on the image.
[0114]
The logical expression used in the cardiac cavity region identification circuit 80 is not limited to the above-described one but can be changed according to the state of the diagnosis target. Of course, the threshold value K may be selected as appropriate.
[0115]
In addition, in the sixth and seventh embodiments, the case where the diagnosis target is the myocardium has been described. However, other than this, for example, a large vascular system may be used, and the same between the vascular wall and the inside of the blood vessel. The display / non-display control may be applied.
[0116]
(Eighth embodiment)
An eighth embodiment will be described with reference to FIGS. This embodiment relates to an ultrasonic diagnostic apparatus that simultaneously transmits a plurality of ultrasonic beams having different frequencies into a living body and performs a contrast echo method based on the transmitted ultrasonic beams. That is, a transmission system that transmits a plurality of ultrasonic beams of different frequencies (fundamental wave components f1, f2, f3...) Simultaneously into the living body, and between the basic frequencies generated in the living body and their Sum frequency components between harmonic components of the fundamental frequency (f1 + f2, f2 + f3,..., Nf1 + Mf3,..., M and N are integers) and difference frequency components (f1-f2, f2-f3,..., Nf1 -Mf3, ...; where M and N are integers), a reception / processing system capable of receiving and processing an echo signal in a frequency band including at least one component and a contrast image of the fundamental wave component and the non-fundamental wave component A display system that can display the image, and the sum or difference frequency of transmission frequency components due to nonlinear scattering of the contrast agent in the living body is detected, and based on this, the distribution of the ultrasonic contrast agent is imaged in the living body Turn into It is.
[0117]
The ultrasonic diagnostic apparatus of FIG. 22 showing a specific example of this is intended to simultaneously drive the two frequency components (f1, f2) and to visualize the difference frequency component (f1-f2).
[0118]
The probe 10 provided in this ultrasonic diagnostic apparatus is functionally allocated to the transducer groups A and B as described above. Among these, the transducer group of the transducer group A is used for transmitting the first fundamental wave component f1. Further, the transducer group of the transducer group B is applied for transmission of the second fundamental wave component f2. All the transducers of the probe 10 have sufficient transmission / reception sensitivity in both the fundamental wave band (f1, f2) and the difference frequency band (f1-f2).
[0119]
As shown in the figure, a clock generation circuit 20 and a transmission delay circuit 21 for transmission focus are provided as the transmission system. On the output side of the transmission delay circuit 21, a first pulser circuit 22a and a first transmission resonance circuit 23a are provided. A series circuit and a series circuit of the second pulser circuit 22b and the second transmission resonance circuit 23b are provided side by side. Among these, each pulser of the first pulser circuit 22a generates a driving pulse having the first fundamental wave component f1 as a center frequency, and each pulser of the second pulser circuit 22b has a second fundamental wave component f2 as a center frequency. A drive pulse having the same is generated. The first transmission resonance circuit 23a can resonate in a set band having the first fundamental wave component f1 as the center frequency, and is connected to each transducer of the transducer group A. The second transmission resonance circuit 23b can resonate in a set band having the second fundamental wave component f2 as a center frequency, and is connected to each transducer of the transducer group B. Since these transmission resonance circuits 23a and 23b each function in the same manner as described above, even if the pulsar is not completely sine wave driven and includes harmonic components of the driving pulse, those harmonic components are not included. Are removed, and drive pulses including the first and second fundamental wave components f1 and f2 are supplied to the transducer groups A and B, respectively.
[0120]
The pulser side ends of the first and second transmission resonance circuits 23a and 23b are connected to a reception delay / adder circuit 31 via a preamplifier circuit 30 equipped with preamplifiers for all channels. The output terminal of the circuit 31 is connected to the receiver circuit 33 through a fundamental wave BPF 32a for extracting the first fundamental wave component f1 and a difference frequency BPF 32b for extracting the difference frequency component “f1-f2” in parallel. Has been. A DSC 35 and a monitor 36 are sequentially provided on the output side of the receiver circuit 33.
[0121]
Therefore, the echo signal including the fundamental wave components (f1, f2) and the difference frequency component “f1-f2” received by the probe 10 is sent to the preamplifier circuit 30 via the non-resonant transmission resonance circuits 23a, 23b. . The echo signal amplified for each channel by the preamplifier circuit 30 is subjected to reception focus by the reception delay / adder circuit 31. The echo signal Sf1 of one fundamental wave component f1 is extracted from the echo signal subjected to the reception processing by the fundamental wave BPF 32a, and the echo signal Sf1-f2 of the difference frequency component “f1-f2” is extracted by the difference frequency BPF 32b. Are respectively sent to the receiver circuit 33 and subjected to envelope detection and logarithmic compression processing. As a result, image data of B-mode images based on the echo signals Sf1 and Sf1-f2 of the one fundamental wave component f1 and the difference frequency component “f1-f2” are individually created and sent to the monitor 36 via the DSC 35. And displayed as a divided image or a superimposed image.
[0122]
Therefore, in addition to obtaining the same effect as the first to fourth embodiments according to the present embodiment, in order to visualize the B-mode image based on the difference frequency component, the second harmonic is easily generated at the time of transmission. No difference frequency component is generated. Therefore, there is a special advantage that there is a possibility that detection can be performed with a better S / N ratio than using the second harmonic.
[0123]
In the eighth embodiment, the number of ultrasonic beams simultaneously driven is “2 frequencies”, but may be “3 frequencies” or more. Further, the other second fundamental wave component f2 not described above may be used as the fundamental wave component forming the fundamental wave image. Furthermore, an image based on the scattering of the contrast agent that is paired with the fundamental wave image may be generated using the sum frequency component. Furthermore, in this embodiment, various modifications can be made to the transmission / reception system as in the first embodiment.
[0124]
Furthermore, for a configuration in which ultrasonic beams having a plurality of frequencies are transmitted simultaneously, a transmitter, a synthesizer, or the like that can transmit a time waveform in which a plurality of frequency components are linearly added can be provided.
[0125]
(Ninth embodiment)
A ninth embodiment will be described with reference to FIG. Similarly to the eighth embodiment, the ultrasound diagnostic apparatus according to this embodiment also detects and displays the sum or difference frequency components of the transmission beam signals generated in the living body, thereby contrasting in the living body. The purpose is to visualize the distribution of the agent.
[0126]
The probe 10 used in this ultrasonic diagnostic apparatus is a composite probe, and includes a phased array probe 10a and a single probe 10b. The phased array probe 10a is responsible for transmission / reception of one of the two fundamental wave components f1 and f2 and reception of the difference frequency component “f1-f2”, and the frequencies of “f1-f2” to f1. It has sufficient ultrasonic transmission / reception sensitivity in the band (see FIG. 23 (a) or (b)). On the other hand, the single probe 10b is dedicated to the transmission of the other fundamental wave component f2, and has sufficient transmission sensitivity in the band of the fundamental wave component f2.
[0127]
Similarly to the eighth embodiment, the transmission system is provided with first and second pulser circuits 22a and 22b, and the first pulser circuit 22a for outputting the drive pulse of the first fundamental wave component f1 is phased A second pulser circuit 22b that is connected to the array probe 10a for each channel and outputs a drive pulse of the second fundamental wave component f2 is connected to the single probe 10b. The phased array probe 10a is connected to a reception / processing preamplifier circuit 30. Thereafter, signal processing is performed in the same manner as in the eighth embodiment. The two ultrasonic beam signals individually radiated from the phased array probe 10a and the single probe 10b are set in the beam direction and position so as to intersect at the position of the desired diagnostic site, and indicate the intersecting region. An image is displayed on the monitor 36.
[0128]
As a result, by performing delay addition processing by the reception delay / adder circuit 31 so as to receive and focus on the intersection region, that is, the diagnostic part, as in the eighth embodiment, the first fundamental wave component f1 and the difference frequency component “ A B-mode image based on the echo signal of “f1-f2” is obtained. In this embodiment, of the two fundamental wave components f1 and f2, the second fundamental wave component f2 is transmitted by the single probe 10b, so that the phased array probe can be configured by using a conventionally used probe. Has a unique effect.
[0129]
The single probe may be configured to mechanically deflect the beam direction. Further, it is possible to adopt a configuration in which the transmission resonance circuit is inserted between the first pulsar circuit and the single probe and between the second pulsar circuit and the phased array probe.
[0130]
(Tenth embodiment)
Tenth embodiment of the present invention The figure This will be described with reference to FIG.
[0131]
The tenth embodiment relates to calculation and display of the moving speed of a reflection echo source that emits a receivable nonlinear wave component (high frequency, subharmonic, ultrasonic wave, or sum / difference frequency).
[0132]
The ultrasonic diagnostic apparatus shown in the figure includes a speed calculation unit 90 in the reception / processing system in addition to the same configuration as that of the first embodiment, that is, FIG. Specifically, the output side of the nonlinear wave BPF 32 b that extracts the second harmonic component reaches the DSC 35 via the speed calculation unit 90, and the output side of the fundamental wave BPF 32 a reaches the DSC 35 via the receiver circuit 33. The speed calculation unit 90 calculates two-dimensional motion speed data using a conventionally known technique such as Doppler method or cross-correlation method.
[0133]
For this reason, the echo signal including the fundamental wave component and the non-fundamental wave component focused by the reception delay / adder circuit 31 is sent from the fundamental wave BPF 32a to the receiver circuit 33 as the echo signal Sf of only the fundamental wave component. . Therefore, B-mode image (fundamental wave image) data as morphological information of the tissue is supplied from the receiver circuit 33 to the DSC 35. On the other hand, the non-fundamental wave BPF 32 b extracts an echo signal S 2 f composed of the second harmonic component of all the echo signals and sends it to the velocity calculation unit 90. The speed calculation unit 90 is configured as shown in, for example, Japanese Patent Application Laid-Open No. 6-114059, and particularly includes a filter that extracts a Doppler signal only in a frequency band corresponding to an a priori known speed range of a target part. ing. Based on the echo signal S2f, the velocity calculation unit 90 generates an echo reflection source that generates a second harmonic component, for example, a two-dimensional distribution including an ultrasound contrast agent (ie, venous blood flow) when the contrast echo method is performed. Motion speed data is calculated. This motion speed data is sent to the monitor 36 together with the aforementioned B-mode image data via the DSC 35, and for example, a speed distribution image with the B-mode image as a background is displayed. Thereby, there exists an advantage that the blood-flow velocity in a structure | tissue (for example, intramyocardium) can be evaluated.
[0134]
Note that the motion speed of the echo source of the region of interest set on the B-mode image on the scan plane may be calculated simultaneously, and the change with time may be displayed.
[0135]
(Eleventh embodiment)
Eleventh embodiment of the present invention The figure This will be described with reference to FIG. The ultrasonic diagnostic apparatus according to this embodiment is configured to apply tissue contrast information based on an echo level of a fundamental wave component and tissue information based on an echo level of a non-fundamental wave component when applying a contrast echo method using an ultrasound contrast agent. In addition to the internal blood flow information, the motion speed of the tissue (for example, myocardium) can be calculated based on the echo level of the fundamental wave component. And “tissue motion speed” can be displayed simultaneously.
[0136]
More specifically, this ultrasonic diagnostic apparatus has a configuration equivalent to that of FIG. 1 (first embodiment), a clutter removal filter 91, a blood flow velocity calculation unit 92, and a tissue velocity calculation unit 93. As shown in the figure. That is, between the output end of the fundamental wave BPF 32a and the DSC 35, one receiver circuit 32a, a clutter removal filter 91 that removes unnecessary clutter components, and a blood flow velocity calculation unit 92 that calculates a blood flow motion velocity are connected in series. A tissue speed calculator 93 that calculates the structure and the motion speed of the tissue such as the myocardium is provided in parallel.
[0137]
The non-fundamental wave BPF 32b reaches the DSC 35 via the other receiver circuit 32b.
[0138]
Among these, as the tissue speed calculation unit 93, for example, a structure disclosed in Japanese Patent Laid-Open No. 5-84246 is known. That is, the echo signal subjected to reception focus is phase-detected with respect to the Doppler frequency by the phase detection unit, and the Doppler signal due to the blood flow or the heart valve is removed from the phase detection signal by the LPF of the filter unit. Using the echo signal thus obtained, the frequency analysis unit calculates the data of the two-dimensional distribution of the Doppler shift frequency of the tissue based on the autocorrelation method or the FFT method. Therefore, the tissue calculation unit 92 for blood flow uses the two-dimensional distribution data of the Doppler deflection shift frequency to obtain the maximum value and average value of the tissue motion speed. The analysis method of the frequency analysis unit may be a cross correlation method.
[0139]
For this purpose, the fundamental wave component Sf is extracted by the fundamental wave BPF 32a from the echo signal including the fundamental wave component and the non-fundamental wave component, which is focused by the reception delay / adder circuit 31, and the non-fundamental wave. The secondary high frequency component S2f is extracted by the BPF 32b. Among these, the echo signal of the fundamental wave component Sf is generated into the image data of the B mode image by the receiver circuit 32a, while the blood flow velocity distribution image (for example, the blood flow velocity calculation unit 92) (for example, Color Doppler (CFM) image) image data, and the tissue velocity calculation unit 93 generates image data of a motion velocity distribution image of a tissue (for example, myocardium). On the other hand, the echo signal of the second harmonic component S2f is generated into image data of a B mode image of the second harmonic component by the other receiver circuit 33b. These four types of image data are each sent to the DSC 35, and then converted into frame image data in the display mode instructed at that time (including selection and synthesis of each image data) and displayed on the monitor 36. .
[0140]
This display example will be described with reference to FIG. 27 in the case where the contrast echo method related to the ultrasonic contrast agent by intravenous injection is applied to the heart. As shown in the figure, the echo signal that has passed through the receiver circuit 33a of the fundamental wave system of the reception / processing system forms the image data of the B-mode image IMf of the heart. Provide information. In addition, the echo signal that has passed through the second harmonic system of the reception / processing system provides image data of a distribution image (perfusion) IM2f of intramyocardial blood flow. As an aspect of the display, the composite image IMf + 2f is displayed on the monitor 36 by superimposing the image data of both IMf and IM2f in the DSC 35, and the blood flow perfusion region RB in the myocardium (filled black in the image IMf + 2f) Part) is visualized in real time.
[0141]
The echo signal that has passed through the tissue velocity calculator 93 of the fundamental wave system forms image data of a two-dimensional distribution image of the myocardial motion velocity. Accordingly, a two-dimensional distribution image (not shown) of this motion speed may be displayed as it is, and for example, whether or not the speed V> Vt (Vt: given threshold value) is determined for each pixel in the DSC 35. Determination is made, and image data of a two-dimensional distribution image IMv having a motion speed equal to or higher than the threshold value Vt that matches the determination condition is formed. By displaying the two-dimensional distribution image IMv, the myocardial wall motion abnormal region Rw (the white portion in the image IMv) is visualized. As another display mode, the DSC 35 performs a superimposing operation on the DSC 35 with the two-dimensional distribution image IMv of the myocardial motion velocity, the myocardial B-mode image IMf, and the intramyocardial blood flow distribution image IM2f subjected to threshold processing as described above (wall The logical product of the movement abnormality region Rw and the blood flow perfusion region RB is calculated). Thereby, the composite image IMf + 2f + v is displayed on the monitor 36, and the motion of the myocardial wall is stopped against the background of the myocardial B-mode image (specifically, the wall motion speed is below a certain threshold), but the blood flow is A diagnostically interesting region RW + B that is perfused is visualized in real time.
[0142]
Thus, according to this embodiment, for example, the myocardium can be individually diagnosed in real time from the viewpoints of morphology, movement, and blood perfusion, while they can be diagnosed comprehensively in real time, and so-called myocardial viability evaluation can be performed. It becomes possible. Thereby, useful information which has not existed before can be provided.
[0143]
(Twelfth embodiment)
A twelfth embodiment of the present invention will be described with reference to FIGS. The ultrasonic diagnostic apparatus of this embodiment collects image data of non-fundamental wave components related to an ultrasonic contrast agent at regular time intervals, calculates a luminance change curve (TDC: Time Density Curve) from this collected data, The feature amount (parameter) of the change curve is calculated.
[0144]
The ultrasonic diagnostic apparatus of this embodiment shown in FIG. 28 has an ECG (electrocardiograph) in order to collect the above-mentioned image data at regular intervals in addition to the configuration of FIG. 1 (first embodiment) described above. 95, an ECG amplifier 96, and a trigger signal generator 97. ECG95 is ECG information (ECG signal) of each cardiac phase of the subject. , E The signal is sent to the trigger signal generator 97 via the CG amplifier 96. This trigger signal generator 97 is for example an R wave of the ECG signal. Rise The trigger pulse in response to the above is generated and sent to the transmission / reception timing determination unit of the clock generation circuit 20 and the DSC 35. For this reason, the transmission / reception timing determination unit of the clock generation circuit 20 determines an optimum data collection timing Tn in each cycle of the ECG signal by counting a certain time from the arrival of the trigger pulse, and includes a transmission / reception timing that matches this timing Tn. A series of transmission / reception is performed by the transmission system and the reception / processing system. This data collection timing Tn is set at the left ventricular end diastole (for example, after a certain time from the R wave), for example, as shown in FIG. Therefore, image data is collected every time the data collection timing Tn synchronized in this way with ECG arrives.
[0145]
Further, the ultrasonic diagnostic apparatus includes an image memory circuit 98, a luminance change curve calculation unit 99, and a parameter calculation unit 100 connected to the DSC 35 as a part of the reception / processing system. The image memory circuit 98 stores the second harmonic component image data as the non-fundamental component sent to the DSC 35 one by one for each data collection timing Tn. The luminance change curve calculation unit 99 has a CPU function, and the ROI set in a part of the myocardium in the image data stored in the image memory circuit 98 (this ROI is set in advance or after image collection). Image data corresponding to the position is read out, and data of the luminance change curve TDC is calculated.
[0146]
As a result, for each ECG-synchronized data collection timing Tn in each cardiac cycle (see FIG. 29A), for example, image data of a left ventricular short axis image (see FIG. 29B) is collected, and these images are collected. Data is stored in the image memory circuit 98. Therefore, after all the image data is collected by the luminance change curve calculation unit 99, data corresponding to the ROI position of each image data is read, and calculation such as averaging the data in the ROI is performed, and the elapsed time from the contrast agent injection time t0. Luminance change data (see FIG. 29C) with respect to t is calculated. Note that this calculation can also be performed at regular timings during the collection of image data, thereby reducing the memory capacity of the image memory circuit 98.
[0147]
Further, a parameter calculation unit 100 is provided between the luminance change curve calculation unit 99 and the DSC 35. The parameter calculation unit 100 has a CPU function and sequentially performs the processing of FIG. That is, it is determined whether or not the luminance change curve data calculation in the luminance change curve calculation unit 99 is completed (step 100a in FIG. 30), and if completed, the curve data is fitted (step 100b in FIG. 30). This fitting process fits the obtained brightness change curve data with an appropriate function (gamma function, Gaussian function, exponential function, etc.), which reduces the effects of noise and measurement errors, and is essential. Brightness change is extracted. The fitting process may be performed by the luminance change curve calculation unit 99 or may be performed only when necessary.
[0148]
The parameter calculation unit 100 further uses the brightness change curve data subjected to the fitting process to perform various parameters representing the characteristic amount of the brightness change curve, for example, the maximum brightness level LMAX, the maximum brightness time tMAX, the brightness half level LHF, and the brightness half time tHF. Luminance half time (= maximum luminance time tMAX−luminance half time tHF), maximum luminance arrival time (injection time t0−maximum luminance time tMAX), contrast duration (duration of the luminance level above the threshold), and the like are calculated ( (See step 100c in the figure).
[0149]
The parameter data calculated in this way is sent to the DSC 35 together with the luminance change curve data (see step 100d in the figure). For example, the parameter data is divided and displayed on the superimposed image IMf + 2f of the fundamental wave image IMf and the second harmonic image IM2f. In this manner, it is displayed on the monitor 36.
[0150]
As a result, in addition to the advantages equivalent to those of the first embodiment described above, when the contrast echo method using the ultrasonic contrast agent is performed, the luminance change and the characteristic amount of only the contrast agent, that is, the blood flow distribution image in the tissue, are considered. It is possible to automatically grasp in a state that is not influenced by the cycle, and it is possible to obtain information useful for diagnosis.
[0151]
Note that the number of ROIs set in this embodiment may be plural. Further, the image collection timing is not limited to the ECG synchronization timing, but may be simply a fixed time interval or a timing for each frame. Further, the means for storing the collected image data is not limited to the image memory circuit in its own apparatus, and may be an MO (magneto-optical disk) or a workstation connected to the apparatus.
[0152]
In the twelfth embodiment, as is well known, it is highly possible that the luminance change curve does not make sense unless it is for the same part of the tissue. For this reason, the luminance change curve data is usually intended for (1) non-moving tissues (such as abdominal organs) and (2) ECG-synchronized myocardial images. However, if the tissue still moves slightly, a means for finely adjusting the position of the ROI may be added for each frame. The ROI fine adjustment may be simply performed by a manual fine adjustment mechanism that finely adjusts the position of the ROI with a mouse or the like.
[0153]
Further, the process of the twelfth embodiment described above is expanded to cause the luminance change curve calculation unit and the parameter calculation unit to execute the same calculation for all the pixels of each acquired image or a set of all the plurality of pixels. Thus, for example, a parameter such as a maximum luminance level can be displayed two-dimensionally. As a result, the two-dimensional distribution of the maximum luminance level can be observed at a glance, which is useful for diagnosis. Hand It becomes.
[0154]
According to the present invention, the non-fundamental wave component is intentionally (Or positive ) As a suppression means for suppressing, a transmission system filter that passes only the fundamental wave component may be used.
[0155]
Further, when a filter or a transmission resonance circuit using series resonance is used as suppression means in the present invention, an arrangement configuration as shown in FIGS. 31 (a) and 31 (b) can be employed. That is, in FIG. 2A, the filter 110 is inserted between the probe 10, the pulsar circuit 22 and the preamplifier circuit 30, and only the filter 110 is operated during transmission, and the filter 110 is disconnected from the circuit during reception. A change-over switch 111 that forms a bypass path for reception is provided. In FIG. 5B, a series resonance inductance 112 as a transmission resonance circuit is inserted between the probe 10 and the pulsar circuit 22 and the preamplifier circuit 30 in parallel. The change-over switch 113 is provided. These circuit configurations can provide the same effects as those described above.
[0156]
【The invention's effect】
The ultrasonic diagnostic apparatus of the present invention is an ultrasonic pulse A probe capable of bi-directional conversion between a signal and an electric quantity signal, and a signal level of a non-fundamental wave component with respect to a fundamental wave component centered on a desired excitation frequency Repress Transmitting means for supplying a drive pulse signal of an electric quantity substantially consisting of an excitation frequency of the fundamental wave component to the probe; and the probe emits the ultrasonic signal in accordance with the drive pulse signal, and the ultrasonic signal An echo signal having an electrical quantity output from the probe in response to reception of the reflected signal is input, and the fundamental wave component from the echo signal and a non-fundamental wave component with respect to the fundamental wave component included in the echo signal are related to Since the main part is provided with a reception processing means for generating image data and a display means for displaying the image data, even in a site (myocardium, organ parenchyma, etc.) where the influence of tissue echo from the surroundings is large, By performing the contrast echo method by intravenous injection, an image of brightness enhancement by the contrast agent can be accurately obtained.
[0157]
In particular, the perfusion region of the intramyocardial blood flow based on the myocardial distribution image can be evaluated by the contrast echo method using intravenous injection.
[0158]
Furthermore, heart wall motion information and myocardial perfusion information can be collected and evaluated at the same time. In the stress echo method used to diagnose angina pectoris, heart wall motion information and myocardial blood flow under each load condition can be obtained. Perfusion information can be collected and evaluated at the same time, enabling more comprehensive diagnosis.
[Brief description of the drawings]
FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention.
FIG. 2 is a circuit diagram showing an example of a transmission resonance circuit.
FIG. 3 is a diagram showing an example of an image obtained in the first embodiment.
FIG. 4 is a circuit diagram showing another example of a transmission resonance circuit.
FIG. 5 is a partial block diagram of an ultrasonic diagnostic apparatus according to a modification of the first embodiment.
FIG. 6 is a partial block diagram of an ultrasonic diagnostic apparatus according to another modification of the first embodiment.
FIG. 7 is a block diagram of an ultrasonic diagnostic apparatus according to still another modification of the first embodiment.
FIG. 8 is a block diagram of an ultrasonic diagnostic apparatus according to still another modification of the first embodiment.
FIG. 9 is a block diagram of an ultrasonic diagnostic apparatus according to a second embodiment of the present invention.
FIG. 10 is a block diagram of an ultrasonic diagnostic apparatus according to a modification of the second embodiment of the present invention.
FIGS. 11A and 11B are diagrams showing frequency characteristics of a vibrator. FIG.
FIG. 12 is a block diagram of an ultrasonic diagnostic apparatus according to a third embodiment of the present invention.
FIG. 13 is a block diagram of an ultrasonic diagnostic apparatus according to a modification of the third embodiment of the present invention.
FIGS. 14A to 14C are diagrams showing frequency characteristics of a vibrator. FIG.
FIG. 15 is a block diagram of an ultrasonic diagnostic apparatus according to a fourth embodiment of the present invention.
FIG. 16 is a block diagram of an ultrasonic diagnostic apparatus according to fifth and sixth embodiments of the present invention.
FIGS. 17A and 17B are schematic flowcharts each showing an example of processing by a manager.
FIG. 18 is a schematic flowchart showing a processing example of a manager of the ultrasonic diagnostic apparatus according to the sixth embodiment of the present invention.
FIG. 19 is a schematic flowchart showing a DSC process example of the ultrasonic diagnostic apparatus according to the sixth embodiment of the present invention.
FIG. 20 is an explanatory diagram showing a change in luminance change curve and a second harmonic image of the myocardium accompanying injection of a contrast agent.
FIG. 21 is a block diagram of an ultrasonic diagnostic apparatus according to a seventh embodiment of the present invention.
FIG. 22 is a block diagram of an ultrasonic diagnostic apparatus according to an eighth embodiment of the present invention.
23A and 23B are diagrams showing frequency characteristics of a vibrator.
FIG. 24 is a block diagram of an ultrasonic diagnostic apparatus according to a ninth embodiment of the present invention.
FIG. 25 is a block diagram of an ultrasonic diagnostic apparatus according to a tenth embodiment of the present invention.
FIG. 26 is a block diagram of an ultrasonic diagnostic apparatus according to an eleventh embodiment of the present invention.
FIG. 27 is a diagram showing a combination example of various images in the eleventh embodiment.
FIG. 28 is a block diagram of an ultrasonic diagnostic apparatus according to a twelfth embodiment of the present invention.
FIG. 29 is a diagram for explaining a relationship among an ECG signal, image collection timing, and a luminance change curve (TDC).
FIG. 30 is a schematic diagram of a flowchart for calculating a parameter of a feature amount of a luminance change curve.
FIGS. 31A and 31B are diagrams showing a modification of the suppression means and its arrangement. FIGS.
[Explanation of symbols]
10, 10a, 10b probe
11 Device body
20 Clock generation circuit (transmission means)
21 Transmission delay circuit (transmission means)
22, 22a, 22b Pulser circuit (transmission means)
23, 23a, 23b Transmission resonance circuit (transmission means / suppression means)
30, 30a, 30b Preamplifier circuit (receiving means)
31, 31a, 31b Reception delay / adder circuit (reception means)
32a, 32b BPF (receiving means)
33, 33a, 33b Receiver circuit (receiving means)
35 DSC (display means)
36 Monitor (display means)
50 input device
51 Manager
52 Image memory circuit
53 Speaker
54 Control circuit
55 Arithmetic circuit
80 Heart chamber identification circuit
81 Heart chamber display control circuit
90 Speed calculator
93 Speed calculator for tissue
95 ECG
96 ECG amplifier
97 Trigger signal generator
98 Image memory circuit
99 Luminance change curve calculation part
100 Parameter calculator

Claims (49)

A probe capable of bidirectional conversion between an ultrasonic pulse signal and an electric quantity signal;
A drive pulse signal having an electric quantity substantially consisting of the excitation frequency of the fundamental wave component is positively suppressed by actively suppressing the level of the signal of the non-fundamental wave component with respect to the fundamental wave component having the center frequency at the desired excitation frequency. Sending means to give,
Enter the amount of electricity echo signal outputted from the probe in response to the probe receives the reflected signals ultrasonic pulse signal with emitting the ultrasonic pulse signal in response to the drive pulse signal comprising: a reception processing means for generating image data related to said non-fundamental component to fundamental wave component contained in the fundamental wave component and the echo signal from the echo signal, and display means for displaying the image data, the An ultrasonic diagnostic apparatus. 2. The fundamental wave component comprises one fundamental frequency, and the non-fundamental component comprises at least one of a harmonic component, a subharmonic component, and a superharmonic component of the fundamental component. Ultrasound diagnostic equipment. The ultrasonic diagnostic apparatus according to claim 2, wherein the non-fundamental wave component is a second harmonic component of the fundamental wave component. The ultrasonic diagnostic apparatus according to claim 1, wherein the transmission unit includes a suppression unit that positively suppresses the non-fundamental wave component. The suppression means is a transmission filter that passes only the fundamental component of the drive pulse signal, a transmission notch filter that cuts the non-fundamental component, or a resonance state that occurs only during transmission, and only the fundamental component of the drive pulse signal. The ultrasonic diagnostic apparatus according to claim 4, further comprising: a transmission resonance circuit that passes the light. The ultrasonic diagnostic apparatus according to claim 5, wherein the probe is a phased array type probe in which a plurality of transducers are arranged. All oscillators of the probe has a transmission and reception sensitivity in both the fundamental component and the non-fundamental component, together with the suppression unit is coupled to the whole vibrator, wherein the reception processing means, said echo signals A preamplifier circuit for receiving, a reception delay / adder circuit connected to the preamplifier circuit, a first filter connected to the reception delay / adder circuit and extracting the fundamental wave component, and the non-fundamental wave component are extracted. The ultrasonic diagnostic apparatus according to claim 6, further comprising a second filter. The suppression means is interposed between a pulsar circuit that forms part of the transmission means and the probe, and forms a reception path that bypasses the transmission system filter, transmission system notch filter, or transmission resonance circuit at least during reception 7. The ultrasonic diagnostic apparatus according to claim 6, further comprising a preamplifier circuit connected between the suppression unit and the pulser circuit. The ultrasonic diagnostic apparatus according to claim 5, wherein the probe is a phased array type probe in which a plurality of transducers are arranged, and the plurality of transducers are divided into two transducer groups as roles related to transmission and reception thereof. . All oscillators of the probe has a transmission and reception sensitivity in both the fundamental component and the non-fundamental component, the suppression means is connected to the vibrator of the one transducer group, the receiving processing means A first preamplifier circuit that receives an echo signal from the transducer of the one transducer group, a first reception delay circuit connected to the first preamplifier circuit, and a first reception delay circuit A first filter that is connected and extracts the fundamental wave component; a second preamplifier circuit that receives an echo signal from the transducer of the other transducer group; and a second filter that is connected to the second preamplifier circuit. The ultrasonic diagnostic apparatus according to claim 9, further comprising: a second reception delay circuit; and a second filter connected to the second reception delay circuit and extracting the non-fundamental wave component. All oscillators of the probe has a transmission and reception sensitivity in both the fundamental component and the non-fundamental component, the suppression means is connected to the vibrator of the one transducer group, the receiving processing means A preamplifier circuit connected to the transducer of the other transducer group, a reception delay / adder circuit connected to the preamplifier circuit, and a first component connected to the reception delay / adder circuit and extracting the fundamental wave component The ultrasonic diagnostic apparatus according to claim 9, further comprising: a second filter that extracts the non-fundamental wave component and a second filter that extracts the non-fundamental wave component. All oscillators of the probe has a transmission and reception sensitivity in both the fundamental component and the non-fundamental component, the suppression means is connected to the vibrator of the one transducer group, the receiving processing means A preamplifier circuit that receives echo signals from the transducers of the one transducer group and the other transducer group for each channel, a reception delay addition circuit connected to the preamplifier circuit, and a reception delay addition circuit The ultrasonic diagnostic apparatus according to claim 9, further comprising: a first filter that is connected and extracts the fundamental component, and a second filter that extracts the non-fundamental component. Said reception processing means includes a receiver circuit for processing the fundamental wave component extracted by the first and second filters and said non-fundamental component in the image data of the individual B-mode image, the image data of the fundamental wave component The ultrasonic diagnostic apparatus according to claim 7, further comprising a converter that superimposes the image data of the non-fundamental wave component and generates the image data for monitor display. The ultrasonic diagnostic apparatus according to claim 5, wherein the transmission unit includes a transmission pulser circuit that also serves as the suppression unit, and the pulser circuit includes a circuit configuration that generates the drive pulse signal with a duty ratio of 50%. The ultrasonic diagnostic apparatus according to claim 5, wherein the transmission unit includes a transmission pulser circuit that also serves as the suppression unit, and the pulser circuit includes a circuit configuration that generates the drive pulse signal in a class A operation. The ultrasonic diagnostic apparatus according to claim 9, wherein the transducer of the one transducer group has sensitivity only to the fundamental wave component, and the transmission unit is connected to the transducer. Together with the transducer of the other transducers group sensitive to both of the fundamental wave component and the non-fundamental component, the reception processing means includes a preamplifier circuit connected to the transducers of the other transducer group A reception delay adding circuit connected to the preamplifier circuit; a first filter connected to the reception delay adding circuit for extracting the fundamental wave component; and a second filter extracting the non-fundamental wave component. The ultrasonic diagnostic apparatus according to claim 16. The vibrator of the other vibration group has sensitivity only to the non-fundamental wave component, and the reception processing means includes a first preamplifier circuit connected to the vibrator of the one vibrator group, and the first preamplifier circuit. A first reception delay adding circuit connected to the preamplifier circuit, a second preamplifier circuit connected to the vibrator of the other vibrator group, and a second reception connected to the second preamplifier circuit. The ultrasonic diagnostic apparatus according to claim 9, further comprising a delay addition circuit. The fundamental wave component includes a plurality of components having different fundamental frequencies , and the non-fundamental wave component is composed of at least one of frequency components that are between the fundamental frequencies or a sum or difference of harmonic components of the fundamental frequencies. Item 2. The ultrasonic diagnostic apparatus according to Item 1. The ultrasonic diagnostic apparatus according to claim 19, wherein the number of the plurality of different fundamental frequencies is two, and the non-fundamental component is a difference or sum of the harmonic components. The ultrasonic diagnostic apparatus according to claim 20, wherein the transmission unit includes a suppression unit that positively suppresses the non-fundamental wave component. The suppression means includes a transmission system filter that passes only two fundamental wave components of the drive pulse signal, a transmission system notch filter that cuts the non-fundamental wave component, or a resonance state that occurs only during transmission, and two of the drive pulse signals. The ultrasonic diagnostic apparatus according to claim 21, further comprising a transmission resonance circuit that allows only a fundamental wave component to pass. The probe is a phased array type probe in which a plurality of transducers sensitive to both of the fundamental wave component and the non-fundamental component, and the plurality of transducers 2 as role for the transmission and reception The ultrasonic diagnostic apparatus according to claim 22, wherein the ultrasonic diagnostic apparatus is divided into two transducer groups. The ultrasonic diagnostic apparatus according to claim 23, wherein the suppression unit is provided corresponding to each of the two transducer groups. The reception processing means is connected to a preamplifier circuit that receives an echo signal from each transducer of the one and the other transducer group, a reception delay addition circuit connected to the preamplifier circuit, and the reception delay addition circuit. and first ultrasonic diagnostic apparatus according to claim 24, further comprising a second filter for extracting each of said fundamental wave component and the non-fundamental component. The transmitting means is provided with a two pulser circuit for outputting a driving pulse signal containing each of the two fundamental components individually, the probe, the first and second are connected to each other to the two pulsar circuit, The ultrasonic diagnostic apparatus according to claim 20, comprising two probes. The ultrasonic diagnostic apparatus is an apparatus that applies an ultrasonic contrast echo method for injecting an ultrasonic contrast agent into a subject from a vein to obtain an ultrasonic echo image, and notifies the injection timing of the ultrasonic contrast agent And a superimposing unit that superimposes elapsed time data after injection of the ultrasound contrast agent on image data of at least the non-fundamental wave component obtained after injection of the ultrasound contrast agent. Ultrasonic diagnostic equipment. The ultrasonic diagnostic apparatus is an apparatus that applies an ultrasonic contrast echo method for obtaining an ultrasonic echo image by injecting an ultrasonic contrast agent into a subject from a vein, and enhancing an echo level of a tissue such as a myocardium or a blood vessel wall. The ultrasonic diagnosis according to claim 1, further comprising: a region discriminating unit that discriminates a region from a region outside a tissue such as a heart chamber or a blood vessel; and a region display unit that selectively displays only an echo level enhancement region of the tissue. apparatus. The region distinguishing means includes means for creating an image representing a slice of the tissue based on the image data obtained by an ultrasonic contrast echo method before injection of the ultrasonic contrast agent, and the tissue based on the reference image. Means for identifying an outer region and creating a mask image of the region, and means for masking the image data obtained by the ultrasonic contrast echo method after injection of the ultrasonic contrast agent with the data of the mask image The ultrasonic diagnostic apparatus according to claim 28. The region discriminating unit identifies a region outside the tissue using a ratio or difference between levels of the fundamental wave component and the non-fundamental wave component, and the image data according to the identified region outside the tissue. The ultrasonic diagnostic apparatus according to claim 28, further comprising a masking unit. The reception processing means includes extraction means for extracting the non-fundamental wave component from the echo signal, and two-dimensional distribution data of motion velocity of a reflected echo source that generates the non-fundamental wave component based on the non-fundamental wave component. 27. The ultrasonic diagnostic apparatus according to claim 2 or 26, further comprising speed calculating means for calculating, and wherein the display means includes speed display means for displaying two-dimensional distribution data of the motion speed. 32. The ultrasonic diagnostic apparatus according to claim 31, wherein the speed calculation means is means for calculating a movement speed based on a Doppler method. The ultrasonic diagnostic apparatus according to claim 32, wherein the speed calculation means includes a filter that extracts a Doppler signal only in a frequency band corresponding to a speed range known a priori of the target part. 32. The ultrasonic diagnostic apparatus according to claim 31, wherein the speed calculation means is a means for calculating a motion speed based on a cross-correlation method. The reception processing means includes first and second extraction means for extracting the fundamental wave component and the non-fundamental wave component from the echo signal, and first image data for obtaining tissue morphology information based on the fundamental wave component. Blood flow information in the tissue for generating the non-fundamental wave component based on the non-fundamental wave component, the second computing means for obtaining image data of tissue motion information based on the fundamental wave component And third image calculation means for obtaining the image data, and image data output means for outputting at least one image data of the tissue morphology information, tissue motion information, and blood flow information in the tissue to the display means. The ultrasonic diagnostic apparatus according to claim 26 . 36. The ultrasonic wave according to claim 35, wherein the image data output means superimposes each image data of the tissue shape information, tissue motion information, and blood flow information in the tissue in accordance with a desired display mode. Diagnostic device. The ultrasonic diagnostic apparatus according to claim 36, wherein the image data output means includes means for discriminating the motion information of the tissue with a predetermined threshold and using the discriminated motion information for the superposition. The reception processing means includes extraction means for extracting the non-fundamental wave component from the echo signal, extraction means for extracting the non-fundamental wave component, and generation means for generating image data based on the non-fundamental wave component; Storage means for storing the image data of the non-fundamental component for a plurality of frames over a certain period of time, and time series data calculation for calculating the luminance change curve data of the same part of the tissue based on the image data for the plurality of frames 2. The method according to claim 1, further comprising: feature means; and feature amount calculating means for calculating a feature amount of the curve from data of the brightness change curve; and the display means includes means for displaying the brightness change curve together with the feature amount. Ultrasound diagnostic equipment. 39. The ultrasonic diagnostic apparatus according to claim 38, further comprising timing command means for commanding the storage timing of the image data for the plurality of frames by the storage means for each fixed cardiac time phase based on electrocardiogram information. 40. The ultrasonic diagnostic apparatus according to claim 39, wherein the time-series data calculating means includes means for fitting the calculated luminance change curve data with a known function. 41. The ultrasonic diagnostic apparatus according to claim 40, wherein the feature quantity calculating means is a means for calculating a feature quantity including at least a physical quantity related to a maximum luminance level of the luminance change curve subjected to the fitting process. The transmission unit and the reception processing unit further include a synchronization unit that collects the echo signal by ECG synchronization, and the reception processing unit applies to the tomographic image data of a plurality of frames of the echo signal collected by the ECG synchronization. The ultrasonic diagnostic apparatus according to claim 1, further comprising a calculation unit that performs calculation for extracting a luminance change between frames and generates the image data. Monitor means for monitoring a biological signal that changes over time of the subject, time phase detection means for detecting an optimal time phase of the ultrasound image based on the biological signal, and time phase detected by the time phase detection means And a collection control unit that causes the transmission unit and the reception processing unit to collect an ultrasonic image, and the reception processing unit stores a tomographic image data of the echo signal collected for each detection time phase. The ultrasonic diagnostic apparatus according to claim 1, further comprising: means for generating image data of a luminance change curve using a time-series tomographic image data group stored in the storage means. 44. The ultrasonic diagnostic apparatus according to claim 43, wherein the generating means uses an echo level signal of the fundamental wave component or non-fundamental wave component corresponding to the position of the ROI set on the tomographic image. The reception processing means extracts each non-fundamental component tomographic image data by ultrasonic contrast echo method before and after the drug load on the subject, and extracts a luminance change between the tomographic images. The ultrasonic diagnostic apparatus according to claim 1, further comprising a calculation unit that performs the calculation of and generates the image data. The ultrasonic diagnostic apparatus according to claim 10 or 18, wherein the reception processing means includes gain control means capable of individually setting gains of the first and second preamplifier circuits. The ultrasonic diagnosis according to claim 1, wherein at least one of the transmission unit and the reception processing unit includes an adjustment unit that adjusts a condition related to transmission / reception of the echo signal or generation of the image data according to a scan position in a tomographic plane. apparatus. 48. The ultrasonic diagnostic apparatus according to claim 47, wherein the adjustment means is provided in the transmission means and controls the drive voltage of the drive pulse signal in accordance with the depth of the scan position. The adjustment means is provided in the reception processing means and stores in advance correction data related to non-uniformity of the collection condition depending on the scan position, and the non-basic based on the correction data 48. The ultrasonic diagnostic apparatus according to claim 47, comprising correction means for correcting the signal level of the wave component.

Images