JP2004000620A - Ultrasonic diagnostic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable evaluation of a blood perfusion region in a cardiac muscle with an image of cardiac muscle distribution by obtaining an exact image having reinforced luminosity through a contrast agent. <P>SOLUTION: An ultrasonic diagnostic system comprises means (20-23) to impart a drive pulse signal of electrical amount having a fundamental wave component of a desired excitation frequency to a probe (10), means (30,31,32a,32b) for generating an image data with respect to a non-fundamental wave component included in an echo signal coming from a probe (10) and the fundamental wave component, and means (33,35,36) to display the image data. For example, the non-fundamental wave component is extracted from the echo signal, and then a two-dimensional distribution data of moving speed of a reflective echo source is calculated to be displayed. <P>COPYRIGHT: (C)2004,JPO

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。
【０１１２】
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。
【０１１３】
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。
【０１１４】
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。
【０１１５】
（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。
【０１１６】
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。
【０１１７】
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。
【０１１８】
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。
【０１１９】
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。
【０１２０】
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。
【０１２１】
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。
【０１２２】
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。
【０１２３】
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。
【０１２４】
（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。
【０１２５】
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。
【０１２６】
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。
【０１２７】
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。
【０１２８】
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。
【０１２９】
（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。
【０１３０】
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。
【０１３１】
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。
【０１３２】
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。
【０１３３】
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。
【０１３４】
（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。
【０１３５】
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。
【０１３６】
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。
【０１３７】
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。
【０１３８】
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。
【０１３９】
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。
【０１４０】
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。
【０１４１】
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。
【０１４２】
（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。
【０１４３】
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。
【０１４４】
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。
【０１４５】
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。
【０１４６】
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。
【０１４７】
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）。
【０１４８】
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。
【０１４９】
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。
【０１５０】
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。
【０１５１】
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。
【０１５２】
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。
【０１５３】
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。
【０１５４】
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。
【０１５５】
【発明の効果】
本発明の超音波診断装置は、所望の励振周波数の基本波成分を有する電気量の駆動パルス信号を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当該超音波信号の反射信号を受信したことに応じて当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当該エコー信号から前記基本波成分と当該エコー信号に含まれ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を備え、基本波成分及び非基本波成分を用いた画像処理、計測、解析、表示などを行うので、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 applications]
The present invention relates to an ultrasonic diagnostic apparatus in which an ultrasonic contrast agent is injected into a subject, and a contrast image is obtained by utilizing the property that echo is enhanced by strong scattering characteristics of the contrast agent with respect to ultrasonic waves.
[0002]
[Prior art]
In recent years, a contrast echo method using an ultrasonic contrast agent has been attracting 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 ultrasonic contrast agent is injected from an artery has been studied, and is used for evaluation of a perfusion area of myocardial blood flow using a myocardial distribution image (perfu-sion). It's being used. In this myocardial contrast echo method, an ultrasonic 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 area of the blood flow in the myocardium by the contrast agent is displayed as a brightness enhancement area on the B mode. Similarly, in order to evaluate the perfusion area of blood flow or the vasculature dominating the tumor, a contrast echo method by arterial infusion in the abdominal region has been studied. An ultrasonic diagnostic apparatus for general inspection or a workstation is used as a diagnostic apparatus for performing these contrast echo methods. Thus, the luminance enhancement of the B-mode image is visually evaluated, or the change in the luminance level is quantitatively evaluated after appropriately processing the image data stored in the memory on the workstation.
[0004]
In recent years, an ultrasonic contrast agent capable of evaluating the left heart system by injecting the ultrasonic contrast agent from a vein has been developed, and an ultrasonic contrast echo method using the agent has been attempted.
[0005]
As the ultrasonic contrast agent, an average particle diameter of about 4 μm in which air is contained in an albumin film formed when sonicating 5% human serum albumin, which is imported and sold by Shionogi & Co., Ltd. No air sphere ”(brand name: Albunex Note 5 ml).
[0006]
This contrast echo method by vein injection is currently in the testing and research stages, and its usefulness in the diagnosis of the head, heart cavity, abdomen, etc. is expected to increase in the future.
[0007]
[Problems to be solved by the invention]
Among the conventional contrast echo methods described above, the contrast echo method based on arterial infusion requires that the catheter be placed in the aorta, so that the facility (operating room) that can perform the procedure is limited to a relatively large hospital. It is assumed that it will not be easily spread to general clinical practice in the future due to the fact that the burden on the patient is large due to the sexual diagnosis.
[0008]
On the other hand, the contrast echo method using intravenous infusion is extremely invasive and the burden on the patient is small, but the contrast agent reaches the myocardium and other target sites through the lungs. Compared with the contrast echo method, the contrast agent concentration is lower, and the degree of luminance enhancement is reduced. For this reason, it is extremely difficult to observe the enhancement of the brightness by the contrast agent in a region where the influence of the tissue echo from the periphery is large, such as the myocardium and the peripheral region of the abdomen. Cannot be applied to the evaluation of
[0009]
The present invention has been made in view of the current state of the contrast echo method using such a conventional ultrasonic contrast agent, and enables an image of brightness enhancement by the contrast agent to be accurately obtained, by using a myocardial distribution image. An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of evaluating a perfusion area of myocardial blood flow.
[0010]
In addition, the contrast echo method by vein injection is performed even at a site where the influence of the tissue echo from the surroundings (cardiac muscle, organ parenchyma, etc.) is large, so that an image of the brightness enhancement by the contrast agent can be obtained accurately. Another object is to provide an ultrasonic diagnostic apparatus capable of simultaneously collecting and evaluating wall motion information and myocardial blood flow perfusion information.
[0011]
Furthermore, even in areas where the influence of tissue echo from the surroundings is large (eg, myocardium, organ parenchyma, etc.), the contrast echo method by vein injection can be performed so that an image of brightness enhancement by a contrast agent can be obtained accurately, and stress 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 blood flow perfusion information in each load state in the echo method.
[0012]
[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.
[0013]
The ultrasonic diagnostic apparatus according to the present invention is a probe that can bidirectionally convert between an ultrasonic signal and a signal of an electric quantity, and a drive pulse signal of an electric quantity having a fundamental component of a desired excitation frequency. Transmitting means for providing a probe, and an echo signal of an electric quantity output from the probe in response to receiving the reflected signal of the ultrasonic signal while the probe emits the ultrasonic signal in response to the drive pulse signal Receiving processing means for generating image data relating to the fundamental wave component and the non-fundamental wave component included in the echo signal from the echo signal, and a display means for displaying the image data. Having a configuration.
[0014]
According to one aspect of the present invention, in the basic configuration described above, the reception processing unit includes an extraction unit configured to extract the non-fundamental component from the echo signal, and the non-fundamental component based on the non-fundamental component. Speed calculating means for calculating the two-dimensional distribution data of the movement velocity of the reflection echo source for generating the fundamental wave component, and the display means includes speed display means for displaying the two-dimensional distribution data of the movement velocity. It is characterized by.
[0015]
According to another aspect of the present invention, in the above-described basic configuration, the reception processing means includes a first and a second extraction unit for extracting the fundamental wave component and the non-fundamental wave component from the echo signal. Means, first computing means for obtaining image data of tissue morphological information based on the fundamental wave component, second computing means for acquiring image data of tissue motion information based on the fundamental wave component, A third calculating means for obtaining image data of blood flow information in the tissue that generates the non-fundamental wave component based on the non-fundamental wave component; morphological information of the tissue, motion information of the tissue, and blood flow in the tissue Image data output means for outputting at least one image data of information to the display means.
[0016]
Further, according to another aspect of the present invention, in the basic configuration described above, the reception processing unit extracts the non-fundamental component from the echo signal, and extracts the non-fundamental component based on the non-fundamental component. Generating means for generating image data; storage means for storing image data of the non-fundamental component for a plurality of frames over a predetermined period; and a luminance change curve of the same part of the tissue based on the image data for the plurality of frames. A time-series data calculating unit that calculates data; and a feature calculating unit that calculates a feature of the curve from the data of the brightness change curve, and the display unit displays the brightness change curve together with the feature. It is characterized by comprising means for performing.
[0017]
Further, according to another aspect of the present invention, in the above-described basic configuration, the reception processing means includes a tomographic image data of the non-fundamental wave component by an ultrasonic contrast echo method before and after a drug is loaded on a subject. And an arithmetic unit for performing an operation for extracting a change in luminance between the tomographic images to generate the image data.
[0018]
Preferably, the transmitting means positively reduces the level of the signal of the non-fundamental wave component with respect to the fundamental wave component of the drive pulse signal to generate a drive pulse signal substantially consisting of the excitation frequency of the fundamental wave component. Configured to provide to the probe. Preferably, the transmission unit includes a suppression unit that actively suppresses the non-fundamental wave component. The suppression means may be, for example, a transmission filter that passes only the fundamental wave component of the drive pulse signal, a transmission notch filter that cuts the non-fundamental wave component, or a resonance state only at the time of transmission, and the fundamental wave of the drive pulse signal It has a transmission resonance circuit that passes only components.
[0019]
The transmitting means may include a transmitting pulser circuit also serving as the suppressing means, and the pulser circuit may include a circuit configuration for generating the driving pulse signal having a duty ratio of 50%. A transmission pulser circuit also serving as a suppression means may be provided, and this pulser circuit may be configured to include a circuit configuration for generating the drive pulse signal in class A operation.
[0020]
Further, as an example, the fundamental component is composed of one fundamental frequency, and the non-fundamental component is at least one of a harmonic component, a subharmonic component, and a superharmonic component of the fundamental component. Consists of For example, the non-fundamental component is a second harmonic component of the fundamental component.
[0021]
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 sum or difference between the fundamental wave frequencies or the harmonic components of the fundamental frequency. It may be configured as follows.
[0022]
[Action]
According to the ultrasonic diagnostic apparatus of the present invention, using the fundamental wave component and the non-fundamental wave component obtained from the reception processing means, a process of displaying the two-dimensional distribution of the movement velocity based on the non-fundamental wave component, the fundamental wave component A process of displaying at least one image data of tissue morphological information, tissue motion information, and blood flow information in tissue using a non-fundamental component, and a brightness change curve based on the non-fundamental component. Processing such as display with the feature amount, processing of extracting a luminance change between tomographic image data of a non-fundamental wave component by performing an ultrasonic contrast echo method before and after drug loading on the subject, and the like are executed. For this reason, it is effective for intramyocardial diagnosis, and it is possible to collect heart wall motion information at the same time, or to implement it in combination with the stress echo method to comprehensively evaluate cardiac function in relation to myocardial blood flow. You.
[0023]
At this time, in particular, the level of the non-fundamental wave component (such as the second harmonic component) is substantially and positively reduced in the driving pulse signal given to the probe from the transmitting means, and most of the fundamental wave component is Only to be given to the probe. This intentional suppression of the non-fundamental wave component is preferably performed, for example, 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 the ultrasonic contrast agent from the vein is performed, the nonlinear ultrasonic beam scattering of the ultrasonic contrast agent directly reflects on 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 contained in the echo signal depends on the nonlinear scattering of the contrast agent. Therefore, by imaging the non-fundamental wave component, it is possible to grasp the flow of the contrast agent. As described above, since the ultrasonic beam signal substantially processed in advance only to the fundamental wave component is made incident, even for a site where the influence of the tissue echo is large, the contrast echo method of vein injection is applied, For example, it is possible to suitably evaluate the perfusion area of the blood flow in the myocardium based on the myocardial distribution image.
[0025]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0026]
(First embodiment)
A first embodiment will be described with reference to FIGS. The ultrasonic diagnostic apparatus according to the first embodiment employs 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. It is to be implemented.
[0027]
As shown in FIG. 1, the ultrasonic diagnostic apparatus includes an ultrasonic probe 10 that transmits and receives an ultrasonic signal to and from a subject, drives the ultrasonic probe 10, and converts a received signal of the ultrasonic probe 10 into a signal. It consists of an apparatus body 11 for processing.
[0028]
The ultrasonic probe (hereinafter, referred to as “probe”) 10 is configured as a phased array type in which a plurality of transducers are arranged in a scanning direction. The receiving characteristics of each vibrator are formed identically, and have a sufficiently wide signal pass band capable of detecting a fundamental wave component for driving the vibrator and a second harmonic component generated in a living body.
[0029]
The apparatus main body 11 has a transmission system for driving the probe 10, a reception / processing system for receiving and processing a signal from the probe 10, and a display system for displaying a processed image. In addition, there are an input system such as an operation panel and a biosignal detection system such as an ECG, but these are omitted in the drawings.
[0030]
The transmission system includes a clock generation circuit 20, a transmission delay circuit 21, a pulser 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 an ultrasonic signal, and the transmission delay circuit 21 is a circuit that delays transmission and performs transmission focus. The pulsar circuit 22 incorporates pulsars corresponding to the number of individual paths (hereinafter, referred to as “channels”) corresponding to the respective vibrators, generates a drive pulse at a delayed transmission timing, and supplies the driving pulses to the respective vibrators of the probe 10. Supply.
[0031]
The transmission resonance circuit 23 is a circuit corresponding to one of the features of the present invention, and is provided for efficiently detecting the second harmonic component of the echo signal generated by the ultrasonic contrast agent in the living body. . That is, unless the pulsar is driven completely by sine waves at the time of transmission, the pulsar has a function of removing generated harmonic components without fail. Specifically, as shown in FIG. 2, the transmission resonance circuit 23 includes a limiter 24 composed of a diode anti-parallel circuit and a coil unit that resonates with a capacitive impedance such as a probe or a cable and has a pass band only near a 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 when transmitting with a high signal level, and remains in a non-resonance state when receiving. The series circuit of the limiter 24 and the coil unit 25 is actually provided for each channel.
[0032]
Further, the reception / processing system includes, on the output side of the probe 10, a preamplifier circuit 30, a reception delay / addition circuit 31, band pass filters (BPF) 32a and 32b, and a receiver circuit 33, for example, in this order. The preamplifier circuit 30 amplifies the power of the reception echo for each reception channel and sends the amplified power to the reception delay / addition circuit 31. The reception delay / addition circuit 31 has a delay unit for each reception channel and an addition unit for adding these delay results, and performs reception focusing on the reception echo signal. On the output side of the reception delay / addition circuit 31, bandpass filters 32a and 32b for the fundamental wave and the non-linear wave are connected in parallel. The passband of the bandpass filter 32a for the fundamental wave matches the fundamental wave component of the echo signal, while that of the bandpass filter 32b for the nonlinear wave matches the second harmonic component of the echo signal. Further, the receiver circuit 33 is a reception processing circuit that performs processing such as envelope detection and log compression for each of the fundamental wave component and the second harmonic component to obtain an image signal of a B-mode image.
[0033]
Further, the receiving / processing system has a DSC (Digital Scan Converter) 35 and a monitor 36. The DSC 35 includes an A / D converter, a multiplexer, a frame memory, a write / read circuit, a D / A converter, and the like, and forms an image signal of one frame corresponding to a commanded display mode, and generates the image signal. Reading is possible by the standard TV system. The image signal read from the DSC 35 is output to the monitor 36 and displayed.
[0034]
Next, the operation and effect of the first embodiment will be described.
[0035]
At the time of transmission, a driving voltage signal is supplied from the pulser circuit 22 to each transducer of the probe 10 for each channel via the transmission resonance circuit 23 in a state where the transmission focus is applied by the transmission delay circuit 21. At this time, the limiter 24 of the transmission resonance circuit 23 is kicked on because the drive voltage signal is higher than the 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.
[0036]
Complete sine wave driving of the pulsar circuit 22 is practically difficult, and usually includes a harmonic component in the generated driving voltage signal. However, such a harmonic component is intentionally removed by the transmission resonance circuit 23 described above. And each vibrator is excited by the drive voltage signal of only the fundamental wave component.
[0037]
When each transducer of the probe 10 is excited in this way, the probe 10 transmits an ultrasonic beam signal with transmission focus applied to a diagnosis site such as a myocardium of the subject. This ultrasonic beam signal is an ultrasonic echo signal reflected and scattered by each tissue of the diagnostic site and the injected ultrasonic contrast agent (for example, the above-mentioned “Albunex Injection 5 ml”: trade name). In particular, the ultrasonic contrast agent is composed of minute bubbles, and the echo signal is enhanced by strong scattering characteristics of the bubbles. This scattering has a nonlinear characteristic, and a harmonic component is also generated by the scattering of the nonlinear characteristic. As a result, the ultrasonic echo signal includes an echo component (fundamental wave component) from a biological tissue other than the contrast agent (bubble) and an echo component (fundamental wave component and its harmonic components) from the contrast agent.
[0038]
This ultrasonic echo signal is received by each transducer of the probe 10 and is converted into a corresponding electric signal. Since the power of the echo signal of this electric quantity 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 wave component reaches the preamplifier circuit 30 without any involvement in the transmission resonance circuit 23 and is amplified in power. Are added. Thereby, the reception focus is set. This 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 receiver circuit 33 at the subsequent stage. 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.
[0039]
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 to generate image data of a B-mode image (amplitude luminance modulation image) of the fundamental wave component. On the other hand, the echo signal of the second harmonic component S2f sent to the receiver circuit 33 is subjected to the same processing, and the image data of the B-mode image of the second harmonic component is generated.
[0040]
The image data of each of the B-mode images of the fundamental wave component and the second harmonic component is then converted by the DSC 35 into image data of a designated display mode. There are various display modes for the B-mode image IMf based on the fundamental wave component (hereinafter, simply referred to as “fundamental wave image”) and the B-mode image IM2f based on the second harmonic component (hereinafter, simply referred to as “second harmonic image”). When the contrast echo method is performed, for example, 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 combines the two image data and supplies them to the monitor 36. Therefore, as shown in FIG. 3, the image "IMf + 2f" in which the second harmonic image IM2f is superimposed on the fundamental wave image IMf is displayed on the monitor 36. Is displayed, and the morphology of the living tissue and the distribution of the ultrasonic contrast agent therein can be observed.
[0041]
As described above, in the present embodiment, the transmission resonance circuit 23 intentionally (aggressively) cuts harmonic components other than the fundamental wave component, and transmits the ultrasonic beam substantially in the state of only the fundamental wave component. Therefore, most of the second harmonic components included in the echo signal are only due to the non-linear scattering characteristics of the ultrasonic contrast agent. In other words, since only the second harmonic component caused by the scattering of the contrast agent can be selectively processed and imaged with respect to the transmitted ultrasonic signal of the fundamental wave component, the biological attenuation and transmission / reception system band can be reduced. Considering this, an excellent use of the second harmonic component is obtained.
[0042]
In the above embodiment, the case where the nonlinear wave component to be extracted is the second harmonic component is exemplified, but the present invention is not necessarily limited to this. For example, as other nonlinear wave components, an Nth harmonic component (N × f: f is a fundamental frequency, N is a positive integer), an Nth subharmonic component (f / N: f is a fundamental frequency, N is a positive integer) ) And superharmonics (M × f / N: f is the fundamental frequency, M and N are positive integers other than 1), and those frequency components are selectively selected by the non-linear wave BPF as described above. May be extracted. In addition, in order to simultaneously target a plurality of harmonic components, a plurality of signal extraction / processing systems are individually provided for each of the plurality of harmonic components, or a plurality of nonlinear wave components are passed through one system without being separated. It may be configured.
[0043]
In the above embodiment, the signal processing of the fundamental wave component and the signal processing of the non-linear wave component are respectively performed by separate systems. However, after receiving by the preamplifier circuit, the signal is digitized. The signal processing of the fundamental wave component and the nonlinear wave component may be performed in a time division manner. Further, a memory can be provided to perform signal processing on a desired component.
[0044]
Further, in the above embodiment, two BPFs for extracting the fundamental wave component and the non-linear wave component are inserted after the reception delay / addition circuit. May be provided. However, when the BPF is provided on the output side of the reception delay / addition circuit as in the above embodiment, the number of filters can be reduced, which is advantageous for avoiding an increase in the size of the device and an increase in manufacturing cost. is there.
[0045]
Further, the probe according to the ultrasonic diagnostic apparatus is not limited to the electronic array probe, but may be a mechanical scanning probe.
[0046]
Further, various modifications of the ultrasonic diagnostic apparatus according to the first embodiment are possible.
[0047]
First, FIG. 4 shows a modification of the transmission resonance circuit 23. The transmission resonance circuit 23 has an electronic switch SW that is turned on and off between the limiter 24 and the transmission / reception line, and turns on the electronic switch SW in the diagnostic mode for the non-linear scattering component of the contrast agent. A resonance state at the time of transmission similar to that of the first embodiment is obtained, and in a normal diagnostic mode for a linear scattering component (fundamental wave component), the electronic switch SW is turned off, and non-resonance is applied to both transmission and reception. This is to get the state. The on / off state of the electronic switch SW is switched by, for example, energizing a control signal from a controller (not shown). By configuring and functioning in this manner, the transmission resonance circuit 23 can be separated from the circuit in the normal mode, and the functions can be enhanced.
[0048]
Further, in the first embodiment, the beamforming (phasing addition) is performed with the RF (high frequency) signal as it is. However, a receiving system that performs the beamforming after shifting the signal band to the intermediate frequency is also possible. 5 and 6 show modified examples. The receiving system shown in FIG. 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 / addition circuit 31, and a signal shifted to an intermediate frequency. BPFs 32a and 32b for extracting a fundamental component and a non-linear component. The receiving system according to the modification shown in FIG. 6 has the same functions as those in FIG. 5, and the reference signal generator 40 * converts the reference frequency fr of the reference signal into a non-linear signal such as fr = fr (1) for the fundamental wave. Wave fr = fr (2) can be changed. Thus, the frequency of the reference signal given to the mixer circuit 41 can be changed between the detection of the fundamental wave component and the detection of the non-linear wave component, so that both components can be detected by one system of receiving circuit. . The change of the reference frequency fr may be performed on the same channel in a time-division manner, or may be performed for each channel in which the reception channel group is divided into a group for detecting a fundamental wave component and a group for detecting a non-linear wave component. .
[0049]
Furthermore, in the above-described first embodiment, the configuration is such that the harmonic components generated in the transmission pulser circuit 22 are reduced. Modifications corresponding to this configuration are shown in FIGS. In the modification according to FIG. 7, a sine-wave driving pulser circuit 43 capable of driving a sine wave is provided instead of the pulser circuit 22 of the first embodiment. Specifically, for example, when the second harmonic component is reduced, the pulser circuit 43 is realized by a circuit configuration including a pulser capable of driving a rectangular wave having a duty ratio of 50% and a pulser capable of operating class A for each channel. As a result, harmonic components can be reduced without using the transmission resonance circuit as described above, which contributes to simplification and downsizing of the device.
[0050]
On the other hand, the ultrasonic diagnostic apparatus according to the modified example shown in FIG. 8 has a transmission circuit for removing a harmonic component other than a fundamental component, a subharmonic component, and the like during transmission in a transmission circuit between the pulsar circuit 22 and the probe 10. The filter circuit 44 is inserted and the transmission resonance circuit is removed. This also makes it possible to reduce the number of harmonics during transmission to a desired level, although the circuit becomes somewhat larger than when the transmission resonance circuit is provided.
[0051]
(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 will be omitted or simplified.
[0052]
The ultrasonic diagnostic apparatus shown in FIG. 9 includes a phased array type probe 10 in which a plurality of transducers 101... 10n (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 and the frequency band of the second harmonic component of the signal to be handled. The vibrator group of the probe 10 is functionally divided into a vibrator group A for transmitting and receiving a fundamental wave component and a vibrator group B for receiving a second harmonic component. As an example of this division, as shown in the figure, odd-numbered transducers are assigned to a transducer group A, and even-numbered transducers are assigned to a transducer group B.
[0053]
The resonators 101, 103,..., 10n-1 of the resonator group A are connected to the transmission resonance circuit 23 which is formed and functions similarly to 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 pulser circuit 22.
[0054]
Further, a preamplifier circuit 30a, a reception delay / addition circuit 31a, a BPF 32a for fundamental wave, and a receiver 33 circuit are connected to the transmission resonance circuit 23 in parallel with the pulser circuit 22 to form a reception / processing system for fundamental wave components. ing. On the other hand, the vibrators 102, 104,... 10n of the vibrator group B include a preamplifier 30b, a reception delay / addition circuit 31b, a non-linear wave component BPF 32b, and a receiver circuit which constitute a reception / processing system for non-linear wave components. 33 are connected. The output side of the receiver circuit 33 is connected to a DSC 35 and a monitor 36 forming a display system.
[0055]
The operation and effect of the second embodiment will be described. The transducers 101, 103,..., 10n-1 of the transducer group A are excited by the respective circuits of the transmission system, and the 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 not being completely sine-wave driven, the harmonic component is accurately removed by the transmission resonance circuit 23, and almost all of them are removed. 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 is composed of the fundamental wave component. This ultrasonic beam signal is reflected and scattered by the tissue in the subject and the ultrasonic contrast agent, received by all the transducers of the probe 10 as in the case of the first embodiment, and converted into a corresponding electric quantity echo signal. Is done.
[0056]
Among them, the echo signals including the fundamental component and the second harmonic component output from the transducers 101, 103,..., 10n-1 of the transducer group A pass through the transmission resonance circuit 23 in the non-resonant state. Is amplified by a preamplifier for each odd channel of one preamplifier circuit 30a. The amplified echo signal is delayed by the reception delay / addition circuit 31a for each channel, and then added to focus the reception. From the delayed and added echo signal, only the fundamental wave component Sf is extracted by the fundamental wave component BPF 32 a and sent to the receiver circuit 33.
[0057]
On the other hand, the echo signals including the fundamental wave component and the second harmonic component output from the oscillators 102, 104,... 10n of the oscillator group B are amplified by the other preamplifier circuit 30b. The other reception delay / addition circuit 31b similarly focuses the reception. The echo signal is further sent to a band-pass filter 32b for a non-linear wave component, where a second harmonic component S2f is extracted. This component S2f is also output to the receiver circuit 33.
[0058]
The echo signal of the fundamental component Sf and the echo signal of the second harmonic component S2f sent to the receiver circuit 33 are respectively subjected to envelope detection and logarithmic compression processing, and are converted into B-mode image signals. It is sent to the DSC 35. Therefore, the monitor 36 displays the images of the fundamental wave image IMf and the second harmonic image IM2f (for example, their weight images) according to the desired display mode, as in the case of the first embodiment.
[0059]
Therefore, according to the second embodiment, the same effect as that of the first embodiment can be obtained. In particular, the transducer group of the probe 10 is divided into the transmitting and receiving transducer group A and the receiving-only transducer group B. Due to the division, there is no need for a circuit configuration that is turned ON only for transmission to a transmission resonance circuit or the like. 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 later with reference to FIG.
[0060]
Note that the band-pass 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 may be provided at other positions such as the output stages of the preamplifier circuits 30a and 30b. There may be. As in the case of FIG. 8 described above, a transmission resonance filter circuit (see reference numeral 44 in FIG. 8) is provided instead of the transmission resonance circuit 23, and this filter circuit 23 is set to be in operation even during reception. It may be.
[0061]
Further, a modified example according to the second embodiment is shown in FIGS. The phased eyelet 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 its frequency band set so as to respond to only the fundamental wave component f (see FIG. 11A). . Each of the oscillators 102, 104,..., 10n of the oscillator group B has its frequency band set so as to respond to only 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.
[0062]
By forming the probe 10 in this manner, transmission / reception of the ultrasonic signal of only the fundamental wave component is performed via the transducer group A, and the preamplifier circuit 30a and the reception delay / addition circuit connected to the transducer group A An echo signal of only the fundamental wave component Sf is directly obtained from 31a. Similarly, an echo signal of only the second harmonic component S2f among the nonlinear wave components generated by the nonlinear scattering of the ultrasonic 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 directly obtained from the circuit 30b and the reception delay / addition circuit 31b. Therefore, there is no need to provide the transmission resonance circuit 23 and the band-pass filters 32a and 32b at the time of reception used in the second embodiment, which simplifies the circuit configuration, which also has the same effect as that of the second embodiment. Is obtained. When a bandpass filter is also provided, a second harmonic having a higher S / N ratio can be detected.
[0063]
Furthermore, various circuit configurations are added to the modification shown in FIG.
[0064]
The first is that the signal strength of the non-fundamental component is smaller than that of the fundamental component. The preamplifier gains of the preamplifier circuits 30a and 30b of the fundamental wave component system and the non-fundamental wave component system are variable, and a signal for setting the gain 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 component preamplifier circuit 30a. Thereby, the signal intensities of the fundamental wave component and the non-fundamental wave component can be adjusted to be the same or almost the same, and the imbalance of the S / N ratio between the two can be eliminated.
[0065]
Second, when the ultrasonic beam signal enters the subject, attention is paid to the fact that 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 pulser 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 pulser circuit 22 in multiple steps, for example, as the transmission focus position becomes deeper from the surface of the subject.
[0066]
As a result, the transmitted sound pressure is maintained substantially constant even when the focus position is deepened, so that a tissue image having substantially the same luminance can be obtained regardless of the depth position in the same blood flow state.
[0067]
Third, the non-uniformity of various conditions depending on the position in the image (tomogram) is dealt with on the reception processing side. To do this, a data table 35S is connected to the DSC 35 of the reception processing system. In the data table 35S, corresponding data of “position-correction coefficient” for various conditions that change depending on the position in the image, such as the transmission sound pressure in the tomography, the ultrasonic beam width, the scan mode, the specificity of the target tissue, etc. Is stored. Therefore, when generating an image based on the non-fundamental wave component, the DSC 35 reads out the corresponding correction coefficient for each position in the tomography with reference to the data table 35S, and reads the echo level of the non-fundamental wave component with the read out correction coefficient. Image data is generated while correcting. As a result, a situation in which the image quality changes depending on the position in the tomographic plane can be accurately avoided.
[0068]
In other words, by the control or correction according to the second and third circuit configurations, if the distribution of the contrast agent in the tomographic image is uniform at the time of applying the ultrasonic contrast echo method by intravenous injection of the ultrasonic contrast agent, the same luminance or the same luminance is obtained. Images of the same color are obtained.
[0069]
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 by the read correction coefficient, or the gain of the receiver circuit 33 may be changed.
[0070]
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 together.
[0071]
On the other hand, the same various modifications as described in the first embodiment can be made to the second embodiment and its modifications (for example, see FIGS. 4 to 8). Further, the second harmonic component has been exemplified as the non-linear wave component. However, an image may be formed by targeting other harmonic components, low harmonic components, and super harmonic components.
[0072]
(Third embodiment)
Next, a third embodiment will be described with reference to FIG. The ultrasonic diagnostic apparatus shown in FIG. 9 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 the transducer groups A and B. In this embodiment, the transducer group A Are assigned for transmission, and the transducer group B is assigned for reception.
[0073]
As shown, the oscillators 101, 103,..., 10n-1 of the oscillator group A are provided with a clock generation circuit 20, a transmission delay circuit 21, a pulsar circuit 22, and a transmission resonance circuit 23 connected in series in this order. I have. On the other hand, the vibrators 102, 104,... 10n of the vibrator group B are connected to a reception delay / addition circuit 31 via a preamplifier circuit 30, and the output side of this circuit 31 is for a fundamental wave and a non-linear wave. Through the band pass filters 32a and 32b in parallel to the receiver circuit 33, DSC 35, and monitor 36.
[0074]
Next, the operation and effect of the third embodiment will be described. Each of the vibrators of the vibrator group A passes a drive signal for each odd-numbered channel from the pulsar circuit 22 through the transmission resonance circuit 23, whereby harmonic components are almost removed and a drive signal mainly composed of a fundamental wave component is used. Excited. As a result, an ultrasonic beam signal consisting essentially of only the fundamental wave is transmitted into the subject.
[0075]
On the other hand, an echo signal including a fundamental component and a second harmonic component is output from each transducer of the transducer group B corresponding to the ultrasonic signal reflected and scattered in the subject. The echo signal is amplified by the preamplifier circuit 30, subjected to reception focus processing by the reception delay / addition circuit 31, and then supplied to both the 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 are converted into image signals for respective B-mode images. A B-mode fundamental wave image and a second harmonic image are displayed on the monitor 36 based on the image signals for the fundamental wave and the second harmonic.
[0076]
As a result, the same effects as those of the above-described embodiments can be obtained, and the number of sets of the preamplifier circuit and the reception delay / addition circuit can be reduced to one compared with the configuration of FIG. 9 (the second embodiment).
[0077]
Modifications of the third embodiment are shown in FIGS. The ultrasonic diagnostic apparatus shown in FIG. 13 includes a phased array type probe 10, and transducer groups of the probe 10 are functionally divided into transducer groups A and B as in the third embodiment. . Of these, the oscillators 101, 103,..., 10n-1 of the oscillator group A respond only to the fundamental wave component f by using a technique such as changing the oscillator thickness (FIG. 14A). .. 10n of the vibrator group B respond to the fundamental wave component f and the second harmonic component “2 · f”. (See FIG. 14 (b) or (c)), the frequency band is set. As shown, 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, and a preamplifier circuit 30 is connected to the output side of each transducer of the transducer group B. A reception delay / addition circuit 31, BPFs 32a and 32b for a fundamental wave and a non-linear wave, a receiver circuit 33, a DSC 35, and a monitor 36 are provided. Thus, the same operation and effect as those of the third embodiment (FIG. 12) can be obtained, and the transmission resonance circuit 23 is not required as compared with the third embodiment (FIG. 12).
[0078]
It should be noted that modifications similar to those in the first embodiment can be further made to the third embodiment and its modifications (see, for example, FIGS. 4 to 8). Although the second harmonic component has been exemplified as the non-linear wave component, other harmonic components, subharmonic components, and superharmonic components may be imaged.
[0079]
(Fourth embodiment)
A fourth embodiment will be described with reference to FIG. The ultrasonic diagnostic apparatus shown in FIG. 9 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 the 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.
[0080]
As shown, the oscillators 101, 103,..., 10n-1 of the oscillator group A are provided with a clock generation circuit 20, a transmission delay circuit 21, a pulsar circuit 22, and a transmission resonance circuit 23 connected in series in this order. I have. On the other hand, the respective channels corresponding to the vibrator of the vibrator group B and the vibrator group A between the transmission resonance circuit 23 and the pulsar circuit 22 individually receive the delay of the reception delay / addition circuit 31 via the preamplifier of the preamplifier circuit 30. The output side of this circuit 31 reaches a receiver circuit 33, a DSC 35, and a monitor 36 via band-pass filters 32a, 32b for a fundamental wave and a non-linear wave in parallel.
[0081]
Next, the operation and effect of the fourth embodiment will be described. Each of the vibrators of the vibrator group A excites a drive signal for each channel from the pulsar circuit 22 through a transmission resonance circuit 23, whereby a harmonic component is almost removed and a drive signal mainly including a fundamental wave component. Is done. As a result, an ultrasonic beam signal, which is mostly composed of only the fundamental wave, is transmitted into the subject.
[0082]
On the other hand, echo signals including the fundamental wave component and the second harmonic component are output from the transducers of the transducer groups A and B corresponding to the ultrasonic signals reflected and scattered in the subject. This echo signal is amplified by the preamplifier circuit 30 for both groups A and B, subjected to reception focus processing by the reception delay / addition 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 are converted into image signals for respective B-mode images. Based on the image signals for the fundamental wave and the second harmonic, a B-mode fundamental wave image IMf and a second harmonic image IM2f are displayed on the monitor 36.
[0083]
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 configuration of FIGS. 12 and 13 (the third embodiment and its modification) (the transducer groups A and Since B is involved in the reception, twice), a higher-level echo signal is obtained, which is advantageous in terms of the S / N ratio.
[0084]
(Fifth embodiment)
A fifth embodiment will be described with reference to FIGS. The fifth embodiment is intended to improve the workability of contrast agent injection and the convenience of image recognition after injection when performing a contrast echo method using an ultrasonic contrast agent.
[0085]
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), but has an input device 50 operated by an operator and a procedure stored in advance. It has a manager 51 that performs processing according to (see FIG. 17), an image memory circuit 52 and a speaker 53 that operate in response to instructions from the manager 51. The input unit 50 includes one or more of a keyboard, a trackball, a mouse, and a voice input unit. The input unit 50 is used to schedule a contrast echo method (for example, a contrast agent injection time). Is input to the manager 51. In addition, as the input device 50, a storage medium such as a floppy (registered trademark) 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 the image data of the superimposed image of the fundamental wave image and the second harmonic image, for example, converted by the DSC 35. The DSC 35 converts the image data for display, combines the character data specified by the manager 51, and outputs it to the monitor 36.
[0086]
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.
[0087]
That is, first, the conditions of the contrast echo method trial (image quality conditions, measurement conditions (ROI, measurement time interval) of TDC (Time-Density-Curve), ECG synchronization conditions, etc.) and the schedule of the contrast echo method trial (contrast agent injection) (Scheduled) time, and when other drugs are used together, data of the amount and timing) are input from a floppy disk or the like (step 60).
[0088]
Next, the time measurement is started, and the display of the time measurement time is started on the screen of the monitor 36 (step 61). After this, collection of necessary data is started before the injection of the contrast agent (step 62). The data includes an image and luminance data before the injection of the contrast agent, image data at desired timing and time intervals, and ROI luminance data at desired timing and time intervals. Further, these data are transferred to the MO or the workstation.
[0089]
Then, when the scheduled injection time is reached, the operator instructs the contrast agent injection timing by voice via the speaker 53 (step 63).
[0090]
Thereafter, while collecting the post-injection data in the same manner as described above (step 64), at a predetermined time, an instruction to inject another drug is given by voice or the like (step 65), and the data after the drug injection is collected (step 65). Step 66). Then, when the end time of the predetermined schedule is reached, the collection of the image data, the collection of the luminance data of the ROI, the transfer of the data to the MO or the work station, and the timing are ended (step 67).
[0091]
The processing to be executed by the manager 51 can be configured as shown in FIG. This allows an operator to instruct the timing of injection of a contrast agent by voice. The same processing as in FIG. Is attached.
[0092]
First, data is input as in step 60 of FIG. 17A (step 60a), but this data does not include the “contrast agent injection (planned) time”. When the data input in this step is completed, collection of data before injection (image before injection, luminance data of ROI) is started, and data transfer to the MO or the work station is started (step 60b).
[0093]
Next, the operator instructs the injection (timing) of the contrast agent from the microphone of the input device 50 at any appropriate time (step 60c). Along with this, timing is also started.
[0094]
Then, after the injection of the contrast agent, an image is started to be collected at a desired timing and a time interval, and brightness data of the ROI is started to be collected at a desired timing and a time interval.
[0095]
Thereafter, the same processing as in FIG. 17A is performed (steps 65 to 67).
[0096]
By configuring and functioning as described above, when performing the contrast echo method using the ultrasonic contrast agent, the operator or the doctor can accurately perceive the injection timing of the contrast agent and synchronize with the injection timing. Then, the image data including the elapsed time can be automatically obtained, which facilitates later image processing and image interpretation.
[0097]
In the fifth embodiment, ECG data may be fetched, and control may be performed to automatically acquire an image of a desired cardiac phase at a desired time after the injection of the contrast agent. 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 specific to the diagnostic apparatus.
[0098]
Further, as a modified example of this 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 inputs 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 perform data collection 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. When receiving the command signal, the arithmetic circuit 55 performs a subtraction between images and a maximum value hold operation between pixels between the images with respect to tomographic image data of a plurality of frames stored in the image memory circuit 52 by ECG synchronization. An image indicating a change between images is displayed on the monitor 36 via the DSC 35. Thereby, for example, the state of the change between the images of the second harmonic image can be easily grasped visually.
[0099]
When calculating the subtraction, it is particularly desirable to subtract the reference image IMref (see FIG. 20) before the injection of the contrast agent.
[0100]
Further, the ultrasonic diagnostic apparatus according to the configuration of FIG. 16 can be used together with the ultrasonic stress echo method. That is, an ultrasonic contrast echo method by injecting an ultrasonic contrast agent into a vein is performed before and after drug loading. To this end, 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 drug loading. Then, the arithmetic circuit 55 is caused to perform a desired operation such as subtraction between pixels between images before and after the load, and an image of the operation result is displayed on the monitor 36 via the DSC 35. Thereby, the myocardial site where blood circulation disappears before and after the load can be clearly observed.
[0101]
(Sixth embodiment)
The sixth embodiment will be described with reference to FIG. 16 (also used as the fifth embodiment) and FIGS. The sixth embodiment relates to a case where the contrast echo method is applied to the myocardium, and particularly relates to an ultrasonic diagnostic apparatus suitable for obtaining a myocardial distribution image. Specifically, when obtaining a myocardial distribution image, since the brightness enhancement by the contrast agent in the heart chamber is significantly larger than that of the myocardium, identification of the brightness enhancement by the contrast agent of the myocardium may be hindered. In such a situation, the brightness of the myocardial distribution image may not be accurately identified.
[0102]
In order to prevent such a situation from occurring, the ultrasonic diagnostic apparatus of this embodiment has the configuration shown in FIG. 16 while executing the processing shown in FIG. 18 on the manager 51 and executing the processing shown in FIG. I try to make it.
[0103]
Referring to FIG. 18, when displaying a myocardial distribution image by the contrast echo method, first, at an appropriate timing t0-1 before a time t0 at which a contrast agent is injected (see FIG. 20), a manager of a device (not shown) For example, an instruction to shoot a B-mode reference image of the myocardium is issued (steps 70 and 71). By this photographing, a reference image IMref is obtained as shown in FIG. 20, 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.
[0104]
Next, the heart chamber region is manually or automatically identified using the reference image IMref (step 72). In the case of manual operation, the operator is identified by operating the input device 50 to trace the outline of the heart chamber region on the reference image IMref displayed on the monitor 36. In the case of automatic, for example, it can be identified by discriminating the luminance level of the B-mode image (reference image IMref) with a desired threshold. As a result, the heart chamber region HSP is determined, for example, as shown in FIG. 20 (see the heart chamber region image IMHSP).
[0105]
Therefore, a mask image is created from the heart cavity region image IMHSP, and the data is stored in the image memory circuit 52 (step 73).
[0106]
Further, the process of FIG. 19 is performed by the DSC 35 for each frame after the contrast agent injection time t0. First, when one frame of image data (for example, data of a superimposed image of a fundamental wave image and a second harmonic image) is generated, the corresponding pixel of the mask image (heart cavity region image IMHSP) is generated for each pixel. The pixel value is referred to (step 75). When the pixel value of the corresponding pixel of the 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 equal to zero, the pixel is recognized as a non-display pixel, and the pixel data is set to zero (step 77).
[0107]
As a result, after the injection of the contrast agent, the spread of the contrast agent and its intensity (luminance) change over time, and the images of the myocardium HM in which the heart chamber HSP is masked (for example, IM1 to IM1 in FIG. 20). IM3) is formed and displayed every moment. Therefore, when obtaining a myocardial distribution image, the cardiac cavity region is not displayed, and only the luminance change of the myocardial region is displayed in real time, and the myocardial contrast agent can accurately enhance the luminance.
[0108]
Note that the luminance curve in FIG. 20 shows a change in the average luminance value of a part of the myocardium as a representative value of the whole image in order to easily show the luminance enhancement by the contrast agent.
[0109]
(Seventh embodiment)
A seventh embodiment will be described with reference to FIG. Similarly to the sixth embodiment, when the contrast echo method is applied to the myocardium, the seventh embodiment will improve the display effect due to the fact that the contrast enhancement in the heart cavity is significantly stronger than that of the myocardium. As in the case of 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. The difference from the sixth embodiment lies in the method of identifying the heart chamber region, and focuses on the level difference or level ratio between the fundamental wave component and the non-linear wave component.
[0110]
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 further includes a heart chamber region identification circuit 80 and a cardiac circuit between the receiver circuit 33 and the DSC 35. A cavity display control circuit 81 is provided.
[0111]
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 the case of the contrast echo method by intravenous injection, both the generation of the fundamental wave component and the nonlinear wave component in the heart chamber region are caused by the contrast agent in the heart chamber, whereas the fundamental wave component is mainly caused by the myocardial tissue in the myocardial region. The non-linear 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,
(Equation 1)
(P1 / P2) <K
Can be defined as a heart chamber region (or a non-myocardial region).
[0112]
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 area where “P1 / P2” is smaller than the threshold value K as the heart chamber area. Automatically identify as pixels. Based on this identification result (ie, whether “(P1 / P2) <K” or not), 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 in which the heart chamber region is not displayed is obtained, and a change in brightness enhancement of the myocardium due to the contrast agent can be easily and accurately identified on the image.
[0113]
The logical expression used in the heart chamber region identification circuit 80 is not limited to the one described above, and can be changed according to the state of the diagnosis target. Of course, the threshold value K may be appropriately selected.
[0114]
In the sixth and seventh embodiments, the case where the diagnosis target is a myocardium is described. However, other than this, for example, a large vascular system may be used. May be applied to the display / non-display control of.
[0115]
(Eighth embodiment)
An eighth embodiment will be described with reference to FIGS. This embodiment relates to an ultrasonic diagnostic apparatus which simultaneously transmits a plurality of ultrasonic beams having different frequencies into a living body and performs a contrast echo method based on the ultrasonic beams. That is, a transmission system that simultaneously transmits a plurality of ultrasonic beams having different frequencies (fundamental wave components f1, f2, f3,...) Into a living body, a transmission system generated in the living body, between the fundamental frequencies, and between them. , Nf1 + Mf3,..., N and M are integers, and difference frequency components (f1-f2, f2-f3,..., Nf1). −Mf3,...; M and N are integers), a receiving / processing system capable of receiving and processing an echo signal in a frequency band including at least one component, and a contrast image of a fundamental component and a non-fundamental component. A display system capable of displaying the sum or difference frequency of transmission frequency components due to non-linear scattering of the contrast agent in the living body, and based on this, the distribution of the ultrasonic contrast agent in the living body is imaged. Also It is.
[0116]
The ultrasonic diagnostic apparatus of FIG. 22 showing a specific example of this is intended to simultaneously drive two frequency components (f1, f2) and to visualize the difference frequency component (f1-f2).
[0117]
The probe 10 provided in this ultrasonic diagnostic apparatus is functionally assigned to the transducer groups A and B in the same manner as described above, and the transducer group of the transducer group A is used for transmitting the first fundamental wave component f1. Also, the vibrator group of the vibrator group B is used for transmitting the second fundamental wave component f2. All transducers of the probe 10 have sufficient transmission / reception sensitivity in both the fundamental band (f1, f2) and the difference frequency band (f1-f2).
[0118]
As shown in the drawing, a clock generation circuit 20 and a transmission delay circuit 21 for transmission focus are provided as a transmission system. An output side of the transmission delay circuit 21 includes a first pulser circuit 22a and a first transmission resonance circuit 23a. A series circuit and a series circuit of the second pulser circuit 22b and the second transmission resonance circuit 23b are provided in parallel. Among them, each pulser of the first pulser circuit 22a generates a driving pulse having the first fundamental wave component f1 at the center frequency, and each pulser of the second pulser circuit 22b has the second fundamental wave component f2 at the center frequency. Drive pulse. The first transmission resonance circuit 23a is capable of resonating in a set band with the first fundamental wave component f1 as a 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 around 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 a harmonic component of a driving pulse, the harmonic component of the driving pulse is included. Is removed, and drive pulses composed of the first and second fundamental wave components f1 and f2 are supplied to the vibrator groups A and B, respectively.
[0119]
Pulser-side ends of the first and second transmission resonance circuits 23a and 23b are connected to a reception delay / addition circuit 31 via a preamplifier circuit 30 having preamplifiers for all channels. An output terminal of this circuit 31 is connected to a receiver circuit 33 via a BPF 32a for a fundamental wave for extracting the first fundamental wave component f1 and a BPF 32b for a difference frequency for extracting the difference frequency component "f1-f2" in parallel. Have been. On the output side of the receiver circuit 33, a DSC 35 and a monitor 36 are sequentially provided.
[0120]
For this reason, 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 / addition 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 BPF 32a for fundamental wave, and the echo signal Sf1-f2 of the difference frequency component "f1-f2" is extracted by the BPF 32b for difference frequency. Are sent to the receiver circuit 33 and subjected to envelope detection and logarithmic compression processing. As a result, image data of a B-mode image based on the echo signals Sf1 and Sf1-f2 of one of the fundamental wave component f1 and the difference frequency component “f1-f2” is individually generated, and transmitted to the monitor 36 via the DSC 35. And displayed as a divided image or a superimposed image.
[0121]
Therefore, according to this embodiment, the same effects as those of the first to fourth embodiments can be obtained. In addition, since the B-mode image based on the difference frequency component is visualized, the second harmonic is easily generated at the time of transmission. No difference frequency component is generated. Therefore, there is also a special advantage that detection may be performed with a better S / N ratio than using the second harmonic.
[0122]
In the eighth embodiment, the simultaneous driving number of the ultrasonic beam is set to "2 frequencies", but may be set to "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. Further, an image based on the scattering of the contrast agent, which is paired with the fundamental wave image, may be generated using the sum frequency component. Further, in this embodiment, various modifications can be made to the transmission / reception system as in the first embodiment.
[0123]
Further, for a configuration that simultaneously transmits ultrasonic beams of a plurality of frequencies, a transmitter, a synthesizer, or the like that can transmit a time waveform obtained by linearly adding a plurality of frequency components can be provided.
[0124]
(Ninth embodiment)
A ninth embodiment will be described with reference to FIG. Similarly to the eighth embodiment, the ultrasonic diagnostic apparatus according to this embodiment detects and displays the sum or difference frequency components between the frequency components of the transmission beam signal generated in the living body, thereby enabling the imaging in the living body to be performed. It aims to visualize the distribution of agents.
[0125]
The probe 10 used in the 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 frequency of "f1-f2" to "f1". It has a 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 transmission of the other fundamental wave component f2, and has sufficient transmission sensitivity in the band of the fundamental wave component f2.
[0126]
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 that outputs a driving 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. Further, a preamplifier circuit 30 of a receiving / processing system is connected to the phased array probe 10a, and thereafter, signal processing is performed in the same manner as in the eighth embodiment. Two ultrasonic beam signals individually radiated from the phased array probe 10a and the single probe 10b have their beam directions and positions set so as to intersect at the position of a desired diagnostic site, and indicate the intersection area. An image is displayed on the monitor 36.
[0127]
As a result, the delay addition processing is performed by the reception delay / addition circuit 31 so that the reception area is focused on the intersection area, that is, the diagnosis site, so that the first fundamental wave component f1 and the difference frequency component “ A B-mode image based on the echo signal “f1−f2” is obtained. In this embodiment, since the second fundamental wave component f2 of the two fundamental wave components f1 and f2 is transmitted by the single probe 10b, the phased array probe can be constructed by diverting a conventionally used probe. Has a unique effect.
[0128]
The single probe may have a configuration in which the beam direction can be mechanically deflected. Further, a configuration in which the transmission resonance circuit is interposed between the first pulser circuit and the single probe and between the second pulser circuit and the phased array probe, respectively, is also possible.
[0129]
(Tenth embodiment)
A tenth embodiment of the present invention will be described with reference to FIG.
[0130]
The tenth embodiment relates to the calculation and display of the moving speed of a reflection echo source which emits a receivable nonlinear wave component (high frequency, subharmonic wave, ultrasonic wave or sum / difference frequency).
[0131]
The ultrasonic diagnostic apparatus shown in the figure includes a speed calculating unit 90 in a receiving / processing system in addition to the first embodiment, that is, the same configuration as that of FIG. Specifically, the output side of the non-linear wave BPF 32b for extracting the second harmonic component reaches the DSC 35 via the speed calculator 90, and the output side of the fundamental wave BPF 32a reaches the DSC 35 via the receiver circuit 33. The speed calculation unit 90 calculates two-dimensional motion speed data using a conventionally known method such as the Doppler method or the cross-correlation method.
[0132]
For this reason, the echo signal including the fundamental wave component and the non-fundamental wave component focused on the reception by the reception delay / addition circuit 31 is sent from the fundamental wave BPF 32a to the receiver circuit 33 as the echo signal Sf including only the fundamental wave component. . Therefore, B-mode image (fundamental wave image) data as tissue morphological information is supplied from the receiver circuit 33 to the DSC 35. On the other hand, from the non-fundamental-wave BPF 32b, an echo signal S2f composed of the second harmonic component of all the echo signals is extracted and sent to the speed 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 for extracting a Doppler signal only in a frequency band corresponding to a speed range known a priori of a target portion. ing. Based on the echo signal S2f, the velocity calculator 90 generates an echo reflection source that generates a second harmonic component, for example, a two-dimensional distribution including an ultrasonic contrast agent (ie, venous blood flow) at the time of performing the contrast echo method. Exercise speed data is calculated. The motion speed data is sent to the monitor 36 via the DSC 35 together with the B-mode image data, and, for example, a speed distribution image with the B-mode image as a background is displayed. Thereby, there is an advantage that the blood flow velocity in the tissue (for example, in the myocardium) can be evaluated.
[0133]
Note that the movement speed of the echo source in the region of interest set on the B-mode image on the scan plane may be simultaneously calculated, and the time change thereof may be displayed.
[0134]
(Eleventh embodiment)
An eleventh embodiment of the present invention will be described with reference to FIG. The ultrasound diagnostic apparatus according to the present embodiment is configured such that, when the contrast echo method using an ultrasonic contrast agent is applied, morphological information of a tissue such as a myocardium based on the echo level of the fundamental wave component and tissue based on the echo level of the non-fundamental wave component In addition to the internal blood flow information, the motion velocity of the tissue (for example, myocardium) can be calculated based on the echo level of the fundamental component, and these three factors, namely, “tissue morphological information”, “tissue blood flow information”, And "tissue movement speed" can be simultaneously displayed.
[0135]
More specifically, this ultrasonic diagnostic apparatus has a configuration similar to that of FIG. 1 (first embodiment), and further includes a clutter removal filter 91, a blood flow velocity calculator 92, and a tissue velocity calculator 93. Are provided as shown in the figure. That is, a series connection of one receiver circuit 32a, a clutter removal filter 91 for removing unnecessary clutter components, and a blood flow speed calculator 92 for calculating a blood flow movement speed is provided between the output terminal of the fundamental wave BPF 32a and the DSC 35. A structure and a tissue speed calculation unit 93 for calculating the movement speed of a tissue such as a myocardium are juxtaposed.
[0136]
The non-fundamental wave BPF 32b reaches the DSC 35 via the other receiver circuit 32b.
[0137]
Among them, as the tissue speed calculating section 93, for example, one having a configuration disclosed in Japanese Patent Application Laid-Open No. 5-84246 is known. That is, the echo signal to which the reception focus is applied is phase-detected by the phase detector with respect to the Doppler frequency, and from the phase-detected signal, the Doppler signal caused by the blood flow, the heart valve, and the like is removed 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 calculates the maximum value and the average value of the movement speed of the tissue using the two-dimensional distribution data of the Doppler deflection transfer frequency. The analysis method of the frequency analysis unit may be a cross-correlation method.
[0138]
For this reason, the fundamental wave component Sf is extracted by the fundamental wave BPF 32a from the echo signal containing the fundamental wave component and the non-fundamental wave component focused on the reception by the reception delay / addition circuit 31, and the non-fundamental wave The secondary high frequency component S2f is extracted by the use BPF 32b. Among them, the echo signal of the fundamental wave component Sf is generated as image data of a B-mode image by the receiver circuit 32a, while the clutter removal filter 91 and the blood flow velocity calculating unit 92 generate a blood flow velocity distribution image (for example, It is generated as image data of a color Doppler (CFM) image, and is generated as image data of a motion velocity distribution image of a tissue (for example, a myocardium) by the tissue speed calculation unit 93. On the other hand, the echo signal of the second harmonic component S2f is generated as image data of a B-mode image of the second harmonic component by the other receiver circuit 33b. After these four types of image data are sent to the DSC 35, they are converted into frame image data of the display mode instructed at that time (including selection and synthesis of each image data) and displayed on the monitor 36. .
[0139]
This display example will be described with reference to FIG. 27 in a case where a contrast echo method for an 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 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 myocardial blood flow. As one mode of display, the composite image IMf + 2f is displayed on the monitor 36 by superimposing the image data of both IMf and IM2f on the DSC 35, and the blood flow perfusion region RB in the myocardium (the black solid image in the image IMf + 2f) Part) is visualized in real time.
[0140]
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 movement velocity of the myocardium. Therefore, a two-dimensional distribution image (not shown) of the movement speed may be displayed as it is, or, for example, the DSC 35 determines whether or not the speed V> Vt (Vt: given threshold) for each pixel. It is determined, and image data of the two-dimensional distribution image IMv having a motion speed equal to or higher than the threshold value Vt, which meets this determination condition, is formed. By displaying the two-dimensional distribution image IMv, the myocardial wall motion abnormal region Rw (open portion in the image IMv) is visualized. As yet another display mode, the DSC 35 superimposes the three-dimensional image of the myocardial kinetic velocity IMv, the myocardial B-mode image IMf, and the myocardial blood flow distribution image IM2f, which have been subjected to the threshold processing as described above (wall). The logical product of the abnormal movement region Rw and the blood flow perfusion region RB is calculated). Accordingly, the composite image IMf + 2f + v is displayed on the monitor 36, and the movement of the myocardial wall is stopped with the myocardial B-mode image as the background (specifically, the wall motion speed is equal to or less than a certain threshold), but the blood flow is A diagnostically interesting region RW + B, which is perfused, is visualized in real time.
[0141]
As described above, according to the present embodiment, for example, while the myocardium can be individually diagnosed in real time from each viewpoint of morphology, exercise, and blood perfusion, they can be comprehensively diagnosed in real time, and so-called myocardial viability evaluation can be performed. Will be possible. As a result, useful information that has not been available can be provided.
[0142]
(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 a non-fundamental wave component related to an ultrasonic contrast agent at regular time intervals, calculates a luminance change curve (TDC: Time Density Curve) from the collected data, and The feature amount (parameter) of the change curve is calculated.
[0143]
The ultrasonic diagnostic apparatus of this embodiment shown in FIG. 28 has an ECG (electrocardiograph) for performing the above-described image data collection at a fixed time interval in addition to the configuration of FIG. 1 (first embodiment). 95, an ECG amplifier 96, and a trigger signal generator 97. The ECG 95 sends the electrocardiogram information (ECG signal) of each cardiac phase of the subject to the trigger signal generator 97 via the ECG amplifier 96. The trigger signal generator 97 generates a trigger pulse in response to, for example, a rising edge of an R wave in the ECG signal and sends the trigger pulse 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 the optimum data collection timing Tn in each cycle of the ECG signal by counting a fixed time from the arrival of the trigger pulse, and includes the transmission / reception timing that matches this timing Tn. A series of transmission / reception is performed by the transmission system and the reception / processing system. The data acquisition timing Tn is set, for example, at the end of the left ventricle diastole (for example, a certain time after the R wave) as shown in FIG. Therefore, image data is collected every time the data collection timing Tn synchronized with the ECG arrives.
[0144]
Further, the ultrasonic diagnostic apparatus includes an image memory circuit 98, a luminance change curve calculator 99, and a parameter calculator 100 connected to the DSC 35 as a part of the receiving / processing system. The image memory circuit 98 stores the image data of the second harmonic component as the non-fundamental component sent to the DSC 35 one by one at each data collection timing Tn. The luminance change curve calculation unit 99 has a CPU function, and of the image data stored in the image memory circuit 98, the ROI set for a part of the myocardium (this ROI is set in advance or after image acquisition). The image data corresponding to the position is read, and the data of the luminance change curve TDC is calculated.
[0145]
As a result, at each ECG-synchronized data acquisition timing Tn in each cardiac cycle (see FIG. 29A), for example, image data of the left ventricular short-axis image (see FIG. 29B) is acquired, and these images are acquired. The data is stored in the image memory circuit 98. Therefore, after the entire 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 calculations such as averaging the data in the ROI are performed, and the elapsed time from the contrast agent injection time t0 is performed. The change data of the luminance with respect to t (see FIG. 29C) is calculated. Note that this calculation can be performed at regular intervals during image data collection, and thus the memory capacity of the image memory circuit 98 can be reduced.
[0146]
Further, a parameter calculator 100 is provided between the brightness change curve calculator 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 data calculation of the brightness change curve in the brightness change curve calculation unit 99 has been completed (step 100a in FIG. 30). When the calculation has been completed, fitting processing of the curve data is performed (step 100b in FIG. 30). In this fitting process, the obtained luminance change curve data is fitted with an appropriate function (gamma function, Gaussian function, exponential function, etc.), thereby reducing the effects of noise and measurement errors, A great change in luminance is extracted. The fitting process may be performed by the luminance change curve calculation unit 99, or may be performed only when necessary.
[0147]
The parameter calculating unit 100 further uses the fitting-processed brightness change curve data to set various parameters representing the characteristic amount of the brightness change curve, such as the maximum brightness level LMAX, the maximum brightness time tMAX, the brightness half-decrease level LHF, and the brightness half-time tHF. The luminance half time (= maximum luminance time tMAX-luminance half time tHF), the maximum luminance arrival time (injection time t0-maximum luminance time tMAX), the contrast duration (the duration of the luminance level equal to or higher than the threshold), and the like are calculated ( (See step 100c in the figure).
[0148]
The parameter data calculated in this manner is sent to the DSC 35 together with the data of the luminance change curve (see step 100d in the figure), for example, for the division display of the fundamental image IMf and the second harmonic image IM2f with the superimposed image IMf + 2f. In this manner, it is displayed on the monitor 36.
[0149]
Accordingly, in addition to the same advantages as those of the first embodiment, when the contrast echo method using the ultrasonic contrast agent is performed, the brightness change and the characteristic amount of only the contrast agent, that is, the blood flow distribution image in the tissue are measured. The information can be automatically grasped without being affected by the cycle, and useful information for diagnosis can be obtained.
[0150]
Note that the number of ROIs set in this embodiment may be plural. The image acquisition 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 storage means of the collected image data is not limited to the image memory circuit in its own device, but may be an MO (magneto-optical disk) or a workstation connected to the device.
[0151]
In the twelfth embodiment, as is well known, there is a high possibility that the brightness change curve has no meaning unless it is for the same part of the tissue. For this reason, the data of the luminance change curve usually targets (1) immobile tissues (abdominal organs and the like), (2) myocardial images synchronized with ECG, and the like. However, if the tissue still slightly moves, a means for finely adjusting the position of the ROI for each frame may be added. The fine adjustment of the ROI may be simply performed by a manual fine adjustment mechanism for finely adjusting the position of the ROI with a mouse or the like.
[0152]
Further, the processing of the twelfth embodiment described above is enlarged, and the same calculation is performed by the luminance change curve calculation unit and the parameter calculation unit on all the pixels or the set of all the plurality of pixels of each collected image. Thus, parameters such as the maximum brightness 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 a useful measure for diagnosis.
[0153]
According to the present invention, a transmission filter that passes only the fundamental wave component can be used as the suppression unit that intentionally (or positively) suppresses the non-fundamental wave component.
[0154]
Further, when a filter or a transmission resonance circuit based on series resonance is used as the suppression means in the present invention, an arrangement configuration as shown in FIGS. 31A and 31B can be adopted. That is, in FIG. 2A, a filter 110 is inserted between the probe 10 and the pulser circuit 22 and the preamplifier circuit 30, and only the filter 110 is operated during transmission, and the filter 110 is separated from the circuit during reception. A changeover switch 111 for forming a bypass for reception is provided. In FIG. 2B, a series resonance inductance 112 as a transmission resonance circuit is inserted between the probe 10 and the pulser circuit 22 and the preamplifier circuit 30. The transmission resonance is turned off and the reception is turned on in parallel with the inductance 112. Is provided. With these circuit configurations, the same functions and effects as those described above can be obtained.
[0155]
【The invention's effect】
An ultrasonic diagnostic apparatus according to the present invention includes a transmitting unit that supplies a drive pulse signal of an electric quantity having a fundamental component of a desired excitation frequency to a probe, and the probe emits the ultrasonic signal according to the drive pulse signal. With the echo signal of the electric quantity output from the probe in response to receiving the reflected signal of the ultrasonic signal, the fundamental wave component and the non-fundamental wave component included in the echo signal are input from the echo signal. Reception processing means for generating image data related to the image processing, measurement, analysis, display, etc. using the fundamental wave component and the non-fundamental wave component, so that heart wall motion information and myocardial blood flow perfusion information In addition to simultaneous collection and evaluation, the stress echo method used to diagnose angina pectoris simultaneously collects heart wall motion information and myocardial blood flow perfusion information under each load condition. Etc., can be evaluated, it is possible to 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 illustrating 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 the 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 modified example 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.
11A and 11B are diagrams illustrating frequency characteristics of a vibrator, respectively.
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.
14A to 14C are diagrams illustrating frequency characteristics of a vibrator.
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.
17A and 17B are schematic flowcharts each showing a processing example of 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 processing example of DSC of the ultrasonic diagnostic apparatus according to the sixth embodiment of the present invention.
FIG. 20 is an explanatory diagram showing a luminance change curve and a change in a second harmonic image of a 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 an example of combinations 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 view for explaining a relationship among an ECG signal, an image acquisition 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. 31 (a) and (b) are diagrams showing a modification of the suppressing means and its arrangement.
[Explanation of symbols]
10,10a, 10b probe
11 Main unit
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 / addition 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 Tissue speed calculator
95 ECG
96 ECG amplifier
97 Trigger signal generator
98 Image memory circuit
99 Luminance change curve calculator
100 Parameter calculator

Claims (12)

A probe capable of bidirectionally converting between an ultrasonic signal and a signal of an electric quantity, transmitting means for supplying the probe with a drive pulse signal of an electric quantity having a fundamental component of a desired excitation frequency, and the probe In response to receiving the reflected signal of the ultrasonic signal while emitting the ultrasonic signal in response to the drive pulse signal, inputting an echo signal of an electric quantity output from the probe in response to receiving the reflected signal of the ultrasonic signal, the basic Reception processing means for generating image data related to wave components and non-fundamental wave components included in the echo signal, and display means for displaying the image data,
The reception processing means extracts the non-fundamental wave component from the echo signal, and the two-dimensional distribution data of the motion velocity of the reflection echo source that generates the non-fundamental wave component based on the non-fundamental wave component. And speed calculation means for calculating
An ultrasonic diagnostic apparatus, wherein the display unit includes a speed display unit that displays two-dimensional distribution data of the movement speed. A probe capable of bidirectionally converting between an ultrasonic signal and a signal of an electric quantity, transmitting means for supplying the probe with a drive pulse signal of an electric quantity having a fundamental component of a desired excitation frequency, and the probe In response to receiving the reflected signal of the ultrasonic signal while emitting the ultrasonic signal in response to the drive pulse signal, inputting an echo signal of an electric quantity output from the probe in response to receiving the reflected signal of the ultrasonic signal, the basic Reception processing means for generating image data related to wave components and non-fundamental wave components included in the echo signal, and display means for displaying the image data,
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 obtaining image data of tissue morphological information based on the fundamental wave component. (1) calculating means, second calculating means for obtaining image data of tissue motion information based on the fundamental wave component, and blood flow in tissue for generating the non-fundamental wave component based on the non-fundamental wave component A third calculating means for obtaining image data of information; and an image data output means for outputting at least one image data of the morphological information of the tissue, exercise information of the tissue, and blood flow information in the tissue to the display means. An ultrasonic diagnostic apparatus, comprising: A probe capable of bidirectionally converting between an ultrasonic signal and a signal of an electric quantity, transmitting means for supplying the probe with a drive pulse signal of an electric quantity having a fundamental component of a desired excitation frequency, and the probe In response to receiving the reflected signal of the ultrasonic signal while emitting the ultrasonic signal in response to the drive pulse signal, inputting an echo signal of an electric quantity output from the probe in response to receiving the reflected signal of the ultrasonic signal, the basic Reception processing means for generating image data related to wave components and non-fundamental wave components included in the echo signal, and display means for displaying the image data,
The reception processing unit includes: an extraction unit configured to extract the non-fundamental component from the echo signal; a generation unit configured to generate image data based on the non-fundamental component; Storage means for storing image data of components; time-series data calculating means for calculating data of a brightness change curve of the same part of the tissue based on the image data of the plurality of frames; Characteristic amount calculating means for calculating the characteristic amount of
The ultrasonic diagnostic apparatus according to claim 1, wherein the display unit includes a unit that displays the luminance change curve together with the feature amount. A probe capable of bidirectionally converting between an ultrasonic signal and a signal of an electric quantity, transmitting means for supplying the probe with a drive pulse signal of an electric quantity having a fundamental component of a desired excitation frequency, and the probe In response to receiving the reflected signal of the ultrasonic signal while emitting the ultrasonic signal in response to the drive pulse signal, inputting an echo signal of an electric quantity output from the probe in response to receiving the reflected signal of the ultrasonic signal, the basic Reception processing means for generating image data related to wave components and non-fundamental wave components included in the echo signal, and display means for displaying the image data,
The reception processing unit includes a storage unit that stores tomographic image data of the non-fundamental wave component by an ultrasonic contrast echo method before and after drug loading on a subject, and a luminance change between the tomographic images. And a calculating means for generating the image data by performing the above calculations. The transmitting means positively reduces the level of the signal of the non-fundamental wave component with respect to the fundamental wave component of the drive pulse signal, and provides the probe with a drive pulse signal substantially comprising the excitation frequency of the fundamental wave component. The ultrasonic diagnostic apparatus according to any one of claims 1 to 4, wherein the ultrasonic diagnostic apparatus is configured as described above. The ultrasonic diagnostic apparatus according to claim 5, wherein the transmitting unit includes a suppressing unit that actively suppresses the non-fundamental wave component. The suppression means may include 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 only at the time of transmission, and only the fundamental component of the drive pulse signal. 7. The ultrasonic diagnostic apparatus according to claim 6, further comprising a transmission resonance circuit that allows transmission of the ultrasonic wave. 7. An ultrasonic wave according to claim 6, wherein said transmission means includes a transmission pulser circuit also serving as said suppression means, and said pulser circuit includes a circuit configuration for generating said drive pulse signal having a duty ratio of 50%. Diagnostic device. 7. The ultrasonic diagnostic apparatus according to claim 6, wherein said transmission means includes a transmission pulser circuit also serving as said suppression means, and said pulser circuit includes a circuit configuration for generating said drive pulse signal in class A operation. apparatus. The fundamental 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. The ultrasonic diagnostic apparatus according to claim 1. The ultrasonic diagnostic apparatus according to claim 5, wherein the non-fundamental component is a second harmonic component of the fundamental component. The fundamental component comprises a plurality of different fundamental frequencies, and the non-fundamental component comprises at least one of a frequency component of a sum or a difference between the fundamental frequencies or a harmonic component of the fundamental frequency. The ultrasonic diagnostic apparatus according to any one of claims 1 to 9, wherein:

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