1274578 九、發明說明： 【發明所屬之技術領域】 本發明疋有關於一種顧部超音波成像之方法，特別是 指一種以超音波對比劑並應用特殊信號處理技術之顱部超 音波成像方法。 【先前技術】 醫用超音波具有安全、價格低廉等優點，因此目前醫 療界廣泛應用超音波影像技術於身體各部位的臨床診斷， 如心臟、腹部、婦產超音波檢查等。 然而’腦部因外圍顱骨包覆形成阻礙，造成超音波信 號傳遞及穿透時的嚴重衰減（attenuati〇n)，因此一直以來 超音波影像技術最多僅用於偵測顱内中線結構是否偏移、 腦室擴大與否，而鮮少應用於腦部病灶一如腦血腫、動靜 脈瘤、動靜脈畸形等的診斷。目前對於顱部的影像，可改 透過斷層掃描、核磁共振等昂貴儀器取得，並仍有下述針 對顱部超音波影像的研究及改進方式： 其’藉由快速廣角多元組的扇形掃描器（sect〇r )由新生兒未閉闔的囪門，或成人可由枕骨大孔（ 、 magnum)、眼窩等特定部位一窺顱内究竟。其缺點 為一發射超音波信號及成像的位置受限於特定部位，且對 方、4寸別疋一歲以上幼兒或成人而言，顱内偵測死角多。 其一，近年來更高解像力的掃描轉換器（ 「一 er )及向頻率的探頭（transducer)相繼問世，期以 〜員仏虎發射、高頻信號接收」的技術提高超音波影像 5 1274578 解析度。然而，上述技術及工具對顱部 1向5 ，依舊無法古 服而頻超音波經顱骨嚴重衰減的問題，梯 忧侍顱部影傻 度品質提高有限，最終無法獲得顱内深部或血管性疒土、 清晰影像。因此一般仍採用低頻發射信卢， 焫灶的 〜武圖達到較隹 牙透率，但解析度極差。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for ultrasonic imaging of a portion, and more particularly to a method for imaging a cranial ultrasound using a supersonic contrast agent and applying a special signal processing technique. [Prior Art] Medical ultrasound has the advantages of safety and low price. Therefore, the medical field has widely applied ultrasonic imaging technology to clinical diagnosis of various parts of the body, such as heart, abdomen, and ultrasound examination of maternity. However, 'the brain is obstructed by the outer skull coating, causing severe attenuation of the ultrasonic signal transmission and penetration (attenuati〇n), so the ultrasound imaging technique has been used only to detect whether the midline structure of the skull is biased. Shift, ventricle enlargement or not, and rarely used in the diagnosis of brain lesions such as cerebral hematoma, arteriovenous tumor, arteriovenous malformation. At present, the image of the cranial region can be obtained through expensive instruments such as tomography and nuclear magnetic resonance, and there are still the following research and improvement methods for the cranial ultrasound image: [by a wide-angle multi-group fan scanner ( Sect〇r) From the neonatal incontinence of the uterus, or the adult can see the inside of the skull from a specific part of the occipital foramen (magnum), orbit. The disadvantage is that the position of a supersonic signal and imaging is limited to a specific part, and the intracranial detection of more dead angles is more than that of a child or an adult who is more than one year old. First, in recent years, higher resolution scanning converters ("one" and frequency-transmitting transducers have been introduced one after another, and the technology of high-frequency signal reception has been improved by ~ 仏 仏 发射 、 、 高频 高频 5 5 5 12 12 12 12 12 12 12 12 12 12 12 12 12 12 degree. However, the above techniques and tools for the cranial 1 to 5, still can not be ancient and the frequency of supersonic waves through the skull is seriously attenuated, the ladder is difficult to improve the quality of the skull and shadow, and ultimately can not obtain deep intracranial or vascular spasm Earth, clear image. Therefore, the low-frequency emission letter is generally used, and the 武 武 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到 达到
二，對於血流訊號的取得，目前普遍採用在血液或 淋巴液中加入對比齊“contrast agent)的輔助方法，基於其 中微氣泡（microbubble )對聲波具有良好回波特性了達到 ^幵彳§號品質的目的，有助於相關參數的量取。 配合參閱圖1 ’有關對比劑之超音波回波信號，進行頻 譜分析可發現習知之-基頻響應（fundamemal啊。職）^ 、一第二諧振響應（sec〇nd harm〇nic resp〇nw) ^，及一次 諧振響應（subharmonic)。後二者皆屬氣泡的非線性反應， 且需要較高的發射聲壓才能使微氣泡產生，其中又以次諧 振響應13所需的聲壓最高。 其中，基頻響應在血流與周圍組織中皆可發現，因此 無法用以比對及辨識，失去利用價值。 就第二諧振響應而言，一方面由於其屬高頻，經過顱 骨後衰減的程度特別顯著；另一方面則由於在哺乳類動物 組織中也能發現第二諧振響應，使得利用第二諧振響應來 區別血液、淋巴液與周圍組織的能力大為降低。 就次譜振響應而言，由於其需受高聲壓激發才能產生 ’往往導致微氣泡破裂，對安全構成威脅，因此並不適於 顱内偵測使用。 1274578 【發明内容】 因此，本發明之目的，即在 像位置之顧部超音波成像方法及系統。種不侷限於特定成 本發明之另一目的，在於提供一種 流信號並成像的量測方法及系統。 3取得顱内血 本發明之再一目的，在於提供一種精確 超音波成像方法及系統。 之顱邛 於是，本發明顧部超音波成像方法及系統 顧部血管進行探測並建立影像，該血管内之血㈣注= 對比劑而存在多數微氣泡。該 f ~音波探頭（ rans ucei·、與超音波探頭相連的—發射模組、— ，及一信號處理模組。 杲、、且 该方法則包含以下步驟： 該血二發:"莫組產生驅動訊號’令超音波探頭對顱骨内 A B 鲞射3旻數帶狀頻寬之超音波發射信號，亦β 脈衝信號（-η«。由於本發明所操取用以 二 號’受顧骨衰減的程度微小（ί羊細說明於下文），因此。 音波探頭可選擇自顧部任意位置進行量測，使超音波^ 顱骨等介質進入顱部血管。 牙远 (2)超音波探頭探測得來自微氣泡之回波信號， 送至接收模組。 ^、 (3 ) ^唬處理模組接收回波信號，並將回波信號進疒 頻讀分析，得到—基頻響應、ϋ振響應、-次错= 曰C及低頻響應（low-frequency response )。該低并員鄉 !274578 應發生在頻譜中拉iff ^ ''ώ , “分，其頻寬近似於基頻響應 見’或§兄疋發射信號之頻寬。低頻響應的產生可在本 發明所推導之理論；5每岭+ 在本 … ϋ κ，’’、双中共同被支持一當微氣泡受雔 率聲波信號同時刺激，且該雔 又^ 豕又頻夠接近時（適當發射頻實） ，該雙頻之差值在頻譜巾彡 、、 低頻響應。 ι中接近直流的部分被激發’也就是 )'就處理&組利用帶通濾波器擷取低頻響應，避 “自直流電與基頻的干擾。此步驟相當於僅保 仏號，對於血管成像有極大幫助。 (5)依據該低頻響應推算得該等微氣 ’並建立血管影像。 ，木度 超音波整體影像品質同時 J寸取决於發射與接收信號，以 =無法克服信號經顱骨衰減的問題，故在發射及接收方 =採低頻㈣，因此得到較低的影像解析度。而本發明 可改善上述狀況，在發射彳士祙 在七射仏虎部分採高頻’雖發射過程仍 又哀減，但重點在於—對於 廄^ . 對夂裱軋泡的回波信號僅採低頻響 ‘…所叉到顱骨之衰減程度相較於高頻極少，因此僅需 :適當強：之發射信號，或在發射信號時補償以適度的能 里，讓超音波信號經過顱骨衰減 應的能量，即可達到的較、、青晰…：持足以產生低頻響 日… 的“晰血官成像。也就是說，本發 ^ “ 接收」的方式，較以往「低頻發射、 低須接收」所後得之影像解析度佳。 由於本發明採用的低頻響應，並不需要如次諧振響應 所而之高聲壓，即可被激發產生， 固此不會有微氣泡破裂 1274578 乂於習知技術顯然更安全且適用於顱部超音波 纟夕卜’本發明非僅限制於人體顧部的成像，可 應用於哺乳類動物其他，尤其受骨#各包圍的器官:遍 成方'鋼肋内的龜裂空隙，成功克服了以 遇南衣減係數介質而大幅衰 皮 度的問題。 中田农減I必須採取降低影像解析 【實施方式】 、有關本發明之前述及其他技術内容、特點與功效 以下配合參考圖式之一個較 清楚的呈現。 Κ說明中，將可 μ如圖2所示’本發明顱部超音波成像系統建構在—般 起曰波糸統上，fe伟奋# γ θ 又 例是m部血管進行探測並建 立衫像舉例說明，需读、丹重止 而透過事先靜脈注射對比劑的方式 管内之血液存在多數微氣泡。該系統包含-超音波揮 頭U、與超音波探頭相連的一發射模組22、一接收模组Μ ’及一信號處理模組20。 信號處理模組20内部又包含依序相連之-滤波單元25 、一低頻擷取單元26，及一成像單元27。 :配合參閱圖3’本發明顧内❹測方法則包含以下步驟 步驟31-發射模組22產生—驅動訊號，傳遞至超立波 探頭21。該超音波探頭21應預先貼靠於顱部外表任意處曰。/ 步驟32-超音波探頭21依據該驅動訊號，對顱骨㈣ 血管依序發射複數帶狀頻寬之超音波發射信號。由於超音 1274578 波嶽質需同時取決於發射與接收信號，在本發明之發 广虎部分採高頻’可獲得較佳之影像解析度。此外，發 =就之能量在本實施例是以補償的方式，藉此使超音^ =過顧骨衰減後，維持足以產生低頻響應的能量，以 血管成像。補償量是依據該發射信號強度* 4減係數的乘積，-般而言，㈣的衰減係數為η分貝 / 厘米· MHz。 、 步驟33-超音波探頭21探測得來自微 ，並傳送至接收模組23。 1口就 步驟34—接收模組23將回诚彷％扁 , 口波彳5唬傳遞至信號處理模組 2〇之濾波單元25 ,進行濾波處理使 、、 品質提昇。 便4铋利付到的回波信號 步驟35—信號處理模組2〇接收回波信號 ::收來自渡波單元25之回波信號，並進行頻譜分: 依據仙波信號之财分布，可得到—與發㈣率 ^頻率及頻寬相當的基頻響應、41，及—接近直流的部 低頻響應42,並利用帶通濾波器梅取—低頻響應仏 頻響應42頻寬近似於基頻響應41之頻寬。此步驟相當於 僅保留血管内信號’對於血管成像有極大幫助。 田' 步驟36—依據該低頻響應推算得該等微氣泡 深度，並建立血管影像。 歸納上述’本發明所述發射信號雖發射過程 ’但重點在於：對於來自管内血流中之微氣泡的回波 ，僅採低頻響應作為成像基準，其所受到㈣之衰減^ 10 1274578 相:=極少，因此僅需在發射信號時補償適度的能量 像位…的較凊晰血管成像。因此確實可達到本發明成 ,、又侷限，且安全、經濟、精確成像之目的。 、上所述者，僅為本發明之較佳實施例而已，當不 μ、此限定本發明實施之範圍，即大凡依本發明申請專利 軌圍及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 【圖式簡單說明】Second, for the acquisition of blood flow signals, the auxiliary method of adding contrast agents in blood or lymph is generally adopted, based on which microbubble has good echo characteristics for sound waves. The purpose of the quality is to help the measurement of the relevant parameters. Refer to Figure 1 for the ultrasound echo signal of the contrast agent, and the spectrum analysis can find the conventional-based frequency response (fundamemal.) ^, one The second resonance response (sec〇nd harm〇nic resp〇nw) ^, and the primary resonance response (subharmonic). Both of them are nonlinear reactions of bubbles, and require higher emission sound pressure to generate microbubbles. The sound pressure required by the secondary resonance response 13 is the highest. Among them, the fundamental frequency response can be found in both the blood flow and the surrounding tissue, so it cannot be used for comparison and identification, and the utilization value is lost. On the one hand, because of its high frequency, the degree of attenuation after the skull is particularly significant; on the other hand, because the second resonance response can also be found in mammalian tissues, the second is utilized. The ability of the vibration response to distinguish blood, lymph and surrounding tissues is greatly reduced. In terms of secondary spectral response, it is required to be excited by high sound pressure to generate 'often causing microbubble rupture, posing a threat to safety, and therefore uncomfortable. Intracranial detection is used. 1274578 SUMMARY OF THE INVENTION Accordingly, the object of the present invention, that is, the image processing method and system in the image position, is not limited to the specific purpose of the invention, and is to provide a flow signal. And measuring method and system for imaging. 3 Obtaining intracranial blood Another object of the invention is to provide an accurate ultrasonic imaging method and system. The cranial sputum is then used in the present invention. Detect and create an image, the blood in the blood vessel (4) Note = contrast agent and there are many microbubbles. The f ~ acoustic probe (rans ucei, connected to the ultrasonic probe - the transmitting module, - and a signal processing module杲,, and the method includes the following steps: The blood second hair: "Mo group generates a driving signal' so that the ultrasonic probe is in the skull AB 鲞3 带 band-shaped bandwidth of the ultrasonic wave transmitting signal, also β pulse signal (-η«. Since the operation of the present invention for the second 'because of the degree of bone attenuation is small (ί 细 细 述 hereinafter) The sonic probe can be selected from any position of the camera to make the medium such as ultrasonic wave and skull enter the cranial blood vessel. The far tooth (2) ultrasonic probe detects the echo signal from the microbubble and sends it to the receiving module. ^, (3) ^ The processing module receives the echo signal, and the echo signal is analyzed by frequency reading to obtain - fundamental frequency response, oscillating response, - sub-error = 曰 C and low-frequency response (low-frequency response) ). The low and the township! 274578 should occur in the spectrum pull iff ^ ''ώ, "minute, its bandwidth is similar to the fundamental frequency response see ' or § brothers and sisters transmit the bandwidth of the signal. The generation of low-frequency response can be derived from the theory of the present invention; 5 per ridge + in the present... ϋ κ, '', double-in-one is supported together when the microbubble is stimulated by the acoustic signal at the same time, and the 雔 ^ ^ When the frequency is close enough (appropriate transmission frequency), the difference between the dual frequencies is in the spectrum frame, and the low frequency response. The part of ι that is close to DC is excited 'that is'. The processing & group uses the bandpass filter to extract the low frequency response, avoiding the interference from the direct current and the fundamental frequency. This step is equivalent to only the 仏, for vascular imaging (5) Based on the low-frequency response, the micro-gas is calculated and the blood vessel image is established. The overall image quality of the wood-based ultrasound is determined by the transmission and reception signals, so that the signal cannot be overcome by the skull attenuation. The problem is that the transmitting and receiving sides = low frequency (four), so that a lower image resolution is obtained. However, the present invention can improve the above situation, and in the launching of the gentleman, the high frequency is collected in the seven-shot tiger part, although the launching process is still Sorrow, but the focus is on - for 廄^. The echo signal of the 夂裱 夂裱 仅 仅 仅 ' ' ' ' ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Or, when transmitting the signal, compensate for the moderate energy, and let the ultrasonic signal pass through the energy of the skull to attenuate the energy, which can be achieved, clear, and clear...: A blood-stained image that is sufficient to produce a low-frequency sound. In other words, the method of "receiving" is better than the previous "low-frequency transmission, low-receiving" image resolution. Since the low frequency response adopted by the present invention does not require a high sound pressure such as a sub-resonant response, it can be excited, so that there is no microbubble rupture. 1274578. It is obviously safer and suitable for the cranial part of the prior art. Ultrasonic 纟 ' 'The invention is not limited to the imaging of the human body, can be applied to other mammals, especially the organs surrounded by bones: the cracks in the steel ribs of the square, successfully overcome In the case of Nanyi, the coefficient of medium is greatly reduced. The above-mentioned and other technical contents, features and effects of the present invention will be described below with reference to a clear description of the reference drawings. In the Κ description, the cranial ultrasound imaging system of the present invention can be constructed as shown in Fig. 2, and the 伟 奋 # fe fe fe fe fe fe fe fe m m m m m m m m m m m m m m m m m m m m m m m For example, there is a large number of microbubbles in the blood in the tube by reading and injecting the contrast agent in advance. The system includes an ultrasonic wave U, a transmitting module 22 coupled to the ultrasonic probe, a receiving module ’ ' and a signal processing module 20. The signal processing module 20 further includes a filtering unit 25, a low frequency capturing unit 26, and an imaging unit 27 connected in sequence. The method of the present invention includes the following steps: Step 31 - The transmitting module 22 generates a driving signal and transmits it to the super-wave detecting probe 21. The ultrasonic probe 21 should be placed in front of the cranial surface at any position in advance. / Step 32 - The ultrasonic probe 21 sequentially transmits a plurality of supersonic transmission signals of the band width to the skull (four) blood vessels according to the driving signal. Since the supersonic 1274578 wave quality depends on both the transmitted and received signals, a high frequency can be obtained in the Guanghu part of the present invention to obtain a better image resolution. In addition, the energy in the present embodiment is compensated in such a manner that the supersonics are attenuated and the energy sufficient to generate a low frequency response is maintained to image the blood vessels. The amount of compensation is based on the product of the transmitted signal strength * 4 minus the coefficient. In general, the attenuation coefficient of (4) is η dB / cm · MHz. Step 33 - The ultrasonic probe 21 is detected from the micro and transmitted to the receiving module 23. In the first step, the receiving module 23 transmits the homing to the flat panel, and the port wave 彳5唬 is transmitted to the filtering unit 25 of the signal processing module 2 to perform filtering processing to improve the quality. The echo signal received by the 4th profit step 35 - the signal processing module 2 receives the echo signal: receives the echo signal from the wave unit 25, and performs spectrum division: according to the wealth distribution of the fairy wave signal, (4) rate ^ frequency and bandwidth equivalent fundamental frequency response, 41, and - close to the DC low frequency response 42 and use the bandpass filter to take - low frequency response 仏 frequency response 42 bandwidth approximate to the fundamental frequency response 41 bandwidth. This step is equivalent to retaining only intravascular signals', which is of great help to vascular imaging. Field' Step 36 - Calculate the depth of the microbubbles based on the low frequency response and establish a vascular image. The above-mentioned 'transmitting signal of the present invention is emitted although the process of transmitting' is focused on: for the echo from the microbubbles in the blood flow in the tube, only the low frequency response is taken as the imaging reference, and the attenuation is received by (4) ^ 10 1274578 Phase: = Very few, so it is only necessary to compensate for the more vascular imaging of a moderate energy image when transmitting a signal. Therefore, the invention can be achieved, and is limited, and is safe, economical, and accurate for imaging purposes. The above is only the preferred embodiment of the present invention, and does not limit the scope of the present invention, that is, the simple equivalent change of the patent application and the description of the invention according to the present invention. Modifications are still within the scope of the invention. [Simple description of the map]
圖1是一超音波回波信號的頻譜圖，說明在習知技術 文獻揭露之基頻、第二諧振，及次諧振響應； 圖2是本發明顱部超音波成像系統一較佳實施例之系 統方塊圖；及 圖3是本發明顱部超音波成像方法一較佳實施例之流 程圖。1 is a spectrogram of an ultrasonic echo signal illustrating a fundamental frequency, a second resonance, and a sub-resonant response disclosed in the prior art; FIG. 2 is a preferred embodiment of the cranial ultrasound imaging system of the present invention. System block diagram; and Fig. 3 is a flow chart of a preferred embodiment of the cranial ultrasound imaging method of the present invention.
11 1274578 【主要元件符號說明】 11 · · •基頻響應 23· · ·. 接收模組 12 ·. •第二諧振響應 25· · · · 濾波單元 13 · · •次諧振響應 26· · · · 低頻擷取單元 20 · · • 信號處理模組 27· · · · 成像單元 21 · · • 超音波探頭 31〜36 · 步驟 22 · · • 發射模組11 1274578 [Description of main component symbols] 11 · · • Fundamental frequency response 23 · · · Receiver module 12 ·. • Second resonance response 25 · · · · Filter unit 13 · · • Sub-resonance response 26 · · · · Low frequency extraction unit 20 · · • Signal processing module 27 · · · · Imaging unit 21 · · • Ultrasonic probes 31~36 · Step 22 · · • Transmitter module
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