实时三维超声心动图评价冠心病的研究进展

传统的三维超声心动图因获取图像费时而限制了其临床应用。实时三维超声心动图是近年出现的一项新的三维成像技术。其快速成像这一特点使三维成像应用于临床成为可能。本文对实时三维超声心动图在评价冠心病方面的进展加以综述     

立体三维超声心动图的成像原理、应用概况及其发展前景

三维超声心动图历经数年的发展已趋向于成熟,在此基础上近年研发部门又推出一种新的超声成像技术--立体三维超声心动图(stereo 3D echocardiography),现已成为评价各种器质性心脏病新的方法.本文将对立体三维超声心动图的成像原理、临床应用概况及其发展前景作一简要综述.     

实时三维超声心动图的临床应用及研究进展

实时三维超声心动图技术是超声成像领域内一项重大的技术性突破。它不仅能够精确、可靠的评价心功能的定性及定量参数,而且对于瓣膜结构、先天性心脏病各种畸形提供新的图像视角。可使临床医师方便、立体、准确、实时的观察心脏的解剖结构和功能。实时三维超声心动图必定在各类心脏疾病的诊断、治疗及预后评估方面起到越来越重要的作用。现就三维超声成像原理、临床应用、研究进展予以综述。     

三维超声成像诊断颈动脉粥样硬化中风的临床价值

对经二维彩色多普勒超声检查存在颈动脉粥样硬化脑血管患者进行三维超声检查，并与二维彩色多普勒成像进行比较。结果颈动脉粥样硬化的三维超声图像可显示多种形态的粥样斑块的立体形状及表面特征，在斑块内部的组织结构及表面形态等方面的成像明显优于二维成像。对斑块性质显示更准确，增加了颈动脉粥样硬化中风预报的可靠性，具有重要的临床应用价值。     

实时三维超声心动图与临床

实时三维超声成像是心脏超声发展的重大飞跃,可为心血管疾病的准确诊断提供更多的有用信息。实时三维超声无论在定性和定量两个方面都对临床诊断具有重要作用。现就实时三维超声心动图在心脏瓣膜、先天性心脏病、心脏占位、心肌病、主动脉夹层、左室室壁瘤、Bental术后人造血管吻合口漏、左心功能评价等方面的临床价值做一综述。     

立体三维超声心动图解读

超声影像技术自问世以来，发展迅速，从初期的一维超声成像（A型和M型），随后出现的灰阶二维超声成像（复合成像和实时成像），直至三维超声（静态、动态和实时成像）应用于临床，目前技术日趋成熟，在临床诊断上发挥巨大的作用^1-3]。近时GE公司对其多维星Vivid 7进行升级，在原有三维成像模式的基础上添加新的模式（版本BT 08），     

三维超声引导在经皮穿刺硬化术治疗甲状腺囊肿中的应用

近年来，随着超声技术的不断完善，超声引导下各脏器疾病的介入治疗取得很大进展，尤其是囊性病变的介入治疗已成为临床非手术微创治疗领域的新技术。三维超声成像技术可提供更加丰富的三维空间信息，具有通过多平面、多角度观察病变内部细微结构和与周围脏器空间位置关系、对感兴趣区域作任意观察等特点。近年来。我们采用三维超声引导经皮穿刺硬化术治疗甲状腺囊肿48例，效果满意。现报告如下。     

慢性肺心病患者右心室功能超声评价研究进展

右心室功能在慢性肺心病的诊断和治疗中的意义日益受到关注,目前临床可用于评价右心室功能的超声技术和方法包括二维超声心动图、M型超声心动图、多普勒超声、Tei指数、定量组织速度成像、应变和应变率显像、自动边缘检测技术、造影超声心动图、三维超声心动图等。该文对这些超声技术的研究进展进行综述。     

超声在诊断糖尿病并发肾病患者中的应用

目的对临床糖尿病肾病患者采用超声检查技术的诊断效果进行比较分析,探讨超声结果对患者临床诊断效果的影响。方法分析采用各项超声检查对糖尿病肾病患者诊断效果的差异。结果糖尿病肾病患者早期血、尿检查结果正常时,可根据超声检查结果确定肾脏体积及血流变化。结论超声在动态监测糖尿病肾病患者早期诊断及病程进展等方面的准确度明显高于其它方法,特别是三维超声技术和超声弹性成像准确度更高。     

超声心动图发展概要

影像学检查通过人体脏器的扫查,提供重要的解剖学信息,而超声心动图能够实时评价心脏解剖结构、功能以及血流动力学信息。三维超声心动图、应变成像等定量评估方法以及超声增强显影不再是纸上谈兵,已经广泛应用于临床并且为患者的诊断和预后提供了丰富信息。本文主要通过超声心动图新技术在心脏移植等新领域的应用来阐述其重要性,从而指导治疗。     

Comparison of intravascular ultrasound, external ultrasound and digital angiography for evaluation of peripheral artery dimensions and morphology

Validation of catheter-based intravascular ultrasound imaging has been based on comparisons with histology and digital angiography, each of which may have limitations in the assessment of arterial size and morphology. External, high-frequency ultrasound can accurately determine vessel dimensions and morphology and because, like ultravascular ultrasound, it also provides cross-sectional arterial ultrasound images, it may be a more appropriate technique for the in vivo comparison of arterial dimensions and morphology determined by intravascular ultrasound. Thus, intravascular ultrasound, external 2-dimensional ultrasound, Doppler color-flow imaging and digital angiography were compared for assessment of arterial dimensions and wall morphology at 29 femoral artery sites in 15 patients. Intravascular ultrasound and the other 3 imaging modalities correlated well in determination of lumen diameter (2-dimensional, r = 0.98, standard error of the estimate [SEE] = 0.14; Doppler color flow, r = 0.91, SEE = 1.11; angiography, r = 0.95, SEE = 0.91) and cross-sectional area (2-dimensional, r = 0.97, SEE = 0.04; Doppler color flow, r = 0.92, SEE = 0.14; angiography, r = 0.96, SEE = 0.08). However, lumen size measured by Doppler color flow was consistently smaller than that measured by the other 3 imaging modalities. Intravascular ultrasound detected arterial plaque at 15 sites, 5 of which were hypoechoic (soft) and 10 hyperechoic with distal shadowing (hard). Plaque was identified at 12 of 15 sites by Z-dimensional imaging (p = 0.30 vs intravascular ultrasound), but at only 6 of 15 sites by angiography (p = 0.003 vs intravascular ultrasound), only 1 of which was thought to be calcified plaque.(ABSTRACT TRUNCATED AT 250 WORDS)     

Validation of computerized three-dimensional reconstruction of intravascular ultrasound: measurements of absolute luminal diameter and cross-sectional area in ex vivo human coronary arteries

Computer based 3-dimensional reconstruction transforms 2-dimensional intravascular ultrasound images into a longitudinal format facilitating analysis of luminal narrowing. To validate the accuracy of current software in measuring coronary artery diameter and cross-sectional area, in arteries with atherosclerosis, we performed 3-dimensional reconstruction in 10 human pathologic coronary arterial segments of 10-25mm length. Images were obtained using a 4.8 French catheter with pullback speed of 1mm/sec acquired at 3 frames/sec onto VHS tape. The data were digitized and intraluminal 3-dimensional reconstruction performed using a voxel-based program. Pathologic sections were obtained every 3mm, and dimensions were measured with a resolution of 0.01 mm. Maximum, minimum, and 3 other representative diameters were recorded by an observer blinded to the ultrasound diameters. Average histo-pathologic diameters were reported, and specimen cross-sectional area was then calculated. Results: In 53 sections, pathological diameters ranged from 1.4-4.5mm (mean 2.7 +/- 0.68mm) while 3-dimensional reconstructed diameters were 1.9 to 3.8mm (mean 2.6 +/- 0.54mm). Pathologic and ultrasound derived 3-dimensional reconstruction diameters had an excellent correlation (r=0.86, SEE=+/-0.36). Pathology and 3-dimensional reconstruction cross-sectional area also correlated closely (r=0.88, SEE=+/-1.50). Diameters less than 2.0mm were systematically overestimated and diameters greater than 3.5mm underestimated by 3-dimensional reconstruction. Most 3 dimensional reconstruction values were within +/- 10% of pathology, but diverged at each diameter extreme, approaching +/- 20%. Thus, computerized 3-dimensional reconstruction of ultrasound images shows excellent quantification of luminal size in the 2.0-3.5mm range, suggesting important investigative and clinical applications.     

Imaging of the abdomen

In the last decade, innovative ultrasound technology has become the primary imaging method in Gastroenterology. Compared to other imaging techniques (e. g., computed tomography and magnetic resonance imaging), conventional ultrasound images have the disadvantage of a restricted field-of-view (width), thus producing images that are not always easy to read. During the examination, the many mosaic-like single images obtained in real-time sonography must be mentally pieced together by the user, in order to obtain a complex 3-dimensional picture of the anatomical structure and its surrounding tissue. The extended field-of-view of the Panoramic Imaging technique is a useful addition to conventional diagnostic ultrasound since it provides the enhanced overview required for exact topography of surrounding structures. This is especially true for the Power Mode Panoramic Imaging technique that allows the trading of vessels over greater distances, e.g., in the extremities. Thus, accuracy and reproducibility of measurements in the examination of larger structures and organs has improved. A clearer representation of these anatomical structures increases understanding and acceptance by referring clinicians. An exact diagnosis based on ultrasound imaging will certainly result in cost savings in health-care, since the use of further imaging methods (and therefore the total examination time) may be reduced.     

Three dimensional transrectal ultrasound imaging of the prostate: initial experience with an emerging technology

PURPOSE: A three-dimensional ultrasound system (3-D US) was evaluated for its clinical utility in transrectal prostate imaging, in comparison with the current standard 2-dimensional transrectal ultrasound (TRUS) imaging system. METHODS AND MATERIALS: The computer program developed in our laboratory was coupled with a commercially available ultrasound transducer. Geometric validation and volumetric assessment was performed with "stretched-string" wire models and solution-containing balloons respectively. Anatomic correlation of 3-D TRUS images was performed with cadaveric prostates. Intraprostatic lesion localization by 3D-TRUS was assessed clinically by 2 observers in 11 patients prior to radical prostatectomy and the data compared with those yielded by 2-D TRUS. RESULTS: Geometric assessment by 3D TRUS in comparison with the "between strings in the phantom" model (true dimensions) had an error of up to 1.2%. Volume measurement by 3-D TRUS had an error, compared to the true volume, of 0.9%. The correlation coefficient (r) was 0.99985 for the end-firing probe and 0.978 for side firing. The 3-D images provided accurate representation of the true anatomy in the sagittal, transverse and most uniquely, the coronal plane. Two observers achieved better diagnostic accuracies with intraprostatic abnormalities using 3-D instead of standard 2-D TRUS. The negative predictive value and the specificity were improved. CONCLUSION: 3-D TRUS appears to provided accurate representation of the true anatomy with geometric and volumetric validation. Areas of potential clinical application of 3-D TRUS include treatment monitoring with volume measurements and various intervention and therapeutic procedures for both benign and malignant prostatic disorders.     

Computer-assisted evaluation of perianal fistula activity by means of anal ultrasound in patients with Crohn's disease

OBJECTIVES: Assessment of the activity of perianal fistulas may be of clinical relevance in patients with Crohn's disease. Fistula activity is currently evaluated by means of magnetic resonance imaging; anal ultrasound can also be used, but its diagnostic performance in this setting remains to be defined. Our aims were to evaluate the agreement between clinical examination, magnetic resonance imaging, and anal ultrasound in assessing perianal fistula activity, and to apply computerized analysis to improve the assessment of ultrasound images. METHODS: Thirty-one consecutive patients with Crohn's perianal fistulas underwent clinical examination, and magnetic resonance and anal ultrasound imaging. Active fistulas were defined as the presence of active drainage or signs of local inflammation on clinical examination, and the definition was confirmed by surgical examination. Activity was assessed on the basis of T2 hyperintensity on magnetic resonance imaging and the degree of hypoechogenicity on anal ultrasound; the anal ultrasound images were also analyzed using dedicated computer image-analysis software. RESULTS: Twenty-five patients had an active fistula at clinical examination. The agreement between clinical examination and magnetic resonance imaging was good (k-value = 0.739), whereas that with anal ultrasound was only fair (k-value = 0.266-0.294); computer-assisted analysis of the anal ultrasound images improved the agreement from fair to good (k-value = 0.608-0.670). CONCLUSIONS: Anal ultrasound can be used to assess fistula track activity in patients with Crohn's disease. The diagnostic performance of the technique can be improved to values comparable with those of magnetic resonance imaging by using a computer-assisted evaluation of the anal ultrasound images.     

Real-time intravascular ultrasound imaging in humans

The capability of obtaining cross-sectional, high resolution images of arteries with the use of ultrasound catheters has recently been demonstrated in animal studies. In this study the in vivo feasibility of intravascular ultrasound imaging in humans was evaluated. In 26 patients who had undergone diagnostic cardiac catheterization or iliofemoral arteriography, 1 of 3 different models of 20-MHz ultrasound catheters was advanced retrograde, into the iliac arteries and aorta or anterograde into the femoral arteries and real-time cross-sectional images of the arteries were obtained in all. In 10, the iliac arteries were normal and appeared circular and pulsatile with a 3-layered wall and crisply defined lumens. In 7 patients with nonobstructive plaques, the plaque was easily identified in the ultrasound image as a linear, bright, adynamic echo-dense structure. In 4 with obstructive disease in the iliac artery, the arterial lumen appeared irregular, bordered by a thickened, nonpulsatile wall. Variable grades of atheromatous abnormalities in the wall could be visualized. In all 5 patients with arteriographic evidence of obstructive disease of the femoral artery, intravascular ultrasound displayed reduced lumens and irregular borders with protruding high-intensity echoes in the wall. In all patients, the arterial lumen and the normal or abnormal wall were well visualized in the ultrasound images. There were no complications. This study thus demonstrates the feasibility of intravascular ultrasound imaging of arterial circulation in humans. With further improvements in catheter design and image quality, this imaging approach is likely to have a number of potential applications in the assessment of peripheral and coronary arterial diseases and in guiding interventional therapeutic procedures.     

Diagnosis of carotid artery atheroma by magnetic resonance imaging

Atheroma appears as a very low signal intensity area on 2-dimensional time-of-flight (TOF) magnetic resonance (MR) images, and its components have various signal intensities on spin-echo (SE) images. The present study investigated atheroma of the carotid arteries in 37 subjects with risk factors (63+/-10 years of age; 19 men) by magnetic resonance imaging (MRI). On 2-dimensional (2D) TOF images, the carotid arteries were clearly demonstrated in all cases and atheroma was detected in 23 patients. The most common location of atheroma was at the origin of the internal carotid artery. There was vascular remodeling in all patients with atheroma. 2D-TOF images showed 97% agreement with ultrasonography. SE images clearly demonstrated atheroma in all 23 patients with atheroma. All patients with atheroma showing high signal intensity on T1-weighted images had hyperlipidemia. These findings indicate that the 2D-TOF imaging method is useful for detecting atheroma and SE-images are useful for its characterization.     

Three-dimensional echocardiography: the benefits of the additional dimension.

Over the past 3 decades, echocardiography has become a major diagnostic tool in the arsenal of clinical cardiology for real-time imaging of cardiac dynamics. More and more, cardiologists' decisions are based on images created from ultrasound wave reflections. From the time ultrasound imaging technology provided the first insight into the human heart, our diagnostic capabilities have increased exponentially as a result of our growing knowledge and developing technology. One of the most significant developments of the last decades was the introduction of 3-dimensional (3D) imaging and its evolution from slow and labor-intense off-line reconstruction to real-time volumetric imaging. While continuing its meteoric rise instigated by constant technological refinements and continuing increase in computing power, this tool is guaranteed to be integrated in routine clinical practice. The major proven advantage of this technique is the improvement in the accuracy of the echocardiographic evaluation of cardiac chamber volumes, which is achieved by eliminating the need for geometric modeling and the errors caused by foreshortened views. Another benefit of 3D imaging is the realistic and unique comprehensive views of cardiac valves and congenital abnormalities. In addition, 3D imaging is extremely useful in the intraoperative and postoperative settings because it allows immediate feedback on the effectiveness of surgical interventions. In this article, we review the published reports that have provided the scientific basis for the clinical use of 3D ultrasound imaging of the heart and discuss its potential future applications.     

Three-dimensional echocardiography: the benefits of the additional dimension

Over the past 3 decades, echocardiography has become a major diagnostic tool in the arsenal of clinical cardiology for real-time imaging of cardiac dynamics. More and more, cardiologists' decisions are based on images created from ultrasound wave reflections. From the time ultrasound imaging technology provided the first insight into the human heart, our diagnostic capabilities have increased exponentially as a result of our growing knowledge and developing technology. One of the most significant developments of the last decades was the introduction of 3-dimensional (3D) imaging and its evolution from slow and labor-intense off-line reconstruction to real-time volumetric imaging. While continuing its meteoric rise instigated by constant technological refinements and continuing increase in computing power, this tool is guaranteed to be integrated in routine clinical practice. The major proven advantage of this technique is the improvement in the accuracy of the echocardiographic evaluation of cardiac chamber volumes, which is achieved by eliminating the need for geometric modeling and the errors caused by foreshortened views. Another benefit of 3D imaging is the realistic and unique comprehensive views of cardiac valves and congenital abnormalities. In addition, 3D imaging is extremely useful in the intraoperative and postoperative settings because it allows immediate feedback on the effectiveness of surgical interventions. In this article, we review the published reports that have provided the scientific basis for the clinical use of 3D ultrasound imaging of the heart and discuss its potential future applications.