16层螺旋CT在冠心病诊断中的应用

目的：探讨16层螺旋CT及其心电门控CT冠状动脉造影（multi—slice spiral CT coronary angiography.MSCTA）在冠心病中的诊断应用。方法：52例患者均行16层螺旋CT冠状动脉造影及经皮导管法冠状动脉造影，图象质量分为可评估冠脉和不可评估冠脉，并逐支逐段进行分析，以冠脉血管狭窄大于50％为阳性，     

稳定性胸痛患者CT冠状动脉造影对诊断的灵敏度影响观察

目的:探讨稳定性胸痛患者CT冠状动脉造影对诊断的灵敏度影响。方法:选取于我院2017年1月～2018年6月就诊的稳定性胸痛患者50例,对患者进行CT冠状动脉造影检查,然后再进行选择性冠脉造影检查来明确诊断结果,对比两种检查方法对冠脉病变程度与冠脉血管内斑块性质的影响。结果:与选择性冠脉造影检查方法相比,CT冠状动脉造影对病变血管的总检出率为93.81%,其中对轻度狭窄的血管的检出率为91.67%,对中度狭窄的血管的检出率为93.10%,对重度狭窄的血管的检出率为95.45%,都在90%以上,经统计学检验P0.05;与冠脉造影检查方法相比,CT冠状动脉造影对斑块的总检出率为94.44%,其中对钙化斑块检出率为91.38%,对非钙化斑块的检出率为98.00%,经统计学检验P0.05。结论:CT冠状动脉造影是一种无创、简单、经济、安全的检查方法,对稳定性胸痛患者具有较高的诊断价值,值得在临床中推广。     

彩色多普勒超声心动图诊断冠状动脉瘘的价值——与冠状动脉造影及手术结果比较分析

本文对９例冠状动脉瘘患者的彩色多普勒超声心动图、冠状动脉造影及手术所见进行了对比。超声心动图所见扩张的冠状动脉及其走行以及瘘口部位与手术及冠状动脉造影基本一致。超声心动图所测扩张冠脉直径与术中测量的冠脉直径的平均误差百分比为６．６７％，与冠状动脉造影所测冠脉直径的平均误差百分比为１８．０％。超声心动图对罕见的冠状动脉瘘也能提供与冠脉造影相近的信息。     

彩色多普勒超声心动图诊断冠状动脉瘘的价值：与冠状动脉造影及 …

本文对９例冠状动脉瘘患者的彩色多普勒超声心动图，冠状动脉造影及手术所见进行了对比。超声心动图所见扩张的冠状动脉及其走行以及瘘口部位与手术及冠状动脉造影基本一致。超声心动图所测扩张冠脉直径与术中测量的冠脉直径的平均误差百分比为６．６７％，与冠状动脉造影所测冠脉直径的平均误差百分比为１８．０％。超声心动图对罕见的冠状动脉瘘也能提供与冠脉造影相近的信息。     

颈动脉硬度与冠心病的相关性

目的:应用高分辨率彩色多普勒测量颈动脉血管内径,并计算颈动脉硬度,探讨其与冠心病的相关性.方法:对年龄≥65岁的185例不明原因的胸痛,疑诊冠心病患者,进行冠状动脉造影,在冠状动脉造影前或后1周行高分辨率彩色多普勒超声测量颈动脉血管内径,并根据有关公式计算颈动脉硬度,包括动脉紧张度、动脉扩张性、动脉硬度.根据冠状动脉造影的结果分成两组,即冠状动脉造影阴性组101例,阳性组84例,阳性组再根据冠脉狭窄程度分为50%≤冠脉狭窄＜75%组(36例)和冠脉狭窄≥75%组(48例).用统计学方法分别比较各组间的颈动脉硬度的差异性.结果:冠状动脉造影阴性组与阳性组比较,50%≤冠脉狭窄＜75%组与冠脉狭窄≥75%组比较,动脉紧张度、动脉扩张性、动脉硬度差异均有显著性意义.结论:颈动脉硬度与冠状动脉粥样硬化程度平行,可客观、定量评价其发生、发展,作为老年冠心病患者的的预测指标,以及评价药物防治疗效的依据.     

64层螺旋CT诊断冠状动脉病变的临床价值

目的：通过对64排螺旋CT（MSCT）冠状动脉造影与选择性冠状动脉造影检测冠状动脉病变（冠状动脉狭窄≥50%）的对比分析,探讨64层螺旋CT评估冠状动脉病变诊断的准确性。方法：回顾性收集2007年12月～2008年10月于我院同期接受64层螺旋CT冠状动脉成像和常规经皮冠脉造影的112位冠心病患者的影像资料,以常规冠脉造影为参考标准,对2种检查方法的结果进行对比分析,评估64层螺旋CT冠脉造影对冠状动脉病变诊断的准确性。结果：按常规冠脉造影计算,112例患者共发现374处病变用于评价,MSCT造影检测冠脉病变总的准确性为90.6%,假阳性率和假阴性率分别为4.3%和5.1%;其中MSCT检测为假阴性均发生在左回旋支和右冠远段,假阳性均为冠状动脉伴有钙化。结论：64排螺CT冠状动脉造影检测冠状动脉病变诊断的准确性较高,但血管解剖和冠状动脉钙化可能会影响其对冠状动脉病变的评价和检测。     

64层螺旋CT对冠状动脉成像能力的评价

目的评价64层螺旋CT（MSCT）冠状动脉成像的质量及对冠状动脉狭窄的诊断价值。方法选择100例患者的MSCT图像,进行成像质量评价。其中32例患者行冠脉造影,评价MSCT对冠脉狭窄的诊断价值。结果①MSCT对冠状动脉近段血管成像质量高,可评价的血管比例在90%以上,对冠状动脉远段血管成像质量相对差,可评价的血管比例在55%～75%,总的可评价的血管比例为83.6%。②MSCT对冠状动脉狭窄的诊断的准确率比较高,尤其对近段血管的准确率达90%以上;对诊断冠状动脉狭窄有比较高的特异性及阴性预测值。结论MSCT对冠状动脉成像质量高,对狭窄的诊断能力强,是目前冠状动脉病变最理想的无创检查方法之一。     

血管内超声与冠状动脉造影在冠状动脉支架置入中的应用比较

目的:冠状动脉支架置入已成为治疗冠状动脉狭窄性病变的主要方法,支架治疗策略的选择成为主要技术问题,文章对冠脉造影后的血管狭窄分析和血管内超声成像的血管分析应用效价进行探讨.方法:根据文献报道对冠状动脉造影血管狭窄分析及血管内超声在冠脉支架置入前后的应用,结合南昌大学第二附属医院冠状动脉支架置入前后的血管造影及血管内超声的应用进行对比分析.结果:冠状动脉造影对支架置入前后的影像学造影检查,只能观其血管外壁形态、血流变化.对管腔黏膜病变情况、内支架贴壁情况,支架是否完全对称性扩张,以及支架对病变段的覆盖情况,不能精确显示.血管内超声对靶血管的狭窄程度、血管内斑块及黏膜病变情况能够精确实时显示,可实时显示支架是否完全扩张,支架扩张是否均匀对称,支架对血管壁斑块的挤压支撑情况如何.结论:血管内超卢在冠脉支架置入前后的应用,较冠状动脉造影更能全面的评价血管内病变情况,对支架的选取策略及支架释放后的评价与指导,防止血管内再狭窄具有重要的意义.     

多层螺旋CT血管成像评价冠状动脉血管旁路移植术

目的评价多层螺旋CT(MSCT)冠状动脉成像对冠状动脉桥血管的临床价值。方法28例患者的69条冠状动脉桥血管接受16层和64层螺旋CT冠状动脉成像。对桥血管成像进行影像质量评估,使用多元线性回归方法评估患者心率、心率波动幅度、呼吸运动以及不同CT扫描机对冠状动脉成像质量的影响。其中10位患者26条桥血管的CT血管成像结果与冠状动脉血管造影结果进行对比。结果呼吸运动伪影与冠状动脉桥血管成像质量呈负相关,相关系数为-0.838。64层CT扫描机的影像质量高于16层CT扫描机的影像质量。以CAG结果为参考标准,MSCT冠脉成像诊断桥血管及吻合口狭窄的特异性和敏感性分别为95.7%和92.3%。结论MSCT可以提供可靠的冠状动脉桥血管影像以及较高的诊断准确性。     

冠脉造影术中因造影剂推入引发RCA(段)痉挛致阿—斯综合征1例

冠状动脉造影(CAG)是指向左右冠状动脉开口处插入一种特制的冠状动脉导管,注入非离子造影剂可直接显示冠脉解剖形态(血管走行和病变)的临床检查方法。同时是冠脉血管外科手术或经导管重建冠脉血液治疗(冠脉内溶栓术和血管扩张术等)前必须进行的检查项目之一,亦是目前能在活体显示其解剖结构的唯一方法。在行数千例冠状动脉造影检查中,亦曾有过数10例因血管迷走神经反射引起心率、血压下降,均在撤除导管或静脉推入阿托品后症状缓解。近期一位患者在行常规冠状动脉造影术过程中,出现因导管刺激及造影剂推入后出现血管痉挛引发阿一斯综合征,现报告如下。1临床资料患者男性,59岁。原发性高血压Ⅱ期3年,无明显诱因,反复出现胸闷、心慌14年。曾多次住院治疗。近2月上述症状加重,初诊以GHD、心绞痛收住入院。择期行冠脉造影检查。手术医生为患者选择经右侧桡动脉穿刺,成功后置入6F桡动脉鞘管,送入6F冠脉造影导管,造影显示左主干正常,前降支中段血管壁不光滑,第一对角支开口处狭窄60%～70%,回旋支正常。右冠远端有局限性斑块、狭窄40%～50%,此时造影图象显示右冠中段血管痉挛,在医生及时撤出导管后,体表心电图及腔内心电图均提示心率下降至50次/mi...     

Digital subtraction angiography of the coronary arteries

The application of digital coronary arteriography in the evaluation of patients with known or suspected coronary artery disease is considered. Digital imaging of coronary arteries and bypass grafts can augment 35-mm cineangiography and may eventually replace film for coronary arteriography. The clinical efficacy of both selective and nonselective digital coronary arteriography is not yet established, however, a number of advantages over 35 mm cine have now been delineated including high contrast sensitivity image subtraction and digital image processing. One particular advantage of digital coronary arteriography is the ability to perform an immediate quantitative analysis of coronary images providing a reliable and consistent measure of the significance of a stenotic lesion. Technical requirements for digital coronary arteriography include a high output X-ray generator, low noise television chain, a 512 X 512 digital image matrix, frame rates of at least 15 fps, and high data storage capacity of c500 megabytes. The utilization of digital coronary imaging as a supplement or in place of 35-mm cine angiography will provide improved coronary imaging and enable quantification for more accurate and clinically significant coronary artery imaging.     

Automatic detection method of stenotic lesions in coronary cineangiograms

A new image processing procedure enabling the automatic detection of coronary artery stenoses by cineangiography was developed. Detection of stenoses was performed using computer image processing by the following procedure. The path of the arteries was extracted by a subtraction method. The thresholding image was obtained from the subtraction image, and converted to a ‘thinning’ image, which represented the center line of the artery. For measurement of the arterial diameter, the vessel edges were determined by unilateral Gaussian fit to profile curves in sections perpendicular to the center line. Stenoses could then be detected on the basis of the normal diameter of artery estimated by Hough transformation. This method facilitates the detection of stenotic lesions from coronary cineangiograms.     

Digital Flashing Tomosynthesis (DFTS) — A technique for three-dimensional coronary angiography

Digital Flashing Tomosynthesis (DFTS) represents a technique for three-dimensional (3D) coronary angiography. Four ECG-gated simultaneously flashed X-ray tubes generate a multiperspective digital substraction image as DFTS multiangiogram for 3D reconstruction and visualization. Computerized morphologic and morphometric quantitative analysis can be performed including videodensitometry. Postmortem coronary angiography of 30 human hearts with suspected coronary artery disease was performed by 35-mm cine technique and by DFTS. The results of angiographic measurements in 50 stenotic arterial segments were compared with the histologic reference and show excellent regression results with correlation coefficients of more than 0.95 (p?-0.0001). No significant differences in standard errors of estimates between the techniques were found. DFTS yields an accuracy in depiction of the coronary arteries and angiographic estimation of arterial lumen equivalent to 35-mm cineangiography. DFTS images can be directly used for visual interpretation and for computerized morphologic and morphometric quantitative analysis. DFTS technology reduces the amount of radiation exposure, the amount of contrast medium, and the time of the procedure. DFTS offers the possibility to obtain 3D images of the coronary artery tree.     

Limitation of detection and evaluation of coronary arterial stenosis by densitometry

In coronary cineangiography, both X-ray absorption and light scatter in the image intensifier tend to degrade image quality, and so affect the accuracy of densitometric measurement of vessel diameter. To investigate this problem, we compared the accuracy and precision of the densitometric method and the edge detection method in the automated detection of stenosis in both vessel phantom and clinical studies. In the phantom study, the X-ray penetration was varied by altering the thickness of the model, and the change in the measured diameter obtained by each of the two methods was evaluated simultaneously. A difference of 5 mm in the thickness of the model was found to alter significantly (P < 0.01) measurement of the diameter obtained using the densitometric method, but not that obtained by the edge detection method. In the clinical part of the study, the accuracy of each method in the automated detection of coronary stenosis was evaluated. With respect to the detection of stenosis, the level of disagreement between the assessment of the 3 observers and what was detected by densitometry (22.8%) was 2.9 times higher than the disagreement between the observers' assessment and what was detected using the edge detection method (7.9%). When the background density of the coronary cineangiogram along the axis of the vessel was uneven, many vessel segments which had been evaluated as normal when edge-detection was used were evaluated as stenosed when densitometry was used. This study, then, demonstrates that the Lambert-Beer law does not apply in cases where the thickness of the subject varies in different locations along the axis of the same vessel. We therefore conclude that densitometry is not a reliable means of assessing coronary stenosis in such cases, due to veiling-glare and scatter, and recommend that it not be routinely used in the automated detection of coronary arterial stenosis.     

口腔数字成像系统在阻生牙拔除中的应用评价

目的:评价口腔数字成像系统在阻生牙拔除手术中的作用。方法:应用ODIS-I型口腔数字成像系统对138例拟行阻生牙拔除的患者拍片,并对成像质量进行判断。应用该系统的图像处理功能进行阻生牙拔除的术前手术设计,配合应用系统的内窥镜与患者交待病情和拔除方法。结果:ODIS-I型口腔数字成像系统拍摄的阻生牙图像可以基本满足临床的使用需求;应用该系统的图像处理功能可方便地进行阻生牙拔除的手术设计,提高了手术的准确率;配合利用系统的内窥镜可直观地与患者交流。利用数据库管理功能可以完成图像及病历资料的管理和检索及调阅,对患者的复诊和治疗都十分有益;数字化摄像采用的传感器质硬、不易随意摆放、放入患者口内有不适感是其不足。结论:应用口腔数字成像系统可提高阻生牙的临床治疗和科研水平;尚须改进传感器性能以提高拍片质量。     

Using digital image processing for the assessment of postural changes and movement patterns in bodywork clients

A number of scientific/research quality software packages exist for the capture, display and analysis of digital images. This article discusses the use of a high resolution video camera and a desktop computer coupled with the freeware scientific visualization software package NIH Image to visually represent and record posture and movement protocols in the clinical, research or educational setting. Existing digital image processing techniques and tools can be extrapolated to the purposes of research, data gathering and clinical application in the field of bodywork.     

The influence of image enhancement and reconstruction on quantitative coronary arteriography

In the coming years, cinefilm will gradually be replaced by some digital medium for the archiving of angiographic images. However, not only the question which digital archiving medium will be used in the future is important, but also wich images are to be stored. Options are to either archive the raw, unprocessed images, or the enhanced images as they are displayed on the viewing monitor in the catheterization laboratory. In the first case, an off-line workstation will need additional hardware to display the images with the same image quality as they were acquired; in the second case, the question remains whether quantitative analysis programs still provide reliable results. Goal of this study was to investigate the possible effects of image enhancement and reconstruction on the results from quantitative coronary arteriographic (QCA) measurements with the Philips ACA-package (Automated Coronary Analysis). Image enhancement was achieved by an unsharp masking approach; the reconstruction of the original image from the enhanced image was attempted by an iterative deconvolution approach. The evaluation study consisted of two parts; a technical evaluation on eleven phantom tubes with known dimensions, and a clinical evaluation study on 48 coronary lesions. The results of the technical evaluation demonstrate that the measurement errors increase for the smaller vessel sizes (<1.2 mm) when QCA is applied to reconstructed images. The systematic difference on the smallest phantom tube (0.687 mm) on unprocessed images was limited to 0.050 mm, while it increased to 0.089 mm for the reconstructed images. Moreover, the random differences for the smaller vessel sizes increased for all processed images: for 0.159 mm for the unprocessed image to 0.189 mm for the enhanced and 0.204 mm for the reconstructed image (p<0.01). For the larger vessels, in general, no significant differences could be observed between the results of the unprocessed and processed images. The results of the clinical evaluation study demonstrate that especially the obstruction diameter is overestimated when QCA is applied to reconstructed images (0.113 mm). Although the measurements on the enhanced images did not show a significant overestimation of the obstruction diameter, the intra-observer random difference was much higher (0.199 mm for the enhanced images versus 0.140 mm for the unprocessed images, p<0.01). In more general terms, applying QCA on enhanced images increases the random difference values, while reconstructing the original image from the enhanced images increases the systematic errors in the measured diameters. This study has clearly demonstrated that especially the smaller diameter values (<1.2 mm) are influenced by image enhancement. Therefore, to obtain quantitative results with the desired small values for systematic and random differences, requires that the raw, unprocessed image data be archived.     

Digital photography: a primer for pathologists

The computer and the digital camera provide a unique means for improving hematology education, research, and patient service. High quality photographic images of gross specimens can be rapidly and conveniently acquired with a high-resolution digital camera, and specialized digital cameras have been developed for photomicroscopy. Digital cameras utilize charge-coupled devices (CCD) or Complementary Metal Oxide Semiconductor (CMOS) image sensors to measure light energy and additional circuitry to convert the measured information into a digital signal. Since digital cameras do not utilize photographic film, images are immediately available for incorporation into web sites or digital publications, printing, transfer to other individuals by email, or other applications. Several excellent digital still cameras are now available for less than 2,500 dollars that capture high quality images comprised of more than 6 megapixels. These images are essentially indistinguishable from conventional film images when viewed on a quality color monitor or printed on a quality color or black and white printer at sizes up to 11x14 inches. Several recent dedicated digital photomicroscopy cameras provide an ultrahigh quality image output of more than 12 megapixels and have low noise circuit designs permitting the direct capture of darkfield and fluorescence images.There are many applications of digital images of pathologic specimens. Since pathology is a visual science, the inclusion of quality digital images into lectures, teaching handouts, and electronic documents is essential. A few institutions have gone beyond the basic application of digital images to developing large electronic hematology atlases, animated, audio-enhanced learning experiences, multidisciplinary Internet conferences, and other innovative applications. Digital images of single microscopic fields (single frame images) are the most widely utilized in hematology education at this time, but single images of many adjacent microscopic fields can be stitched together to prepare "zoomable" panoramas that encompass a large part of a microscope slide and closely simulate observation through a real microscope. With further advances in computer speed and Internet streaming technology, the virtual microscope could easily replace the real microscope in pathology education. Later in this decade, interactive immersive computer experiences may completely revolutionize hematology education and make the conventional lecture and laboratory format obsolete. Patient care is enhanced by the transmission of digital images to other individuals for consultation and education, and by the inclusion of these images in patient care documents. In research laboratories, digital cameras are widely used to document experimental results and to obtain experimental data.     

The virtual blood film

The computer and the digital camera offer unprecedented possibilities for improving hematology education, research, and patient service. Peripheral blood smear images of exceptional quality can be acquired rapidly and conveniently from the peripheral blood smear with a modern, high-resolution digital camera and a quality microscope. Digital cameras use CCD or CMOS image sensors to measure light energy and additional circuitry to convert the measured information into a digital signal. Because digital cameras do not use photographic film, images are immediately available for incorporation into web sites or digital publications, printing, transfer to other individuals by e-mail, or other applications. Several excellent consumer digital still cameras are now available for less than $1000 that capture high-quality images comprised of more than three megapixels. These images are essentially indistinguishable from conventional film images when viewed on a quality color monitor or printed on a quality color or black and white printer at sizes up to 8 x 10 in. Several recent dedicated digital photomicroscopy cameras provide an ultrahigh quality image output of more than 12 megapixels and have low noise circuit designs permitting the direct capture of darkfield and fluorescence images. There are many applications of digital images of peripheral blood smears. Because hematology is a visual science, the inclusion of quality digital images into lectures, teaching handouts, and electronic documents is essential. A few institutions have gone beyond the basic application of digital images to develop large electronic hematology atlases; animated, audio-enhanced learning experiences; multidisciplinary Internet conferences; and other innovative applications. Digital images of single microscopic fields (single-frame images) are the most widely used in hematology education at this time, but single images of many adjacent microscopic fields can be stitched together to prepare zoomable panoramas that encompass a large part of a microscope slide and closely stimulate observation through a real microscope. With further advances in computer speed and Internet streaming technology, the virtual microscope could easily replace the real microscope in pathology education. Interactive, immersive computer experiences may completely revolutionize hematology education and make the conventional lecture and laboratory format obsolete later in this decade. Patient care is enhanced by the transmission of digital images to other individuals for consultation and education, and by the inclusion of these images in patient care documents. In research laboratories, digital cameras are widely used to document experimental results and obtain experimental data.     

Iterative reconstruction for coronary CT angiography: finding its way

Image reconstruction algorithms play a critical role in defining the quality and integrity of medical imaging using computed tomography. Since the advent of CT, image reconstruction has largely been performed by filtered back projection (FBP). This reconstruction technique has served CT well particularly at a time when there were significant limitations in computer processing capabilities. Iterative image reconstruction algorithms were, in fact available and were used to generate images with the very first commercial clinical computed tomographic (CT) scanner. This technique did not see significant adoption in clinical CT use owing to the ease of implementation and the faster image reconstruction of filtered back projection. Over the past decade, the need for finer resolution, greater volume coverage, faster scan times and the desire to lower radiation dose at the same time have pushed the performance of FBP reconstruction to its limits. Recently, there has been a re-introduction of iterative reconstruction for CT imaging with recently published studies in other organ systems showing that iterative reconstructions can produce higher-resolution images with greater robustness for the reduction of various imaging artifacts. There has been subsequent early adoption and experience with iterative reconstruction in coronary CT angiography (CCTA). We herein review the various iterative reconstruction platforms released for use for CCTA and the initial experiences implementing and integrating these reconstruction algorithms in clinical practice.