双源CT双期增强血管成像对急性肠缺血的诊断

目的:探讨双源CT(DSCT)双期增强扫描血管成像对急性肠缺血(acute mesenteric ischemia,AMI)患者的诊断价值。方法:回顾性分析经手术或介入治疗证实的26例AMI患者的DSCT资料。所有患者均行DSCT双期增强扫描即动脉期和门静脉期血管成像。结果:肠系膜上动脉栓塞8例,肠系膜上动脉血栓形成4例,肠系膜上静脉血栓形成14例。CT直接征象为肠系膜血管内低密度充盈缺损,受累血管腔闭塞(17例)或重度狭窄(9例)。间接征象:肠壁增厚(21例),肠管扩张、肠腔内积液积气(18例),肠壁强化程度降低(7例),肠壁积气(5例),肠系膜脂肪水肿及渗出(19例),"缆绳征"14例,腹腔积液12例。结论:DSCT增强扫描及双期血管成像可清楚显示AMI血管阻塞的部位、范围、程度及继发改变,对明确诊断和指导治疗具有较高的应用价值。     

Multidetector CT angiography in the evaluation of acute mesenteric ischemia

The aim of this study was to determine the accuracy of multidetector row CT angiography in the diagnosis of acute mesenteric ischemia. Ninety-three consecutive studies on 91 patients with clinically suspected acute mesenteric ischemia underwent abdominal CT angiography as the first, and usually the sole, diagnostic procedure. CT was performed with a multidetector 16-row CT system from the level of the diaphragm to the pelvis in two phases: early arterial and late portal phase. CT examinations were reviewed by the duty radiologist. Final diagnosis was established by a senior radiologist. CTA was diagnostic in 92 studies. Mesenteric ischemia was diagnosed in 18 patients, 14 of them were of the thromboembolic type and four from the nonocclusive type. Positive CTA findings were confirmed by surgery in 13 patients and by clinical follow-up in three cases. Other reasons for abdominal pain were diagnosed by CT in 38 patients out of the remaining 74. There were two false positive and two false negative CT results, resulting in an overall accuracy of 95.6%. Multidetector CT angiography is a fast and accurate investigation for the diagnosis of acute mesenteric ischemia and in most cases can be used as the sole diagnostic procedure.     

ECG门控双源CT胸痛检查模式的辐射剂量估测

目的是评估应用ECG门控双源CT检查胸痛的模式的辐射剂量。采用装有热释光剂量仪的Alderson Rando模型测定剂量。在不同模拟心率（HR）下应用双源CT系统以评估胸痛的标准模式（120kV,320mAs／r）曝光,并测量标准胸部CT检查（120kV,160mAs）的剂量。胸痛模式的有效剂量男、女分别为19．3、21．9mSv（HR60）,17．9、20．4mSv（HR80）和14．7、16．7mSv（HR100）。     

Evaluating mesenteric ischemia with multidetector-row CT angiography

Multidetector-row computed tomographic (MDCT) angiography is an established non-invasive imaging modality to evaluate the mesenteric vasculature. It has an important role in diagnostic algorithms for assessment of suspected acute and chronic mesenteric ischemia. Clinical success for synchronizing a MDCT volumetric acquisition with a bolus of contrast medium and also for depicting vascular pathology with high accuracy relies on implementing several key principles. This can be more challenging with advanced generation MDCT scanners. This article reviews the technical principles fundamental to evaluating the mesenteric vasculature with MDCT angiography. An overview of clinical application is also presented.     

Multidetector CT and CT angiography in mesenteric ischemia

Purpose

To evaluate the role of 64-multidetector CT in assessment of mesenteric vascular ischemia in clinically suspected patients.

Patients and methods

This study included 38 patients during period from October 2009 to October 2011. The patients age ranged from 38 to 72 year old (mean age was 57 ± 11.2 years). All cases met the criteria of acute non traumatic (28 patients) or chronic abdominal pain (10 patients) and suspected mesenteric vascular ischemia. All 38 cases were evaluated in surgery department, then underwent CT of the abdomen and pelvis & CTA by using 64 multislice GE light speed VCT. MDCT& CT angiographic findings were correlated with surgical findings in acute mesenteric ischemia (AMI) cases & conventional angiography in chronic mesenteric ischemia (CMI) cases.

Results

MDCT findings alone were nonspecific for detection of MI. The sensitivity, specificity& accuracy of CTA in diagnosis of AMI after surgical confirmation were 96%, 66.6% & 92.8% respectively, while in CMI the sensitivity, specificity & accuracy were 88.8%, 100%, 90% respectively, after confirmation by conventional angiography.

Conclusion

CTA scan appears to be an excellent tool to find out and localize cases of AMI rather than in CMI cases.     

Multidetector CT angiography in the diagnosis of mesenteric ischemia

Multidetector CT is an ideal tool for the diagnosis of acute and chronic mesenteric ischemia. Advanced CT scanners and expertise in three-dimensional imaging are becoming increasingly widespread, opening the door to new opportunities and challenges in the evaluation of patients suspected of having mesenteric ischemia. This article reviews contrast administration and image acquisition protocols, the anatomy of the mesenteric vasculature, the etiology of acute and chronic mesenteric ischemia, and CT findings diagnostic for these conditions.     

急性肠系膜缺血的MSCT诊断

目的:探讨MSCT对急性肠系膜缺血的诊断价值.方法:回顾性分析经手术或介入治疗证实的36例急性肠系膜缺血患者的CT表现.所有患者均行CT检查,包括平扫、增强扫描动脉期、增强扫描门脉期并进行血管重建.后处理采用容积显示技术(VRT)、多平面重组(MPR)和薄层最大密度投影(MIP)进行动脉和门脉成像.结果:肠系膜上动脉栓...     

多层螺旋CT周围血管成像的初步应用

目的 :探讨多层螺旋CT(MSCT)在周围血管疾病中的应用价值。方法 :对 18例临床怀疑周围血管疾病的患者 ,均行上肢或下肢动脉或静脉CT血管造影。动脉系统疾病经肘前静脉以 3ml/s流率注入 10 0ml对比剂 ,延迟 2 5～40s后扫描 ;静脉性疾病经足背静脉或手背静脉以 1ml/s流率注入 5 0ml对比剂 ,延迟时间为 60～ 70s。扫描条件为层厚3 .2mm ,重建间隔 1.6mm ,螺距 1.2 5。结果 :动脉系统疾病 10例 ,狭窄或闭塞性疾病 9例 ,其中 1例合并动脉瘤 ,1例传统血管造影均不能插管操作 ,1例动脉瘤MRA以及传统血管造影均没有做出正确诊断 ;1例为正常下肢动脉。静脉系统疾病 3例 ,其中下肢深静脉血栓 2例 ,上肢多发性静脉瘤 1例 ,经传统血管造影证实。结论 :应用MSCT诊断周围血管疾病有一定的临床价值。     

双源CT冠状动脉成像在早搏患者中应用的初步体会

目的 探讨应用双源CT对早搏患者进行冠状动脉成像的可行性.方法 对70例临床可疑冠心病的早搏患者进行双源CT增强扫描.利用回顾性心电门控重建心电图编辑前后的图像,以4级记分评价图像质量.比较心电图编辑前后的图像质量采用配对t检验.结果 70例中28例患者的心率波动范围较小[(41.0±18.4)次/min],无需心电图编辑可获得诊断级图像;其余42例患者的心率波动范围较大[(71.4±28.7)次/min],心电图编辑前后的冠状动脉图像质量评分分别为(2.09±1.27)和(1.50±0.79)分,差异有统计学意义(t=13.764,P＜0.01);不可评价的冠状动脉节段比例从24.8%(154/620)降至3.4%(21/620).差异有统计学意义(X2=121.846,P＜0.01).70例患者98.0%(1014/1035)的冠状动脉节段可以评价.结论 拥有高时间分辨率的双源CT能够为早搏患者提供可评价的图像;对于心率波动范围大的患者,心电图编辑能够显著改善图像质量.     

肠系膜静脉结扎致急性肠缺血的多层螺旋CT研究

目的 探讨MSCT显示肠系膜静脉结扎致急性肠缺血的早期征象及其动态演化规律.方法 12只巴马猪,采用数字表法随机分成3个实验组(术后6、12、18 h组)和1个对照组,每组3只.实验组9只猪剖腹结扎肠系膜上静脉(SMV)主干远端空肠、回肠和回结肠支,分别于术前及术后6、12和18 h采用MSCT行平扫和增强后动脉、静脉和延迟期扫描.对照组3只猪仅剖腹分离暴露SMV,并于上述时间点进行扫描,比较手术前后肠系膜血管、肠道、腹腔形态的动态变化,结果与病理对照.结果 9只实验组猪均显示急性肠缺血病理改变,随时间延长,缺血进行性加重.CTA可准确显示SMV主干、大属支及其远端小分支直至肠壁边缘的直小静脉,显示SMV分支各结扎点.静脉堵塞性肠缺血的早期CTA改变为肠系膜上动脉痉挛、充盈欠佳、显影延迟和延长;SMV显影淡、延迟;肠壁增厚,系膜水肿,腹水,肠壁强化高于正常;随时间推移,出现肠壁变薄,肠腔扩张、积液,系膜水肿,腹水加重,肠壁强化减弱.结论 CTA能清晰显示肠系膜血管解剖、堵塞的静脉、早期肠缺血改变及其动态演化规律,于病变早期可靠地诊断静脉堵塞性肠缺血.     

Coronary artery: quantitative evaluation of normal diameter determined with electron-beam CT compared with cine coronary angiography initial experience

Eight male heart transplant recipients underwent contrast material-enhanced electron-beam computed tomographic angiography. Coronary artery diameters measured with fixed thresholds and adaptive line density profile (LDP) methods were calculated relative to findings at quantitative coronary angiography. Variation with fixed-threshold methods was significantly greater than that with LDP methods because of variations in vessel enhancement. Thus, more accurate measurements of vessel diameter were obtained with LDP methods.     

双能量CT冠状动脉成像结合CT心肌灌注诊断冠心病准确性的初步研究

目的 探讨心脏双能量CT冠状动脉造影(DE-CTA)结合CT心肌灌注(DE-CTP)对冠心病诊断的准确性.方法 对31例临床可疑或已知冠心病的患者行心脏双能量CT和负荷-静息SPECT检查,所有患者在1个月内接受导管造影检查.重建冠状动脉DE-CTA和DE-CTP图像用于冠状动脉狭窄程度和心肌灌注缺损的评判,并以冠状动脉造影为参考标准,建立DECT对冠状动脉狭窄诊断价值的基线值,进而计算DE-CTA加DE-CTP对冠心病诊断的敏感性、特异性、阳性预测值、阴性预测值和准确性.结果 28例患者获得满意的图像质量,以冠状动脉造影为参考标准:(1)DE-CTA显示112支冠状动脉,其中41支冠状动脉狭窄≥50%,诊断冠状动脉狭窄的敏感性、特异性、阳性预测值、阴性预测值分别为81%(38/47)、95%(62/65)、93%(38/41)、87%(62/71),准确性为89%(100/112);(2)DE-CTP显示46支狭窄冠状动脉供血区域心肌灌注缺损,诊断狭窄≥50%冠状动脉的敏感性、特异性、阳性预测值、阴性预测值分别为76%(36/47)、85%(55/65)、78%(36/46)、83%(55/66),准确性为81%(91/112);(4)DE-CTA加DE-CTP诊断52支冠状动脉狭窄≥50%,诊断冠状动脉狭窄的敏感性、特异性、阳性预测值、阴性预测值分别为96%(45/47)、89%(58/65)、86%(45/52)、97%(58/60),准确性为92%(103/112).结论 DE-CT一次扫描即能获得冠状动脉解剖学和血流灌注信息,可以对冠心病做出综合性诊断.DE-CTP能够为CTA提供有益的补充.

Abstract：

Objective To evaluate the combination of dual-energy CT angiography (DE-CTA) and dual-energy CT peffusion (DE-CTP) in the diagnosis of coronary artery disease. Methods Thirty-one patients with angina pectoris were examined using dual-source dual energy CT and conventional coronary angiography. For DE-CTA, we used a contrast-enhanced ECG-gated coronary scan protocol with energy levels of two tube detector arrays at 140 and 100 kVp. Two kinds of acquired images were fused for the CT angiogram and further calculated to construct a perfusion map (Siemens DE Heart PBV). The compared the following results: DE-CTA vs. CA, DE-CTP vs. CA to assess the sensitivity and specificity, and further compared DE-CTA plus DE-CTP with CA. Results DECT obtained diagnostic image quality in 28 patients.DE-CTA detected 41/112 arterial stenosis. Using CA as a reference, the sensitivity of DE-CTA was 81%(38/47), specificity was 95% (62/65), positive predictive value was 92% (38/41), negative predictive value was 87% (62/71), and accuracy was 89% (100/112). DE-CTP detected 46 perfusion defects in artery territories. Using CA as a reference, the sensitivity of DE-CTP was 76% ( 36/47), specificity was 85% (55/65), positive predictive value was 78% (36/46), negative predictive value was 83% (55/66),and accuracy was 81% (91/112). DE-CTA plus DE-CTP diagnosed 52 arteries stenosis. Using CA as a reference, combination of DE-CTA and DE-CTP gave sensitivity of 95% ( 45/47 ), specificity of 89%(58/65) , NPV of 97% (58/60), and accuracy of 92% (103/112). Conclusions DECT can provide perfusion blood volume information as well as vessel pathology in one scan. DECT can provide comprehensive diagnosis and improve diagnosis of CAD.     

CT evaluation of musculoskeletal trauma: initial experience with cinematic rendering

Multi-detector computed tomography (MDCT) scanners that can quickly acquire volumetric datasets composed of isotropic voxels laid the groundwork for the widespread clinical implementation of 3D MDCT reconstructions, with maximum intensity projection (MIP) and volumetric rendering (VR) becoming important parts of the imaging evaluation of patients with a wide variety of pathologic conditions. Recently, a new 3D reconstruction technique known as cinematic rendering (CR) has become available and is now U.S. FDA approved. CR bears fundamental similarities to VR, but utilizes a more complex lighting model to bring about photorealistic reconstructions. While a tremendous amount of work remains to be done in order to understand the advantages and disadvantages of CR in comparison to traditional 3D reconstruction methods, the images themselves are strikingly detailed and can be interactively manipulated to highlight a variety of different tissue types and anatomic structures. In the following pictorial essay, we provide a number of clinical examples of the use of CR in musculoskeletal imaging, including the evaluation of complex fractures, the delineation of the relationship of fractures to adjacent vasculature and overlying soft tissues, and the visualization of vascular and soft tissue injuries.     

急性肠缺血的双源CT诊断价值探讨

目的:探讨双源CT(DSCT)腹部血管成像在肠缺血性疾病诊断中的价值。方法:对8例临床拟诊为肠缺血性疾病的患者行DSCT腹部动静脉血管成像,利用工作站分别对腹部血管尤其是肠系膜动静脉血管进行重组,结合横断面图像对疾病进行诊断,评价缺血肠管出现的异常征象,并将DSCT与数字减影血管造影(DSA)结果进行比较。所有患者均经介入或手术治疗。结果:8例患者DSCT腹部动静脉血管成像:诊断肠系膜上动脉栓塞4例,动脉期DSCT横断面、MIP及VRT重组图像表现为肠系膜上动脉不同程度的充盈缺损;肠系膜上动脉斑块并形成致相应管腔明显狭窄(管腔的狭窄程度大于75%)的1例;肠系膜上静脉血栓形成3例,其中伴有门静脉血栓1例,DSCT显示肠系膜上静脉不规则的充盈缺损。DSCT表现为不同程度肠梗阻5例,表现为肠腔内见气液平,其中4例强化后肠壁呈层状增厚,腹腔内不同程度积液。与手术及DSA结果比较DSCT诊断准确率100%。结论:DSCT能准确诊断急性肠缺血并明确病因,是肠系膜血管缺血性疾病理想的检查方法之一。     

Automated computer-aided stenosis detection at coronary CT angiography: initial experience

Objective  

To evaluate the performance of a computer-aided algorithm for automated stenosis detection at coronary CT angiography (cCTA).