Does addition of CT pelvic venography to CT pulmonary angiography protocols contribute to the diagnosis of thromboembolic disease?

AIM: To evaluate the contribution which addition of pelvic computed tomography venography (CTV) to a standard CT pulmonary angiography (CTPA) imaging protocol makes to a definitive diagnosis of thromboembolic disease. MATERIALS AND METHODS: One hundred and six consecutive patients over the age of 55 years referred for (CTPA) for suspected pulmonary embolism between June and November 1999 had pelvic CTV performed at the time of the CTPA study. RESULTS: Ninety-six of 106 CTPA studies were technically adequate. In total, 29/96 (29.6%) CTPA studies were positive for pulmonary embolism, 10/96 (10.4%) CTV studies were positive and five of these 10 examinations showed venous thrombus when the CTPA study was negative (n = 4) or equivocal (n = 1). CONCLUSION: Addition of CTV shows residual thrombus in the pelvis in a proportion of patients with positive CTPA studies and demonstrates venous thrombus in a small number of patients with no CT evidence of pulmonary embolism.     

肺灌注显像与磁共振肺血管成像对急性肺栓塞诊断价值的比较研究

目的 对比研究单光子发射计算机断层显像(SPECT)和磁共振肺血管成像(MRPA)评估对急性肺栓塞(APE)的临床诊断价值.方法 检索Cochrane图书馆、Medline数据库、Springerlink数据库及ovid循证医学数据库2004-2013年的英文文献,以及中国期刊网包括中国知网、万方医学数据库以及Google学术搜索2004 2013年的中文文献,按照cochrane协作网推荐的诊断实验纳入标准筛选文献,提取纳入研究的诊断信息(真阳性值、假阳性值、真阴性值、假阴性值).采用Stata12软件和Meta-disc1.4软件对纳入文献行统计学处理,包括异质性检验,计算灵敏度和特异度及其95％可信区间,并选择相应的效应模型予以加权定量合并,绘制汇总工作特征曲线(SROC),最后行敏感性分析.结果 按照纳入标准共获取文献16篇,其中纳入SPECT诊断肺栓塞(PE)文献9篇,MRPA文献7篇.都满足诊断性研究质量评价工具(QUADAS) 14条目中的10条以上,按照随机效应模型对纳入文献进行汇总分析.结果显示,以多排CT(MDCT)为金标准,SPECT诊断PE的敏感度、特异度和95％可信区间分别为0.86(0.83～0.88)和0.94(0.93～0.95),MRPA为0.85(0.80～0.89)和0.98(0.97～0.99),SROC曲线下面积(AUC)分别为96％和99％.结论 基于CTPA诊断PE为辐射暴露检查方法,汇总分析非辐射暴露检查SPECT和MRPA评估PE的诊断价值,二者诊断PE的灵敏度及特异度均很高,其诊断价值无明显差异,SPECT和MRPA检查方法可作为PE诊断辐射暴露禁忌的重要替代检查.     

多层螺旋CT肺动脉造影联合静脉造影诊断深静脉血栓的研究

目的应用16层螺旋CT肺动脉造影联合静脉造影(CTVPA)探讨深静脉血栓发生率及部位,并与下肢彩色超声多普勒对照评价其诊断下肢深静脉血栓(DVT)的价值。方法临床怀疑肺栓塞(PE)的147例病人行CTVPA检查,以病人为单位计算两医师诊断DVT一致性;102例患者同时行下肢超声检查,计算股静脉-腘静脉段DVT诊断敏感度、特异度、阳性预测值、阴性预测值。结果147例患者中33例(22.4%)有DVT,27例合并PE。33例DVT的患者CTV共发现156个部位的血栓,腹盆腔静脉血栓共48个(31%),股静脉-腘静脉段血栓58个(37%),小腿静脉血栓50个(32%)。DVT血栓CT值为(42±13)HU。2医师诊断DVT的一致率为90%,Kappa值为0.86。以超声作为对照,CTV诊断股静脉-腘静脉段DVT的敏感度为92.3%,特异度为100%。结论CTV对股静脉-腘静脉段DVT诊断准确率高,并能显示下腔静脉、滤器内及盆腔静脉血栓,CTV的观察者间诊断一致性非常好。     

Venous thromboembolism: additional diagnostic value and radiation dose of pelvic CT venography in patients with suspected pulmonary embolism

Purpose

To assess the additional diagnostic value of indirect CT venography (CTV) of the pelvis and upper thighs performed after pulmonary CT angiography (CTA) for the diagnosis of venous thromboembolism (VTE).

Materials and methods

In a retrospective analysis, the radiology information system entries between January 2003 and December 2007 were searched for patients who received pulmonary CTA and additional CTV of the pelvis and upper thighs. Of those patients, the radiology reports were reviewed for the diagnosis of pulmonary embolism (PE) and deep venous thrombosis (DVT) in the pelvic veins and veins of the upper thighs. In cases with an isolated pelvic thrombosis at CTV (i.e. which only had a thrombosis in the pelvic veins but not in the veins of the upper thigh) ultrasound reports were reviewed for the presence of DVT of the legs. The estimated radiation dose was calculated for pulmonary CTA and for CTV of the pelvis.

Results

In the defined period 3670 patients were referred to our institution for exclusion of PE. Of those, 642 patients (353 men, 289 women; mean age, 65 ± 15 years, age range 18–98 years) underwent combined pulmonary CTA and CTV. Among them, PE was found in 227 patients (35.4%). In patients without PE CTV was negative in all cases. In patients with PE, CTV demonstrated pelvic thrombosis in 24 patients (3.7%) and thrombosis of the upper thighs in 43 patients (6.6%). Of those patients 14 (2.1%) had DVT in the pelvis and upper thighs. In 10 patients (1.5%) CTV showed an isolated pelvic thrombosis. Of those patients ultrasound reports were available in 7 patients, which revealed DVT of the leg veins in 5 cases (1%). Thus, the estimated prevalence of isolated pelvic thrombosis detected only by pelvic CTV ranges between 1–5/642 patients (0.1–0.7%). Radiation dose ranges between 4.8 and 9.7 mSv for additional CTV of the pelvis.

Conclusion

CTV of the pelvis performed after pulmonary CTA is of neglectable additional diagnostic value for the detection of VTE, because the additional radiation dose is high and isolated pelvic DVT is very rare. Venous imaging of the legs (preferably by radiation-free ultrasound) is sufficient for the diagnosis of underlying DVT in patients with suspected PE.     

Computed tomography and magnetic resonance imaging of pulmonary hypertension: Pulmonary vessels and right ventricle

Pulmonary hypertension (PH) is very heterogeneous and the classification identifies five major groups including many associated disease processes. The treatment of PH depends on the underlying cause and accurate classification is paramount. A comprehensive assessment to identify the cause and severity of PH is therefore needed. Furthermore, follow-up assessments are required to monitor changes in disease status and response to therapy. Traditionally, the diagnostic imaging work-up of PH comprised mainly echocardiography, invasive right heart catheterization, and ventilation/perfusion scintigraphy. Due to technical advances, multidetector row computed tomography (CT) and magnetic resonance imaging (MRI) have become important and complementary investigations in the evaluation of patients with suspected PH. Both modalities are reviewed and recommendations for clinical use are given.     

MRA is useful as a follow-up technique after endovascular repair of aortic aneurysms with nitinol endoprostheses

PURPOSE: To evaluate whether MR angiography (MRA) is a useful tool for the follow-up of aortic aneurysms treated with nitinol endoluminal grafts. MATERIALS AND METHODS: We examined 28 patients treated with nitinol endovascular stents to repair an aortic aneurysm with CT angiography (CTA) and MRA. Eleven patients (group 1) underwent an MRA after a positive CTA for endoleak was observed. Afterwards, 17 patients (group 2) were scheduled for both follow-up examinations. The kind of endoleak that occurred and the maximum aortic diameter were compared. The sensitivity of CTA relative to MRA for detecting endoleaks in group 2 was calculated. Signal-to-noise ratios (SNRs) were measured in the aortoiliac lumen at the arterial phase in, above, and below the endoprostheses. Student's t-test was used to compare aneurysm dimensions and SNR measurements. RESULTS: Three type III leaks were correctly assessed at both examinations; however, CTA was less sensitive (50%) than MRA in depicting type II or unclassified leaks. No differences in aneurismal size were observed between the two examinations or between arterial SNRs observed in or out of the devices. CONCLUSION: MRA can provide all relevant information necessary for the follow-up of patients treated with nitinol endoprostheses, and performs better than CTA in detecting endoleaks.     

An unusual cause of mediastinal widening: bilateral innominate vein aneurysms

We present a case of aneurysm of bilateral innominate veins and vena cava superior. Chest X-ray, computed tomography, and 3D contrast enhanced magnetic resonance angiography findings are described. The etiology of venous aneurysms is reviewed and clinical management options are discussed.     

Multidetector row CT pulmonary angiography and indirect venography for the diagnosis of venous thromboembolic disease in intensive care unit patients

RATIONALE AND OBJECTIVES: To determine the diagnostic quality, performance characteristics and interreader reliability of computed tomography pulmonary angiography (CTPA) and venography (CTV) in intensive care unit (ICU) patients with suspected venous thromboembolism (VTE). MATERIALS AND METHODS: A total of 100 consecutive ICU patient CT examinations performed for clinically suspected VTE on a four-row CT scanner were reviewed. Three readers rated the diagnostic quality of each CTPA and CTV examination as excellent, acceptable, or nondiagnostic. Readers scored the overall determination for pulmonary embolism (PE) and deep venous thrombosis (DVT) using a 5-point scale, and scored the determination for PE by anatomic level. Receiver operator characteristic (ROC) analysis was performed for each reader and the original clinical report, using consensus interpretation as the reference standard. Interobserver variability for PE and DVT was determined using kappa analysis, and was stratified by examination quality. RESULTS: A total of 25% of CTPA examinations were nondiagnostic, most commonly because of motion artifact and poor contrast opacification. A total of 24% of CTV examinations were nondiagnostic, most commonly because of poor contrast opacification and metallic hardware. Using receiver operating characteristic analysis, the areas under the curve (Az) for PE diagnosis were 0.875, 0.923, 0.888, and 0.674 for the three readers and clinical reading, respectively, and for DVT diagnosis were 0.842, 0.859, 0.952 and 0.669. Interobserver agreement for detection of PE was moderate at the supralobar level (kappa = 0.55), very good at the lobar level (kappa = 0.69), and moderate for segmental (kappa = 0.54) and subsegmental arteries (kappa = 0.44). Overall reader agreement was good for excellent/good quality CTPA examinations (kappa = 0.52-0.56), and poor when examination quality was poor (kappa = 0.06). CONCLUSIONS: CTPA and CTV are sufficiently accurate and reliable techniques for evaluating VTE in ICU patients, particularly in light of patient complexity.     

Accuracy of CT angiography versus pulmonary angiography in the diagnosis of acute pulmonary embolism: evaluation of the literature with summary ROC curve analysis

RATIONALE AND OBJECTIVES: The authors performed this study to estimate, by using published data, the sensitivity and specificity of computed tomographic (CT) angiography in the evaluation of suspected acute pulmonary embolism (PE). MATERIALS AND METHODS: Summary receiver operating characteristic (ROC) curve analysis was used to determine the sensitivity and specificity of CT angiography in the diagnosis of acute PE. Pulmonary angiography was used as the diagnostic standard of reference. The authors reviewed the results of 11 independent studies published in the English-language literature between January 1992 and June 1999. RESULTS: The sensitivity of CT angiography in the diagnosis or exclusion of PE in the central pulmonary arteries (to the level of the segmental pulmonary arteries) ranged from 0.74 to 0.81 on the basis of specificities of 0.89-0.91. The sensitivity of CT angiography in the diagnosis or exclusion of PE in all pulmonary arteries (to the level of the subsegmental pulmonary arteries) was 0.68 on the basis of a specificity of 0.91. CONCLUSION: On the basis of the studies in the current literature, most of which used 5.0-mm collimation and single-detector CT, CT angiography may be less accurate in the diagnosis of PE than previously reported. With improvements in data acquisition, particularly the use of thinner section collimation and multidetector CT, and in the increased use of workstations for data analysis, the accuracy and utility of CT angiography will require continued investigation.     

多层螺旋CT髂静脉成像临床应用价值

目的探讨髂静脉多层螺旋CT成像的临床应用价值。方法50例患者行髂静脉多层螺旋CT血管造影,对比剂注射方案为经患侧足背浅静脉以2.5～3.0ml/s注射浓度为150mgI/ml的非离子型对比剂,延迟16～22s后开始扫描。利用多种重建方法进行重建。分析髂静脉的成像质量以及髂静脉疾病的影像特点。结果50例患者均成功完成CT血管造影。其中31例完全阻塞,9例管腔狭窄或见局部充盈缺损,10例完全通畅。图像质量优良率:优24%(12/50),良60%(30/50),差16%(8/50),总体优良率84%(42/50)。结论多层螺旋CT髂静脉成像对诊断静脉疾病有一定的临床价值。     

320层动态容积CT血管成像在肺动脉栓塞中的诊断价值

目的探讨320层动态容积CT血管成像在诊断肺动脉栓塞中的价值。方法回顾性分析30例临床确诊为肺动脉栓塞的320层动态容积CT肺动脉成像资料,并用最大密度投影(MIP)、多平面重组(MPR)、容积再现(VR)等方法显示肺动脉。结果 30例患者中,其中左右肺动脉栓塞有15支,叶肺动脉栓塞30支,段及亚段肺动脉栓塞60支。偏心型45支,闭塞型40支,中央型12支,附壁环形型5支。结论 320层动态容积CT肺动脉成像可作为肺动脉栓塞诊断的首选方法。     

CTA与MRA诊断动脉瘤及评估动脉瘤破裂风险的比较

 目的 比较CT血管造影术(CT angiography,CTA)与磁共振血管造影(magnetic resonance angiography,MRA)诊断动脉瘤与动脉瘤破裂的风险评估价值。方法 48例高度怀疑为颅内动脉瘤患者随机分为两组,每组24例,记为Ⅰ组和Ⅱ组,其中Ⅰ组行CTA+DSA检查,Ⅱ组行MRA+DSA检查。比较CTA及MRA对颅内动脉瘤的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值及准确率。比较CTA及MRA对5 mm以上动脉瘤的诊断价值。结果 MRA诊断颅内动脉瘤的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值、准确率较CTA稍低,但二者差异无统计学意义。CTA与三维增强MR血管成像(3D CE-MRA)对5 mm以上动脉瘤的诊断能力相当,但与三维时间飞跃法MR血管成像(3D TOF MRA)相比,CTA与CE-MRA的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值、准确率明显较高,差异有统计学意义(P<0.05);CTA能更清楚地显示瘤颈。结论 CTA和MRA可作为诊断动脉瘤与动脉瘤破裂的风险评估的首要手段,CTA诊断的准确率及三维形态高于MRA。     

肺癌类型及分化程度与癌性空洞表现的关系

目的分析肺癌空洞的X线平片、CT与MRI表现,探讨空洞与肿瘤类型及分化程度关系.材料与方法对40例以各种方法证实为肺癌,均摄X线平片,其中30例做CT、10例做MRI检查.40例中30例手术病理检查,病理结果与影像表现对照.结果空洞内缘不规则似癌梁样改变,空洞壁厚度与空洞在肿瘤中位置特别是肿瘤越小,形成的空洞越小;肿瘤越大,空洞偏大,且肿瘤又呈分叶样改变等与肿瘤类型与分化程度有明显关系.CT对空洞内缘与肿瘤边缘显示优于X线平片.MRI对肿瘤组织信号强度变化,如肿瘤液化坏死,甚至对肿瘤性质有潜在定性能力.结论肺癌空洞X线、CT与MRI表现与肿瘤类型及分化程度有明显联系.     

双源CT肺动脉成像的低对比剂量优化研究

目的：探讨双源 CT 大螺距肺动脉成像在低对比剂量优化时的可行性。方法对80例疑似肺栓塞的患者行 CT 肺动脉造影(CTPA)检查。按照随机数表法分为 A、B 2组：A 组,常规组40例,对比剂50 mL,自动跟踪触发扫描;B 组,小剂量测试组40例,对比剂量=体质量×0.3 mL/kg。测量2组肺动脉 CT 值、动静脉 CT 差值、对比噪声比(CNR)、信噪比(SNR)、辐射剂量,进行两独立样本 t 检验。评价图像质量、肺栓塞诊断阳性率,进行卡方检验。结果2组肺栓塞诊断阳性率差异无统计学意义(P =0.655)。主观质量评分差异无统计学意义(P =0.174)。B 组与 A 组的肺动脉干 CT 值与左肺 SⅢ动静脉差值差异有统计学意义(P =0.001)。B 组与 A 组的肺动脉干 SNR、CNR 差异无统计学意义(P =0.250、0.203)。B 组有效辐射剂量明显低于 A 组,差异有统计学意义(P =0.001)。结论双源 CT 大螺距肺动脉成像低对比剂量优化时,在满足临床诊断肺栓塞的需要下,较大程度地减少了对比剂的用量。     

螺旋CT血管成像技术在肺动脉栓塞诊断中的应用

目的探讨螺旋CT肺动脉血管成像(sp iral CT pu lmonary angiography,SCTPA)技术对肺动脉栓塞(pu lmonary embolism,PE)的诊断价值。方法收集SCTPA检查并证实为PE的患者25例,采用单/多排螺旋CT扫描机行肺动脉增强检查并行多平面重建(MPR)、最大强度投影(M IP)和表面遮盖显示(SSD)重建。结果本组25例PE共行29次SCTPA检查,中央型PE 23例(92%),周围型PE 2例(8%)。主肺动脉、左及右肺动脉、叶间肺动脉、叶肺动脉、舌支肺动脉的显示率均达100%,对段肺动脉的显示率达97.77%,对亚段肺动脉的显示率也达68.00%。PE受累血管主要集中在叶、段肺动脉,受累率在46.58%~75.00%之间。结论SCTPA技术为临床及早发现并明确诊断PE的可靠检查手段之一。     

Noninvasive gadolinium-enhanced three dimensional computed tomography coronary angiography

RATIONALE AND OBJECTIVES: Although the use of gadolinium (Gd)-based contrast agents for angiographic studies of abdominal aorta, renal vasculature, and digital subtraction angiography has been reported, no studies have shown their diagnostic efficacy and image quality in coronary computed tomography angiography (CTA). The aim of this study is to evaluate the image quality of Gd-based contrast agents during coronary CTA. MATERIALS AND METHODS: A phantom study was done to evaluate the attenuation of serial dilutions of Gd and iodinated agents. This study was done on a 64-slice multirow detector CT (MDCT) scanner and e-speed scanner and CT attenuation Hounsfield units (CTHU) were compared. We evaluated 35 consecutive patients who underwent Gd-enhanced CTA. CTHU of aorta was measured at first, mid, and lowest slice levels with and without contrast administration. The image quality was graded on the basis of visualization of the coronary arteries (scale I-III; III demonstrating diagnostic image quality of the distal-most vessels). In a substudy, four patients with borderline renal insufficiency underwent CTA using Gd and iodinated contrast agents admixed in a 50:50 ratio. RESULTS: The phantom study showed that enhancement of various dilutions of Gd and iodine resulted in near identical CTHU with both e-speed and 64-slice scanners (r(2) > or = 0.997). Mean CTHU with contrast at the top slice was 116 HU, at middle slice was 125 HU, and at the lower slice was 93 (111.14 +/- 22). Quality evaluation showed 2 grade III, 9 grade II, and 24 grade I images (average quality of images 1.35). Mean CTHU was 222. CONCLUSION: Gd-enhanced contrast medium provides adequate enhancement of coronary vasculature, allowing for diagnostic evaluation of coronary arteries with new CT systems. Use of newer generations of multirow detector CT scanners should further enhance the quality of images.