16层螺旋CT血管造影诊断肺动脉栓塞并下肢深静脉血栓

目的 探讨下肢深静脉血栓和肺栓塞的多层CT联合成像的诊断价值。方法 31例患者行CT肺动脉血管造影,其中15例同时行下肢深静脉联合成像,采用16层螺旋CT,1.25mm×16模式采集,注射对比剂120～150ml,注射流率3.5～4.0ml/s,肺动脉延迟20～25s扫描,下肢静脉延迟150～180s扫描。并结合容积重建（VR）、最大密度投影（MIP）、多平面重建（MPR）、曲面重建（CPR）等重建技术进行图像分析。结果 共发现下肢深静脉血栓15例16侧,肺栓塞31例51处,其中肺栓塞和下肢深静脉血栓同时存在15例。结论 多层螺旋CT肺动脉和下肢静脉联合成像可一次性评价肺动脉和下肢静脉,是肺栓塞首选的影像检查方法。     

应用间接CT静脉成像检查深静脉血栓

深静脉血栓是一种世界范围的严重临床疾患,必须准确检测,该文目的是评价在肺动脉CT成像基础上附加间接CT静脉成像检查怀疑肺栓塞的患者是否有深静脉血栓的临床优势。作者前瞻性选择1998年5月～1999年3月期间541例怀疑肺栓塞病人行肺动脉CT成像及CT静脉成像。男性233例,女性308例。年龄18～98岁,平均65岁。通过臂静脉以3ml/s注射对比剂140ml。延迟28s后进行螺旋CT扫描。扫描从下肺静脉直至主动脉弓,层厚     

多层螺旋CTA联合CTV在肺栓塞及下肢静脉血栓诊断中的应用

目的 评价多层螺旋CT肺动脉造影(MSCTA)及多种重建技术联合双下肢静脉扫描(CTV)在肺栓塞(PE)及下肢静脉血栓诊断中的应用价值.方法 47例经临床确诊的PE患者经MSCTA检查,扫描条件包括电压120 kV,电流210 mA,准直器宽度0.75 mm,对比剂注射速率为3～4 ml/s,延时时间的设定采用自动团注触发技术,MSCTA完成后延迟170 s行盆腔及CTV.结果 47例PE患者MsCTA及MPR、MIP、VRT等重建处理后均可显示两侧肺动脉主干、叶动脉、段及亚段肺动脉.受累动脉共363支,PE伴下肢深静脉血栓(DVT)31例,占65.9%.结论 MSCTA联合CTV诊断肺动脉栓塞及下肢静脉血栓具有重要价值.     

多层螺旋CT联合扫描对肺栓塞及下肢静脉血栓形成的应用价值

目的 探讨肺栓塞(PE)及下肢深静脉血栓形成(DVT)行多层螺旋CT联合扫描的重要性及最佳延迟扫描时间. 资料与方法 21例疑为PE患者于16层螺旋CT上先行肺动脉血管成像(CTPA),对比剂注入后延迟22～25 s开始扫描,然后间隔一定时间行静脉成像(CTV),扫描范围为髂嵴水平至腓肠静脉丛上部水平,延迟扫描时间分别设定为90 s、120 s、180 s及240 s.扫描结束后对比分析不同延迟时间下静脉管壁强化情况. 结果 发现15例PE患者,计栓子58处,栓子均显示清晰;DVT 18例,计栓子42处,静脉壁强化效果随延迟时间不同而不同, 180 s～240 s静脉壁强化效果最佳.其中,PE和DVT共存13例,单纯PE 2例,单纯DVT 5例,1例未见明显充盈缺损征象. 结论 多层螺旋CT联合扫描可同时检出PE和DVT,具有重要临床意义;在PE和DVT联合扫描中,静脉成像延迟扫描时间以180～240 s较适合.     

多层螺旋CT在肺栓塞检查中的方法与技巧

目的 :探讨多层螺旋CT对诊断急性肺动脉栓塞及下肢深静脉血栓的检查方法、技巧以及临床应用价值。方法 :对 2 1例临床上疑肺动脉栓塞 (PE)的病例先行常规平扫 ,后经肘静脉注入适量对比剂 ,首先延迟 2 0s ,从膈下到主动脉弓上缘从足侧向头侧方向采用多层螺旋CT行薄层 (4i× 1mm ,螺距 3 .5 ,0 .5s/周 )肺动脉成像 (CTPA) ,延迟约 15 0s行间接法深静脉成像 (CTV) ,由膈下至膝关节下缘的非螺旋扫描。结果 :2 1例患者中检出 12例急性PE ,间接法CTV检出 8例深静脉血栓 (其中 7例合并急性PE)。延迟 2 0s及 15 0s行CTPA及CTV ,肺动脉及深静脉充盈良好 ,血栓表现为部分或完全腔内充盈缺损。对PE的显示MPR优于SSD及MIP。结论 :螺旋CT肺动脉造影是急性肺动脉栓塞安全、迅速、有效、无创伤的诊断方法 ,联合下半身深静脉造影 ,对栓子的来源和肺栓塞的治疗及预后有非常重要的作用 ,而且具有较高的成本 效益比。     

16层CT在显示腔静脉滤器植入防治肺栓塞的实验研究

目的:探讨16层螺旋CT在腔静脉滤器植入防治肺栓塞治疗中的应用价值.方法:20条家犬分为实验组15条,空白对照组5条.实验组分别于滤器植入术前、术后用16层CT行肺动脉与深静脉联合造影.术前观察下腔静脉及其属支解剖位置.术后经股静脉插管植入滤器并注入血栓,观察下腔静脉及远端静脉内血栓显影情况及滤器植入位置和肺动脉显影.对照组不放滤器,同法注射血栓,CT扫描观察肺栓塞情况.结果:15例犬模型术前检查腔静脉及下肢深静脉显影良好.下腔静脉血栓CT值为(77±5.7)HU, 肺动脉CT值为(330±9.3)HU,深静脉CT值为(172±8.5)HU,血栓与深静脉CT值具有显著性差异(t=56.04,P<0.001).对照组均发生肺栓塞.结论:16层螺旋CT肺动脉联合深静脉扫描对介入手术入路选择及滤器正确放置能提供指导作用,并在术后监测中有较大的应用价值.     

16层螺旋CT对肺动脉栓塞及下肢静脉血栓行联合成像的技术优势

目的探讨16层螺旋CT同时扫描肺动脉和下肢静脉的联合成像技术。方法40例疑为肺动脉栓塞(简称肺栓塞)的病人于16层螺旋CT上行肺动脉和下肢静脉联合成像。CT后处理包括最大密度投影(MIP)、多平面重建(MPR)及容积再现(VR)。采用t检验进行统计学分析。结果肺栓塞、下肢静脉血栓同时存在者25例，单纯下肢静脉血栓者8例，单纯肺栓塞者2例，二者均正常者5例。不同重建层厚均可清晰显示肺动脉栓子。肺动脉、下肢静脉增强后的CT值显著高于栓子的CT值。MPR、MIP、VR三者对肺栓塞的显示率分别为100％、100％、65％，下肢静脉血栓的显示率分别为100％、60％、50％。结论16层螺旋CT联合肺动脉、下肢静脉成像将为肺栓塞的诊断提供新的方法。     

螺旋CT肺动脉与下肢静脉联合成像对静脉血栓栓塞症的诊断价值

目的评价螺旋CT肺动脉与下肢深静脉联合成像技术（CTVPA）对静脉血栓栓塞症（VTE）的诊断价值。方法对临床拟诊为肺栓塞（PE）的46例患者行CTVPA成像，先行肺动脉CT成像，后行下肢深静脉扫描，深静脉CT扫描范围从胭静脉至双肾静脉水平。结果46例患者中，CTVPA显示PE患者37例，下肢深静脉血栓（DVT）34例，两者同时存在者30例。37例PE均为多发肺动脉栓子，共累及动脉189支，其中，左右肺动脉主干栓子2．6％（5／189）支，叶动脉30．2％（57／189）支，段动脉50．2％（95／189）支。亚段及亚亚段肺动脉16．9％（32／189）支。34例DVT患者中，左侧20例，右侧12例，盆腔内静脉血栓2例。CTVPA成像检出率较CTPA高10．8％（4/37）。结论16层螺旋CT CTVPA可实现“一站式”检查，对评价肺动脉与下肢深静脉血栓栓塞性疾病有较高的敏感性与特异性。     

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。     

CT血管造影后深静脉扫描对深静脉血栓的诊断价值

目的探讨肺动脉CT血管造影后深静脉扫描对深静脉血栓的位置、范围及管腔狭窄程度的诊断价值,并与下肢静脉造影结果进行对照。方法19例疑诊肺栓塞的患者,接受肺动脉CT血管造影后深静脉扫描,其中男8例,女11例,年龄38~73岁。CT肺动脉造影扫描范围从膈顶至主动脉弓水平。其中15例接受双下肢静脉造影,扫描范围从膈顶至小腿上端。分别观察2种检查方法的影像结果,并将下肢静脉影像进行比较分析。结果全部19例患者行肺动脉CT血管造影后深静脉扫描,所有病例均获得满意的肺部图像,18例获得良好的深静脉扫描图像,1例深静脉显影不良,不能诊断。7例有不同程度和范围的肺动脉栓塞,11例见有深静脉血栓,其中既有肺动脉栓塞又有深静脉血栓者6例,1例仅有肺动脉栓塞而无深静脉血栓,5例仅有深静脉血栓而无肺动脉栓塞。15例患者在CT检查前后24h接受下肢静脉造影检查,10例呈阳性,显示血栓分别位于静脉和股静脉。10例下肢静脉血栓病例,CT检查发现9例,漏诊1例;而CT发现的股静脉以上平面的深静脉血栓4例,下肢静脉造影受其技术方法限制,均未能显示。结论CT肺动脉造影除能够发现肺栓塞的部位及其他非栓塞病变外,对下肢、盆腔及腹部的静脉扫描,还可准确地诊断深静脉血栓。     

Computed tomography pulmonary angiography with pelvic venography in the evaluation of thrombo-embolic disease

A prospective study was performed to evaluate the usefulness of CT pelvic venography (CTV) in the detection of pelvic vein thrombosis in patients referred for CT pulmonary angiography (CTPA) for suspected pulmonary embolism. Fifty consecutive patients referred for CTPA had CTV performed at the time of CTPA. All patients had duplex ultrasound (DUS) of the lower limb veins for evaluation of deep venous thrombosis (DVT) within 24 h of the CT study. Twelve (24%) of the 50 patients had pulmonary embolism diagnosed on CTPA. Associated DVT was detected in six of these patients; two cases were detected by CTV alone, while one case was detected by both CTV and DUS. The remaining three cases had DVT diagnosed by DUS alone. In the 38 patients with a negative CTPA, three patients had venous thrombus diagnosed by CTV. Of these three patients, two had a negative DUS study. CTV therefore led to a definitive imaging diagnosis of thrombo-embolic disease in two (4%) more patients. CTV adds little time and cost to the CTPA examination and leads to a moderate increase in definite imaging diagnosis of thrombo-embolic disease.     

肺动脉栓塞的CT血管造影检查

目的研究CT肺动脉血管造影联合下肢深静脉血管造影在肺栓塞的诊断中的作用及多层螺旋CT的优势。方法采用单层螺旋CT或16层螺旋CT对临床拟诊肺栓塞的所有患者行肺动脉血管造影(CTPA)及下肢静脉血管造影,统计栓塞的数目及类型。结果44例肺栓塞中,肺栓塞合并下肢静脉栓塞的34例,单纯肺栓塞的10例。单层螺旋CT及16层螺旋CT检查的病人总的栓塞显示率分别为12.1%及19.0%,差异有统计学意义(P=0.004);肺段及肺段以上肺动脉栓塞的显示率分别为25.3%及29.7%,差异无统计学意义(P=0.104);亚段及亚段以下显示率分别为1.1%及10.2%,差异有统计学意义(P=0.000)。结论CT肺动脉血管造影联合下肢血管造影是肺栓塞的无创、快速、敏感性和特异性均较高的诊断方法。16层螺旋CT在检查肺栓塞方面优于单层螺旋CT。     

肺肾双能量CTA筛查肾病综合征患者静脉血栓栓塞的发生率

目的：利用CT筛查肾病综合征患者静脉血栓栓塞事件的发生率及其临床意义。方法：2010年5月-2012年8月974例患者行双能量CT肺动脉成像（CTPA）,其中451例肾病综合征患者（包括66例儿童）进行了肺肾联合双能量CT扫描以筛查肺栓塞和肾静脉栓塞。153例患者同时进行了下肢超声检查用于筛查深静脉血栓。记录肺栓塞、肾静脉栓塞、下肢深静脉血栓的发生率及其相互关系。结果：177（39．2％）例患者至少有一个静脉血栓栓塞事件,其中以肺栓塞最常见（149／177,84．1％）,76例肺栓塞患者合并肾静脉栓塞,孤立性肺栓塞54例。大多数肺栓塞患者（118／149,79．2％）无临床症状。106例（106／451,23．5％）例患者有肾静脉栓塞,26例（26／153,17．0％）患者有深静脉栓塞。儿童患者静脉血栓事件发生率（13／66,19．7％）低于成人（164／385,42．6％）。在组织学证实的肾病类型中,膜性肾病最常伴有静脉血栓事件（72／153,47．1％）。结论：肺栓塞是肾病综合征患者最常见的血栓并发症且大多是无症状的,常伴有肾静脉血栓或孤立发生,因此对本病的可疑静脉血栓患者的筛查是需要的。     

Correlation between the site of pulmonary embolism and the extent of deep vein thrombosis: evaluation by computed tomography pulmonary angiography and computed tomography venography

Purpose  

The aim of this study was to evaluate the relation between the sites of pulmonary embolism (PE) and deep vein thrombosis (DVT) by computed tomography pulmonary angiography (CTPA) and CT venography (CTV) of the pelvis and lower extremities.     

CT venography vs ultrasound in the diagnosis of thromboembolic disease in patients with clinical suspicion of pulmonary embolism

To assess the reliability of indirect computed tomography venography (CTV) in the detection of deep venous thrombosis (DVT) in patients with clinical suspicion of pulmonary embolism (PE). 235 consecutive patients with suspicion of PE underwent an imaging protocol composed of a CT pulmonary angiography (CTPA), a CTV and an ultrasound study of the deep venous system, which was considered the “gold standard.” Sensitivity, specificity, and predictive values were calculated for CTV. ith CTV, 30 (12.8%) cases of DVT were detected, 9 (3.8%) of them without pulmonary embolism in CTPA, increasing the diagnosis of thromboembolic disease in 3.8%. However, six of these nine diagnoses were false positives, and CTV missed six cases of DVT. CTV rendered a sensitivity of 58.8%, specificity of 95.0%, a positive predictive value of 66.7%, and a negative predictive value of 93.2%. In patients with clinical suspicion of pulmonary embolism, ultrasound is preferred to CTV for the detection of DVT.     

A retrospective study of the value of indirect CT venography: a British perspective

Objective

The aim of this study was to establish the value of indirect CT venography (CTV) in clinical practice within the UK.

Methods

804 combined CT pulmonary angiogram and CTV studies were retrospectively reviewed. CTV was performed 180 s after the injection of contrast using an incremental technique with a 5-mm collimation and a 5-cm interspace between images extending from the iliac crests to the tibial plateaus.

Results

12.9% of studies had isolated pulmonary emboli (PE), 3.0% had both a PE and deep vein thrombosis (DVT) and 1.1% had an isolated DVT. The proportion of positive cases diagnosed by CTV alone was 6.6%.

Conclusion

In a UK-based practice, the incidence and the proportion of isolated DVT diagnosed by CTV are lower than expected from published data. An analysis of possible causes for this is made within the paper.More than 250 000 cases of pulmonary embolism were identified in the UK between 1996 and 2006, yet the accurate diagnosis of this condition remains problematic [1]. Autopsy studies indicate that 88% of pulmonary emboli (PE) are unsuspected clinically prior to death. Although the majority of these PE are an incidental complication of an underlying comorbid condition, less than half of cases of fatal PE are correctly diagnosed ante-mortem [2,3]. It is accepted that PE originate from distant sites of venous thrombosis and that both PE and deep vein thrombosis (DVT) are facets of the same disease process, with the majority of DVT arising within the lower limb veins. The evaluation of the presence of DVT is therefore considered part of the investigation of PE, and the presence of DVT in the absence of radiological evidence of PE can be accepted as surrogate evidence of venous thromboembolism (VTE). Lower limb indirect CT venography (CTV) may be added to CT pulmonary angiography (CTPA) to identify the presence of DVT, but this is at the expense of an increased examination time and an increased radiation dose, particularly to the reproductive organs. The prospective investigation of the PE diagnosis II study demonstrated the addition of CTV to CTPA increased the sensitivity for detection of PE from 83% to 90% [4]. Despite this, the routine addition of CTV to CTPA is not recognised in current British Thoracic Society guidelines, and it is not known how many centres in the UK have adopted this technique [5].The aim of this study is to establish the incremental value of CTV in clinical practice within a British institution and ascertain whether factors such as image quality significantly influence the value of the examination. To our knowledge this is the first large British study of the value of CTV in the investigation of PE.     

CT lower extremity venography in suspected pulmonary embolism in the ED

The purpose of this study was to evaluate the added benefit of computed tomography lower extremity venography (CTLV)—performed following CT pulmonary angiography (CTPA)—in the emergency department (ED) patient suspected of pulmonary embolism (PE). A retrospective review of 427 consecutive patients having both CTPA and CTLV performed to evaluate patients suspected of PE at two community hospitals was conducted. Three-month follow-up was performed on all patients to ensure that no case of PE or deep venous thrombosis (DVT) was missed. Forty patients were positive for PE, and 11 were positive for DVT. There were 6 CTPA studies read as indeterminate for PE and 11 CTLV studies indeterminate for DVT. Only 1 patient was positive for DVT, who did not have a concurrent PE identified by CTPA. The estimated charges for detecting the single case of isolated DVT was US $206,400. In our ED setting, the additional benefit of adding CTLV to the standard ED work-up of PE was minimal.     

CT for thromboembolic disease

Pulmonary embolism (PE) and deep venous thrombosis (DVT) constitute the two clinical manifestations of venous thromboembolic disease (VTE). The recent innovation of computed tomography venography (CTV) in conjunction with CT pulmonary arteriography (CTPA) provides a single noninvasive diagnostic test that can evaluate both components of VTE. PE is often an underestimated, underdiagnosed, and, consequently, undertreated disease entity. Herein, we review the epidemiology of thromboembolic disease, the diagnostic algorithm used in evaluation of patients with suspected VTE, and protocols for performing CTPA and CTV. Interpretation of these examinations is discussed in detail, because CTPA may pose new challenges to the practicing radiologist.