CT肺动脉成像诊断肺栓塞的一致性研究

目的评价CT肺动脉成像（CTPA）诊断肺栓塞（PE）时,不同经验的读片者间和同一读片者内的一致性。方法 55例临床可疑PE患者行CTPA检查,6位不同经验的放射科医生独立地分析CTPA图像来评价读片者间的一致性。3位放射科医生3个月后第二次分析CTPA图像来评价读片者内的一致性。PE的表现分为阳性、阴性和难以确定。读片者一致性用百分比及Kappa系数表示。结果 6位读片者判定29～31例（平均29.2例）患者CTPA为PE阳性,1～5例（平均3.0例）患者CTPA为难以确定。6位读片者在48例（87.3%）患者CTPA的诊断上取得一致意见,5位读片者在4例患者（7.3%）的诊断上取得一致意见,4位读片者在2例患者（3.6%）的诊断上取得一致意见,3位读片者在1例患者（1.8%）的诊断上取得一致意见。在诊断PE上,如果以每例患者为观察单位,读片者间的一致性＂非常好＂（Kappa值为0.91）。以每个肺动脉为观察单位,读片者间的一致性＂好＂（85%,Kappa值为0.74）;以肺叶动脉为观察单位,读片者间的一致性＂好＂（89%,Kappa值为0.78）;以肺段动脉为观察单位,读片者间的一致性＂中等＂（75%,Kappa值为0.59）。如果以每例患者为观察单位,同一读片者内的平均一致性＂非常好＂（96%,Kappa值为0.93）。结论在CTPA上诊断PE时,经验不同的读片者间和同一读片者内的一致性均较好。     

急性肺栓塞所致右心功能不全的CTPA诊断价值

目的 探讨CT肺血管造影(CTPA)对急性肺栓塞(PE)所引起的右心功能不全(RVD)的诊断价值.方法 回顾性分析经CTPA确诊的、并于24 h内行超声心动图(UCG)检查的急性肺栓塞患者36例,并按病情严重性分为大面积肺栓塞组(24例)和非大面积肺栓塞组(12例).本研究以UCG的结果作为RVD的诊断标准,将CTPA的结果与UCG的结果相对照.CTPA诊断RVD的标准为在横切位CT图像上显示右心室增大(RVd/LVd>1)或室间隔异常移位.结果 36例肺栓塞患者中,UCG共诊断RVD阳性13例,阴性23例.CTPA诊断RVD阳性16例,阴性20例.以UCG为标准,CTPA的诊断敏感性为84.61%、特异性为78.26%、阳性似然比为3.892、阴性似然比为0.197、阳性预测值为68.75%、阴性预测值为90%,Kappa值为0.60,诊断具有中等一致性.24例大面积肺栓塞患者中,UCG诊断RVD阳性13例,阴性11例.CTPA诊断RVD阳性14例,阴性10例.以UCG为标准,CTPA的诊断敏感性为84.61%、特异性为72.73%、阳性似然比为3.103、阴性似然比为0.212、阳性预测值为78.57%、阴性预测值为80%,Kappa值为0.58,诊断具有中等一致性.12例非大面积肺栓塞患者中,UCG诊断均为RVD阴性.CTPA诊断RVD阳性2例,阴性10例,诊断特异性为83.33%.统计学分析发现,2组之间的RVd/LVd值有显著性差异,CTPA与UCG结果在大面积肺栓塞组有较好的相关性,而在非大面积肺栓塞组无明显相关性.结论 CTPA不仅可以对肺栓塞做出直接诊断,而且通过分析心脏的形态学改变,可以较为准确地判定肺栓塞患者是否伴发右心功能不全.     

慢性血栓栓塞性肺动脉高压双能量CT表现

目的:探讨慢性血栓栓塞性肺动脉高压(CTEPH)的双能量CT表现.方法:对经临床及心脏超声证实的13例CTEPH患者进行双能量CT扫描.由两位放射科医师以肺叶为单位独立分析双能量CT肺血容量灌注成像(LungPBV)肺灌注缺损的数目、位置,分析CTEPH患者的CT肺动脉成像(CTPA)表现.利用Kappa检验分析两位阅片者诊断CTEPH的一致性.结果:13例CTEPH表现为血栓沿肺动脉内壁分布,呈不规则偏心性、附壁性充盈缺损或肺动脉突然狭窄.肺梗死1例,“马赛克”样肺灌注6例,胸腔积液1例,肺动脉主干直径/同层主动脉直径(PA/AA)＞1者12例,对比剂腔静脉返流3例.以肺叶为分析单位,阅片者1、2利用双能量CT肺灌注成像均发现21个肺叶出现灌注缺损,两位阅片者联合发现20个肺叶有灌注缺损.两位阅片者诊断的一致性Kappa值为0.918(P＜0.001),灌注缺损主要为分布于肺外带的楔形灌注减低区.结论:双能量CT能同时获得CTPA及肺灌注成像图像,可为CTEPH的诊断提供重要信息,可作为临床CTEPH疑似患者的首选检查方法.     

核素肺灌注显像结合PISA-PED评价标准与CT肺动脉造影诊断肺栓塞的对比研究

目的 比较核素肺灌注显像结合PE诊断前瞻性研究(PISA-PED)评价标准与CT肺动脉造影(CTPA)诊断PE的效能.方法 前瞻性纳入104例连续性疑似PE患者,其中男54例,女50例,年龄(50±15)岁.排除标准为:孕妇、肾功能衰竭患者、已接受溶栓或抗凝治疗患者或有造影剂过敏史患者.所有患者均行核素肺灌注显像、CTPA及胸部X线检查.采用PISA-PED评价标准判读核素肺灌注显像图.最终诊断采用临床综合诊断.应用Kappa检验分析肺灌注显像与CTPA结果的一致性,应用非参数检验或x2检验分析2种诊断方法结果间的差异性.结果 104例患者中55例被最终诊断为PE.在排除3例(2.9％)CTPA“不能诊断”者后,肺灌注显像的灵敏度、特异性、阳性预测值及阴性预测值分别为92.6％ (50/54)、83.0％( 39/47)、86.2％( 50/58)和90.7％ (39/43);CTPA的灵敏度、特异性、阳性预测值及阴性预测值分别为96.3％ (52/54)、93.6％( 44/47)、94.5％( 52/55)和95.7％ (44/46).2种显像方法的诊断符合率为89.1％(90/101),Kappa =0.78,P＜0.05.在肺段水平,共分析了1664个肺段,肺灌注显像与CTPA的诊断符合率为79.7％ (1327/1664),Kappa=0.58,P＜0.05.结论 核素肺灌注显像结合PISA-PED评价标准与CTPA诊断PE的效能相近,两者均有较好的诊断效能.2种显像方法在肺段水平为中度符合.     

双源CT双能量肺灌注成像在可疑肺栓塞患者的初步应用

目的 评价双源CT双能量肺灌注成像(DEPI)在可疑肺栓塞(PE)患者的临床诊断价值.资料与方法 19例临床拟诊PE的患者在双源CT上行对比增强双能量模式扫描.利用双能量分析软件(Lung PBV)分析.以肺叶为单位,记录DEPI和CT肺动脉成像(CTPA)上PE的数目和位置.以CTPA为参照标准,评价DEPI诊断PE的敏感性和特异性.分析DEPI上肺灌注异常的范围与心血管测量参数的关系.结果 19例共行20次DECT扫描,共有98个肺叶纳入分析.10例未检出PE,9例确诊为PE,23个肺叶的肺动脉内可见充盈缺损.以CTPA为参照标准,两位医师利用DEPI诊断PE的敏感性、特异性分别为96%、96%和82%、95%.PE患者肺灌注异常的范围似与右室功能障碍有关.结论 利用双源CT双能量模式扫描可同时获得全肺的解剖和功能信息,在PE的诊断和随访中有较高的临床价值.     

不同层厚的CT肺血管成像对肺栓塞的诊断价值

目的 探讨不同层厚的CT肺血管成像(CTPA)对肺栓塞的诊断价值.方法 50例CTPA确诊的、准直为0.625 mm的肺栓塞患者,于工作站按1.25 mm、2.5 mm和5 mm层厚行无间隔重建,由2名影像学医师独立阅片,以0.625 mm层厚的CTPA为标准,分析不同层厚的CTPA的诊断结果及其对具体栓子的显示情况.结果 与0.625 mm层厚CTPA相对照,50例肺栓塞患者于1.25 mm、2.5 mm和5 mm层厚CTPA的漏诊率分别为4%、10%和20%,对具体动脉分支有无栓子的诊断一致性(Kappa值)分别为0.9、0.68和0.5,诊断符合率分别为84%、34%和0%.结论 1.25 mm层厚的CTPA与0.625 mm层厚的CTPA的诊断价值相似,因此,在工作站行CTPA重建时,重建层厚不应超过1.25 mm.     

CAD整合入前列腺多参数MRI结构化报告：低经验读片者诊断效能研究

【摘要】目的：模拟真实临床工作场景,评估将计算机辅助诊断（CAD）作为“第二读片者”整合入前列腺多参数MRI（mpMRI）结构化报告中对低经验一线放射科医师诊断效能的影响。方法：回顾性搜集具有完整临床资料前列腺mpMRI数据30例,其中经前列腺根治术后逐层切片病理证实为前列腺临床显著癌（Gleason评分≥3+4）13例,经穿刺及随访确诊为非癌者17例。18名低年资一线放射科医师使用结构化报告对前列腺mpMRI病例进行独立盲法评估：首先,浏览mpMRI图像,按照日常工作流程依据前列腺影像报告及数据系统（PI-RADS v2）完成结构化报告;之后,参考CAD预测图对以上诊断报告进行修改。以PI-RADS＞3分判为诊断前列腺临床显著癌阳性,评价18名读片者使用CAD前、后的对前列腺临床显著癌的诊断效能。结果：以患者为单位分析18名读片者使用CAD后平均灵敏度及特异度分别从83.8%、76.1%提高至90.6%、82.7%。以病灶为单位分析读片者使用CAD后对癌灶检出平均灵敏度由83.6%提高至90.2%,且位于尖部小癌灶检出提高读片者最多。读片者使用CAD后平均诊断信心显著提高（P=0.001）,CAD作为“第二读片者”平均每个病例读片时间增加0.7min。结论：将CAD作为“第二读片者”整合入前列腺mpMRI结构化报告后低经验一线放射科医师平均诊断效能高于其独立诊断,平均诊断信心显著提高。     

多排螺旋CT肺动脉造影诊断肺栓塞的价值

目的 探讨多排螺旋CT肺动脉造影(CTPA)诊断肺栓塞(PE)的应用价值.方法 回顾分析374例可疑PE而应用CTPA的患者,对比血栓的检出率、急或慢性及单或多发率.通过研究多种影像学检查,探讨其诊断PE的价值.结果 CTPA诊断阳性及经临床证实为PE 105例,单发栓塞14例,多发栓塞91例,急性栓塞63例,慢性栓塞42例.结论 CTPA诊断PE简单、安全、准确,应作为临床首选影像检查.     

基于判别分析模型的乳腺BI-RADS计算机辅助分类

目的:在经典应用的乳腺影像报告数据系统(BI-RADS)基础上,通过量化分析影响评估分类的变量,建立BI-RADS判别分析模型,评估其在临床应用中的价值。方法:10年中共561例有完整影像学资料及经病理或随访证实的BI-RADS分类结果(金标准),对与乳腺病变相关的各种变量进行量化,基于Bayes判别分析方法建立判别模型并编写软件,将除去病理及随访结果的以上病例资料由两位医师分别进行人工分类和软件分类,评估两种方法下医师分类判别与金标准的一致性,以及两位医师之间分类判别的一致性。结果:建立了完整的判别分析模型,其误判概率为1.25%,模型与金标准有高度一致性(Kappa值为0.981)。两位医师使用软件分类的诊断结果与金标准的一致性(Kappa值分别为0.904和0.901)要高于人工分类(Kappa值为0.695和0.632)。人工分类时两位医师诊断结果间的Kappa值为0.575,明显低于软件分类时(Kappa值为0.841)。结论:通过大样本的统计学分析建立标准、合理的判别分析模型,能够有效的预测乳腺肿块的BI-RADS类型,减少对BI-RADS 0类患者的召回率,提高对BI-RADSⅠ～Ⅴ类病变的诊断准确性,并提高不同诊断者间的诊断一致性。     

CT和MRI对乙肝肝硬化背景下肝细胞癌诊断评分的一致性：基于LI-RADS的多中心、个体内对照研究

目的：基于肝脏影像报告和数据系统（LI-RADS）2014版评分系统,探讨CT和 MRI对乙肝肝硬化基础上的肝细胞肝癌（HCC）的诊断价值。方法：本研究为多中心、个体内对照研究,搜集51例（54个 HCC 病灶）经病理证实的慢性乙型肝炎肝硬化合并HCC患者的病例资料,所有患者均行CT和MRI平扫及动态增强扫描（两项检查间隔时间不超过1个月）。由2位不同年资的放射科医师根据LI-RADS标准分别对所有入组病例的动态增强CT、平扫联合动态增强MRI两个阅片单元进行独立盲法读片,每位阅片者每个单元读片结束后需等待至少一个月方能进入下个读片单元。通过Kappa检验对两位阅片者间的评分一致性进行分析。结果：两位阅片者对51例 HCC 患者 CT 图像进行评价,LI-RADS评分分别为4．13±1．10和4．07±1．13,一致性中等（Kappa＝0．550）;而基于平扫联合动态增强 MRI,两位阅片者的LI-RADS评分分别为4．61±0．65和4．31±0．91,一致性一般（Kappa＝0．398）。结论：针对 HCC 病灶,使用LI-RADS进行诊断评分时,动态增强CT的阅片者间一致性较好,优于平扫联合动态增强 MRI。     

Prospective comparison of helical CT with angiography in pulmonary embolism: global and selective vascular territory analysis. Interobserver agreement

The objective of this prospective study was to evaluate the sensitivity, specificity, positive and negative predictive values, and interobserver agreement in the diagnosis of pulmonary embolism with helical CT, compared with pulmonary angiography, for both global results and for selective vascular territories. Helical CT and pulmonary angiography were performed on 66 consecutive patients with clinical suspicion of pulmonary embolism. The exams were blindly interpreted by a vascular radiologist and by two independent thoracic radiologists. Results were analyzed for the final diagnosis as well as separately for 20 different arterial territories in each patient. Pulmonary angiography revealed embolism in 25 patients (38%); 48% were main, 28% lobar, 16% segmental, and 8% subsegmental. The sensitivity, specificity, and positive and negative predictive values of helical CT for observer 1 were, respectively, 91, 81.5, 75, and 94%; in 7.5% of the patients the exam was considered indeterminate. For observer 2 the values were, respectively, 88, 86, 81.5, and 91%; in 9% of the patients the exam was considered indeterminate. Main arteries were considered as non-valuable in 0–0.8%, the lobar in 1.5%, the segmental in 7.5–8.5%, and the subsegmental in 55–60%. Interobserver agreement for the final diagnosis was 80% (kappa 0.65). For each vascular territory, this was 98% (kappa 0.91) for main arteries, 92% (kappa 0.78) for lobar arteries, 79% (kappa 0.56) for segmental arteries, and 59% (kappa 0.21) for subsegmental arteries. Helical CT is a reliable method for pulmonary embolism diagnosis, with good interobserver agreement for main, lobar, and segmental territories. Worse results are found for subsegmental arteries, with high incidence of non-valuable branches and poor interobserver agreement. Electronic Publication     

Interobserver agreement in the diagnosis of pulmonary embolism with helical CT

PURPOSE: Our objective was to asses the interobserver agreement in the detection of pulmonary embolism (PE) with contrast-enhanced helical CT at the main pulmonary, lobar and segmental arteries. A prospective study was carried out in 51 patients with suspected PE. Finally, 29 patients were diagnosed of PE. SUBJECTS AND METHODS: All patients were studied with helical CT. Images (5 mm collimation, 1.5 pitch factor, 3 mm reconstruction interval) were obtained after bolus contrast injection (120 ml, 4 ml/s, 15 s delay time). All cases were blinded and independently interpreted in three ways: two radiologists with different level of expertise and two expert radiologists reading by consensus. Agreement was evaluated by means of the kappa test. RESULTS: Kappa values for thrombi detection expressed an excellent agreement at the main (between 0.802 and 0. 946), lobar (between 0.915 and 0.958) and segmental (between 0.879 and 0.718) levels. For all vessels, mean kappa values were similar and excellent for all three combinations of readers. Arteries with more discrepancies were located mainly at the anterior and posterior areas of the upper lobes. CONCLUSIONS: The high degree of agreement shown in this study indicates that helical CT is a reproducible test in the diagnosis of PE to the segmental level. Isolated readings and levels of expertise do not influence agreement.     

多层螺旋CT肺血管造影对肺栓塞解剖分布及形态的评价

目的 评价肺栓塞（PE）在多层螺旋CT肺血管造影（CTPA）上的解剖位置分布及形态特点. 资料与方法 75例PE患者作CTPA,由两名有经验的放射科医师阅片,根据血栓在最大肺血管分支内的位置分为5型：肺动脉干型、左或右肺动脉型、肺叶动脉型、肺段动脉型和肺亚段动脉型;同时观察血栓在血管内的形态. 结果 75例PE中,肺动脉干型6例（8%）,左或右肺动脉型12例（16%）,肺叶动脉型28例（37.3%）,肺段动脉型19例（25.3%）和肺亚段动脉型10例（13.3%）.PE形态为：中央型51例（68%）,附壁型7例（9.3%）,闭塞型17例（22.7%）. 结论 CTPA可准确、清晰地显示PE的解剖位置分布及形态,能提高小PE的检出率,为临床治疗方案的选择提供依据.     

Intraindividual comparison of gadolinium- and iodine-enhanced 64-slice multidetector CT pulmonary angiography for the detection of pulmonary embolism in a porcine model

This study is an evaluation of the diagnostic accuracy of gadolinium-enhanced computed tomography pulmonary angiography (CTPA) for the detection of pulmonary embolism (PE) in comparison with iodine-enhanced CTPA. PE was induced in five anesthetized pigs by administration of blood clots through an 11-F catheter inside the jugular vein. Animals underwent CTPA in breathhold with i.v. bolus injection of 50 ml gadopentetate dimeglumine (0.4 mmol/kg, 4 ml/s). Subsequently, CTPA was performed using the same imaging parameters but under administration of 70 ml nonionic iodinated contrast material (400 mg/ml, 4 ml/s). All images were reconstructed with 1 mm slice thickness. A consensus readout of the iodium-enhanced CTPAs by both radiologists served as reference standard. Gadolinium-enhanced CTPAs were evaluated independently by two experienced radiologists, and differences in detection rate between both contrast agents were assessed on a per embolus basis using the Wilcoxon signed-rank test. Interobserver agreement was determined by calculation of қ values. PE was diagnosed independently by both readers in all five pigs by the use of gadolinium-enhanced CTPA. Out of 60 pulmonary emboli detected in the iodine-enhanced scans, 47 (78.3%; reader 1) and 44 (62.8%; reader 2) emboli were detected by the use of gadolinium. All 13 (100%) emboli in lobar arteries (by both readers) and 26 (reader 1) and 25 (reader 2) out of 27 emboli (96.3% and 92.6%) in segmental arteries were detected by the use of the gadolinium-enhanced CTPA. In subsegmental arteries, only 8 (40%; reader 1) and 6 (30%; reader 2) out of 20 emboli were detected by the gadolinium-enhanced CTPA. By comparing both scans on a per vessel basis (Wilcoxon test), Gd-enhanced CTPA was significantly inferior in emboli detection on subsegmental level (P < 0.0001). The interobserver agreement was excellent on lobar and segmental level (қ = 1.0 and 0.93, respectively), whereas readers only reached moderate agreement for PE evaluation on subsegmental level (қ = 0.56). Compared to conventional CTPA with iodinated contrast media, gadolinium-based contrast agents achieve an equivalent diagnostic accuracy in detection of PE down to segmental level. Gadolinium-enhanced CTPA may be considered as an alternative for the diagnostic workup of acute pulmonary embolism in patients with contraindications to iodinated contrast agents.     

Pulmonary embolism: optimization of small pulmonary artery visualization at multi-detector row CT

PURPOSE: To compare the frequency of well-visualized pulmonary arteries according to anatomic level by using different collimation with single- and multi-detector row computed tomography (CT) in patients suspected of having acute pulmonary embolism. MATERIALS AND METHODS: Sixty patients were examined with one of three techniques (20 patients each). Group 1 was examined with single-detector row CT with 3-mm collimation and 1.3-1.6 pitch; groups 2 and 3, with multi-detector row CT with 2.5- and 1.25-mm collimation, respectively. Three thoracic radiologists independently reviewed examination findings to determine if each main, lobar, segmental, and subsegmental artery was well visualized for presence of pulmonary embolism. chi2 tests were performed. For well-visualized vessels, the presence and/or absence of pulmonary embolism was recorded and kappa statistic was determined. RESULTS: Reader 1 scored 95% (114 of 120), 96% (115 of 120), and 99% (119 of 120) of lobar arteries (P >.05); 76% (304 of 400), 86% (346 of 400), and 91% (363 of 400) of segmental arteries (P <.001); and 37% (300 of 800), 56% (448 of 800), and 76% (608 of 800) of subsegmental arteries as well visualized (P <.001) using techniques 1, 2, and 3, respectively. Reader 2 scored 97% (116 of 120), 95% (114 of 120), and 99% (119 of 120) of lobar arteries (P >.05); 77% (308 of 400), 87% (349 of 400), and 93% (371 of 400) of segmental arteries (P <.001); and 39% (310 of 800), 53% (422 of 800), and 78% (621 of 800) of subsegmental arteries (P <.001) as well visualized using techniques 1, 2, and 3, respectively. Reader 3 scored 86% (103 of 120), 82% (98 of 120), and 91% (109 of 120) of lobar arteries (P >.05); 63% (252 of 400), 70% (280 of 400), and 85% (339 of 400) of segmental arteries (P <.001); and 39% (310 of 800), 56% (451 of 800), and 71% (572 of 800) of subsegmental arteries (P <.001) as well visualized using techniques 1, 2, and 3, respectively. Sixteen patients had pulmonary embolism. Interobserver agreement for detection of pulmonary embolism was significantly better for segmental and subsegmental arteries for all readers with technique 3 (segmental, kappa = 0.79-0.80; subsegmental, kappa = 0.71-0.76) than that with technique 1 (segmental, kappa = 0.47-0.75; subsegmental, kappa = 0.28-0.54). CONCLUSION: Multi-detector row CT at 1.25-mm collimation significantly improves visualization of segmental and subsegmental arteries and interobserver agreement in detection of pulmonary embolism.     

Waiting to exhale: salvaging the nondiagnostic CT pulmonary angiogram by using expiratory imaging to improve contrast dynamics

We attempted to investigate whether computed tomography pulmonary angiography (CTPA) in the expiratory phase can improve contrast enhancement of the pulmonary arteries and mitigate the effect of inspiratory transient attenuation artifact, potentially salvaging nondiagnostic studies. Eighteen patients with indeterminate inspiratory CTPA, despite proper contrast bolus were studied. Patients were rescanned in expiration using the same contrast bolus and scanning parameters. The attenuation of each pulmonary arterial segment, superior and inferior vena cava, and atria and ventricles during the two phases of respiration was measured independently by three radiologists. All pulmonary segments were evaluated for filling defects during the two phases. In addition, the studies were graded for diagnostic quality of enhancement and probable impact on management. A statistically significant increase in pulmonary arterial enhancement was seen during expiration from the pulmonary trunk to the segmental pulmonary arteries (P < 0.001) and for the inferior vena cava, the right atrium, and the ventricle. The incidence of nondiagnostic inspiratory studies ranged from 89 to 100%, depending on the observer. All studies were upgraded to fully acceptable diagnostic quality with follow-up expiratory imaging (P < 0.0001). Expiratory phase imaging was observed to have diagnostic impact in 78 to 88% of cases, with overall good to moderate interobserver agreement. In one case, pulmonary embolism was detected on the expiratory scan, which was not seen on the inspiratory scan. Expiratory imaging for nondiagnostic CTPA improves pulmonary arterial enhancement and improves diagnostic quality of CTPA by eliminating transient attenuation artifact, thus facilitating more accurate diagnosis and providing earlier treatment of pulmonary embolism.     

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.     

多层螺旋CT肺血管造影不同重组间距在肺栓塞诊断中的应用

目的 探讨多层螺旋CT血管造影(MSCTA)不同重组间距在肺动脉栓塞(pulmonary embolism,PE)中的诊断价值.资料与方法 对36例经MSCTA检查的PE患者分别行10%、50%、70%横断位重叠重组,并将上述不同重组间距的横断位图像分别进行多平面重组(MPR).比较不同重组间距的横断位图像及MPR图像对肺动脉栓子的显示情况.结果 36例PE患者病变共累及肺动脉298支.对于主肺动脉及肺叶动脉柃塞,3种重组间距的横断位及对应的MPR图像栓子检出结果一致.但对于肺段及亚段动脉栓塞的显示,50%和70%重组间距的图像优于10%,差异有统计学意义(P<0.01),50%与70%重组间距的图像间差异无统计学意义(P>0.05).结论 MSCTA 50%重组间距较10%重组间距的横断位图像能明显提高肺段、亚段PE的显示率,而进一步提高重组间距到70%意义不大.     

Evaluation of pulmonary embolisms using coronal reformations on 64-row multidetector-row computed tomography: Comparison with axial images

OBJECTIVE: To evaluate coronal reformations of the chest on 64-row multidetector-row computed tomography (MDCT) for detection of pulmonary embolisms compared with axial images. METHODS: Thirty-eight consecutive patients who underwent pulmonary computed tomography angiography (CTA) on 64-row MDCT for a suspected pulmonary embolism were retrospectively studied. Contiguous 2-mm axial and coronal images were reviewed independently. A pulmonary embolism was assessed in the main, lobar, or segmental pulmonary arteries and was scored using a 5-point scale. RESULTS: A pulmonary embolism was demonstrated in 10% (4 of 38) of axial images and 16% (6 of 38) of coronal images. Interpretation was concordant in 95% to 100% of cases for a main or lobar pulmonary embolism and in 80% to 82% of cases for a segmental pulmonary embolism. Agreement of scores was almost perfect for a a main or lobar pulmonary embolism (mean weighted kappa value = 0.969) and moderate to good for a segmental pulmonary embolism (mean weighted kappa value = 0.560). CONCLUSION: Coronal reformations of the chest on 64-row MDCT were as informative as axial images for the detection of main, lobar, and segmental pulmonary embolisms.