Unresolved major pulmonary embolism: importance of follow-up lung scan in diagnosis

Unresolved major pulmonary embolism (UMPE) is an uncommon condition which causes pulmonary hypertension, cor pulmonale and death. An accurate and prompt diagnosis of UMPE is very important in the management of such patients with pulmonary embolectomy. Follow-up lung scans can lead to earlier diagnosis of UMPE, especially in patients who have a history of acute pulmonary embolism and present with pulmonary hypertension, respiratory insufficiency and cor pulmonale. We report a case of UMPE strongly suggested by follow-up lung scans and subsequently confirmed by pulmonary angiography and postmortem examination.     

超声检查对肺栓塞的诊断价值探讨

目的:探讨超声对肺栓塞(pulmonary embolism,PE)患者的临床诊断价值。方法:回顾性分析9例经临床确诊的PE患者,其彩色多普勒超声心动图和静脉血管超声的改变。结果:血管超声检查9例患者中有7例发现下肢静脉血栓,l例发现盆底静脉血栓。超声心动图检查6例患者发现右心室扩大,7例患者存在不同程度的肺动脉高压。结论:超声心动图及静脉超声检查的联合应用,可以为PE的临床诊断提供依据。     

64层CT肺动脉造影对肺栓塞诊断及治疗后复查的应用研究

目的:探讨64层CT肺动脉造影(CTPA)对肺栓塞的诊断效果及治疗后复查的价值。方法:对32例肺动脉栓塞的患者采用64层CT行CTPA检查,并进行多平面重建(MPR)、最大密度投影及容积重建处理。患者复查采用相同CT检查及后处理重建。结果:32例患者中15例有下肢静脉栓塞、4例有恶性肿瘤、3例有近期手术病史,2例有近期外伤史。CTPA对肺动脉主干、左右肺动脉及叶、段、亚段动脉显示良好,32例患者中显示受累肺动脉221支,其直接征象为肺动脉血管内充盈缺损,间接征象包括肺梗死实变、肺野少血征、胸腔积液等。肺栓塞治疗后复查有24例患者1月内肺动脉栓子消失或明显吸收缩小(占75%);6例患者吸收不明显(占18.7%);2例死亡。结论:64层CT能清楚地显示肺栓塞的形态、部位及其它间接征象,并能有效监测治疗效果,为临床提供有益帮助。     

99 Tcm-MAA肺显像对深静脉血栓患者无症状肺栓塞的应用

目的　用99Tcm 大颗粒聚合白蛋白 (MAA)肺灌注显像研究肾病综合征伴下肢深静脉血栓患者的无症状肺栓塞发病情况。方法　 75例肾病综合征伴下肢深静脉血栓而无任何肺部疾病临床症状的患者 ,均经临床和超声检查证实。所有患者同时进行99Tcm MAA下肢静脉和肺灌注显像 ,其中 45例并行99Tcm DTPA肺通气显像。结果　① 75例患者中有 83% (62例 )发生下肢窝静脉以下血栓 ;②99Tcm MAA肺灌注显像示 61% (4 6例 )患者发生肺栓塞 (2 8例为单侧肺栓塞 ,18例为双侧肺栓塞 ) ;③ 45例患者99Tcm DTPA肺通气显像未见异常。结论　大部分肾病综合征下肢深静脉血栓患者伴有无症状性肺栓塞 ;对下肢深静脉血栓患者肺显像应作为常规检查     

D-二聚体在肺栓塞疾病诊断中的应用研究

目的：探讨肺栓塞患者中血浆D-二聚体（DD）含量的变化,为肺栓塞疾病（PE）的早期诊断提供依据。方法：采用免疫比浊法检测肺栓塞住院患者和非肺栓塞患者D-二聚体的含量。结果：肺栓塞患者血浆D-二聚体（DD）含量均值为（3.01±2.81）μg/ml,非肺栓塞患者为（1.11±0.90）μg/ml,前者显著高于后者（P〈0.01）。结论：血浆D-二聚体测定可作为诊断肺栓塞疾病的重要指标之一,特别对于临床低概率肺栓塞疾病的排查具有非常重要的临床价值。     

双源CT肺动脉成像在肺动脉栓塞诊断中的应用价值

目的:探讨双源CT肺动脉成像对肺动脉栓塞(PE)的诊断价值.方法:对58例临床拟诊为PE的患者行双源CT肺动脉成像,总结PE的直接、间接征象及分型,并比较MPR、MIP、VR和CTVE对肺动脉栓子的显示效果.结果:直接征象:58例中45例诊断为PE,共发现栓子 658支(中心型170支,偏心型208支,附壁型74支,完...     

Is the lung scan alive and well? Facts and controversies in defining the role of lung scintigraphy for the diagnosis of pulmonary embolism in the era of MDCT

Purpose  The last decade has seen a changing pattern of utilization of multidetector CT (MDCT) versus lung perfusion scintigraphy in the investigation of pulmonary venous thromboembolism (VTE). In response to this the International Atomic Energy Agency (IAEA) determined that the subject required an overview. Method  The IAEA has invited a group of five specialists in the relevant fields to review the current status and optimum role of scintigraphy, to explore some of the facts and controversies surrounding the use of both modalities and to make recommendations about the continued role of nuclear medicine for the investigation of pulmonary embolism. This paper identifies the relative merits of each technique, highlights benefits, focuses on complementary roles and seeks a nonadversarial symbiosis. Conclusion  The consultants reached a consensus that the continued use of scintigraphy for diagnosis of thromboembolic disease is recommended, particularly in scenarios where scintigraphy confers specific benefits and is complementary to MDCT. An Editorial Commentary to this paper is available at .     

The value of lung scintigraphy in the diagnosis of pulmonary embolism

The role of lung scintigraphy in the diagnostic management of patients with clinically suspected pulmonary embolism is reviewed. Evidence is provided that a normal perfusion scan excludes clinically relevant pulmonary embolism, and that a high probability lung scan, defined as a segmental perfusion defect with locally normal ventilation, sufficiently confirms the presence of pulmonary embolism in the majority of these patients. Furthermore, this review assesses the possibility of non-invasive tests for the diagnosis or exclusion of venous thromboembolic disease as a means of avoiding pulmonary angiography in patients with lung scan outcomes that are neither normal nor high probability.E.J.R. van Beek is the recipient of a grant from the Netherlands Health Executive Insurance Board (OG91-036). H.R. Büller is the recipient of a fellowship of the Royal Netherlands Academy of Arts and Sciences. Correspondence to: E.J.R. van Beek     

Multislice CT imaging of pulmonary embolism

In recent years CT has been established as the method of choice for the diagnosis of central pulmonary embolism (PE) to the level of the segmental arteries. The key advantage of CT over competing modalities is the reliable detection of relevant alternative or additional disease causing the patient's symptoms. Although the clinical relevance of isolated peripheral emboli remains unclear, the alleged poor sensitivity of CT for the detection of such small clots has to date prevented the acceptance of CT as the gold standard for diagnosing PE. With the advent of multislice CT we can now cover the entire chest of a patient with 1-mm slices within one breath-hold. In comparison with thicker sections, the detection rate of subsegmental emboli can be significantly increased with 1-mm slices. In addition, the interobserver correlation which can be achieved with 1-mm sections by far exceeds the reproducibility of competing modalities. Meanwhile use of multislice CT for a combined diagnosis of PE and deep venous thrombosis with the same modality appears to be clinically accepted. In the vast majority of patients who receive a combined thoracic and venous multislice CT examination the scan either confirms the suspected diagnosis or reveals relevant alternative or additional disease. The therapeutic regimen is usually chosen based on the functional effect of embolic vascular occlusion. With the advent of fast CT scanning techniques, also functional parameters of lung perfusion can be non-invasively assessed by CT imaging. These advantages let multislice CT appear as an attractive modality for a non-invasive, fast, accurate, and comprehensive diagnosis of PE, its causes, effects, and differential diagnoses.     

MR灌注成像在肺栓塞诊断中的应用

目的探讨MR二维快速扰相梯度回波序列（2DFSPGR）显示肺实质灌注的可能性,以及在实验性肺栓塞中的应用价值。方法11只在体犬肺栓塞模型在平静呼吸下行肺MR灌注扫描,定性及定量评价图像质量,与病理解剖对照分析肺灌注扫描诊断肺栓塞的敏感性。结果10只犬的MR图像质量为优良,可显示肺实质灌注情况,平均信号/噪声比（SNR）为67.4±18.0,对比度/噪声比（CNR）为40.9±14.2。正常灌注区的信号强度平均值为39.7±5.1,灌注不良区域信号强度平均值为15.6±2.1,灌注不良区域时间-强度曲线表现为峰值下降或曲线平直。结论MR肺灌注成像是诊断肺栓塞的可行方法。     

肺灌注/通气显像与肺动脉造影诊断肺动脉栓塞的对比研究

目的评价核素肺通气/灌注(V/Q)显像在肺动脉栓塞(PE)诊断中的价值。方法临床疑有PE患者30例,男女各15例,平均年龄(38.2±13.9)岁。均行胸部X线片检查、核素V/Q显像和肺动脉造影。11例患者在行肺灌注显像时,选择双侧足背静脉注射肺灌注显像剂,同时完成双下肢静脉显像。结果30例患者中22例V/Q显像示不相匹配的肺叶、肺段或多发亚肺段的放射性分布稀疏或缺损,提示为PE;但肺动脉造影证实22例中20例为PE。8例患者的V/Q显像为相匹配的肺叶、肺段或多发亚肺段的稀疏或缺损,提示不是PE,与肺动脉造影结果一致。核素V/Q显像诊断PE的灵敏度为100%（20/20例）,特异性为80.0%（8/10例）,准确性为93.3%（28/30例）。X线胸片和核素下肢静脉显像有助于PE的正确诊断。结论多数PE患者通过核素肺V/Q显像结合X线胸片可以作出明确诊断,少数肺V/Q显像与临床表现不符的患者需行肺动脉造影。     

肺灌注/通气显像与肺动脉造影诊断肺栓塞的对比分析

目的：评价肺灌注／通气显像诊断肿栓塞的价值。方法：回顾性分析45例疑肺栓塞患者的肺核素显像结果，并与肺动脉造影检查对照。结果：肺动脉造影诊断为肺栓塞的患者26例，有180个肺动脉支为充盈缺损，其肺灌注显像示167个节段呈完全肺段性或亚肺段缺损，符合率为92．7％。肺动脉造影显示为86个肺动脉支为部分充盈缺损，肺灌注显像有63个肺段或亚肺段缺损，符合率为73．2％（P＜0．01）。肺核素显像对肺栓塞诊断的灵敏度为92．3％，特异性为84．2％，阳性预测值和阴性预测值均为88．9％。26例肺动脉造影诊断为肺栓塞的患者，有23例行肺通气显像，通气／灌注均不匹配。结论：肺灌注／通气显像对肺栓塞诊断具有重要的临床价值。     

双源CT双能量肺灌注成像对肺栓塞的初步研究

目的 探讨双源CT双能量扫描肺灌注成像的临床诊断价值.方法 选择临床怀疑肺动脉栓塞30例患者行双源CT双能量扫描,生成140、80 kV和融合系数为0.3的3组数据.根据融合数据的CT肺动脉造影(CTPA)图像将患者分为肺栓塞组和正常组.采用双能量评估软件将薄层重建数据进行灌注成像分析,将双肺野分为上、中、下3部分,正常组受试者肺组织灌注定量的双侧比较行配对t检验,2组间肺组织灌注量比较行独立样本t检验,并对融合图像行MinIP,评估肺组织通气情况.结果 正常组(16例)肺灌注均匀,无明显灌注缺损及减弱,灌注定量分析显示左、右全肺的灌注量分别为(27±7)、(28±8)HU,两侧比较差异无统计学意义(t=-1.73,P＞0.05);左肺上、中、下部的灌注量分别为(23±6)、(24±6)、(28±8)HU,右肺上、中、下部灌注量分别为(26±8)、(27±8)、(28±9)HU,两侧分别比较差异均无统计学意义(t值分别为-1.91、-1.96、-1.73,P值均＞0.05).肺栓塞组(14例)CTPA图像显示肺动脉干、段及亚段充盈缺损,肺灌注成像表现为栓塞血管所支配肺野区域的灌注缺损或缺失,灌注定量分析显示全肺及中、下肺的灌注量分别为(22±5)、(22±8)、(21±8)HU,与正常组分别比较差异均有统计学意义(t值分别为-2.10、-2.32、-2.63,P值均＜0.05＝.MinIP显示通气异常区与灌注异常区具有良好的一致性.结论 双源CT双能量扫描可用于肺栓塞的诊断,有利于肺栓塞的早期发现和精确解剖定位.

Abstract：

Objective To explore the diagnostic values of dual energy lung perfusion in the diagnosis of pulmonary embolism by using dual-source CT (DSCT). Methods Thirty patients with clinically suspected pulmonary embolism underwent dual-energy scanning with dual-source CT. The scanned data were integrated into three groups including 140, 80 kV and coefficient of 0.3. According to the CT pulmonary angiography (CTPA) of the fusion data, the patients were divided into pulmonary embolism group and normal group. The thin-slice reconstruction of data was analyzed using dual-energy perfusion imaging analysis software. The lung field was divided into upper, middle and lower part to make quantitative analysis of lung tissue perfusion. Paired t-tests were used in the normal patients to compare bilateral lungs, and independent samples t-tests were applied to compare the embolism group and normal group, while minimum intensity projection images (MinIP) were utilized in the assessment of lung ventilation. Results Dual energy CT showed symmetrical homogeneous perfusion in 16 normal cases, without significant perfusion defects. Quantitative analysis showed that left and right lung perfusion were (27 ± 7) and (28 ± 8 ) HU respectively, and no significant difference was found between the two sides ( t=-1.73, P ＞0.05 ).Perfusion of the left upper, middle and lower lung was ( 23 ± 6), (24 ± 6), and (28 ± 8) HU respectively, while the perfusion of right upper, middle and lower lung was (26 ±8), (27 ±8), and (28 ±9) HU respectively, showing no statistical significant difference between the two sides (t=-1.91, -1.96,-1.73 ,P＞0.05 ). Angiography of pulmonary embolism group(14 cases)showed filling defects in the pulmonary trunk, segments and sub-segments. Pulmonary perfusion imaging showed low perfusion or defectsin lung field that dominated by embolic vessels. Quantitative analysis showed that the perfusion of the whole lung and the middle and lower lung were (22 ±5), (22 ±8), and (21 ±8) HU in the embolism group,which were significantly different from the normal group (t=-2. 10, -2.32, -2.63, P＜0.05).Minimum intensity projection images showed a good consistency of abnormal ventilation zone area and perfusion abnormalities. Conclusions Pulmonary perfusion status, especially pulmonary embolism, can be analyzed by dual energy CT scanning. It helps to early discover and precisely locate the embolism.     

CT动脉造影对肺动脉栓塞诊断价值的Meta分析

目的 对以肺动脉造影为金标准，研究CT肺动脉造影(CTPA)诊断肺动脉栓塞(PE)的文献进行Meta汇总分析，评价CTPA对PE的临床诊断价值。方法 检索Cochrane图书馆、PubMed，OVID数据库和中国期刊网中的英文和中文文献，按照Cochrane协作网推荐的诊断试验的纳入标准筛选文献，并对纳入文献进行质量评估，提取纳入研究的特征信息。数据分析采用Meta-Test version0．9软件，检验异质性，并根据异质性结果选择相应的效应模型。对所有研究予以加权定量合并，计算灵敏度和特异度及其95％可信区间。绘制汇总受试者工作特征曲线(SROC)，并计算曲线下面积。最后进行敏感性分析。结果 共纳入10篇英文文献，其中7篇为A级，3篇为B级。研究对象共计855人，CTPA诊断PE的灵敏度的范围是0．57～1．00，特异度的范围是0．78～1．00。纳入研究存在异质性。按照随机效应模型计算汇总灵敏度和特异度及95％可信区间分别为0．84(0．73，0．91)和0．91(0．87，0．94)。SROC曲线下面积为94．95％。纳入文献稳定性好。结论 汇总目前关于CTPA诊断PE的研究显示，CTPA是一种灵敏度和特异度较高的无创性检查方法，还需要高质量的前瞻性研究以更准确地评价其临床价值。     

放射性核素肺显像与螺旋CT诊断急性肺栓塞的对比研究

目的 比较肺通气／灌注（V／Q）显像与多层螺旋CT肺动脉造影（CTPA）在诊断急性肺动脉血栓栓塞症（PTE）方面的临床价值。方法 前瞻性分析2005年10月～2006年5月共51例临床疑诊急性PTE患者的肺灌注显像，其中18例行肺通气显像，并与CTPA对比。以汇总所有临床资料、各实验室检查及影像学检查后讨论得出的最终诊断作为“标准”。结果 最终24位患者被诊断为PTE占47．1％（24／51例），V／Q显像与CTPA的灵敏度分别为95．8％（23／24例）和95．8％（23／24例），特异性分别为88．9％（24／27例）和92．6％（25／27例），准确性分别为92．2％（47／51例）和94．1％（48／51例）。在定性诊断方面，2种影像学检查结果差异无统计学意义（χ^2=0．14，P=0．71），两者定性诊断符合率为86．3％（44／51例），Kappa值为0．73。24例PTE患者中，CTPA显示为“完全阻塞”的肺动脉血管所对应的44个肺段中，肺灌注显像显示为“放射性稀疏、缺损”的肺段数为32个（72．7％）；CTPA显示为“部分充盈缺损”的肺动脉血管所对应的266个肺段中，肺灌注显像显示为“放射性稀疏、缺损”的肺段数为155个（58．3％），显示为“亚肺段放射性稀疏、缺损”的肺段数为9个（3．4％）。结论 V／Q显像与CTPA在PTE定性诊断方面符合率高，一致性好，但在定位方面存在差异；两者为互补关系。     

Non-traumatic thoracic emergencies: CT diagnosis of acute pulmonary embolism: the first 10 years

Over the past 10 years, spiral CT angiography of the pulmonary arteries has reached a high accuracy in the evaluation of pulmonary embolism. Major advantages of CT compared with ventilation/perfusion lung scintigraphy and pulmonary angiography is direct visualization of clots in the pulmonary arteries, and to provide alternative findings or diagnosis. The recent introduction of multislice CT has improved the evaluation of peripheral pulmonary arteries, enabling high-resolution CT examinations over the entire thorax in a short breathhold. The examination techniques, imaging findings, pitfalls, and results of CT in the diagnosis of pulmonary embolism are reviewed in comparison with other diagnostic tests.     

双能量CT肺灌注及血管成像与核素肺通气灌注成像诊断肺栓塞的对照研究

目的 通过与核素肺通气灌注显像比较,评价双能量CT肺血管成像(DE-CTPA)及双能量CT肺灌注成像(DE-CTLP)技术诊断肺栓塞的能力.方法 比较50例临床怀疑肺栓塞的患者DE-CTPA、DE-CTLP及核素肺通气灌注显像结果,以非线性相关检验比较DE-CTPA显示肺血管腔内充盈缺损与DE-CTLP显示灌注缺损之间的相关性,以核素为参考标准,应用一致性检验方法(Kappa检验)对照分析两者之间的一致性及DE-CTLP诊断肺栓塞的敏感性和特异性.结果 (1)50例临床怀疑肺栓塞患者中,4例CT图像质量差,不能评价.余46例共920个有效肺段中,DE-CTPA显示262个肺段肺血管腔内充盈缺损,DE-CTLP显示266个肺段明确灌注缺损.核素肺通气灌注扫描显示268个肺段灌注与通气不匹配.(2)DE-CTLP与DE-CTPA两者间显著相关(r=0.883,P<0.01);DE-CTLP与核素肺通气灌注显像的一致性良好(Kappa=0.940,P<0.01);以核素肺通气灌注成像为诊断参考标准,应用DE-CTLP诊断肺栓塞的阳性预测值95.5%(279/292),阴性预测值98.3%(641/652),敏感性96.2%(279/290),特异性98.0%(641/654).(3)应用CareDose 4D技术,DE-CTPA和DE-CTLP患者平均射线损伤剂量为(4.37±0.47)mSv.结论 应用DE-CTPA和DE-CTLP技术可以在一次扫描中同时获得常规CT肺血管成像的血管形态学信息和肺实质血流灌注情况,为临床诊断肺栓塞提供直观、有效的综合影像信息.     

The value of pulmonary angiography for the differential diagnosis of pulmonary embolism

The aim this study was to evaluate potential additional information of pulmonary angiography in patients with suspected pulmonary embolism and non-diagnostic lung scan findings. In a series of 150 patients who underwent pulmonary angiography for suspected venous thromboembolism, the images for potential alternative diagnoses other than pulmonary embolism were evaluated. All patients had non-diagnostic lung scan findings. Angiography was performed both by conventional and by digital subtraction angiography techniques. Images were evaluated by at least two experienced readers. Angiograms were scored for both presence or absence of pulmonary embolism, as well as other diagnoses. Pulmonary embolism was proven in 40 patients (27 %) and excluded in 105 patients (70 %), whereas non-interpretable images were obtained in 5 patients (3 %). A range of alternative diagnoses were detected by angiography: atelectasis (n = 24), pleural effusion (n = 15), pneumonia (n = 11), emphysematous bullae (n = 8), neoplasm (n = 3), atrial septum defect (n = 2), chronic thromboembolism (n = 1), and other diagnoses (n = 3). Overall, only 54 patients (36 %) had completely normal angiograms. Although pulmonary angiography remains the reference method for the diagnosis of pulmonary embolism, one has to be aware of other, often unexpected, but equally important findings which could influence the management of the patient. This aspect of pulmonary angiography has been insufficiently emphasized in the literature. Received: 2 April 1998; Revision received: 22 July 1998; Accepted: 4 November 1998     

脓毒性肺栓塞的多层螺旋CT诊断

目的 探讨脓毒性肺栓塞的多层螺旋CT(MSCT)表现,以提高对该病的认识.方法 回顾性分析12例脓毒性肺栓塞MSCT表现,并与X线胸片比较.结果 所有12例患者,X线胸片和CT表现比较,分别见结节(8、12例),滋养血管征(0、9例),空洞(6、10例),楔形阴影(4、7例),局灶浸润影(2、4例),气囊(2、5例)及胸腔积液、脓胸(3、6例),肺门或纵隔淋巴结肿大(0、3例).发现病灶分布在外周或胸膜下分别为8和12例,CT较X线胸片可更清晰地显示病灶.多平面重组(MPR)、最大密度投影(MIP)显示大多数滋养血管环绕结节周围,MPR显示结节边缘规整.结论 脓毒性肺栓塞的CT表现多样,但MIP、MPR能更好显示滋养血管征及结节的特征.     

Complementarity of lung scintigraphy and D-dimer test in pulmonary embolism

D-dimer assay (DDA), measuring fibrin degradation products, was compared with lung scintigraphy (LS) in a prospective unselected series of 83 consecutive patients referred owing to suspicion of pulmonary embolism (PE). This patient series was also used to compare several methods of performing and interpreting LS images. The final diagnosis was established independently by a separate panel with all available information except for the result of DDA. D-dimer was determined by ELISA (threshold value 500 ng/ml). LS, including perfusion (Q) and pseudo-ventilation (Technegas) (V), was classified according to PIOPED, (1) immediately by the physician on duty, and (2) retrospectively by a blinded panel. A positive (19) or negative (61) diagnosis of PE was achieved in 80 patients, the prevalence of PE being 24%. Only one false-negative was noted on DDA (sensitivity=95%) but there were 42 false-positives (specificity=31%), resulting in a positive predictive value of 30% and a negative predictive value of 95%. Emergency and retrospective interpretations of LS were close (kappa=0.4). In a minority of patients, PE may be excluded with reasonable certainty if DDA is normal, resulting in a significant saving in terms of time and money.