急性肺栓塞CT肺动脉成像的研究进展

目前,CT肺动脉成像（CTPA）被认为是临床诊断急性肺栓塞（PE）的“金标准”。CTPA为诊断急性外周性PE提供了多方面的依据。但CTPA诊断急性外周性PE仍存在较大困难。目前CT辐射剂量及对比剂负荷为研究热点。本文对急性PE的CTPA诊断（尤其是外周性PE）、预后评估、CTPA技术进展等进行综述。     

Value of CT pulmonary angiography to predict short-term outcome in patient with pulmonary embolism

To evaluate the role of CT pulmonary angiography (CTPA) in the assessment of pulmonary embolism (PE) severity and the related CT cardiac changes, reflecting the clinical status of the patients and predicting the outcome. A prospective study of 184 patients presented with suspicious acute PE. All patients underwent CTPA followed by ECHO. Pulmonary artery obstructive index (PAOI) using Qanadli Score was calculated and cardiac changes recorded. The patients’ outcome was followed up for 30 days. Only 150 patients completed the study; 26.7% needed ICU admission while 13.3% died during follow-up. There was a significant relationship between the PAOI and the risk classification, right ventricular dysfunction (RVD) diagnosed by ECHO and the patients’ short outcome. We found PAOI cut off value 45% for mortality and 35% for ICU admission and 27.5% for RVD with 60, 75 and 90% sensitivity and 80, 73.3 and 68.6% specificity respectively. CT RV/LV ratio was the most sensitive parameter to predict RV dysfunction followed by pulmonary artery diameter. CTPA is not only used for diagnosis but also to assess the severity of PE, the effect on the right ventricular function and subsequently the need for ICU admission and prediction of the outcome.     

急性肺血栓栓塞的多排螺旋CT诊断

目的探讨多排螺旋CT对急性肺血栓栓塞(PE)的诊断价值.方法对临床怀疑急性PE的21例患者采用多排螺旋CT行薄层肺动脉造影(CTPA)及间接法深静脉造影(CTV).结果 CTPA检出12例急性PE,间接法CTV检出深静脉血栓8例.1 mm有效层厚图像对段、亚段肺动脉及其内血栓的显示高于3 mm有效层厚图像(P<0.05).结论多排螺旋CT能促进急性PE的诊断.     

肺栓塞36例急诊误诊临床分析

目的提高急诊科医生对肺血栓栓塞（pulmonary thromboembolism,FFE）的认识,探索急诊可行的PrE诊断程序．以提高本病早期确诊率。方法回顾性分析近5年来我院急诊误诊的36例FTE的临床资料,并进行改良Geneva评分评估临床诊断可能性。结果本组36例误诊为心血管疾病25例（69．4％）,误诊为其他呼吸系统疾病9例（25％）,误诊为脑血管疾病2例（5．6％）,其中30例（83．3％）有易患因素。进行改良Geneva评分显示FFE中度可能性26例,低度可能性10例。查D-二聚体36例均升高,后经螺旋CT肺动脉造影（CTPA）确诊32例、肺通气灌注扫描确诊4例,均予抗凝治疗好转出院。结论PTE临床易误漏诊,急诊科医生应加强对奉病的认识,接诊PTE疑诊患者应洵刚有尤易患因索,通过改良Geneva评分进行诊断可能性评估,结合血D-二聚体检测,必要时臼丁行CTFA等,以提高确诊率。     

64层螺旋CT肺动脉造影在肺动脉栓塞诊断中的价值

目的探讨64层螺旋CT肺动脉造影（CTPA）在肺动脉栓塞诊断中的临床应用价值。方法行CTPA检查确诊肺栓塞病人49例,进行容积再现（VRT）、多平面重建（MPR）和最大密度投影（MIP）重建处理并计算CT肺动脉阻塞指数。结果 CTPA扫描肺动脉主干、左右肺动脉及叶、段、亚段动脉显示良好,显示受累肺动脉240条,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、肺野少血征、胸腔积液等。CT肺动脉阻塞指数为0.375-0.825。结论 CTPA能清楚地显示肺栓塞的部位、范围、局部管腔狭窄程度及其他间接征象,并可以此判断肺栓塞的严重程度,为临床选择治疗方法、观察疗效及判定预后提供必要的帮助。     

双能量CT肺灌注在肺栓塞诊断及危险分层中的价值

  目的  探讨双能量CT肺灌注的灌注缺陷对肺栓塞诊断及危险分层。  方法  选取我院2018年1月~2020年12月157例临床疑诊为肺栓塞的患者为研究对象,最终120例患者确诊肺栓塞,所有患者均行双能量CT肺灌注成像(DEPI)及肺动脉CT血管造影成像(CTPA),根据临床生物学标志及影像学改变,将患者分为肺栓塞低危组(n=30)、中危组(n=35)、高危组(n=55)。比较患者肺栓塞数量,肺动脉灌注缺失面积分数、右/左心室短轴最大径比值及心脏生物学标志物。所有患者随访3月并记录结局。  结果  DEPI与CTPA对肺栓塞的诊断相符,诊断符合率为86.1%; CTPA和DEPI联合诊断的曲线下面积为0.95,特异性为89.20%,敏感度为95.80%,Youden指数为0.85,较CTPA和DEPI单独诊断肺栓塞更好。肺栓塞低危组、中危组、高危组的灌注缺损面积、心脏生物学标志物及右/左心室短轴最大径比值经两两比较差异有统计学意义(P < 0.05)。  结论  DEPI可作为CTPA的诊断肺栓塞的补充,并通过肺动脉灌注缺失面积分数危险分层,是一种新的临床诊疗方案的选择。      

Subsegmental pulmonary embolism diagnosed by computed tomography: incidence and clinical implications. A systematic review and meta‐analysis of the management outcome studies

Summary. Background: Multiple‐detectors computed tomographic pulmonary angiography (CTPA) has a higher sensitivity for pulmonary embolism (PE) within the subsegmental pulmonary arteries as compared with single‐detector CTPA. Multiple‐detectors CTPA might increase the rate of subsegmental PE diagnosis. The clinical significance of subsegmental PE is unknown. We sought to summarize the proportion of subsegmental PE diagnosed with single‐ and multiple‐detectors CTPA and assess the safety of diagnostic strategies based on single‐ or multiple‐detectors CTPA to exclude PE. Patients and methods: A systematic literature search strategy was conducted using MEDLINE, EMBASE and the Cochrane Register of Controlled Trials. We selected 22 articles (20 prospective cohort studies and two randomized controlled trials) that included patients with suspected PE who underwent a CTPA and reported the rate of subsegmental PE. Two reviewers independently extracted data onto standardized forms. Results: The rate of subsegmental PE diagnosis was 4.7% [95% confidence interval (CI): 2.5–7.6] and 9.4 (95% CI: 5.5–14.2) in patients that underwent a single‐ and multiple‐detectors CTPA, respectively. The 3‐month thromboembolic risks in patients with suspected PE and who were left untreated based on a diagnostic algorithm including a negative CTPA was 0.9% (95% CI: 0.4–1.4) and 1.1% (95% CI: 0.7–1.4) for single‐ and multiple‐detectors CTPA, respectively. Conclusion: Multiple‐detectors CTPA seems to increase the proportion of patients diagnosed with subsegmental PE without lowering the 3‐month risk of thromboembolism suggesting that subsegmental PE may not be clinically relevant.     

Diagnosing pulmonary embolism: A question of too much choice?

The diagnosis of pulmonary embolism (PE) is difficult with many patients treated without the disease or left untreated without an adequate diagnostic work up. Recent advances in PE diagnosis are reviewed. The use of risk stratification in PE diagnosis is strongly recommended and evidence on how it can best be performed summarized. The Ginsberg/Wells stratification rule is recommended currently as the best validated rule. Computed tomographic pulmonary angiography (CTPA) was found to have quite poor sensitivity and to be poorly validated. It is recommended as adequate as a positive test in moderate/high risk groups and an exclusionary test in low risk groups or where an adequate alternative diagnosis is found. For D‐Dimer tests the only test with adequate sensitivity and validation in management studies is the VIDAS© D‐Dimer. This is in low/intermediate risk groups in the ED population. The Simpli‐Red© test is also reviewed but is too insensitive for most populations. Echocardiography: this is good in compromised patients as it is a bedside test which when negative virtually excludes PE. If positive in the right setting it has a high positive predictive value. A negative echocardiogram predicts a benign clinical course for PE. The rest of the paper details the authors approach to integrating these new techniques with established algorithms and where progress is likely to occur in the next few years. These include improvements in CTPA (plus the addition of CT venography), new point of care D‐Dimer tests, better risk stratification rules and integration of new strategies with artificial neural networks or computerized guidelines.     

广西地区13家综合医院肺栓塞诊断技术分析

目的 了解各种肺栓塞(PE)诊断技术在诊断PE中的应用.方法 对广西地区13家三级甲等综合医院1995年至2007年PE病例的诊断方法进行回顾性调查分析.根据临床表现以及普通检查诊断的PE病例为临床诊断病例,根据特殊影像检查结果或尸体解剖诊断的病例为确诊病例.比较各种PE诊断方法在诊断为PE患者中的比例以及不同年份各种诊断方法所占比例.结果 1995年至2007年13家医院诊断为PE患者460例,其中确诊病例237例(占51.52%),临床诊断病例223例(占48.48%).2002年至2007年确诊病例占同期PE病例的55.13%,较1995年至2001年14.63%明显提高(X~2=24.522,P<0.01).237例确诊病例中,17例由2项检查确诊,由肺动脉造影、CT肺动脉造影、超声检查、磁共振成像以及尸体解剖各诊断27例(11.39%)、214例(90.30%)、6例(2.53%)、5例(2.11%)和2例(0.84%),没有肺通气灌注显像确诊病例.2003年以后采用CT肺动脉造影广西地区确诊PE所占比例升高.其他检查技术则略有下降.结论 CT肺动脉造影是广西地区诊断PE的首选方法,其他诊断技术的临床应用有待加强.     

多排CT对肺动脉栓塞和下肢深静脉血栓检出的研究

目的:评价运用CT肺动脉造影和下肢CT静脉造影(CTVPA)两种方法对肺动脉栓塞(PE)和下肢深静脉血栓(DVT)检出的应用价值。方法:对38例临床怀疑PE的患者行CTVPA检查,分析其影像表现,并探讨其应用价值。结果:38例患者中PE24例,下肢DVT11例。PE主要表现为血管腔内充盈缺损和同侧肺野内病变。下肢DVT主要表现为下肢深静脉管腔内充盈缺损、静脉增粗和患肢软组织肿胀。对于栓子的显示,多层面容积重建(MPVR)优于最大密度投影(MIP)和容积再现(VR)。结论:多排CT(MSCT)联合运用CT肺动脉造影和CTVPA两种方法对PE和下肢DVT检出有很大的应用价值,可作为临床怀疑PE的患者首选检查方法。     

Diagnostic management of clinically suspected acute pulmonary embolism

Summary.  Current diagnostic management of hemodynamically stable patients with clinically suspected acute pulmonary embolism (PE) consists of the accurate and rapid distinction between the approximate 20–25% of patients who have acute PE and require anticoagulant treatment, and the overall majority of patients who do not have the disease in question. Clinical outcome studies have demonstrated that, using algorithms with sequential diagnostic tests, PE can be safely ruled out in patients with a clinical probability indicating PE to be unlikely and a normal D-dimer test result. This obviates the need for additional radiological imaging tests in 20–40% of patients. CT pulmonary angiography (CTPA) has become the first line tool to confirm or exclude the diagnosis of PE in patients with a likely probability of PE or an elevated D-dimer blood concentration. While single-row-detector technology CTPA has a low sensitivity for PE and bilateral compression ultrasound (CUS) of the lower limbs is considered necessary to rule out PE, multi-row-detector CTPA is safe to exclude PE without the confirmatory use of CUS.     

Computed tomography of acute pulmonary embolism

Pulmonary embolism (PE) is a common condition in which diagnostic and therapeutic delays contribute to substantial morbidity and mortality. Advances in spiral computed tomography (CT) scanner technology over the past 10 years have been paralleled by progressive improvement in the ability to identify and accurately evaluate the pulmonary arteries for acute PE using CT pulmonary angiography (CTPA). Preliminary studies indicate multi-detector CT (MDCT) scanners offer improved accuracy for distal segmental and subsegmental PE. The ability to directly visualize emboli using CTPA has led to its widespread implementation. Published studies using optimal techniques have found sensitivity and specificity of approximately 90%. Clinical signs and symptoms are nonspecific. Only 20% to 30% of those patients evaluated for acute PE are found to harbor emboli. Previous imaging algorithms offered limited diagnostic value for the remaining 70% to 80% of patients who proved not to have PE. It has been shown that spiral CT identifies an alternate diagnosis in approximately 70% of these patients, which, along with its rapid and widespread availability, largely accounts for its popularity with referring clinicians. It is noted that meta-analysis studies of the existing data regarding spiral CT in acute PE have shown deficiencies in study designs, indicating that further research is required. However, at this time, spiral CT is being widely employed in the diagnostic work-up of patients with suspected acute PE. This review will discuss the use of spiral CT for acute PE, including scan acquisition parameters, radiation dose, diagnostic findings, interpretive pitfalls and the role of leg vein studies.     

双源双能量CT诊断周围型肺动脉栓塞的价值

目的 探讨双源双能量CT对周围型肺动脉栓塞的诊断价值.方法 从临床怀疑肺动脉栓塞(PE)并行双源双能量CT肺动脉成像的患者中选择周围型PE患者36例(98个栓子)纳入本研究.运用Syngo.via工作站对双源双能量CT扫描数据进行CT肺动脉血管成像(CTPA)和CT双能量Lung Analysis后处理.记录PE的栓塞...     

CT肺动脉造影对肺动脉栓塞的诊断价值

目的探讨CT肺动脉造影对肺动脉栓塞（PE）的诊断价值。方法20例PE患者均行CT肺动脉造影（CTPA）检查。结果Ⅰ型12例,其中4例位于左肺动脉,3例位于右肺动脉,5例左、右肺动脉及肺叶肺动脉皆有;Ⅱ型2例,其中右下叶肺动脉1例,左上叶肺动脉1例;Ⅲ型3例,其中右下叶肺动脉1例,左上叶肺动脉1例,2个以上肺叶肺动脉1例;Ⅳ型3例,均位于双下肺肺段、亚段肺动脉。左、右肺动脉、叶肺动脉、段肺动脉、亚段肺动脉栓塞率分别为77．78％、66．67％、60．00％、12．50％。结论CTPA对肺动脉栓塞有重要的诊断价值。     

CTPA as the gold standard for the diagnosis of pulmonary embolism

Purpose  

The estimated annual incidence of pulmonary embolism (PE) is between 69 to 205 cases per 100,000 persons-years. New imaging studies have been developed during the past decade. Chest CTPA, especially multidetector CT, has proven to be superior or equal to PA angiography, even detecting smaller filling defects. We reviewed the differences in opinion to the diagnosis of PE between chest radiologists (CR) who interpret CTPA and interventional radiologists (IR) who perform PA angiography and what they consider the “gold standard” for the diagnosis of PE.     

64层螺旋CTPA对肺动脉栓塞的诊断价值(附25例分析)

目的评价64层螺旋CTPA及三维成像技术对肺动脉栓塞的诊断价值。方法收集25例经64层SCTPA检查确诊的肺动脉栓塞;回顾性分析其成像条件及薄层容积图像,MPR、MIP、SSD、VR等后处理方法对肺动脉及其栓子的显示情况,并观察肺动脉栓塞征象。结果25例SCTPA图像质量均满足诊断需要;薄层容积图像可清晰显示肺动脉及其各级分支,显示率为100%;MPR、MIP、SSD、CR等后处理法有助于多角度、多方位显示栓子。PE主要累及左右肺动脉等大分支,占90%,其中中央型栓塞18,周围型栓塞7例。栓塞直接征象为栓子形成充盈缺损;间接征象包括肺梗死、胸腔积液、心包积液、膈肌抬高和右心增大等。结论64层螺旋CT极大提高了SCTPA这一技术的临床应用价值,是目前诊断肺动脉栓塞最为快捷、安全、可靠的影像方法。     

双源CT低剂量对比剂肺灌注成像评估肺动脉内血栓与灌注缺损间的关系

目的：应用双源CT低剂量对比剂肺灌注成像评估急性肺动脉栓塞患者血管内血栓与肺灌注缺损间的关系。材料与方法：15例无肺动脉栓塞患者分别行低剂量与常规剂量双能量肺灌注成像,对比分析其图像质量;20例疑肺动脉栓塞患者行低剂量双能量肺灌注成像,同时获得肺动脉CTA（CTPA）及肺灌注图像。用CTPA轴位及三维重建图像分析肺动脉内有无血栓以及血栓的部位、数量、形态特征。用双能量肺灌注分析软件判断有无灌注缺损及缺损的部位、范围。统计肺动脉内血栓与肺灌注缺损间的关系。结果：肺动脉栓塞患者的低剂量与常规剂量双能量肺灌注图像质量无明显差异（P>0.05）。20例患者中,13例肺灌注图像中出现102个肺叶、肺段或亚段灌注缺损,4例共6个灌注缺损无明确血栓。11例患者CTPA轴位及三维重建图像显示43个血栓,2例CTPA显示5个血栓的患者肺内无灌注缺损。9例同时出现血栓与灌注缺损,肺内75个灌注缺损与栓塞肺动脉供血范围一致,21个灌注缺损（8个肺段、13个亚段）与肺动脉供血范围无关。结论：肺动脉内血栓与肺灌注缺损不一定匹配,综合分析双源CT低剂量对比剂双能量肺灌注图像与CTPA,可以提高肺动脉栓塞诊断的准确性。     

Evolving imaging techniques in diagnostic strategies of pulmonary embolism

Modern non invasive diagnostic strategies for pulmonary embolism (PE) rely on the sequential use of clinical probability assessment, D-dimer measurement and thoracic imaging tests. Planar ventilation/perfusion (V/Q) scintigraphy was the cornerstone for more than two decades and has now been replaced by computed tomography pulmonary angiography (CTPA). Diagnostic strategies using CTPA are very safe to rule out PE and have been well validated in large prospective management outcome studies. With the widespread use of CTPA, concerns regarding radiation and overdiagnosis of PE have paved the way for investigating new diagnostic modalities. V/Q single photon emission tomography has arisen as a highly accurate test and a potential alternative to CTPA. However, prospective management outcome studies are still lacking and are warranted before implementation in everyday clinical practice.     

Computed tomography pulmonary angiography in the diagnosis of acute pulmonary embolism in the emergency department

This study was undertaken to evaluate the use of computed tomography pulmonary angiography (CTPA) in patients with pulmonary embolism (PE) who were followed in the emergency department (ED). The files and computer records of 850 patients older than 16 years of age who were seen in the Hacettepe University Hospital ED between April 10, 2001, and December 1, 2005, and who required CTPA for PE prediagnosis and/or another diagnosis, were studied retrospectively. PE was identified by CTPA in 9.4% of 416 women and in 5.8% of 434 men. A significant difference (P< .05) was noted in the women and men in whom PE was detected. The mean age of the patients was 58.13±17.88 y (range, 16–100 y). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for clinical susceptibility to PE among patients who underwent CTPA were assessed at 95.3%, 48.2%, 13%, and 99.2%, respectively. CTPA was done for different reasons: aortic aneurysm dissection (n=1), cough distinctive diagnosis (n=1), dyspnea distinctive diagnosis (n=6), chest pain distinctive diagnosis (n=3), PE prediagnosis (n=51), and other reasons (n=2). Also, sensitivity, specificity, PPV, and NPV were found to be 95.4%, 16.2%, 14.4%, and 96%, respectively, for D-dimer. CTPA, which is accessible on a 24-h basis in the ED, is a valuable tool for the diagnosis of PE.     

Feasibility of gadolinium-enhanced dual energy CT pulmonary angiography: a pilot study in rabbits

The purpose of this study was to evaluate the feasibility of gadolinium-enhanced dual energy CT pulmonary angiography (CTPA) to detect pulmonary embolism (PE) in rabbits. Dual energy CT was performed on phantoms composed of different dilution of gadolinium and iodinated contrast agents, CT numbers of the phantoms were measured at different tube voltages. Ten rabbits, which were subdivided into two groups receiving 3 or 5 ml/kg of gadolinium based contrast agent (n = 5 for each group), underwent baseline gadolinium-enhanced dual energy CTPA. The CT numbers of pulmonary arteries were measured. The following day, sponge gelatin was injected into femoral vein of 6 rabbits to create pulmonary emboli. The rabbit were re-imaged 2 h after sponge gelatin injection. Histopathology analysis of the lung lobes was performed. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Serum creatinine levels were measured on day 1 before gadolinium contrast media injection, and on day 2 prior to PE creation. The phantoms and animal study showed that the CT numbers of gadolinium-based contrast agent and pulmonary arteries at 80 kVp were higher than those at 140 kVp and average weighted 120 kVp. In 6 rabbits, CTPA showed bilateral pulmonary artery emboli, and the reconstructed gadolinium maps showed decreased pulmonary perfusion in the corresponding lung lobes. With the histopathology results as the reference standards, CTPA and Blood flow imaging (BFI) detected PE in 14 and 14 of the 14 pulmonary lobes, 26, 24 lobes without PE, respectively, corresponding to sensitivities of 100 and 100%, and specificities of 100 and 92%, respectively. Serum creatinine level increased by 6.7 and 20.6% in the rabbits receiving 3 and 5 ml/kg gadolinium based contrast medium respectively. Histopathological analysis found no significant tubular necrosis at either gadolinium dose. Gadolinium-enhanced dual energy CT pulmonary angiography is feasible and it can simultaneously provide information on pulmonary artery and lung perfusion in a rabbit model of PE.