CT肺动脉栓塞指数与右心功能及动脉血气分析指标的相关性研究

目的：通过CT肺动脉栓塞指数(PAOI)与右心功能参数及动脉血气分析指标的相关性研究,探讨 CT PAOI 评价肺栓塞(PE)病情严重程度的价值。方法整理本院进行CT肺动脉造影(CTPA)检查并确诊的70例 PE患者的 CT PAOI、右心功能参数及动脉血气分析指标,使用Spearman等级相关系数评价PAOI和右心室/左心室最大短轴直径比(RVd/LVd)、主肺动脉直径(MPAd)、上腔静脉直径(SVCd)、动脉氧分压(PaO2)、动脉二氧化碳分压(PaCO2)、血氧饱和度(SaO2)、肺泡-动脉氧分压差(P(A-a)O2)之间的相关性。结果 PAOI与PaO2呈负相关,相关系数为-0.442;PAOI与RVd/LVd、WPAd、SVCd及P(A-a)O2呈正相关,相关系数介于0.163~0.675之间;PAOI与 SaO2不相关。结论 CT PAOI可以用来评估PE的严重程度,但与患者临床病情严重程度不完全一致。     

CT肺动脉阻塞指数与血气分析值评价急性肺栓塞严重性的研究

目的研究CT阻塞指数与血气分析评价急性肺栓塞(APE)严重性的价值。方法接受CTPA和动脉血气分析检查并且无基础心肺疾病的APE患者共59例。利用肺动脉CT阻塞指数评价肺动脉栓子阻塞程度与范围。动脉血气分析包括PaCO2、PaO2、SaO2及P(A-a)O2。严重APE组和非严重APE组患者之间的CT阻塞指数、动脉血气分析指标之间的统计学差异用t检验评价。阻塞指数与动脉血气分析指标之间的相关性使用Spearman相关系数评价。结果严重APE组患者的PaCO2、PaO2及SaO2明显低于非严重APE组患者(P<0.01),而P(A-a)O2明显高于非严重APE患者(P<0.01)。阻塞指数分别与PaCO2、PaO2、SaO2及P(A-a)O2的相关性有统计学意义(P<0.01)。结论综合分析APE患者的肺动脉阻塞指数、血气分析指标有利于评价APE患者的严重性。     

CT肺动脉栓塞指数的临床应用价值

目的探讨肺动脉栓塞指数(pulmonary satery obstruction Index,PE指数)在指导临床治疗急性肺动脉栓塞(acute pulmonary embolism,APE)的临床应用价值。方法选择经CT肺动脉造影(CT pulmonary angiography,CTPA)证实的急性肺动脉栓塞患者105例,分别以PE指数30%～60%、>60%分成中、重度两组,再依据是否有溶栓禁忌症,将患者分成溶栓组和抗凝组,对每位患者治疗后的效果进行评价,分析PE指数对临床治疗急性肺动脉栓塞的指导作用。结果中度组(PE指数30%～60%)溶栓组和抗凝组治疗效果无显著差异,重度组(PE指数>60%)溶栓组比抗凝组有效率明显提高而死亡率明显降低。结论 PE指数可以作为急性肺动脉栓塞患者是否进行溶栓治疗的一项重要指标。     

New CT index to quantify arterial obstruction in pulmonary embolism: comparison with angiographic index and echocardiography

OBJECTIVE: This study was designed to define and evaluate a specific index to quantify arterial obstruction with helical CT in acute pulmonary embolism. MATERIALS AND METHODS: Fifty-four patients (mean age, 56 years) with proven pulmonary emboli among 158 consecutive patients, who had undergone both CT and pulmonary angiography for clinically suspected pulmonary embolism, were eligible for the study. The CT obstruction index was defined as (n. d) (n, value of the proximal clot site, equal to the number of segmental branches arising distally; d, degree of obstruction scored as partial obstruction [value of 1] or total obstruction [value of 2]). We compared the CT obstruction index with pulmonary arterial obstruction on angiography (assessed by the Miller index), using linear regression, and correlated it with findings on echocardiography. Interobserver variability was determined for both CT and pulmonary angiography indexes. RESULTS: The CT obstruction index (29% +/- 17%) and the Miller index (43% +/- 25%) were well correlated (r = 0.867, p < 0.0001) with an excellent concordance between investigators for both the CT index (r = 0.944, p < 0.0001) and the Miller index (r = 0.904, p < 0.0001). A CT obstruction index greater than 40% identified more than 90% of patients with right ventricular dilatation. CONCLUSION: The degree of arterial obstruction in pulmonary embolism may be quantified by a specific CT index that appears reproducible and highly correlated to the previously described index with pulmonary angiography. Further evaluations are needed to investigate the usefulness of the CT obstruction index for stratification of patient risk and determining therapeutic options.     

急性肺动脉栓塞患者CT阻塞指数与缺氧严重程度的相关性研究

目的:评价急性肺动脉栓塞患者CT阻塞指数(CTOI)与缺氧严重程度的相关性。方法:对24例急性肺动脉栓塞患者(栓塞组)的CT肺动脉造影(CTPA)资料进行回顾性分析,了解肺动脉CTOI与血氧饱和度(SO2)的相关性;以30例无栓塞的患者作为对照组,了解栓塞患者及无栓塞患者的SO2是否有差异;以SO2值94%为标准,将肺动脉栓塞患者分为缺氧组(<94%)和非缺氧组(≥94%),了解引起缺氧的肺动脉栓塞程度。结果:肺动脉栓塞组和对照组的SO2分别为:(89.96±7.68)%和(97.53±5.26)%,肺动脉栓塞组的SO2明显低于对照组(P<0.05);CTOI与SO2之间呈明显负相关(r=0.45,P=0.03),随着CTOI的增加,SO2降低越明显;肺动脉栓塞患者中,非缺氧组CTOI值的95%可信区间为0%～49.20%,缺氧组CTOI值的95%可信区间为39.88%～100%,CTOI值为40%～50%时,患者处于氧供不足的临界状态。结论:急性肺动脉栓塞患者CTOI与缺氧严重程度具有相关性,SO2值低于94%时,提示肺动脉栓塞超过约50%。     

Acute and subacute dual energy CT findings of pulmonary embolism in rabbits: correlation with histopathology

Objective

The purpose of this study was to describe quantitative dual energy CT (DECT) findings and their accuracy in the detection of acute and subacute pulmonary embolism (PE) in rabbits.

Methods

Pulmonary emboli were created in 24 rabbits by gelatin sponge femoral vein injection. Conventional CT pulmonary angiography (CTPA) and DECT were obtained at either 2 h, 1 day, 3 days or 7 days after embolisation (n=6 rabbits for each time point). The location and number of PEs in the different stages were recorded at CTPA and iodine maps from DECT on a per-lobe basis. With histopathology as the reference standard, sensitivity and specificity of CTPA and DECT were calculated. CT and iodine map overlay values of the embolic and non-embolic areas were measured for each scan.

Results

With histopathology as the reference standard, the overall sensitivity and specificity of CTPA were 98% and 100% and those of iodine maps were 100% and 95%, respectively. Conventional CT and iodine map values of the embolised and non-embolised areas were significantly different between 2 h and 1 day (p<0.001), but not between 3 days and 7 days (p>0.05). A statistical difference was found for overlay values measured in the embolic and non-embolic regions for four groups.

Conclusion

Iodine maps derived from DECT show alterations in lung perfusion for acute and subacute PE in an experimental rabbit model and show comparable sensitivity for PE detection and conventional CTPAIn the USA, more than 650 000 cases of pulmonary embolism (PE) occur each year, resulting in as many as 300 000 annual fatalities [1,2]. Despite the high morbidity, the diagnosis of PE may be delayed in the absence of typical clinical symptoms or when emboli are subsegmental and such scenarios may delay the treatment and increase the mortality of PE. Imaging plays an important role in the diagnosis and follow-up of PE. With improvements in multidetector row CT, CT pulmonary angiography (CTPA) has largely replaced digital subtraction angiography (DSA) for the diagnosis and follow-up of PE and has been recommended as the reference of standard for diagnosis of acute PE [3]. However, CTPA has shortcomings, such as a limited sensitivity to detect peripheral or subsubsegmental emboli of the pulmonary artery and an inability to show lung perfusion impairment resulting from acute or chronic PE.With the development of dual source CT (DSCT), in which two orthogonally mounted detectors and tubes arrays operate simultaneously and can be set to different tube potentials to allow for dual energy CT (DECT) acquisitions with minimal patient motion registration artefact, DECT imaging has been used to investigate iodine distribution maps in clinical and pre-clinical studies [4-13]. Such iodine maps, which have been termed blood flow imaging (BFI), have been shown to be valuable supplements to conventional anatomic CTPA for the evaluation of distal pulmonary artery emboli [4-13]. Many studies have focused on the feasibility or diagnostic accuracy of DECT iodine maps to improve the detection of PE, with CTPA, scintigraphy or histopathology as a reference standard in the clinical and experimental studies [5-13], or the evaluation of image quality of dual energy CTPA [14,15]. However, to the best of our knowledge, there are no reports that describe the evolution of CT and DECT imaging findings of PE over time after an embolic event with histopathological correlation. Histopathology correlation is most ethically obtained using an animal model. Therefore, we evaluated DECT findings with histopathology correlation in a rabbit model of PE with different time delays after embolisation and assessed the diagnostic accuracy of DECT in the detection of PE at these different time points.     

CT阻塞指数对肺栓塞的评价及其与D-二聚体相关性分析

目的：探讨肺动脉CT阻塞指数对肺栓塞(PE)高危性的评价及其与D-二聚体之间的关系。方法收集经 CT肺动脉成像(CTPA)及D-二聚体检查的125例PE病例。将其分为高危PE组和非高危PE组,比较分析2组在 CT阻塞指数、D-二聚体、主肺动脉直径间的差异,以及肺动脉 CT 阻塞指数与 D-二聚体、主肺动脉直径之间的相关性(Spearman相关性评价)。结果高危PE组的CT阻塞指数明显高于非高危PE组(P=0.000),高危PE组主肺动脉直径较非高危PE组增粗,差异有统计学意义(P=0.000),而高危PE组和非高危PE组D-二聚体差异无统计学意义(P=0.103)。CT阻塞指数与D-二聚体无相关性(P=0.71)。结论血浆D-二聚体指标可以提示PE,不能评价PE的高危性;肺动脉CT阻塞指数在一定程度上可以反映PE的严重性,其与 D-二聚体间无相关性。     

急性肺栓塞血气及CTPA诊断分析

目的:分析急性肺栓塞(APE)患者基础疾病、实验室及CTPA检查资料,探讨低氧分压及栓子栓塞肺动脉分支差异的机制。方法:分析APE患者基础疾病、血气及CTPA检查资料,观察肺叶及肺段各动脉分支栓子部位、数量。1 5例正常人作为对照组。采用x~2检验对各分支动脉栓塞率比较;对照组与APE组比较用两组独立样本t检验;以P0.05为差异有统计学意义。结果:APE组各项血气分析PaO_2、PaCO_2及SaO_2均较对照组减低(P0.05);本组APE患者,栓子共累及240处肺动脉,右肺动脉153条(栓塞率24.0%),左肺动脉87条(栓塞率17.8%)。右肺上叶动脉累及31条(栓塞率15.8%),右肺中叶动脉累及27条(栓塞率8.4%),右肺下叶动脉累及95条(栓塞率32.3%);左肺上叶动脉累及肺动脉23条(栓塞率15.6%),左肺下叶动脉累及64条(栓塞率18.6%)。结论:临床疑诊APE患者,要重视实验室及CTPA检查,并合理进行应用。     

Acute pulmonary embolism: visualization of high attenuation clot in the pulmonary artery on noncontrast helical chest CT

Helical CT of the thorax is frequently utilized for the evaluation of chest pain or shortness of breath affecting the emergency patient. To improve diagnostic accuracy, thoracic CT examinations are frequently tailored to address specific conditions. Although tailored protocols may enhance diagnostic accuracy, implementing the wrong protocol could result in a misdiagnosis. The proper protocol choice may particularly difficult in the emergency patient due to the nonspecific nature of many chest pain syndromes. Recently, helical CT has been used for the evaluation of suspected pulmonary embolism (PE). Demonstration of an intravascular filling defect surrounded by contrast-enhanced blood is diagnostic of PE. However, because the clinical presentation of PE is frequently nonspecific, awareness of the many potential imaging manifestations of PE is important. Therefore, we present the rare circumstance of high-attenuation clot visible within the pulmonary arteries on noncontrast helical CT; PE was confirmed after the administration of iodinated contrast medium.     

Correlation of CT angiographic pulmonary artery obstruction scores with right ventricular dysfunction and clinical outcome in patients with acute pulmonary embolism

Objective

To correlate CTA pulmonary artery obstruction scores (OS) with right ventricular dysfunction (RVD) and clinical outcome in patients with acute pulmonary embolism (PE).

Materials and methods

In a prospective study of 50 patients (66 ± 12.9 years) with PE pulmonary artery OS (Qanadli, Mastora, and Mastora central) were assessed by two radiologists. To assess RVD all patients underwent echocardiography within 24 h. Furthermore, RVD on CT was assessed by calculating the right ventricular/left ventricular (RV/LV) diameter ratios on transverse (RV/LVtrans) and four-chamber views (RV/LV4ch) as well as the RV/LV volume ratio (RV/LVvol). OS were correlated with RVD and the occurrence of adverse clinical outcomes (defined as death, need for intensive care treatment, or cardiac insufficiency ≥NYHA III).

Results

Mean Mastora, Qanadli, and Mastora central OS were 26.4 ± 17.7, 12.6 ± 9.9 and 7.5 ± 9, respectively. Echocardiography demonstrated moderate and severe RVD in 10 and 5 patients, respectively. Patients with moderate and severe RVD showed significantly higher Mastora central scores than patients without RVD (14 ± 10.8 vs. 5.9 ± 7.8 [p = 0.05]; 17.6 ± 13.2 vs. 5.9 ± 7.8 [p = 0.038]). A relevant correlation (i.e. r ≥ 0.6) between OS and CT parameters for RVD were only found for the Mastora score and the Mastora central score (RV/LV4ch: r = 0.61 and 0.68, RV/LVvol: r = 0.61 and 0.6). 18 patients experienced an adverse clinical outcome. None of the OS differed significantly between patients with and without adverse clinical outcome.

Conclusion

Pulmonary artery obstruction scores can differentiate between patients with and without RVD. However, in this study, obstruction scores were not correlated to adverse clinical outcome.     

值得注意的急性肺动脉栓塞平扫CT征象

目的描述能提示急性肺动脉栓塞的CT平扫征象。方法回顾性分析49例经临床治疗证实的急性肺动脉栓塞病例的螺旋CT影像，发现能提示急性肺动脉栓塞的平扫异常征象。结果在49例平扫影像中，共有10例出现肺动脉密度改变，其中局限性密度增高6例，局限性密度减低4例。结论急性肺动脉栓塞的确诊需要行CT增强扫描，但对于不能使用对比剂或因非典型心肺症状而仅作平扫的病例，肺动脉CT平扫的异常密度改变能提示急性肺动脉栓塞的存在。     

肺动脉栓塞症的螺旋CT检查

目的探讨螺旋CT在诊断肺动脉栓塞中的价值。方法对2 0例肺动脉栓塞症患者行CT检查并对CT图像进行分析,探讨螺旋CT在肺动脉栓塞中的应用价值。结果9例双侧肺动脉主干栓塞,7例单侧肺动脉主干栓塞,2例肺动脉主干及双侧肺动脉主干栓塞,2例发生在与段支气管伴行的肺动脉。结论螺旋CT对肺动脉栓塞的检查无创无痛,结果可靠,可作为本病首选的影像学检查方法。     

Right ventricular dysfunction and pulmonary obstruction index at helical CT: prediction of clinical outcome during 3-month follow-up in patients with acute pulmonary embolism

PURPOSE: To retrospectively quantify right ventricular dysfunction (RVD) and the pulmonary artery obstruction index at helical computed tomography (CT) on the basis of various criteria proposed in the literature and to assess the predictive value of these CT parameters for mortality within 3 months after the initial diagnosis of pulmonary embolism (PE). MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was not required for retrospective study. In 120 consecutive patients (55 men, 65 women; mean age +/- standard deviation, 59 years +/- 18) with proved PE, two readers assessed the extent of RVD by quantifying the ratio of the right ventricle to left ventricle short-axis diameters (RV/LV) and the pulmonary artery to ascending aorta diameters, the shape of the interventricular septum, and the extent of obstruction to the pulmonary artery circulation on helical CT images, which were blinded for clinical outcome in consensus reading. Regression analysis was used to correlate these parameters with patient outcome. RESULTS: CT signs of RVD (RV/LV ratio, >1.0) were seen in 69 patients (57.5%). During follow-up, seven patients died of PE. Both the RV/LV ratio and the obstruction index were shown to be significant risk factors for mortality within 3 months (P = .04 and .01, respectively). No such relationship was found for the ratio of the pulmonary artery to ascending aorta diameters (P = .66) or for the shape of the interventricular septum (P = .20). The positive predictive value for PE-related mortality with an RV/LV ratio greater than 1.0 was 10.1% (95% confidence interval [CI]: 2.9%, 17.4%). The negative predictive value for an uneventful outcome with an RV/LV ratio of 1.0 or less was 100% (95% CI: 94.3%, 100%). There was a 11.2-fold increased risk of dying of PE for patients with an obstruction index of 40% or higher (95% CI: 1.3, 93.6). CONCLUSION: Markers of RVD and pulmonary vascular obstruction, assessed with helical CT at baseline, help predict mortality during follow-up.     

CT及核医学技术在肺栓塞诊断中的应用价值

肺动脉栓塞是指内源性或外源性栓子经静脉回流最终嵌塞在肺动脉及其分支,导致组织血液供应受阻所引起的一系列临床和病理生理综合征,其发病率和病死率均很高。CT和核医学技术是目前临床上诊断肺栓塞最常用的影像技术。随着计算机技术的不断更新,这两种技术也取得了一定的进展。综述CT及核医学技术在肺栓塞诊断上的进展,比较各种诊断方法的优势与不足,以期为临床选择合适的诊断方法提供参考。     

Acute pulmonary embolism: comparison and integration of perfusion lung scintigraphy with multislice spiral CT

PURPOSE: This study compared and integrated the data from perfusion lung scintigraphy and multislice computed tomography (CT) for the emergency diagnosis of acute pulmonary embolism in nuclear medicine and radiology departments operating around the clock. MATERIALS AND METHODS: One hundred and seven patients with a clinical and laboratory suspicion of acute pulmonary embolism who had already undergone chest radiography were divided into four groups according to the time interval between onset of clinical suspicion and performance of the two diagnostic examinations (0-24 h, 24-48 h, 0-48 h, 2-7 days). Cohen's test for the analysis of statistical concordance was used. RESULTS: Perfusion lung scintigraphy and multislice CT were positive in 29/107 (27.1%) and negative in 78/107 (72.89%). Positive concordance (PC) was found in 22 cases and negative concordance (NC) in 71 cases: 0-24 h: PC in 12, NC in 32 cases; 24-48 h: PC in 3, NC in 15 cases; 0-48 h: PC in 15, NC in 47 cases; 2-7 days: PC in 7, NC in 24 cases. CONCLUSIONS: Perfusion lung scintigraphy and multislice CT demonstrated elevated concordance if performed within 7 days of the onset of suspicion of acute pulmonary embolism. Concordance was higher if the examinations were completed within 24-48 h. In suspected acute pulmonary embolism, it is mandatory to reach a correct diagnosis within few hours--48 at the most.     

Acute pulmonary embolism: diagnosis with MR angiography

PURPOSE: To prospectively evaluate pulmonary magnetic (MR) angiography as a diagnostic examination for acute pulmonary embolism (PE). MATERIALS AND METHODS: Thirty-six consecutive patients (19 women, 17 men; age range, 28-84 years) underwent pulmonary digital subtraction angiography (DSA) and pulmonary MR angiography. MR angiograms were obtained during suspended respiration and the pulmonary arterial phase of gadolinium-based contrast medium injection. A steady-state gradient-recalled-echo sequence with free induction decay sampling was used. DSA studies were interpreted for the presence of acute PE by two independent radiologists; an adjudicator made the final decision on discordant interpretations. RESULTS: By using DSA, a total of 19 acute pulmonary emboli were depicted in 13 patients. Prospectively, 13 of these emboli were depicted by using MR angiography. MR angiography missed six emboli: Four required the DSA adjudicator to make the decision, and one was in a patient whose MR angiogram was acquired during breathing. Four of these six emboli were small subsegmental emboli, and two were segmental. CONCLUSION: Performed without pulmonary arterial catheterization, iodinated contrast media, or ionizing radiation, pulmonary MR angiography had a high accuracy for depicting lobar and segmental emboli, but was unable to depict four of five subsegmental emboli.