Prospectively ECG gated CT pulmonary angiography versus helical ungated CT pulmonary angiography: impact on cardiac related motion artifacts and patient radiation dose

Objective

To compare prospectively ECG gated CT pulmonary angiography (CTPA) with routine helical ungated CTPA for cardiac related motion artifacts and patient radiation dose.

Subjects and methods

Twenty patients with signs and symptoms suspicious for pulmonary embolism and who had a heart rate below 85 were scanned with prospectively ECG gated CTPA. These gated exams were matched for several clinical parameters to exams from twenty similar clinical patients scanned with routine ungated helical CTPA. Three blinded independent reviewers subjectively evaluated all exams for overall pulmonary artery enhancement and for several cardiac motion related artifacts, including vessel blurring, intravascular shading, and double line. Reviewers also measured pulmonary artery intravascular density and image noise. Patient radiation dose for each technique was compared. Fourteen clinical prospectively ECG gated CTPA exams from a second institution were evaluated for the same parameters.

Results

Prospectively ECG gated CTPA resulted in significantly decreased motion-related image artifact scores in lung segments adjacent to the heart compared to ungated CTPA. Measured image noise was not significantly different between the two types of CTPA exams. Effective dose was 28% less for prospectively ECG gated CTPA (4.9 mSv versus 6.8 mSv, p = 0.02). Similar results were found in the prospectively ECG gated exams from the second institution.

Conclusion

Compared to routine helical ungated CTPA, prospectively ECG gated CTPA may result in less cardiac related motion artifact in lung segments adjacent to the heart and significantly less patient radiation dose.     

Cardiac causes of pulmonary arterial hypertension: assessment with multidetector CT

The causes of pulmonary arterial hypertension (PAH) are diverse and include multiple congenital and acquired cardiac diseases as well as diseases primarily affecting the pulmonary vasculature, lung, pleura and chest wall. The traditional role of CT in evaluating PAH includes assessment of pulmonary vasculature and lung parenchyma with limited assessment of the heart. Advances in multidetector CT technology with improved spatial and temporal resolution now permit accurate delineation of cardiac morphology. CT pulmonary angiography (CTPA) is widely utilised in the workup of patients with suspected pulmonary vascular disease and can identify both pulmonary and cardiac causes. As the initial presentation for CTPA is often precipitated by nonspecific, unexplained symptoms and therefore undertaken by a general radiologist, it is important that a systematic approach to the interpretation of these studies, including cardiac evaluation, is routinely adopted. This paper reviews the CT evaluation in pulmonary hypertension with a particular focus on the cardiac causes, their subclassification into congenital systemic to pulmonary shunts and secondary to left heart disease, and their imaging features. It emphasises the use of a systematic approach to interpretation of CTPA examinations both in patients with known PAH and those with previously unsuspected disease.     

Diagnostik der akuten Lungenembolie

Pulmonary embolism is an acute and potentially life-threatening condition requiring a differentiated diagnostic algorithm. Assessment of the risk and clinical probability are of utmost importance in order to initiate early treatment or to reliably exclude a pulmonary embolism. Computed tomography of the pulmonary arteries (CTPA) has become the non-invasive gold standard for the diagnostic approach. Alternatively, scintigraphy can also be used. A negative CTPA excludes a pulmonary embolism with a high degree of probability. Furthermore, CTPA can supply additional information, such as estimation of the right ventricular strain (right ventricular dysfunction, RVD) or alternative diagnoses if pulmonary embolism has been ruled out as the primary cause of symptoms. An essential prerequisite is a high quality CTPA with sufficient contrast enhancement in the pulmonary arteries, avoidance of artifacts and optimization of both the radiation dosage as well as the amount of contrast medium, individually determined for each patient.     

Does addition of CT pelvic venography to CT pulmonary angiography protocols contribute to the diagnosis of thromboembolic disease?

AIM: To evaluate the contribution which addition of pelvic computed tomography venography (CTV) to a standard CT pulmonary angiography (CTPA) imaging protocol makes to a definitive diagnosis of thromboembolic disease. MATERIALS AND METHODS: One hundred and six consecutive patients over the age of 55 years referred for (CTPA) for suspected pulmonary embolism between June and November 1999 had pelvic CTV performed at the time of the CTPA study. RESULTS: Ninety-six of 106 CTPA studies were technically adequate. In total, 29/96 (29.6%) CTPA studies were positive for pulmonary embolism, 10/96 (10.4%) CTV studies were positive and five of these 10 examinations showed venous thrombus when the CTPA study was negative (n = 4) or equivocal (n = 1). CONCLUSION: Addition of CTV shows residual thrombus in the pelvis in a proportion of patients with positive CTPA studies and demonstrates venous thrombus in a small number of patients with no CT evidence of pulmonary embolism.     

The use of a D-dimer assay in patients undergoing CT pulmonary angiography for suspected pulmonary embolus.

PURPOSE: To assess the ability of a semi-quantitative latex agglutination D-dimer test Accuclot with bedside measurements of arterial oxygen saturation, respiratory and cardiac rates to exclude pulmonary embolism (PE) on computed tomographic pulmonary angiography (CTPA). MATERIALS AND METHODS: All patients referred to our CT unit for investigation of suspected acute pulmonary embolism were enrolled. Pulse oximetery, respiratory rate, heart rate and blood sampling for D-dimer testing were carried out just before CT. A high resolution CT (HRCT) of the chest was followed by a CT pulmonary angiogram (CTPA). The images were independently interpreted at a workstation with cine-paging and 2D reformation facilities by three consultant radiologists blinded to the clinical and laboratory data. If positive, the level of the most proximal embolus was recorded. Discordant imaging results were re-read collectively and consensus achieved. RESULTS: A total of 101 patients were enrolled. The CTPA was positive for PE in 28/101 (28%). The D-dimer was positive in 65/101 (65%). Twenty-six patients had a positive CT and positive D-dimer, two a positive CT but negative D-dimer, 39 a negative CT and positive D-dimer, and 34 a negative CT and negative D-dimer. The negative predictive value of the Accuclot D-dimer test for excluding a pulmonary embolus on spiral CT was 0.94. Combining the D-dimer result with pulse oximetry (normal SaO2 > or = 90%) improved the negative predictive value to 0.97. CONCLUSION: A negative Accuclot D-dimer assay proved highly predictive for a negative CT pulmonary angiogram in suspected acute pulmonary embolus. If this D-dimer assay were included in the diagnostic algorithm of these patients a negative D-dimer would have unnecessary CTPA rendered in 36% of patients.     

When to perform CTA in patients suspected of PE?

Venous thromboembolic disease (VTE) is a common disorder which may be associated with high morbidity or mortality when left untreated. Specific VTE diagnosis is mandatory, as treatment is associated with significant side effects. Therefore, timely diagnostic tests are necessary to establish the presence or absence of VTE. Computed tomographic pulmonary angiography (CTPA) has reached a high accuracy in the evaluation of pulmonary embolism (PE). Unfortunately, the continuous decrease of the prevalence of PE in the most recent studies can lead to cost-efficacy imbalance and overuse of ionizing radiation when CTPA is used as a single test. Therefore, no single non-invasive test is suitable for all patients and diagnostic strategies based on sequential non-invasive tests are likely to identify patients in whom anticoagulation can be withheld safely and limit the number of patients requiring more invasive or more expensive tests. The cost effectiveness of clinical stratification and D-dimer test has been demonstrated as it reduces the requirement for invasive tests. In this paper, the current role of CTPA in the diagnosis of PE will be reviewed.     

Fusion imaging of computed tomographic pulmonary angiography and SPECT ventilation/perfusion scintigraphy: initial experience and potential benefit

Purpose The objective of this study was to examine the feasibility of fusing ventilation and perfusion data from single-photon emission computed tomography (SPECT) ventilation perfusion (V/Q) scintigraphy together with computed tomographic pulmonary angiography (CTPA) data. We sought to determine the accuracy of this fusion process. In addition, we correlated the findings of this technique with the final clinical diagnosis. Methods Thirty consecutive patients (17 female, 13 male) who had undergone both CTPA and SPECT V/Q scintigraphy during their admission for investigation of potential pulmonary embolism were identified retrospectively. Image datasets from these two modalities were co-registered and fused using commercial software. Accuracy of the fusion process was determined subjectively by correlation between modalities of the anatomical boundaries and co-existent pleuro-parenchymal abnormalities. Results In all 30 cases, SPECT V/Q images were accurately fused with CTPA images. An automated registration algorithm was sufficient alone in 23 cases (77%). Additional linear z-axis scaling was applied in seven cases. There was accurate topographical co-localisation of vascular, parenchymal and pleural disease on the fused images. Nine patients who had positive CTPA performed as an initial investigation had co-localised perfusion defects on the subsequent fused CTPA/SPECT images. Three of the 11 V/Q scans initially reported as intermediate could be reinterpreted as low probability owing to co-localisation of defects with parenchymal or pleural pathology. Conclusion Accurate fusion of SPECT V/Q scintigraphy to CTPA images is possible. This technique may be clinically useful in patients who have non-diagnostic initial investigations or in whom corroborative imaging is sought.     

Spiral computed tomographic pulmonary angiography for investigating suspected pulmonary embolism: clinical outcomes.

PURPOSE: To assess the clinical outcomes of patients who were suspected of having acute pulmonary embolism and underwent spiral computed tomographic pulmonary angiography (CTPA) for diagnosis. METHODS: We evaluated the clinical outcomes of 62 patients with suspected pulmonary embolism; 82 CTPA scans were performed in a 15-month period. Clinical outcomes were recorded for all patients for a minimum of 3 months. RESULTS: Acute pulmonary embolism was diagnosed and treated in 11 (18%) of the 62 patients evaluated via CTPA. Scans of the other 51 (82%) patients were negative for pulmonary embolism. Seven (14%) of these patients died during the 3-month follow-up period; pulmonary embolism was considered to be a contributing factor in 1 of these deaths. Seven (14%) of the 51 patients were lost to follow-up, and 37 (74%) showed no evidence of disease at least 3 months after a negative CTPA study. Despite the presence or absence of an acute pulmonary embolism, an alternate or additional diagnosis was made on 32 (52%) CTPA scans. CONCLUSION: Spiral CTPA can be effectively used to rule out clinically significant pulmonary emboli and also serves to provide alternate diagnoses in patients who do not have a pulmonary embolism.     

When, why, and how to examine the heart during thoracic CT: Part 2, clinical applications

OBJECTIVE: CT examination of the thorax is often requested for the investigation of disorders that may have an important underlying cardiac cause or association that is not clinically obvious. Conditions such as idiopathic and acquired cardiomyopathy, ischemic heart disease, and valvular dysfunction may underlie symptoms such as dyspnea, chest pain, and hemoptysis that prompt the request for CT of the thorax. Other conditions such as pulmonary thromboembolic disease, chronic obstructive airways disease, pectus excavatum, sleep apnea, and many intrathoracic malignancies may have an important effect on cardiac structure and function. Patients undergoing thoracic surgery may have unsuspected coronary artery disease that can be detected in the course of preoperative evaluation by CT; similarly, postoperative complications often have a cardiogenic basis. CONCLUSION: Examination of the heart in the course of CT of the chest often can provide important and clinically relevant information that is not otherwise easily available.     

肺通气/灌注显像与多层螺旋CT诊断慢性血栓栓塞性肺动脉高压的对比研究

目的 对比肺通气/灌注(V/Q)显像与多层螺旋CT肺血管造影(CTPA)诊断慢性血栓栓塞性肺动脉高压(CTEPH)的准确性,评价2种影像学方法的诊断符合程度.方法 49例肺动脉高压患者,经超声心动图排除瓣膜性心脏病和先天性心脏病,既往无急性肺栓塞病史.所有患者先后行肺V/Q显像和CTPA检查,并以肺动脉造影为"金标准"进行对比评价.对V/Q显像和CTPA检查结果比较进行χ2检验,采用SPSS 12.0统计软件.结果 肺V/Q显像对CTEPH的诊断灵敏度、特异性和准确性分别为100.0%(17/17),71.9%(23/32)和81.6%(40/49),CTPA分别为94.1%(16/17),81.2%(26/32)和85.7%(42/49).肺V/Q显像与CTPA的诊断符合率为75.5%(37/49),Kappa值为0.513,2种影像学方法的诊断结果差异无统计学意义(χ2=0.75,P>0.05).结论 肺V/Q显像和CTPA均是诊断CTEPH有效的无创性影像学方法,两者结合应用有助于更好地诊断CTEPH.     

64层螺旋CT肺血管造影在肺栓塞诊疗中的应用价值

目的 探讨64层螺旋CT在肺栓塞诊断及治疗中的指导作用。方法 63例患者均行64层螺旋CT肺血管造影(CTPA),并进行多种形式的图像重建结合轴位图像分析。结果 64层螺旋CTPA对63例患者肺动脉各级管腔内的栓子均明确显示,共累及肺动脉303支;图像分析结果伞部显示肺栓塞的直接征象为:主肺动脉和(或)左右肺叶、段、亚段血管腔内充盈缺损和血管阻塞;部分显示肺栓塞的间接征象为:马赛克征、右心房及右心室肥厚及扩张、肺动脉扩张、胸腔积液、肺不张及实变(肺梗死)等。62例患者经溶栓治疗后复查CTPA,其中,栓子完全消失者47例,栓子明显缩小者11例,溶栓治疗效果差者3例,考虑为慢性肺栓塞。结论 64层螺旋CTPA是临床最有效的诊断肺栓塞及溶栓后疗效评价的无创性方法之一。     

多层螺旋CT在肺动脉栓塞诊断中的应用(附27例报告)

目的:探讨多层螺旋CT肺动脉成像(CTPA)对肺动脉栓塞的诊断价值.方法:对27例经MSCT确诊肺动脉栓塞患者进行回顾性分析.结果:多发肺动脉栓塞18例,其中双侧多发15例,左侧多发1例,右侧多发2例;单发9例,其中肺动脉干4例,叶动脉1例,段动脉4例.肺动脉栓塞的直接征象包括肺动脉主干或其分支的充盈缺损及肺动脉段面细小及管腔内不均匀密度减低;间接征象可以有肺内"马赛克征"、楔形影或索条状影,胸腔积液或胸膜肥厚.结论:CTPA对肺动脉栓塞的检查是一种价格便宜,无创伤的检查,诊断结果可靠,可作为急诊和普通临床工作中怀疑本病时首选的影像学检查方法.     

双源CT双能量肺灌注成像诊断急性肺栓塞的实验研究

目的 评价双源CT(DSCT)双能量肺灌注成像(DEPI)的可行件及其诊断急性实验性肺栓塞的价值.方法 对8只新两兰白兔制备成急性肺栓塞模型的前、后行DSCT平妇及双能量增强扣描,并进行数据后处理,分别得到CT解剖图像(CTPA)、DEPI及两者融合图像,观察肺动脉内有无栓子,分析栓塞前、后的肺灌注影像表现;进行家兔肺大体病理解剖和镜下观察.计算CTPA、DEPI及融合图像的诊断敏感度、特异度、阳性预测值(PPV)、阴性预测值(NPV).应用Kappa系数评价两种检查结果的一致性.结果 7只兔模型制作成功,1只因肺内导管头影响图像评价而排除;6只兔30个肺时数据可用于分析.病理共发现18个肺叶栓塞阳件,12个阴性.与正常肺组织相比,肺柃塞区域DEPI表现为灌注不良或缺损,CTPA表现为相应肺动脉中断或充盈缺损.CTPA诊断的敏感度、特异度、PPV、NPV分别为66.7%(12/18)、100.0%(12/12)、100.0%(12/12)、66.7%(12/18),与病理结果吻合度一般(Kappa=0.651);DEPI诊断的敏感度、特异度、PPV、NPV分别为88.9%(16/18)、91.7%(11/12)、94.1%(16/17)、84.6%(11/13),与病理结果吻合度较强(Kappa=0.795).融合图像结果与DEPI一致.结论 DSCT的DEPI能够反映兔肺部『『fL流分布情况,对肺栓塞的诊断有较高的敏感度,并与病理结果有较强的一致性.     

Dual-energy CT pulmonary angiography in patients with suspected pulmonary embolism: value for the detection and quantification of pulmonary venous congestion

Objective:

To evaluate if vascular and pulmonary parenchymal enhancement values in dual-energy (DE) CT pulmonary angiography (CTPA) can suggest the diagnosis of pulmonary congestion.

Methods:

DE-CTPA images of 90 out of 1321 patients negative for pulmonary embolism showed signs of congestive heart failure. We measured DE-derived pulmonary parenchymal [perfused blood volume (PBV)], pulmonary artery (PA) and left atrium (LA) enhancement values in these patients and in 142 control patients. Enhancement values were compared between the populations and correlated with serum values of B-type natriuretic peptide (BNP) and proBNP, where available.

Results:

No significant difference of PBV but significant differences of mean PA and LA enhancement and individual enhancement differences (PA − LA) were found between the populations. PA − LA was higher in patients with elevated BNP and proBNP and was positively correlated with these values. Receiver operating characteristic analysis revealed a moderate discriminatory power of the PA − LA difference for the presence of cardiac biomarker elevations.

Conclusion:

PBV in DE-CTPA is not altered in patients with signs of congestive heart failure. However, differences in enhancement values in the pre- and post-pulmonary vessels were found in comparison with the control population.

Advances in knowledge:

Altered pulmonary vascular haemodynamics in pulmonary venous congestion are not reflected in dual-energy-derived PBV maps. In the diagnosis of left heart failure in patients with chest pain and dyspnoea, density measurements in the pulmonary artery and in the left atrium in CTPA images may be a helpful diagnostic tool.In the diagnostic algorithms for patients with acute dyspnoea, CT pulmonary angiography (CTPA) plays a major role, specifically in cases when pulmonary embolism (PE) is suspected. Whenever no PE can be detected, radiologists face the challenge to detect alternative pathological thoracic findings. An undiagnosed acute or chronic left heart failure with pulmonary congestion can be an alternative cause of acute dyspnoea. Although there are some direct and indirect CT criteria that suggest the diagnosis of congestive heart failure with pulmonary venous hypertension (e.g. dilated pulmonary veins with a blurry appearance of the vessel walls, thickening of the interlobular septal lines, ground-glass opacities/alveolar oedema, pleural effusions and an enlargement of the left atrium and/or ventricle), the diagnosis of left heart failure on the basis of CT findings is often equivocal and rather rater dependent. For suspected left heart failure, chest radiography represents the primary diagnostic tool rather than CT. Still, if CTPA is performed in chest pain workup, an improved, more objective diagnosis of congestive heart failure would be desirable.Dual-energy CTPA (DE-CTPA) can quantify the iodine-related pulmonary beam absorption and thus allow an automated, reader-independent, software-based quantification of the pulmonary content of iodinated contrast material [termed “perfused blood volume” (PBV)].¹ Based on the assumption that an impaired left heart function leads to variances in the pulmonary blood content and in the dynamics of the pulmonary passage of the contrast bolus, we tried to find out if measured absorption values in iodine-enhanced DE-CTPA, that is, DE-based pulmonary PBV values as well as density measurements in the pulmonary trunk and the left atrium, can be helpful in the diagnosis of pulmonary congestion.For this purpose, we retrospectively compared pulmonary parenchymal, pulmonary artery (PA) and left atrium (LA) enhancement values in patients with CT signs of pulmonary congestion with those from patients with no detectable cardiopulmonary pathologies in DE-CTPA and correlated those values with serum levels of established left heart insufficiency markers [cardiac peptides: B-type natriuretic peptide (BNP) and proBNP].     

16排螺旋CT血管造影在肺动脉栓塞诊断中的应用

目的探讨16排螺旋CT血管造影（MSCTA）在肺动脉栓塞（PE）诊断中的临床应用价值。方法8例临床疑诊PE患者行MSCTA检查,并将薄层数据行多平面重组（MPR）与容积重建（VR）。结果CT诊断PE8例,共35处肺动脉栓子,其中,段及段以上栓子26处,亚段及以下栓子9处。栓子显示为部分性充盈缺损,附壁性充盈缺损,中心性充盈缺损以及完全性充盈缺损。结论MSCTA能直观地显示肺动脉各级栓子的部位和形态,对临床治疗方案的选择及疗效评价有较高的应用价值。     

CTPA在急性肺动脉栓塞合并肺动脉高压诊断中的价值

目的探讨CTPA在急性肺动脉栓塞（acutepulmonaryembolism,APE）合并肺动脉高压（pulmonaryarterialhypertension,PAH）诊断中的临床应用价值。方法选择108例临床拟诊APE的患者进行超声心动图及cTPA检查,以肺动脉收缩压~30mmHg为PAH诊断标准,分成PAH组46例,其余肺动脉压〈30mmHg者62例作为对照组,分别在CTPA轴位图像上进行相关测量及影像学表现分析,并进行统计学处理。结果主肺动脉直径、主肺动脉与升主动脉直径比值、主肺动脉与降主动脉直径比值与肺动脉高压程度呈正相关,以主肺动脉直径≥2．9cm诊断PAH的敏感度、特异度均较高（分别为95．65％和88．71％）。主肺动脉与升主动脉直径比值〉1、主肺动脉与降主动脉直径比值〉1．1诊断PAH敏感度分别为53．33％和91．48％,特异度分别为92．41％和65．57％,三者联合诊断PAH的敏感度和特异度分别为56．85％、96．85％。结论CTPA能够对PAH做出较为准确的判断,对评价APE严重程度及预后提供重要依据。     

CT肺动脉成像在COPD中的应用

慢性阻塞性肺疾病(COPD)呈进行性恶化性发展,随病情进展将发生肺血管结构重塑、肺循环血流动力学改变、慢性肺源性心脏病,甚至导致死亡。CT肺动脉成像(CTPA)通过测量肺动脉及右心室各径线,可观察双肺及胸腔的情况,从而对COPD的病变过程进行动态监测,同时能够提供右心改变的信息,完成诊断并评估其严重程度。当CTPA联合超声及MRI检查时,可为临床选择治疗决策提供更多信息。就CTPA在COPD中的应用作一综述。     

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.     

MSCTPA对肺栓塞患者右心功能的诊断价值

目的以超声心动图作为诊断右心功能的标准,探讨64层CT肺血管造影(CTPA)对肺栓塞患者右心功能的诊断价值。方法前瞻性收集了临床疑诊肺栓塞的41例行CTPA检查的患者,阳性组根据右心功能、肺动脉栓塞部位及肺动脉压力指数分组,薄层数据进行最大密度投影(MIP)、多平面重建(MPR)和容积再现(VRT),分析各组数据中右心功能参数的差异。结果 41例患者中肺栓塞阳性24例,阴性17例,CTPA诊断右心功能不全13例,超声心动图诊断右心功能不全11例。以超声心动图为标准,64层CTPA诊断右心功能不全的灵敏度为76.9%,特异度为90.9%,阳性预测值90.9%,阴性预测值76.9%,Kappa值为0.669,诊断具有中度一致性。对于主肺动脉干(PA)、升主动脉(Aorta)、上腔静脉(SVC)、奇静脉(AV)、冠状静脉窦(CS)、PA/Aorta比、LVd、RVd及RVd/LVd比之间比较,第一组中差异有统计学意义的指标有PA、PA/Aorta比,LVd、RVd及RVd/LVd,CS;第二组中差异均无统计学意义;第三组中,差异有统计学意义的指标有PA/Aorta比。结论 MSCTPA及其后处理重建技术可以在诊断肺栓塞的同时对心功能作出评价。     

64层螺旋CT肺血管造影在肺栓塞诊疗中的应用价值

目的 探讨64层螺旋CT在肺栓塞诊断及治疗中的指导作用.方法 63例患者均行64层螺旋CT肺血管造影(CTPA),并进行多种形式的图像重建结合轴位图像分析.结果 64层螺旋CTPA对63例患者肺动脉各级管腔内的栓子均明确显示,共累及肺动脉303支;图像分析结果伞部显示肺栓塞的直接征象为:主肺动脉和(或)左右肺叶、段、亚段血管腔内充盈缺损和血管阻塞;部分显示肺栓塞的间接征象为:马赛克征、右心房及右心室肥厚及扩张、肺动脉扩张、胸腔积液、肺不张及实变(肺梗死)等.62例患者经溶栓治疗后复查CTPA,其中,栓子完全消失者47例,栓子明显缩小者11例,溶栓治疗效果差者3例,考虑为慢性肺栓塞.结论 64层螺旋CTPA是临床最有效的诊断肺栓塞及溶栓后疗效评价的无创性方法之一.