Features of cardiac disease demonstrated on CT pulmonary angiography

The heart and mediastinal structures can be overlooked at CT pulmonary angiogram (CTPA). This pictorial review will demonstrate the features of cardiac disease that may be evident on a CTPA. CTPA allows assessment of not only the pulmonary arteries for embolism, but also of the bronchi, lung parenchyma, mediastinum and heart. Co-existent underlying or incidental cardiac disease is often present. Potentially life-threatening alternative diagnoses in a patient with chest symptoms can be reliably identified. Pathologies of the myocardium including hypertrophic cardio myopathy, pericardial disease, valvular disease, coronary artery disease, and intracardiac abnormalities are demonstrated pictorially. CTPA is increasingly used for the detection of pulmonary embolism. Most patients investigated have pathology other than PE as a cause of their symptoms. Frequently information about the heart is produced that provides important clues to determine the cause for the presenting symptoms and signs or reveals co-existing pathology. It is important to have a clear understanding of the features of cardiac disease which may be seen on a CTPA.     

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.     

Lung neovascularity in pulmonary arterial hypertension associated with congenital heart defects and idiopathic pulmonary arterial hypertension: study of 198 patients

Objectives

To correlate the severity of lung neovascularity (Sheehan vessels) with the cause and haemodynamic severity of pulmonary arterial hypertension (PAH), pulmonary artery (PA) size and heart disease type in patients with PH associated with congenital heart diseases (PAH-CHD) and idiopathic PH (IPAH).

Methods

We reviewed the HRCT and CT pulmonary angiography studies of 87 patients with PAH-CHD and 111 with IPAH; all had undergone right heart catheterisation. We evaluated the PA size and severity of neovascularity on CT.

Results

Neovascularity, which was found in 72% of PAH-CHD (56% with Eisenmenger’s syndrome) and in 22% of IPAH patients, is significantly related to the severity of PH and all patients with severe neovascularity had intermediate or high PH. All PAH-CHD patients had a dilated PA with a greater risk of developing severe dilatation (diameter >5?cm). The neovascularity correlated with the PA size only in IPAH.

Conclusions

Neovascularity even if not pathognomonic for PAH-CHD, is significantly more common in these patients, especially in Eisenmenger’s syndrome. It is often the first CT sign to indicate the severity of PH in PAH-CHD and IPAH. A neovascularity ≥5 on CT indicates a intermediate or high PH.

Key Points

? Large retrospective studying specific lung disorders in patients with pulmonary arterial hypertension. ? Neovascularity is often the first CT sign indicating the severity of pulmonary hypertension Alterations of lung parenchyma on CT in pulmonary hypertension are described ? The first study to assess the severity of pulmonary hypertension by CT ? If substantiated, CT might eventually replace some cardiac catheterisation for evaluating PH     

Pulmonary artery dissection in long standing idiopathic pulmonary arterial hypertension: A case report

Pulmonary arterial dissection (PAD) is a rare and often lethal complication of chronic pulmonary arterial hypertension (PAH), which may occurs in patients with idiopathic pulmonary arterial hypertension (IPAH) and potentially in those with connective tissue disorders. While rare, sudden death often occurs secondary to acute cardiac tamponade, as the pulmonary artery dissects into the pericardium; this diagnosis is often made postmortem. Nevertheless, with the proliferation of multidetector computed tomography (MDCT) as a diagnostic test, patients may be identified very early after symptom onset, prompting rapid intervention with decreased morbidity and mortality. We report a case of IPAH complicated by pulmonary artery aneurysm (PAA) and PAD, diagnosed by CT pulmonary angiogram (CTPA), and treated with bilateral lung transplantation, pulmonic valve replacement, and re-anastomosis of the donor main PA to a pulmonary valve conduit.     

Pulmonary hypertension: the contribution of MDCT to the diagnosis of its different types

Pulmonary hypertension is characterized by progressive involvement of the pulmonary vessels that leads to increased vascular resistance and consequently to right ventricular failure. Vascular lesions are a common factor in a wide spectrum of diseases, and their result, pulmonary hypertension, is a severe clinical condition with a poor prognosis that worsens the normal course of the diseases to which it is associated (COPD, collagen disease, sarcoidosis, and congenital or acquired heart disease). It is important for pulmonary hypertension to be diagnosed as early as possible because nowadays drugs can reduce mortality and improve the quality of life; furthermore, some types of pulmonary hypertension (e.g., chronic thromboembolism and those associated with some congenital heart diseases like left-to-right shunt) can be treated surgically. In cases of suspected pulmonary hypertension, imaging methods can confirm the diagnosis, suggest a cause, help choose the most appropriate treatment, and monitor the response to treatment. This review describes the approach to pulmonary hypertension using different imaging techniques; special emphasis is given to the role of multidetector CT (MDCT), which makes it possible to study all the organs in the thorax in a single acquisition. We review the radiological signs of pulmonary hypertension and the current (Dana Point) radiological criteria for classifying the type of hypertension based on alterations in the lung parenchyma, mediastinum, pleural spaces, and pericardium, as well as on the study of the chambers of the heart.     

Pulmonary arterial hypertension: a contemporary review

Pulmonary arterial hypertension has many causes, only some of which are well understood. The radiographic findings in pulmonary arterial hypertension are very similar regardless of the cause. Some radiographic features such as cardiac chamber enlargement, occur secondary to elevation of pulmonary pressures. In addition, sequential radiographs may demonstrate dramatic changes as the hypertension develops. This article presents examples of the various forms of pulmonary arterial hypertension, with pathologic correlation. Included are chronic pulmonary thromboembolism, plexogenic pulmonary arteriopathy, pulmonary venooclusive disease and persistent fetal circulation. Examples of lesions causing secondary pulmonary arterial hypertension: parenchymal lung disease, pulmonary venous hypertension, and congenital heart disease, are also illustrated.     

Die Computertomographie bei der Bildgebung von Kindern mit kongenitalen Herzvitien

Congenital heart diseases are the most common congenital abnormalities of development. In general, echocardiography and cardiac catheter angiography are considered the gold standard for the evaluation of congenital heart disease. Cardiac magnetic resonance imaging has become an important supplementary imaging modality because of its ability to provide an accurate morphological and functional evaluation. The role of cardiac computed tomography in the imaging of patients with congenital heart disease is becoming increasingly more important due to the development of low radiation dose protocols and improvements in the spatial and temporal resolution. In the preoperative depiction and follow-up after surgical repair of congenital heart diseases, cardiac computed tomography provides detailed information of the heart, the venous and arterial pulmonary circulation as well as systemic arteries. This article reviews the technical aspects of cardiac CT and the modification of examination protocols according to the expected pathology and patient age. The potentials and limitations of the various radiation dose reduction strategies are outlined.     

CT imaging of acute pulmonary embolism

CT pulmonary angiography (CTPA) has become the de facto clinical "gold standard" for the diagnosis of acute pulmonary embolism (PE) and has replaced catheter pulmonary angiography and ventilation-perfusion scintigraphy as the first-line imaging method. The factors underlying this algorithmic change are rooted in the high-sensitivity and specificity, cost-effectiveness, and 24-hour availability of CTPA. In addition, CTPA is superior to other imaging methods in its ability to diagnose and exclude, in a single examination, a variety of diseases that mimic the symptoms of PE. This article reviews the current role of CTPA in the diagnosis of acute PE as well as more recent developments, such as the use of CT parameters of right ventricular dysfunction for patient prognostication and the assessment of lung perfusion with CT.     

Pulmonary MR angiography and perfusion imaging—A review of methods and applications

The pulmonary vasculature and its role in perfusion and gas exchange is an important consideration in many conditions of the lung and heart. Currently the mainstay of imaging of the vasculature and perfusion of the lungs lies with CT and nuclear medicine perfusion scans, both of which require ionizing radiation exposure. Improvements in MRI techniques have increased the use of MRI in pulmonary vascular imaging. Here we review MRI methods for imaging the pulmonary vasculature and pulmonary perfusion, both using contrast enhanced and non-contrast enhanced methodology.In many centres pulmonary MR angiography and dynamic contrast enhanced perfusion MRI are now well established in the routine workflow of patients particularly with pulmonary hypertension and thromboembolic disease. However, these imaging modalities offer exciting new directions for future research and clinical use in other respiratory diseases where consideration of pulmonary perfusion and gas exchange can provide insight in to pathophysiology.     

婴儿先天性心脏病合并肺动脉高压的外科治疗

目的:总结婴儿先天性心脏病合并肺动脉高压的外科治疗和围术期处理的经验。方法:2004年1月～2006年6月共手术治疗婴儿先天性心脏病合并肺动脉高压患者72例,男性45例,女性27例;年龄2个月～1岁,平均(7.3±2.8)月,体重3.5～9.2kg,平均(6.2±3.6)kg。术前肺动脉收缩压为47.4～89.2mmHg,平均(64.3±7.6)mmHg;动脉血氧饱和度81%～98%。结果:手术死亡3例(4.17%)。主要并发症有肺动脉高压危象、低心输出量综合症、肺不张、张力性气胸、呼吸机相关肺炎、血源性感染,呼吸衰竭等。死亡原因:肺动脉高压危象2例,低心输出量综合症1例。术后SaO287%～98%。随访6个月～2年,无晚期死亡,余患者心功能较术前改善。结论:肺动脉高压危象和低心输出量综合症是婴儿先天性心脏病合并肺动脉高压患者术后的主要并发症和死亡原因,早期手术及搞好围术期的处理是提高生存率的关键。     

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.     

双能CT评估肺部血管性病变的研究进展

双能CT(DECT)依据不同能量下物质衰减特性不同进行定性和定量判断。DECT通过后处理可一次性生成碘图、虚拟平扫影像、灌注影像及虚拟单能谱影像等彩色编码影像,可以较全面地反映疾病的形态及功能变化特征。近年DECT已广泛应用于肺动脉栓塞、肺动脉高压、先天性血管发育异常、血管相关肿瘤及血管炎等肺部血管性病变的诊断、治疗及危险分层。就DECT技术原理及在肺部血管性病变中的应用进展进行综述。     

64层CT对先天性心脏病肺动脉发育异常的术前评价

目的 前瞻性研究64层CT心血管造影评价先天性心脏病肺动脉发育异常的可行性和准确性. 资料与方法对心脏超声诊断先天性心脏病并临床怀疑有肺动脉发育异常的49例患儿于手术前7天内行64层CT心血管造影榆查.对所有各向同性扫描的薄层图像行任意方向多平面重组(MPR)及容积再现(VR)重组以显示肺动脉形态及密度,并与手术所见对照分析.结果 49例先天性心脏病患儿术前心血管CT造影诊断肺动脉发育异常42例,其中肺动脉扩张6例,肺动脉广泛变细8例,肺动脉局限性狭窄18例,肺动脉闭锁6例,肺动脉部分缺如4例.与手术结果对照,64层CT造影诊断肺动脉发育异常的敏感性为96.2%,特异性为99.3%,阳性预测值为96.2%,阴性预测值为99.3%,准确性为98.8%.结论 64层CT心血管造影是评价先天性心脏病肺动脉发育异常的可行和准确的方法.     

Pulmonary hypertension and cor pulmonale

Summary Pulmonary hypertension is a severe disorder of the pulmonary circulation and occurs in a variety of vascular and parenchymal lung diseases. It leads to volume and/or pressure overload of the right ventricle and finally to right heart failure. Pulmonary vascular diseases such as chronic pulmonary embolism cause a drastic increase in pulmonary vascular resistance, which results in extremely high pulmonary artery pressures that can even reach systemic levels. On the other hand, moderate pulmonary hypertension can also occur in chronic obstructive and restrictive lung diseases. For a long time, the diagnosis of pulmonary hypertension and cor pulmonale was based upon findings in echocardiography and right heart catheterization. Today modern imaging techniques allow the radiologist to assess right ventricular and pulmonary artery morphology and function. The application of spiral CT, electron-beam CT and MRT permits the diagnosis and differential diagnosis of pulmonary hypertension and also the evaluation and follow-up of underlying vascular or parenchymal lung disorders. In addition, quantification of right ventricular function and calculation of pulmonary hemodynamic parameters are possible. Eingegangen am 28. Januar 1997 Angenommen am 5. Februar 1997     

Evaluation of mosaic pattern areas in HRCT with Min-IP reconstructions in patients with pulmonary hypertension: Could this evaluation replace lung perfusion scintigraphy?

Purpose

The aim of this study is to evaluate a possible correlation between areas of lung attenuation, found in minimum intensity projection (Min-IP) reconstruction images performed with high resolution computed tomography without contrast medium (HRCT), and areas of lung perfusion alteration, found in lung perfusion scintigraphy (LPS).

Materials and methods

Two independent radiologists, unaware of LPS results, evaluated retrospectively a group of 113 patients affected by pulmonary hypertension (HP) of different aetiology. These have been examined in a period of two years in our centre both by spiral computed tomography (CT) with and without contrast-medium and by LPS. The final diagnosis was determined on clinical data, right heart catheterisation and contrast enhanced CT in angiographic phase (CTPA). We reconstructed the Min-IP images of lung parenchyma in all the cases both in HRCT without contrast-medium, and in contrast enhanced CT in angiographic phase (CTPA) in axial, sagittal and coronal planes. The obtained images were qualitatively graded into three categories of pulmonary attenuation: homogeneous, inhomogeneous with non-segmental patchy defects, inhomogeneous with segmental defects. The same criteria of classification were used also for LPS images.In the group of patients with chronic thromboembolic pulmonary hypertension (CTEPH) we also compared the number of areas of lung attenuation found in Min-IP images in HRCT without contrast-medium, and their exact localization, with not perfused areas in LPS.Gold standard for the diagnosis of pulmonary embolism was spiral contrast enhanced CT in angiographic phase (CTPA).

Results

In all cases we found exact correspondence between the Min-IP images in HRCT with and without contras agent.The attenuation pattern seen on Min-IP images was concordant with those of LPS in 96 out of 113 patients (85%). In the remaining 17 cases (15%) it was discordant: in 12 cases inhomogeneous in Min-IP images (7 with non-segmental patchy defects, 5 with segmental defects) and homogeneous in LPS, in 5 cases inhomogeneous (1 with non-segmental patchy defects, 4 with segmental defects) in LPS images and homogeneous in Min-IP.In a general view, Min-IP reconstruction without contrast-medium showed a sensitivity of 100% and specificity of 96.1%, positive predictive value (PPV) of 92.3% and negative predictive value (NPV) of 100%, to recognize a pattern of lung attenuation inhomogeneous with segmental defects correspondent to a chronic thromboembolic condition, no false negative cases and three false positive cases; on the other hand LPS, on its own, showed a sensitivity of 91.67% and specificity of 93.51%, positive predictive value (PPV) of 86.84% and negative predictive value (NPV) of 96%, 3 false negative cases and 5 false positive cases.

Conclusion

Min-IP obtained in HRCT without contrast-medium and in CTPA were equivalent. Min-IP images generally showed a higher sensitivity and specificity than LPS in the evaluation of lung perfusion regarding patients with pulmonary hypertension caused by different etiology, particularly in CTEPH patients.These results can be completed with the evaluation of HRCT and CTPA basal scans, providing more informations than ventilation/perfusion lung scintigraphy.HRCT images integrated by Min-IP reconstruction can represent the first step in the diagnostic algorithm of patients affected by dyspnoea and pulmonary hypertension of unknown causes, reserving the use of contrast-medium only in selected patients and reducing the patients’ X-ray-exposition.     

Performance of computed tomography-derived pulmonary vasculature metrics in the diagnosis and haemodynamic assessment of pulmonary arterial hypertension

BackgroundFew studies have addressed the value of combining computed tomography-derived pulmonary vasculature metrics for the diagnosis and haemodynamic evaluation of pulmonary arterial hypertension (PAH).Materials and methodsWe measured three computed tomography parameters for the pulmonary artery, peripheral vessels, and pulmonary veins: the ratio of the diameter of the pulmonary artery to the aorta (PA/Ao), the cross-sectional area of small pulmonary vessels <5 mm² as a percentage of total lung area (%CSA_<5), and the diameter of the right inferior pulmonary vein (PVD). The measured quantities were compared between patients with PAH (n = 45) and control subjects (n = 56), and their diagnostic performance and associations with PAH-related clinical indices, including right heart catheterization measurements, were examined.ResultsPA/Ao and %CSA_<5 were significantly higher in patients with PAH than in controls. Receiver-operating characteristic curve analysis for ability to diagnose PAH showed a high area under the curve (AUC) for PA/Ao (0.95) and modest AUCs for %CSA_<5 (0.75) and PVD (0.56). PA/Ao correlated positively with mean pulmonary arterial pressure and PVD correlated negatively with pulmonary vascular resistance. The %CSA_<5 correlated negatively with mean pulmonary arterial pressure and pulmonary vascular resistance and positively with cardiac index. Notably, the PA/Ao and PVD values divided by %CSA_<5 correlated better with right heart catheterization indices than the non-divided values.ConclusionPA/Ao, %CSA_<5, and PVD are useful non-invasive pulmonary vasculature metrics, both alone and in combination, for diagnosis and haemodynamic assessment of PAH.     

心脏磁共振评估肺动脉高压的研究进展

肺动脉高压（PH）是一组恶性进展性疾病,可以导致右心衰竭甚至死亡,因此对其进行早期诊断和评估至关重要。心脏磁共振（CMR）作为评估心血管的“一站式”检查,不仅可以采用多参数对PH病人心脏结构、功能、血流动力学及心肌组织特征等进行评价,还可以鉴别不同类型的PH,在PH的诊疗评估中发挥着重要作用,特别是基于CMR的人工智能的应用更是成为PH临床实践的新方向。     

Imaging of acute pulmonary embolism using multi-detector CT angiography: An update on imaging technique and interpretation

Computed tomography angiography (CTA) of the pulmonary arteries has become the main diagnostic test for the evaluation of pulmonary embolism (PE). Not only due to the good availability, low cost and minimal invasiveness of this technique, but mainly because of the introduction of multi-detector CT techniques resulting in significant improvement in resolution, speed and image quality. This continuous gain in image acquisition speed went along with the introduction of new techniques of image acquisition, such as the dual-source CT scanning and novel concepts of image interpretation beyond morphological findings including the definition of the resulting perfusion defects and assessment of the cardiopulmonary circulation as a functional unit.This article will focus on technical and practical aspects to optimize CTPA examinations with modern multi-detector CT scanners, discusses aspects to be considered in specific patient groups (e.g., during pregnancy, young patients) and outlines new advents such as dual-source lung perfusion and automatic detection of pulmonary emboli.     

慢性血栓栓塞性肺动脉高压的MSCT 诊断价值

目的：探讨 MSCT 诊断慢性血栓栓塞性肺动脉高压(CTEPH)的应用价值。方法回顾性收集 CTEPH 患者24例及其他原因肺动脉高压患者8例。分析 CTEPH 患者 CT 肺动脉造影(CTPA)图像特点,总结其直接和间接征象,并与非 CTEPH 患者进行对比。采用 SPSS17.0统计软件,对各项结果进行统计学分析。结果CTPA 24例,744支动脉;CTEPH 直接征象以附壁栓子为最多见,占受累支数的55.35%,其次为完全闭塞,部分充盈缺损,中心型部分充盈缺损,血管壁不规则增厚及偏心性充盈缺损;35.01%的栓塞血管管腔变细,0.89%的血管管腔扩张,无任何变化的占45.24%;CTEPH 最常见的间接征象为肺动脉增宽(100%)及右心增大(95.83%),其次为马赛克征,心包腔或胸腔积液,肺内磨玻璃样影,肺梗死及肺不张或实变。所有患者均有不同程度的肺动脉压力升高,最常见的 CTPA 征象依次为肺动脉增宽、右心室增大、下腔静脉及肝静脉显影、支气管动脉扩张及室间隔位置异常。结论(1)CTPA 能够清楚地显示 CTEPH 的类型、直接和间接影像学征象;(2)心脏的 CT 表现不足以鉴别 CTEPH 和非 CTEPH;(3)慢性肺栓塞的程度并不能够反映 CTEPH 的严重程度。     

Right heart dilatation in adults: congenital causes

OBJECTIVE: The purpose of this article is to illustrate the common congenital cardiac lesions that are characterized by right-sided heart enlargement that may be seen on routine thoracic or cardiac imaging. CONCLUSION: A systematic approach to the evaluation of the right heart and an understanding of the congenital abnormalities causing right chamber enlargement will allow the radiologist to diagnose unsuspected cardiac abnormalities on routine clinical thoracic and cardiac imaging as well as accurately identify these defects on dedicated cardiac CT or MRI examinations.