The complex anatomy of the bronchial arteries: a meta-analysis with potential implications for thoracic surgery and hemoptysis treatment

The present meta-analysis aimed to provide the most detailed and comprehensive anatomical description of bronchial arteries (BAs) using data available in the literature. Adequate knowledge of the normal anatomy and morphological variations of BAs can be clinically significant; for example, this approach can prevent potential risks while undertaking bronchial artery embolization (BAE) procedures and, ultimately, lead to better patient outcomes. Major medical databases such as PubMed, Scopus, Embase, Web of Science, Google Scholar, and the Cochrane Library were searched. The overall search process was conducted in three main stages. The number of BAs varied from one to six, and 16 arterial patterns were observed. The most common variation was in one right BA and one left BA, with a pooled prevalence of 19.54% (95% CI 6.69-36.44%). The pooled prevalence of BAs originating separately from the aorta was 41.42% (95% CI 37.42-45.48%). The number and location of BAs are highly inconsistent. However, the most prevalent pattern involved two BAs: one in the right BA and one in the left BA. Although BAs most frequently originate from the descending aorta, the cooccurrence of at least one ectopic BA is relatively high. The results of our meta-analysis can serve as a source of comprehensive information for thoracic surgeons and physicians performing endovascular procedures, especially BAE, a treatment for life-threatening hemoptysis.

Imaging in Large Vessel Vasculitis-A Narrative Review

Vasculitis refers to a group of rare conditions characterized by the inflammation of blood vessels, affecting multiple systems. It presents a diagnostic and therapeutic challenge due to its broad clinical manifestations. Vasculitis is classified based on the size of the affected vessels: small, medium, large, or variable-sized. Large vessel vasculitis (LVV), particularly giant cell arteritis (GCA) and Takayasu arteritis (TAK), has garnered attention due to its significant morbidity and mortality. Both conditions involve immune-mediated inflammation of the vascular wall, despite differing in epidemiology and presentation. Early identification is crucial to prevent complications like organ ischemia and hemorrhage. Diagnostic accuracy can be hampered by false negative results, making comprehensive investigation essential. Vascular imaging, including computed tomography angiography (CTA), ultrasound (US), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT), is key in diagnosing vasculitis, revealing vessel wall thickening and other suggestive features. This article reviews typical and atypical CT and CTA findings in LVV, discusses imaging modalities, and highlights their role in therapeutic management and prognosis. It emphasizes the importance of a multidisciplinary approach and the critical role of radiologists in improving patient outcomes in LVV.

Prevalence and Clinical Characteristics of Heterozygous RNF213 p.Arg4810Lys Variant Carriers Diagnosed With Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

Ring finger protein 213 (RNF213) p.Arg4810Lys is a susceptibility gene for moyamoya disease, peripheral pulmonary artery stenosis (PPS), and other vascular diseases and thrombosis. We investigated the prevalence and clinical characteristics of RNF213 variant carriers diagnosed with chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS AND RESULTS

We retrospectively analyzed the prevalence of the RNF213 p.Arg4810Lys variant in patients diagnosed with CTEPH (n=112) and PPS (n=10). Clinical and angiographic characteristics were evaluated between RNF213 variant carriers diagnosed with CTEPH and noncarriers with CTEPH and homozygous variant carriers with PPS. Eight heterozygous RNF213 p.Arg4810Lys variant carriers (7.1%) were identified among patients diagnosed with CTEPH, while 5 patients with PPS (50%) carried the homozygous variant. The clinical characteristics of heterozygous variant carriers with CTEPH were not remarkably different from those of noncarriers with CTEPH. All heterozygous variant carriers with CTEPH showed webs/bands lesions at the segmental/subsegmental level, with 75% showing distal tortuous vessels. None of the heterozygous variant carriers with CTEPH exhibited the string-of-beads pattern or elongated stenosis. Homozygous variant carriers with PPS showed the string-of-beads pattern, elongated stenosis, and distal tortuous vessels without webs/bands lesions.

CONCLUSIONS

A subset of patients diagnosed with CTEPH (7.1%) carried the heterozygous RNF213 p.Arg4810Lys variant. Clinical and angiographic characteristics of heterozygous variant carriers were not remarkably different from those of noncarriers of CTEPH. However, both heterozygous variant carriers with CTEPH and homozygous variant carriers with PPS showed tortuous vessels on angiography.

Imaging of chronic thromboembolic pulmonary hypertension before, during and after balloon pulmonary angioplasty

Balloon pulmonary angioplasty (BPA) has recently been elevated as a class I recommendation for the treatment of inoperable or residual chronic thromboembolic pulmonary hypertension (CTEPH). Proper patient selection, procedural safety, and post-procedural evaluation are crucial in the management of these patients, with imaging work-up playing a pivotal role. Understanding the diagnostic and therapeutic imaging algorithms of CTEPH, the imaging features of patients amenable to BPA, all imaging findings observed during and immediately after the procedure and the changes observed during the follow-up is crucial for all interventional radiologists involved in the care of patients with CTEPH. This article illustrates the imaging work-up of patients with CTEPH amenable to BPA, the imaging findings observed before, during and after BPA, and provides a detailed description of all imaging modalities available for CTEPH evaluation.

Massive primary pulmonary artery rhabomyosarcoma: A case report

BACKGROUND

Pulmonary artery sarcomas (PAS) are rare tumours causing an insidiously progressive obstruction of the pulmonary circulation. The clinical presentation is often indistinguishable from chronic thromboembolic pulmonary hypertension (CTEPH). However, the atypical appearance of a heterogeneous filling defect in CT pulmonary angiography (CTPA) should prompt further investigation.

CASE PRESENTATION

A previously healthy young man presented with massive haemoptysis, acute respiratory distress, and progressive exertional dyspnea since the year before. Echocardiography demonstrated severe right ventricular dysfunction and highly probable pulmonary hypertension. CTPA revealed an extensive filling defect with an appearance concerning PAS. Due to syncopal episodes at rest, the patient underwent urgent pulmonary artery endarterectomy (PEA). A massive tree-like tumour was excised as a result. Post-operatively, reperfusion injury and refractory pulmonary oedema mandated extracorporeal membrane oxygenation (ECMO). Unfortunately, ECMO was complicated with massive haemolysis and acute kidney injury. The patient succumbed to multi-organ failure. Through tissue analysis established a diagnosis of embryonal rhabdomyosarcoma.

DISCUSSION

Unfortunately, the patient had not reached out for his worsening dyspnea. PASs should not be mistaken for a thrombus and anticoagulation should be avoided. The urgent condition precluded biopsy and tissue diagnosis. Similarly, neoadjuvant chemotherapy was not feasible. Post-operatively, reperfusion injury and pulmonary oedema ensued, which mandated ECMO. This complication should be anticipated preoperatively. There is a need for more data on PASs to establish a consensus for management.

Predictive Value of Pulmonary Artery Distensibility for Short-Term Adverse Clinical Outcomes in Patients with Acute Pulmonary Embolism

We aimed to explore the relationship between pulmonary artery distensibility obtained from computed tomography pulmonary angiography (CTPA) and short-term adverse clinical outcomes in patients with acute pulmonary embolism (APE). We included patients who underwent retrospective electrocardiogram-gated CTPA and were subsequently diagnosed with APE. Patients were categorized into good and poor outcome groups based on short-term clinical outcomes. Pulmonary artery distensibility (AD), right ventricle/left ventricle (RV/LV) ratio, and pulmonary artery obstruction index (PAOI) were measured, and the receiver operating characteristic curves were constructed. Sixty-four patients with APE (good outcome, 46; poor outcome, 18) were enrolled. AD, RV/LV ratio, and PAOI differed significantly between groups (P < 0.05). Pulmonary artery AD in the good outcome group was greater than that in the poor outcome group (P < 0.001). The poor outcome group exhibited a higher RV/LV ratio and PAOI than the good outcome group (P < 0.05). AD and PAOI were independent predictors of adverse clinical outcomes. Areas under the curve for AD and PAOI were 0.860 (95% confidence interval [CI]: 0.750-0.934) and 0.675 (95%CI: 0.546-0.786), and the combined curve of the AD and RV/LV ratio was 0.906 (95%CI: 0.806-0.965). The calibration curve showed a combined curve superior to the other curves. The decision curve showed high clinical application value of the combined curve. Retrospective electrocardiogram-gated CTPA-derived AD could serve as an indicator for predicting short-term adverse clinical outcomes in APE. Combining AD and PAOI has a high predictive value for short-term adverse clinical outcomes.

Predictive value of reduced pulmonary arterial elasticity in acute pulmonary embolism for right ventricular dysfunction

BACKGROUND

Computed tomography pulmonary angiography (CTPA) yields indices, such as the right ventricular/left ventricular (RV/LV) ratio > 1.0, which are commonly used for risk stratification of patients with acute pulmonary embolism (APE). Although pulmonary artery elasticity (PAE) has been previously described, its relationship with right ventricular dysfunction (RVD) has not been explored. Here, we investigated whether PAE, measured using CTPA, is associated with RVD.

METHODS

Patients who underwent retrospective electrocardiogram-gated CTPA and had a definitive diagnosis of APE were included in the study. The subjects were classified into RVD and non-RVD groups according to the RVD on echocardiography. PAE, involving aortic distensibility (AD), aortic compliance (AC), and aortic stiffness (ASI), and right heart function indices were compared between the two groups, and their correlations were examined. Receiver operating characteristic (ROC) curves were generated to evaluate the specificity and sensitivity of the RVD prediction.

RESULTS

Thirty-five patients with APE were enrolled in the study (RVD: 18, non-RVD: 17). The groups showed no significant differences in age, sex, number of patients receiving thrombolysis, and number of high-risk conditions (P > 0.05). Regarding PAE parameters, AD was significantly reduced in the RVD group compared to that in the non-RVD group (P < 0.05), whereas AC and ASI were not statistically different (P > 0.05). The ratio of the maximum cross-sectional area of PA and AA (PA/AAmax),the ratio of the minimum cross-sectional area of PA and AA(PA/AAmin), diameter of the coronary sinus, RV/LV diameter, RV/Lvarea, the ratio of the end-diastolic volume of right ventricular and left ventricular (RV/LVDV), the ratio of the end-systolic volume of right ventricular and left ventricular (RV/LVSV) were significantly greater in the RVD group than in the non-RVD group (P < 0.05). Correlation analysis of AD and right heart function parameters showed that AD was negatively correlated with PA/AAmax, PA/AAmin, RV/LV diameter, RV/LVDV, and PAE measured by ultrasound, with correlation coefficients ranging from - 0.336 to - 0.580 (P < 0.05). The ROC curves of AD and RV/LVdiameter to predict RVD had areas under the curve of 0.748 and 0.712, sensitivities of 82.35% and 70.59%, specificities of 66.67% and 72.22%, and cutoff values of 4.9433 and 1.1105, respectively.

CONCLUSION

AD obtained by retrospective ECG-gated CTPA may be helpful in assessing RVD in patients with APE while accurately diagnosing APE. It contributes to timely diagnosis and treatment and improves the prognosis of patients with APE.

Enhancing preoperative assessment in chronic thromboembolic pulmonary hypertension: A comprehensive analysis of interobserver agreement and proximity-based CT pulmonary angiography scoring

Background

Surgical risk in chronic thromboembolic pulmonary hypertension (CTEPH) depends on the proximity of thromboembolism on CT pulmonary angiography (CTPA). We assessed interobserver agreement for the quantification of thromboembolic lesions in CTEPH using a novel CTPA scoring index.

Methods

Forty CTEPH patients (mean age, 58 ± 16 years; 19 men) with preoperative CTPA who underwent pulmonary endarterectomy (PEA) (08/2020-09/2021) were retrospectively included. Three radiologists scored each CTPA for chronic thromboembolism (occlusions, eccentric thickening, webs) using a 32-vessel model of the pulmonary vasculature, with interobserver agreement evaluated using Fleiss' kappa. CT level of disease was determined by the most proximal chronic thromboembolism: level 1 (main pulmonary artery), 2 (lobar), 3 (segmental) and 4 (subsegmental), and compared to surgical level at PEA.

Results

Interobserver agreement for CT level of disease was moderate overall (κ = 0.52). Agreement was substantial overall at the main/lobar level (κ, mean = 0.71) when excluding the left upper lobe (κ = 0.17). Though segmental and subsegmental agreement suffered (κ = 0.31), we found substantial agreement for occlusions (κ = 0.72) compared to eccentric thickening (κ = 0.45) and webs (κ = 0.14). Correlation between CT level and surgical level was strong overall (τb = 0.73) and in the right lung (τb = 0.68), but weak in the left lung (τb = 0.42) (p < 0.05). Radiologists often over- and underestimated the proximal extent of disease in right and left lung, respectively.

Conclusions

CT level of disease demonstrated good agreement between radiologists and was highly predictive of the surgical level in CTEPH. Occlusions were the most reliable sign of chronic thromboembolism and are important in assessing the segmental vasculature.

Chronic inflammatory pulmonary artery lesion causing right pulmonary artery stenosis 15 years post Blalock-Taussig shunt ligation

Discrete central endovascular pulmonary arterial lesions raise clinical concern for malignancy such as primary pulmonary artery sarcoma. We present a case of a female in her late teens who had an obstructive mid right pulmonary artery lesion found on follow-up imaging 15 years after Tetralogy of Fallot repair. The lesion was in the vicinity of a previously ligated Blalock-Taussig shunt and causing right PA stenosis with delayed perfusion to the right lung, and a flow-related distal left PA aneurysm. The lesion was excised and confirmed histologically to be inflammatory in nature. Intraoperative microbiology demonstrated growth of the Kytococcus species, and she was managed with 6 weeks of intravenous antibiotics, with a full recovery.

Leveraging open dataset and transfer learning for accurate recognition of chronic pulmonary embolism from CT angiogram maximum intensity projection images

BACKGROUND

Early diagnosis of the potentially fatal but curable chronic pulmonary embolism (CPE) is challenging. We have developed and investigated a novel convolutional neural network (CNN) model to recognise CPE from CT pulmonary angiograms (CTPA) based on the general vascular morphology in two-dimensional (2D) maximum intensity projection images.

METHODS

A CNN model was trained on a curated subset of a public pulmonary embolism CT dataset (RSPECT) with 755 CTPA studies, including patient-level labels of CPE, acute pulmonary embolism (APE), or no pulmonary embolism. CPE patients with right-to-left-ventricular ratio (RV/LV) < 1 and APE patients with RV/LV ≥ 1 were excluded from the training. Additional CNN model selection and testing were done on local data with 78 patients without the RV/LV-based exclusion. We calculated area under the receiver operating characteristic curves (AUC) and balanced accuracies to evaluate the CNN performance.

RESULTS

We achieved a very high CPE versus no-CPE classification AUC 0.94 and balanced accuracy 0.89 on the local dataset using an ensemble model and considering CPE to be present in either one or both lungs.

CONCLUSIONS

We propose a novel CNN model with excellent predictive accuracy to differentiate chronic pulmonary embolism with RV/LV ≥ 1 from acute pulmonary embolism and non-embolic cases from 2D maximum intensity projection reconstructions of CTPA.

RELEVANCE STATEMENT

A DL CNN model identifies chronic pulmonary embolism from CTA with an excellent predictive accuracy.

KEY POINTS

• Automatic recognition of CPE from computed tomography pulmonary angiography was developed. • Deep learning was applied on two-dimensional maximum intensity projection images. • A large public dataset was used for training the deep learning model. • The proposed model showed an excellent predictive accuracy.

Cross-platform privacy-preserving CT image COVID-19 diagnosis based on source-free domain adaptation

In the wake of the Coronavirus disease (COVID-19) pandemic, chest computed tomography (CT) has become an invaluable component in the rapid and accurate detection of COVID-19. CT scans traditionally require manual inspections from medical professionals, which is expensive and tedious. With advancements in machine learning, deep neural networks have been applied to classify CT scans for efficient diagnosis. However, three challenges hinder this application of deep learning: (1) Domain shift across CT platforms and human subjects impedes the performance of neural networks in different hospitals. (2) Unsupervised Domain Adaptation (UDA), the traditional method to overcome domain shift, typically requires access to both source and target data. This is not realistic in COVID-19 diagnosis due to the sensitivity of medical data. The privacy of patients must be protected. (3) Data imbalance may exist between easy/hard samples and between data classes which can overwhelm the training of deep networks, causing degenerate models. To overcome these challenges, we propose a Cross-Platform Privacy-Preserving COVID-19 diagnosis network (CP 3 Net) that integrates domain adaptation, self-supervised learning, imbalanced label learning, and rotation classifier training into one synergistic framework. We also create a new CT benchmark by combining real-world datasets from multiple medical platforms to facilitate the cross-domain evaluation of our method. Through extensive experiments, we demonstrate that CP 3 Net outperforms many popular UDA methods and achieves state-of-the-art results in diagnosing COVID-19 using CT scans.

Update on the roles of imaging in the management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH), classified as group 4 pulmonary hypertension (PH), is caused by stenosis and obstruction of the pulmonary arteries by organized thrombi that are incompletely resolved after acute pulmonary embolism. The prognosis of patients with CTEPH is poor if untreated; however, in expert centers with multidisciplinary teams, a treatment strategy for CTEPH has been established, dramatically improving its prognosis. CTEPH is currently not a fatal disease and is the only curable form of PH. Despite these advances and the establishment of treatment approaches, early diagnosis is still challenging, especially for non-experts, for several reasons. One of the reasons for this is insufficient knowledge of the various diagnostic imaging modalities, which are essential in the clinical practice of CTEPH. Imaging modalities should detect the following pathological findings: lung perfusion defects, thromboembolic lesions in pulmonary arteries, and right ventricular remodeling and dysfunction. Perfusion lung scintigraphy and catheter angiography have long been considered gold standards for the detection of perfusion defects and assessment of vascular lesions, respectively. However, advances in imaging technology of computed tomography and magnetic resonance imaging have enabled the non-invasive detection of these abnormal findings in a single examination. Cardiac magnetic resonance (CMR) is the gold standard for evaluating the morphology and function of the right heart; however, state-of-the-art techniques in CMR allow the assessment of cardiac tissue characterization and hemodynamics in the pulmonary arteries. Comprehensive knowledge of the role of imaging in CTEPH enables appropriate use of imaging modalities and accurate image interpretation, resulting in early diagnosis, determination of treatment strategies, and appropriate evaluation of treatment efficacy. This review summarizes the current roles of imaging in the clinical practice for CTEPH, demonstrating the characteristic findings observed in each modality.

Interventional Imaging Roadmap to Successful Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension

Balloon pulmonary angioplasty (BPA) is an evolving treatment modality for patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are not candidates for pulmonary endarterectomy. Although several imaging modalities currently exist for evaluating CTEPH, their individual use, specifically in the clinical practice of BPA, has not been well described. In this article, we provide a preprocedural, intraprocedural, and postprocedural interventional imaging roadmap for safe and effective BPA performance in routine clinical practice. Preprocedural assessment includes transthoracic echocardiography for right ventricular assessment, ventilation/perfusion scan to identify pulmonary segments with the highest degree of hypoperfusion, cross-sectional chest imaging excluding alternative causes of mismatched defects and providing anatomic and perfusion imaging concurrently, and nonselective invasive pulmonary angiography for risk stratification of individual lesion subtypes. Intraprocedural assessment includes subselective segmental angiography (SSA) for delineating segmental and subsegmental branch anatomy, lesion identification, and vessel sizing. Intravascular ultrasound and optical coherence tomography serve as adjunctive intraprocedural tools for more accurate vessel sizing and lesion characterization when SSA alone is insufficient. Postprocedural considerations include chest radiography to monitor for immediate postprocedure complications and echocardiography for the interval assessment of the right ventricle on longer-term follow-up.

Diagnosing Pulmonary Embolism With Computed Tomography Pulmonary Angiography: Diagnostic Accuracy of a Reduced Scan Range

PURPOSE

Computed tomography pulmonary angiography (CT-PA) is frequently used in the diagnostic workup of pulmonary embolism (PE), even in highly radiosensitive patient populations. This study aims to assess CT-PA with reduced z -axis coverage (compared with a standard scan range covering the entire lung) for its sensitivity for detecting PE and its potential to reduce the radiation dose.

MATERIALS AND METHODS

We retrospectively analyzed 602 consecutive CT-PA scans with definite or possible PE reported. A reduced scan range was defined based on the topogram, where the cranial slice was set at the top of the aortic arch and the caudal slice at the top of the lower hemidiaphragm. Locations of emboli in relation to the reduced scan range were recorded.

RESULTS

We included 513 CT-PA scans with definite acute PE in statistical analysis. Patients' median age was 66 (52 to 77) years, 46% were female. Median dose length product was 270.8 (111.3 to 503.9) mGy*cm. Comparing the original and reduced scan ranges, the mean scan length was significantly reduced by 48.0±8.6% (26.8±3.0 vs. 13.9±2.6 cm, P <0.001). Single emboli outside the reduced range in addition to emboli within were found in 15 scans (2.9%), while only 1 scan (0.2%) had an embolus outside the reduced range and none within it. The resulting sensitivity of CT-PA with reduced scan range was 99.81% (95% confidence interval: 98.74%-99.99%) for detecting any PE.

CONCLUSION

A reduced scan length in CT-PA, as defined above, would substantially decrease radiation dose while maintaining diagnostic accuracy for detecting PE.

Embolized fibrin sheath material presenting as intraluminal calcifications within the pulmonary arteries on CT

Fibrin sheath formation is a well-described sequela of an indwelling central venous catheter. Fibrin sheaths may also develop around other foreign bodies within the venous system. We describe a case of fibrin sheath formation within the left brachiocephalic vein secondary to automatic implantable cardioverter-defibrillator (AICD) leads with subsequent embolization of sheath material presenting as calcifications within the pulmonary vasculature on computed tomography (CT). Most of the relevant literature focuses on catheter-related sheath formation and associated complications while reports on fibrin sheaths from other foreign bodies are sparse. We advise that radiologists who encounter intraluminal calcifications within the pulmonary arteries on CT should consider the possibility of a fibrin sheath as the source and search for its remnants in the central venous system for confirmation.

Decreased Pulmonary Artery Bifurcation Angle: A Novel Imaging Criterion for the Diagnosis of Chronic Pulmonary Thromboembolism

Background

Chronic pulmonary thromboembolism (CTEPH) is an unusual complication of acute pulmonary embolism (PE), which is now considered to be treatable. In modern multi-detector scanners, a detailed evaluation of pulmonary artery geometry is currently possible. This study aimed to evaluate the changes in pulmonary artery bifurcation angle (PABA) in the follow-up computed tomography angiography (CTA) of patients with acute PE.

Methods

In this cross-sectional study, the records of two tertiary-level academic hospitals were gathered from 2012 to 2019. Pulmonary artery (PA) bifurcation angle and diameter were measured. Chi square test, independent samples t test, Mann-Whitney, and Pearson's tests were employed to compare data. To evaluate the cut-off point, we utilized receiver operating characteristic (ROC) curve analysis. The accuracy, sensitivity, and specificity of pulmonary artery bifurcation angle changes were calculated. A P value <0.05 was considered to be significant.

Results

Forty-six patients were included in the study. No significant differences were found between patients with and without CTEPH, and PABA in the dimeters of PA trunk, right PA, and left PA in the first CTA images (P values of 0.151, 0.142, 0.891, and 0.483, respectively), while in the secondary CTA, the mean PABA was significantly smaller in patients with CTEPH (P=0.011). In the receiver operating characteristic (ROC) analysis, delta angle revealed an area under the curve of 0.745 and an optimal cutoff of 0, leading to a sensitivity of 64%, specificity of 87%, and accuracy of 76% for diagnosing CTEPH.

Conclusion

We showed a significant decrease in PABA in patients developing CTEPH. This parameter can be easily measured in lung CTA.

Complex adult congenital heart disease on cross-sectional imaging: an introductory overview

Congenital heart disease is the most common group of congenital pathology. Over the past few decades, advances in surgical treatment have resulted in a rising population of adult patients with repaired complex congenital heart disease. Although the quality of life has greatly improved, a significant proportion of morbidities encountered in clinical practice is now seen in adults rather than in children. These patients often have significant haemodynamic pathophysiology necessitating repeat intervention. CT and MRI are excellent imaging modalities, which help elucidate potential complications that may need urgent management. Although imaging should be performed in specialised centres, occasionally patients may present acutely to emergency departments in hospitals with little experience in managing potentially complex patients. The purpose of this article is to provide an introductory overview to the radiologist who may not be familiar with complex congenital heart disease in adult patients. This educational review has three main sections: (1) a brief overview of the post-operative anatomy and surgical management of the most common complex conditions followed by (2) a discussion on CT/MRI protocols and (3) a review of the various complications and their CT/MRI findings.

An Overview of Different Techniques for Improving the Treatment of Pulmonary Hypertension Secondary in Systemic Sclerosis Patients

In systemic sclerosis (SSc) mortality is mainly linked to lung involvement which is characterized by interstitial lung disease (ILD) and pulmonary hypertension (PH). In SSc, PH may be due to different etiologies, including ILD, chronic thromboembolic disease, pulmonary veno-occlusive disease, and pulmonary arterial hypertension (PAH). The main tool to screen PAH is transthoracic echocardiography (TTE), which has a sensitivity of 90%, even if definitive diagnosis should be confirmed by right heart catheterization (RHC). The radiological evaluation (i.e., HRTC) plays an important role in defining the possible causes and in monitoring the evolution of lung damage. For PAH, identifying individuals who have borderline elevation of pulmonary arterial pressure needs to be appropriately managed and followed. In the past few years, the strategy for the management of PAH has significantly evolved and new trials are underway to test other therapies. This review provides an overview of the tools to evaluate PAH in SSc patients and on treatment options for these patients.

CT pulmonary angiography findings in HIV-infected patients referred for suspected pulmonary thrombo-embolic disease

Background

South Africa bares a significant burden of HIV and imaging is commonly performed as part of the workup for respiratory distress.

Objectives

The aim of this study was to document the prevalence of pulmonary thrombo-embolic disease (PTED) and other findings in HIV-infected patients referred for CT pulmonary angiography (CTPA) for suspected PTED.

Method

Forty CTPA studies of documented HIV-infected individuals investigated for suspected PTED during a 1-year period were retrieved, anonymised and interpreted by three consultant radiologists. Inter-reader reliability was calculated using Free Marginal multi-rater Kappa.

Results

Fourteen of the forty cases (35%) were positive for PTED. In the pulmonary embolism (PE)-positive group, 57.14% had peripheral disease and 42.86% had both peripheral and central disease. Associated findings in the PE-positive cases were pulmonary infarcts (17.5%), mosaic attenuation (17.5%) and linear atelectasis (7.5%). The most common incidental findings were solid pulmonary nodules (52.5%), non-wedge-shaped consolidation (45%), cardiomegaly (52.5%) and enlarged intra-thoracic lymph nodes (52.5%). Thirty per cent of the study population had findings related directly to the presence of PTED, whilst most cases in the study (77.5%) had pulmonary findings unrelated to PTED. In the PE-negative cases, 55% reported emergent findings that warranted immediate or urgent medical attention.

Conclusion

Computed tomography pulmonary angiography imaging is critical for diagnosing PE. However, further investigation into the judicious application of CTPA in HIV-infected patients with suspected PTED is required, as CTPA findings in most of the cases in this study were unrelated to PE.

Isolated congenital interruption of the right interlobar pulmonary artery with unilateral interstitial lung abnormality

We report a case of an isolated congenital interruption of the right interlobar pulmonary artery with unilateral interstitial lung abnormality. 3D-CT with enhancement showed absent right interlobar pulmonary artery without any other abnormalities of the pulmonary artery and an enlarged inferior phrenic artery. High-resolution CT demonstrated ground-glass opacities, reticular changes, and small cysts in the right middle and lower lobes, which were compatible with interstitial lung abnormality. The patient was diagnosed with an isolated congenital interruption of the right interlobar pulmonary artery since chronic pulmonary thromboembolism, structural heart disease, systemic congenital disease, and systemic vasculitis were ruled out.

Tricuspid Valve Imaging and Right Ventricular Function Analysis Using Cardiac CT and MRI

Cardiac computed tomography (CT) and cardiac magnetic resonance imaging (CMR) can reveal the detailed anatomy and function of the tricuspid valve and right ventricle (RV). Quantification of tricuspid regurgitation (TR) and analysis of RV function have prognostic implications. With the recently available transcatheter treatment options for diseases of the tricuspid valve, evaluation of the tricuspid valve using CT and CMR has become important in terms of patient selection and procedural guidance. Moreover, CT enables post-procedural investigation of the causes of valve dysfunction, such as pannus or thrombus. This review describes the anatomy of the tricuspid valve and CT and CMR imaging protocols for right heart evaluation, including RV function and TR analyses. We also demonstrate the pre-procedural planning for transcatheter treatment of TR and imaging of postoperative complications using CT.

Pediatric Pulmonary Embolism: Imaging Guidelines and Recommendations

In contrast with the algorithms and screening criteria available for adults with suspected pulmonary embolism, there is a paucity of guidance on the diagnostic approach for children. The incidence of pulmonary embolism in the pediatric population and young adults is higher than thought, and there is an urgent need for updated guidelines for the imaging approach to diagnosis in the pediatric population. This article presents an up-to-date review of imaging techniques, characteristic radiologic findings, and an evidence-based algorithm for the detection of pediatric pulmonary embolism to improve the care of pediatric patients with suspected pulmonary embolism.

Performance of a 3D convolutional neural network in the detection of hypoperfusion at CT pulmonary angiography in patients with chronic pulmonary embolism: a feasibility study

BACKGROUND

Chronic pulmonary embolism (CPE) is a life-threatening disease easily misdiagnosed on computed tomography. We investigated a three-dimensional convolutional neural network (CNN) algorithm for detecting hypoperfusion in CPE from computed tomography pulmonary angiography (CTPA).

METHODS

Preoperative CTPA of 25 patients with CPE and 25 without pulmonary embolism were selected. We applied a 48%-12%-40% training-validation-testing split (12 positive and 12 negative CTPA volumes for training, 3 positives and 3 negatives for validation, 10 positives and 10 negatives for testing). The median number of axial images per CTPA was 335 (min-max, 111-570). Expert manual segmentations were used as training and testing targets. The CNN output was compared to a method in which a Hounsfield unit (HU) threshold was used to detect hypoperfusion. Receiver operating characteristic area under the curve (AUC) and Matthew correlation coefficient (MCC) were calculated with their 95% confidence interval (CI).

RESULTS

The predicted segmentations of CNN showed AUC 0.87 (95% CI 0.82-0.91), those of HU-threshold method 0.79 (95% CI 0.74-0.84). The optimal global threshold values were CNN output probability ≥ 0.37 and ≤ -850 HU. Using these values, MCC was 0.46 (95% CI 0.29-0.59) for CNN and 0.35 (95% CI 0.18-0.48) for HU-threshold method (average difference in MCC in the bootstrap samples 0.11 (95% CI 0.05-0.16). A high CNN prediction probability was a strong predictor of CPE.

CONCLUSIONS

We proposed a deep learning method for detecting hypoperfusion in CPE from CTPA. This model may help evaluating disease extent and supporting treatment planning.

Evaluation and management of patients with chronic thromboembolic pulmonary hypertension - consensus statement from the ISHLT

ISHLT members have recognized the importance of a consensus statement on the evaluation and management of patients with chronic thromboembolic pulmonary hypertension. The creation of this document required multiple steps, including the engagement of the ISHLT councils, approval by the Standards and Guidelines Committee, identification and selection of experts in the field, and the development of 6 working groups. Each working group provided a separate section based on an extensive literature search. These sections were then coalesced into a single document that was circulated to all members of the working groups. Key points were summarized at the end of each section. Due to the limited number of comparative trials in this field, the document was written as a literature review with expert opinion rather than based on level of evidence.

Evolution of CT findings after anticoagulant treatment for acute pulmonary embolism in patients with and without an ultimate diagnosis of chronic thromboembolic pulmonary hypertension

INTRODUCTION

The pulmonary arterial morphology of patients with pulmonary embolism (PE) is diverse and it is unclear how the different vascular lesions evolve after initiation of anticoagulant treatment. A better understanding of the evolution of computed tomography pulmonary angiography (CTPA) findings after the start of anticoagulant treatment may help to better identify those PE patients prone to develop chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to assess the evolution of various thromboembolic lesions on CTPA over time after the initiation of adequate anticoagulant treatment in individual acute PE patients with and without an ultimate diagnosis of CTEPH.

METHODS

We analysed CTPA at diagnosis of acute PE (baseline) and at follow-up in 41 patients with CTEPH and 124 patients without an ultimate diagnosis of CTEPH, all receiving anticoagulant treatment. Central and segmental pulmonary arteries were scored by expert chest radiologists as normal or affected. Lesions were further subclassified as 1) central thrombus, 2) total thrombotic occlusion, 3) mural thrombus, 4) web or 5) tapered pulmonary artery.

RESULTS

Central thrombi resolved after anticoagulant treatment, while mural thrombi and total thrombotic occlusions either resolved or evolved into webs or tapered pulmonary arteries. Only patients with an ultimate diagnosis of CTEPH exhibited webs and tapered pulmonary arteries on the baseline scan. Moreover, such lesions always persisted after follow-up.

CONCLUSIONS

Webs and tapered pulmonary arteries at the time of PE diagnosis strongly indicate a state of chronic PE and should raise awareness for possible CTEPH, particularly in patients with persistent dyspnoea after anticoagulant treatment for acute PE.

Temporal Analysis of Tachycardia During Catheter Directed Thrombolysis for Acute Pulmonary Embolism

PURPOSE

To evaluate the effect of catheter directed thrombolysis (CDT) on heart rate (HR) in patients with sinus tachycardia and acute pulmonary embolism (PE).

METHODS

A retrospective chart review was performed for patients who underwent CDT with tPA for acute massive or submassive PE between 12/2009 and 2/2020. Included were patients who presented with tachycardia at the time of initiation of CDT. Patients with chronic PE, atrial fibrillation, beta blocker therapy, adjunctive endovascular therapy, systemic thrombolysis, or who expired before conclusion of CDT were excluded. HR was measured approximately every hour during CDT. Graphs were plotted of HR as a function of CDT duration. Two interventional radiologists identified the point of plateau (POP) on the graph where CDT had maximized its benefit in decreasing the patient's HR. Discrepancies were adjudicated by a third interventional radiologist and the median of the 3 measurements was selected. The primary endpoint was the duration of CDT from initiation until the POP.

RESULTS

48 patients were included (52.5 ± 14.7 years, 56.3% female). The POP occurred after 13.1 ± 6.1 hours, by which point HR had been reduced from 110 ± 9.2 bpm to 88 ± 10.6 bpm. Sinus tachycardia was not resolved in 10 patients even though they achieved maximal improvement in HR after 11.3 ± 6.7 hours.

CONCLUSION

Patients presenting with sinus tachycardia related to acute PE achieved maximal, sustained reduction in heart rate from CDT, after approximately 13 hours of infusion. Patients who did not resolve their tachycardia by that point in time were unlikely to resolve it by the conclusion of CDT.

Pulmonary artery obstruction index, pulmonary artery diameter and right ventricle strain as prognostic CT findings in patient with acute pulmonary embolism

OBJECTIVE

This study was designed to determine predictors of pulmonary hypertension and signs of right heart dysfunction caused by pulmonary embolism (PE) that may lead to early detection of high-risk patients. So the predictive value of pulmonary artery obstruction index (PAOI), measured by pulmonary CT angiography (PCTA) in the acute setting, in predicting the patients susceptible to PE cardiac complications was evaluated. Also two other PCTA indices, pulmonary artery diameter (PAD), and right ventricle (RV) strain, in these patients were investigated and their predictive value for cardiac complications on follow up echocardiography were demonstrated.

MATERIALS AND METHODS

In the study 120 patients with a definite diagnosis of PE were included. The PAOI, PAD and RV strain were measured using PCTA at the time of the initial diagnosis. Transthoracic echocardiography was done 6 months after the diagnosis of PE and RV echocardiographic indices were measured. Pearson correlation was used to investigate correlation between PAOI, PAD, RV strain and signs of right heart dysfunction.

RESULTS

PAOI was strongly correlated with systolic pulmonary artery pressure (SPAP) (r=0.83), RV systolic pressure (r=0.78) and RV wall thickness (r=0.61) in long-term follow up echocardiography. A higher rate of RV dysfunction and RV dilation was detected among the patients with higher PAOI (P<0.001). PAOI≥18 was strongly predictive for development of RV dysfunction. Also developments of pulmonary hypertension, RV systolic hypertension, RV dilation, RV dysfunction, and RV hypertrophy were significantly more common among patients with higher PAD and RV strain (P<0.001).

CONCLUSIONS

PAOI, PAD and RV strain are sensitive and specific PCTA indices that can predict the development of long-term complications such as pulmonary hypertension and right heart dysfunction, at the time of initial PE diagnosis.

Safety and efficacy of Wharton's jelly-derived mesenchymal stem cells with teriparatide for osteoporotic vertebral fractures: A phase I/IIa study

Osteoporotic vertebral compression fractures (OVCFs) are serious health problems. We conducted a randomized, open-label, phase I/IIa study to determine the feasibility, safety, and effectiveness of Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) and teriparatide (parathyroid hormone 1-34) in OVCFs. Twenty subjects with recent OVCFs were randomized to teriparatide (20 μg/day, daily subcutaneous injection for 6 months) treatment alone or combined treatment of WJ-MSCs (intramedullary [4 × 107 cells] injection and intravenous [2 × 108 cells] injection after 1 week) and teriparatide (20 μg/day, daily subcutaneous injection for 6 months). Fourteen subjects (teriparatide alone, n = 7; combined treatment, n = 7) completed follow-up assessment (visual analog scale [VAS], Oswestry Disability Index [ODI], Short Form-36 [SF-36], bone mineral density [BMD], bone turnover measured by osteocalcin and C-terminal telopeptide of type 1 collagen, dual-energy x-ray absorptiometry [DXA], computed tomography [CT]). Our results show that (a) combined treatment with WJ-MSCs and teriparatide is feasible and tolerable for the patients with OVCFs; (b) the mean VAS, ODI, and SF-36 scores significantly improved in the combined treatment group; (c) the level of bone turnover markers were not significantly different between the two groups; (d) BMD T-scores of spine and hip by DXA increased in both control and experimental groups without a statistical difference; and (e) baseline spine CT images and follow-up CT images at 6 and 12 months showed better microarchitecture in the combined treatment group. Our results indicate that combined treatment of WJ-MSCs and teriparatide is feasible and tolerable and has a clinical benefit for fracture healing by promoting bone architecture. Clinical trial registration: https://nedrug.mfds.go.kr/, MFDS: 201600282-30937.

Primary Intimal Sarcoma of the Pulmonary Artery in a 25-Year-Old Woman with Dyspnea and Palpitation: A Case Report

Intimal sarcoma arising from the tunica intima of both systemic and pulmonary circulations is a rare disorder, whereas intimal sarcoma with chondroblastic osteosarcomatous differentiation (ISCOS) is even rarer. We present the case of a 25-year-old woman with ISCOS of the pulmonary artery (PA) where the patient went through surgical treatment after careful imaging assessment under a rather emergent situation. A 25-year-old Japanese female presented to our hospital with the chief complaints of dyspnea and palpitations on exertion. Upon arrival, she had systolic murmur, moderate tricuspid regurgitation, and possible pulmonary hypertension. A contrast-enhanced chest computed tomography (CT) showed dilatation of the main PA, filled with a hypodense area with calcification adjacent to the right and left PA. The calcified lesions within the tumor were the key findings suggesting osteoid-forming sarcoma, differentiating it from pulmonary embolism. Due to presence of critical symptomatic obliteration of the pulmonary circulation, an emergency surgery was performed. A whitish shiny mass filled the lumens from the main PA to the bilateral main PAs. The tumor was not attached to the surrounding intima, except for a slight attachment to the left interlobar PA, and could be completely removed from the vessel lumen. Based on the pathological findings, it was diagnosed as a primary ISCOS of the PA, which correlated with the findings of the CT, namely intratumoral calcification. Although the diagnosis-making is quite challenging, multidisciplinary collaboration between clinicians, radiologists, and pathologists is crucial for reaching the correct diagnosis.

Importance of computed tomography in defining segmental disease in chronic thromboembolic pulmonary hypertension

Background

Radiological assessment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) is critical to decide whether patients should be treated with pulmonary endarterectomy (PEA). Although computed tomography pulmonary angiography (CTPA) is increasingly used for decision making in CTEPH, the value of CTPA to predict surgical findings and outcome has never been explored.

Methods

We retrospectively reviewed 100 consecutive patients with high-quality CTPA undergoing PEA for CTEPH between May 2015 and December 2017. The most proximal level of disease in the pulmonary artery on CTPA was classified by two blinded radiologists as level 1 (main pulmonary artery), 2a (lobar pulmonary artery), 2b (origin of basal segmental pulmonary artery), 3 (segmental pulmonary artery) or 4 (predominantly subsegmental pulmonary artery).

Results

CTPA demonstrated level 1 in 20%, level 2a in 43%, level 2b in 11%, level 3 in 23% and level 4 in 3%. A majority of males presented with level 1 (55%) and level 2 (57%), and a majority of females (83%) with level 3 (p=0.01). Levels 3 and 4 were associated with longer duration of circulatory arrest (p=0.03) and higher frequency of Jamieson type III disease at surgery (p<0.0001). Requirement for targeted pulmonary hypertension therapy after PEA was 28% at 3 years in level 2b/3/4 compared with 6% in level 2a and 13% in level 1 (p=0.002). Level 2b/3/4 was an independent predictor for targeted pulmonary hypertension therapy after PEA (hazard ratio 4.23, 95% CI 1.24-14.39; p=0.02).

Conclusions

High-quality CTPA provides accurate evaluation of CTEPH patients. The level of disease on CTPA can help guide peri-operative planning and post-operative monitoring.

A biocompatible theranostic nanoplatform based on magnetic gadolinium-chelated polycyclodextrin: in vitro and in vivo studies

A novel theranostic nanoplatform was prepared based on Fe₃O₄ nanoparticles (NPs) coated with gadolinium ions decorated-polycyclodextrin (PCD) layer (Fe₃O₄@PCD-Gd) and employed for Curcumin (CUR) loading. The dissolution profile of CUR indicated a pH sensitive release manner. Fe₃O₄@PCD-Gd NPs exhibited no significant toxicity against both normal and cancerous cell lines (MCF 10A and 4T1, respectively); while the CUR-free NPs showed more toxicity against 4T1 than MCF 10A cells. In vivo anticancer study revealed appropriate capability of the system in tumor shrinking with no tissue toxicity and adverse effect on body weight. In vivo MR imaging of BALB/c mouse showed both T₁ and T₂ contrast enhancement on the tumor cells. Fe₃O₄@PCD-Gd/CUR NPs showed significant features as a promising multifunctional system having appropriate T₁-T₂ dual contrast enhancement and therapeutic efficacy in cancer theranostics.

Diagnosis of pulmonary infarction in post-mortem computed tomography and post-mortem magnetic resonance imaging-a technical note

Pulmonary thromboembolism may be accompanied by pulmonary infarction. Even though pulmonary thromboembolism (PTE) is a frequently found cause of death at autopsy, pulmonary infarction accompanying PTE is a less common finding and may therefore easily be misinterpreted as infectious or cancerous lung disease. Appearance of pulmonary infarction in post-mortem imaging and acquisition parameters helping to identify pulmonary infarctions are not described yet. Based on a case of a 50-year-old man who died due to PTE and presented pulmonary infarction, we suggest using a pulmonary algorithm in post-mortem computed tomography combined with post-mortem magnetic resonance imaging of the lungs using conventional T1- and T2-weighted sequences.

Assessment of Severity in Chronic Thromboembolic Pulmonary Hypertension by Quantitative Parameters of Dual-Energy Computed Tomography

The objective of this study was to assess the correlation between dual-energy computed tomography quantitative parameters and hemodynamics in patients with chronic thromboembolic pulmonary hypertension.

Case 276: Pulmonary Veno-Occlusive Disease and Pulmonary Capillary Hemangiomatosis Disease

HistoryA 34-year-old man presented to the emergency department of our hospital for progressive shortness of breath and worsening productive cough of 2 weeks duration. He reported a 10-kg weight loss over 4 months but denied experiencing fever, chills, night sweats, or gastrointestinal, musculoskeletal, or neurologic symptoms. His medical history was unremarkable. Although he was a native of Morocco, he had lived in Europe for many years and worked as a truck driver. The patient had a smoking history but had quit smoking 5 years prior to presentation. He denied alcohol abuse or recreational drug use. He did not have any allergies. Besides bilateral clubbing, the physical examination findings were normal. At the time of admission, he had an oxygen (O₂) saturation of 87% at ambient air, which increased to 100% with 1 L of O₂ administered via a nasal cannula. The blood sample revealed a slight increase in his hemoglobin concentration (18.7 g/dL; normal range, 13.6-17.2 g/dL) and hematocrit level (50.8%; normal range, 39%-49%). His inflammatory parameters were normal, as were his hepatic and renal function. The arterial blood gas test showed partially compensated pulmonary alkalosis (pH, 7.43; normal range, 7.35-7.42; PCO₂, 26 mmHg; normal range, 38-42 mmHg; PO₂, 89 mmHg; normal range, 75-100 mmHg; bicarbonate level, 17 mEq/L [17 mmol/L]; normal range 22-26 mEq/L [22-26 mmol/L]). The results of the pulmonary function tests were expressed as the percentage of predicted values and were 92% for forced vital capacity, 93% for forced expiratory volume in 1 second, 116% for total lung capacity, and 60% for diffusing capacity of carbon monoxide. Anteroposterior chest radiography and enhanced chest CT were also performed at admission.

Imaging of Chronic Thromboembolic Disease

Acute pulmonary embolism (PE) is a leading cause of cardiovascular morbidity. The most common long-term complication of acute PE is chronic thromboembolic disease, a heterogenous entity which ranges from asymptomatic imaging sequelae to persistent symptoms. Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease that can develop in this population and represents the only treatable type of pulmonary hypertension. Recognition of the characteristic findings of chronic pulmonary embolism and CTEPH provides not only diagnostic information, but is also crucial for guiding therapy. The present state-of-the-art review focuses on the multimodality imaging features of chronic pulmonary embolism. Detailed description and illustrations of relevant imaging findings will be demonstrated for ventilation/perfusion (V/Q) scan, CT scan and Dual-Energy CT and MRI and features that distinguish chronic PE from common imaging mimics.

The filling defect of pulmonary artery, an imaging finding what we should know

The most common cause of pulmonary artery filling defects on computed tomography pulmonary angiography or magnetic resonance imaging is pulmonary thromboembolism, but not infrequently, the presentation of this finding lacks specificity. Given that the morbidity and mortality associated with pulmonary thromboembolism is high, proper diagnosis of the condition is essential. Unusual or more rarely encountered etiologies must be considered when clinical manifestations and imaging findings are inconsistent. With this review, our purpose is to describe possible causes of pulmonary arterial filling defects. We aim to provide clinicians with a comprehensive list of differential diagnoses to facilitate a measured approach to the assessment of pulmonary arterial filling defects on computed tomography pulmonary angiography or magnetic resonance imaging.

Multimodal indirect imaging signs of pulmonary embolism

The clinical diagnosis of pulmonary embolism is often difficult, as symptoms range from syncope and chest pain to shock and sudden death. Adding complexity to this picture, some patients with non-diagnosed pulmonary embolism may undergo unenhanced imaging examinations for a number of reasons, including the prevention of contrast medium-related nephrotoxicity, anaphylactic/anaphylactoid reactions and nephrogenic systemic fibrosis, as well as due to patients' refusal or lack of venous access. In this context, radiologists' awareness and recognition of indirect signs are cornerstones in the diagnosis of pulmonary embolism. This article describes the indirect signs of pulmonary embolism on chest X-ray, unenhanced CT, and MRI.

Safety of Therapeutic Anticoagulation with Low-Molecular-Weight Heparin or Unfractionated Heparin Infusion during Catheter-Directed Thrombolysis for Acute Pulmonary Embolism

PURPOSE

To examine the safety of therapeutic-dose anticoagulation during catheter-directed thrombolysis (CDT) for acute pulmonary embolism (PE).

MATERIALS AND METHODS

A retrospective review of 156 consecutive cases (age, 56.6 ± 15.4 years; 85 males) of CDT with alteplase for acute PE (symptoms, <14 days) between 2009 and 2019 was performed. All patients received full-dose anticoagulation before, during, and after thrombolysis with low-molecular-weight heparin (LMWH) (n = 45) or unfractionated heparin (n = 111) infusion. Massive PE was diagnosed in 21 of 156 patients at presentation; submassive PE was diagnosed in 135 of 156 patients at presentation. The Simplified Pulmonary Embolism Severity Index was ≥1 in 69 of 156 patients.

RESULTS

There were 4 mild (2.6%), 3 moderate (1.9%), and 3 severe (1.9%) hemorrhagic complications (Global Use of Strategies to Open Occluded Arteries), 1 of which (0.6%) was intracranial. No significant differences in hemorrhagic complication rates (P = .3, P = 1.0, and P = .6, respectively) or general complication rates (Society of Interventional Radiology [SIR] minor, P = .2; SIR major, P = .7) were noted between the LMWH and heparin groups. Mean pulmonary arterial pressure for the entire cohort improved from 28.9 ± 7.6 mmHg to 20.4 ± 6.5 mmHg (P < .001), whereas the Miller score improved from 19.3 ± 4.6 to 7.3 ± 3.9 (P < .001). The average infusion duration was 26 ± 11.9 hours over 2.3 ± 0.6 total visits to the angiography lab, during which a mean of 27.85 ± 14.2 mg of tissue plasminogen activator were infused.

CONCLUSIONS

Therapeutic anticoagulation during CDT for PE appears to be safe. The current study did not find a significant difference between LMWH and heparin infusion with respect to hemorrhagic and general complication rates.

Mimickers of chronic thromboembolic pulmonary hypertension on imaging tests: a review

Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by mechanical obstruction of large pulmonary arteries secondary to one or more episodes of pulmonary embolism. Ventilation perfusion scan is the recommended initial screening test for this condition and typically shows multiple large mismatched perfusion defects. However, not all patients with an abnormal ventilation perfusion scan have CTEPH since there are other conditions that be associated with a positive ventilation perfusion scan. These conditions include in situ thrombosis, pulmonary artery sarcoma, fibrosing mediastinitis, pulmonary vasculitis and sarcoidosis, among others. Although these conditions cannot be distinguished from CTEPH using a ventilation perfusion scan, they have certain characteristic radiological features that can be demonstrated on other imaging techniques such as computed tomography scan and can help in differentiation of these conditions. In this review, we have summarized some key clinical and radiological features that can help differentiate CTEPH from the CTEPH mimics.

Evaluation of the CT imaging findings in the diagnosis of pulmonary hypertension due to chronic thromboembolism

PURPOSE

Chronic thromboembolic pulmonary hypertension (CTEPH) is the only pulmonary hypertension that can be treated surgically. Multidedector computerized tomography angiography (MDCTA) is considered as an important tool. In this study, the important CT findings of CTEPH and the vascular MDCTA findings of CTEPH were classified as central, peripheral, central and peripheral. The aim of this study was to investigate the relationship between these groups with parenchymal and hemodynamic findings.

MATERIALS AND METHODS

MDCTA examinations of 26 patients who had been diagnosed with CTEPH were retrospectively reviewed. Vascular, cardiac and parenchymal findings were examined in MDCTA. Patients were divided into three groups as peripheral, central and peripheral and central chronic thromboembolism. The relationship between these groups with demographic, vascular, parenchymal and hemodynamic findings was investigated.

RESULTS

The most common vascular finding was the wall filling defects attached to the lobar and/or segmental arterial walls, while the parenchymal finding was the fibrotic shrinkage. There were no statistically significant differences between the three groups compared to parenchymal findings which are mosaic pattern, brochiectasis, fibrotic changes and atelectasis, pulmonary artery diameter, right atrial diameter and RV/LV ratio. Age and sex were not different in patients between the three groups.

CONCLUSION

The results of the this study confirm the important role of MDCTA in the evaluation of vascular, cardiac and parenchymal findings in the patients with CTEPH and identifying patients that would most benefit from surgical treatment by visualization of the segmental and subsegmental branches of the pulmonary arteries.

Unenhanced multidetector computed tomography findings in acute central pulmonary embolism

Background

Computed tomography pulmonary angiography (CTPA) is the gold standard for the diagnosis of pulmonary embolism (PE). However, contrast is contraindicated in some patients. The purpose of this study was to determine the diagnostic accuracy of unenhanced multidetector CT (MDCT) for diagnosis of central PE using CTPA as the gold standard.

Methods

The records of patients with suspected PE seen between 2010 and 2013 were retrospectively reviewed. Inclusion criteria were an acute, central PE confirmed by CTPA and non-enhanced MDCT before contrast injection. Patients with a PE ruled out by CTPA served as a control group. MDCT findings studied were high-attenuation emboli in pulmonary artery (PA), main PA dilatation > 33.2 mm, and peripheral wedge-shaped consolidation. Receiver operating characteristic (ROC) analysis was used to determine the sensitivity and specificity of unenhanced MDCT to detect PE. Wells score of all patients were calculated using data extracted from medical records prior to imaging analysis.

Results

Thirty-two patients with a PE confirmed by CTPA and 32 with a PE ruled out by CTPA were included. Among the three main MDCT findings, high-attenuation emboli in the PA showed best diagnostic performance (Sensitivity 72.9%; Specificity 100%), followed by main PA dilatation > 33.2 mm (sensitivity 46.9%; specificity 90.6%), and peripheral wedge-shaped consolidation (sensitivity 43.8%; specificity 78.1%). Given any one or more positive findings on unenhanced MDCT, the sensitivity was 96.9% and specificity was 71.9% for a diagnosis of PE in patients. The area under the curve (AUC) of a composite measure of unenhanced MDCT findings (0.909) was significantly higher than that of the Wells score (0.688), indicating unenhanced MDCT was reliable for detecting PE than Wells score.

Conclusions

Unenhanced MDCT is an alternative for the diagnosis of acute central PE when CTPA is not available.