Congenital and acquired pulmonary artery anomalies in the adult: radiologic overview

Pulmonary Hypertension Induced by Right Pulmonary Artery Occlusion: Hemodynamic Consequences of Bmpr2 Mutation

BACKGROUND

The primary genetic risk factor for heritable pulmonary arterial hypertension is the presence of monoallelic mutations in the BMPR2 gene. The incomplete penetrance of BMPR2 mutations implies that additional triggers are necessary for pulmonary arterial hypertension occurrence. Pulmonary artery stenosis directly raises pulmonary artery pressure, and the redirection of blood flow to unobstructed arteries leads to endothelial dysfunction and vascular remodeling. We hypothesized that right pulmonary artery occlusion (RPAO) triggers pulmonary hypertension (PH) in rats with Bmpr2 mutations.

METHODS AND RESULTS

Male and female rats with a 71 bp monoallelic deletion in exon 1 of Bmpr2 and their wild-type siblings underwent acute and chronic RPAO. They were subjected to full high-fidelity hemodynamic characterization. We also examined how chronic RPAO can mimic the pulmonary gene expression pattern associated with installed PH in unobstructed territories. RPAO induced precapillary PH in male and female rats, both acutely and chronically. Bmpr2 mutant and male rats manifested more severe PH compared with their counterparts. Although wild-type rats adapted to RPAO, Bmpr2 mutant rats experienced heightened mortality. RPAO induced a decline in cardiac contractility index, particularly pronounced in male Bmpr2 rats. Chronic RPAO resulted in elevated pulmonary IL-6 (interleukin-6) expression and decreased Gdf2 expression (corrected P value<0.05 and log2 fold change>1). In this context, male rats expressed higher pulmonary levels of endothelin-1 and IL-6 than females.

CONCLUSIONS

Our novel 2-hit rat model presents a promising avenue to explore the adaptation of the right ventricle and pulmonary vasculature to PH, shedding light on pertinent sex- and gene-related effects.

Hemoptysis Secondary to Anomalous Origin of Right Pulmonary Artery From Ascending Aorta in a Young Male: A Case Report

We report a rare case of a 24-year-old male with a rare anatomic variant of patent ductus arteriosus (PDA). The patient presented with symptoms of productive cough with recurrent and severe bouts of hemoptysis and grade I dyspnea. There were no prior episodes reported. The patient was vitally stable with bilateral clubbing. On cardiopulmonary auscultation, a prominent parasternal heave, loud P2, and right lung crepitus were noted. A complete blood count revealed an elevated hemoglobin and RBC count. An ECG revealed sinus tachycardia and right ventricle (RV) strain. ECHO confirmed these findings, as dilated right atrium (RA) and RV, mild tricuspid valve regurgitation (TR), and severe pulmonary hypertension were noted. CT of the chest demonstrated multiple ground glass opacities, right lung consolidation, and volume loss suggestive of right-sided pneumonia with atelectasis. CT also proved the presence of PDA and an anomalous origin of the right pulmonary artery from the right ascending aorta, causing compression of the right main bronchus. We show the clinical and radiological findings and discuss the implications and approach to this rare congenital cardiovascular malformation, as well as how a patient-centered approach is necessary for its management.

Clinical-radiological-pathological correlation in pulmonary arterial hypertension

Pulmonary hypertension (PH) is defined by the presence of a mean pulmonary arterial pressure >20 mmHg. Current guidelines describe five groups of PH with shared pathophysiological and clinical features. In this paper, the first of a series covering all five PH classification groups, the clinical, radiological and pathological features of pulmonary arterial hypertension (PAH) will be reviewed. PAH may develop in the presence of associated medical conditions or a family history, following exposure to certain medications or drugs, or may be idiopathic in nature. Although all forms of PAH share common histopathological features, the presence of certain pulmonary arterial abnormalities, such as plexiform lesions, and extent of co-existing pulmonary venous involvement differs between the different subgroups. Radiological investigations are key to diagnosing the correct form of PH and a systematic approach to interpretation, especially of computed tomography, is essential.

Pulmonary vein flow split effects in patient-specific simulations of left atrial flow

Disruptions to left atrial (LA) blood flow, such as those caused by atrial fibrillation (AF), can lead to thrombosis in the left atrial appendage (LAA) and an increased risk of systemic embolism. LA hemodynamics are influenced by various factors, including LA anatomy and function, and pulmonary vein (PV) inflow conditions. In particular, the PV flow split can vary significantly among and within patients depending on multiple factors. In this study, we investigated how changes in PV flow split affect LA flow transport, focusing for the first time on blood stasis in the LAA, using a high-fidelity patient-specific computational fluid dynamics (CFD) model. We use an Immersed Boundary Method, simulating the flow in a fixed, uniform Cartesian mesh and imposing the movement of the LA walls with a moving Lagrangian mesh generated from 4D Computerized Tomography images. We analyzed LA anatomies from eight patients with varying atrial function, including three with AF and either a LAA thrombus or a history of Transient Ischemic Attacks (TIAs). Using four different flow splits (60/40% and 55/45% through right and left PVs, even flow rate, and same velocity through each PV), we found that flow patterns are sensitive to PV flow split variations, particularly in planes parallel to the mitral valve. Changes in PV flow split also had a significant impact on blood stasis and could contribute to increased risk for thrombosis inside the LAA, particularly in patients with AF and previous LAA thrombus or a history of TIAs. Our study highlights the importance of considering patient-specific PV flow split variations when assessing LA hemodynamics and identifying patients at increased risk for thrombosis and stroke. This knowledge is relevant to planning clinical procedures such as AF ablation or the implementation of LAA occluders.

Rare Vascular Anomalies in an Adult: Absent Left Pulmonary Artery With a Right-Sided Aortic Arch

Congenital absence of the left pulmonary artery remains a rarely reported anomalous condition and is even less commonly seen in conjunction with a right-sided aortic arch. While most cases are identified during prenatal fetal ultrasonography and require early childhood intervention, some asymptomatic cases can go unrecognized until incidentally detected on chest imaging as an adult. This case details a 31-year-old male with a congenital absence of the left pulmonary artery and right-sided aortic arch with subsequent atretic and fibrotic lung, all found on imaging during admission for acute alcoholic hepatitis.

Reconstruction of a Giant Main Pulmonary Artery Aneurysm Using a Porcine Root in an Adult Patient

Pulmonary artery aneurysm (PAA) is a rare disorder with a difficult diagnosis and debated management in literature due to the limited number of cases. Even if the definitive treatment of PAA is surgery, consistent guidelines still need to be developed to help surgeons determine when intervention is appropriate. We report a case of a 77-year-old female diagnosed with central PAA measuring 61 mm at contrast-enhanced computerized tomography scan which was treated surgically. The patient underwent a successful elective complete pulmonary root replacement with a Medtronic Freestyle (Medtronic Inc, Minneapolis, MN) porcine root. Postprocedural recovery and follow-up at 12 months were uneventful.

Proximal Interruption of Pulmonary Artery: Spectrum of Radiological Findings With Emphasis on Chest Radiograph and Contrast-Enhanced Computed Tomography (CECT)

Introduction Proximal interruption of pulmonary artery (PIPA) is a congenital anomaly presenting with aberrant termination of the pulmonary artery at the hilum. It results in a variety of radiological and clinical manifestations. Clinically, isolated PIPA can be asymptomatic till late adulthood or can present with dyspnoea, chest discomfort, hemoptysis and recurrent infections. PIPA can be associated with multiple cardiovascular anomalies such as tetralogy of Fallot (TOF), ventricular septal defects (VSD), and scimitar syndrome. We present a spectrum of cases with both isolated proximal interruption of the pulmonary artery and cases associated with other cardiovascular abnormalities. Typical chest radiographs and chest contrast-enhanced computed tomography (CECT) findings are discussed and demonstrated in detail. Proper and early diagnosis is a crucial step as it can significantly modify the treatment choice, thereby reducing morbidity. Objective To document the different presentations of the proximal arrest of pulmonary arteries, to document associations with cardiovascular and pulmonary manifestations, and to elaborate on and demonstrate the various radiological imaging findings. Material and methods All the cases that were reported with proximal interruption of pulmonary artery on the CECT studies conducted between 2019 and 2022 at a tertiary care hospital in Telangana, India. The demographic data, clinical presentation, chest radiographs, and chest CECT were collected retrospectively. Data analysis was done using Microsoft Excel 2019 to calculate descriptive statistics. A total of 22 cases were identified of which three cases were excluded of as they were previously operated and 19 cases were taken as the study population. Results Nineteen patients were included in the study. Demographic details, clinical history, CECT, and chest radiographs were collected wherever available. The majority of the cases belonged to the ≤ 10 yrs age group with the most common clinical presentation being a previous diagnosis of tuberculosis or recurrent upper respiratory tract infections. The predominant findings on chest radiographs were deviation of the trachea to the affected side, volume loss in the ipsilateral lung field, and compensatory hyperinflation of the contralateral lung field. On the CECT chest, the main findings were interrupted pulmonary artery, hypoplastic lung fields with bronchiectasis, or ground glassing. Associated cardiovascular and pulmonary malformations were identified with notable cases: TOF, right-sided aortic arch and scimitar syndrome. Their typical imaging findings have been elucidated and discussed in detail. Conclusions Patients with recurrent respiratory infections or hemoptysis having hypoplastic lung field with hyperinflation of the contralateral lung on chest radiographs should be evaluated for pulmonary artery interruptions. Chest CECT allows evaluation of the bronchial tree and lung parenchyma at the same time which helps distinguish pulmonary interruption from conditions such as Swyer-James-Macleod syndrome, pulmonary hypoplasia, thromboembolism and arteritis. Cases with PIPA can also be associated with cardiovascular and pulmonary anomalies such as TOF, partial anomalous pulmonary venous connection (PAPVC), and VSD. The knowledge of these associations is essential as they can influence the mode of treatment and can help reduce the long-term morbidity and mortality associated with the condition.

Exercise feature and predictor of prognosis in patients with pulmonary artery stenosis-associated pulmonary hypertension

AIMS

The prognosis is poor for patients with pulmonary artery stenosis-associated pulmonary hypertension (PAS-PH). Identifying predictors of prognosis in PAS-PH is crucial to preventing premature death, which has rarely been investigated. We aimed to explore the cardiopulmonary exercise testing (CPET) parameters to predict the prognosis of these patients.

METHODS

We prospectively included all patients with PAS-PH who underwent CPET between September 2014 and June 2021 in Fuwai Hospital (ClinicalTrials.gov ID: NCT02061787). The primary outcome was clinical worsening, including death, rehospitalization for heart failure, or deterioration of PH.

RESULTS

Seventy-two patients were included in this study. A median of 2-year follow-up revealed that 18 (25%) patients experienced clinical worsening. The 1-year, 3-year, and 5-year event-free survival rates were 92.5%, 81.7%, and 62.7%, respectively. Patients with clinical worsening demonstrated significantly worse baseline haemodynamics and poorer exercise capacity than their counterparts. Multivariable Cox regression identified that peak O₂ pulse could independently predict clinical worsening [hazard ratio: 0.344, 95% confidence interval (CI) 0.188-0.631, P < 0.001], outperforming other parameters. Peak O₂ pulse correlated with PH severity. Incorporating peak O₂ pulse into the simplified 2015 European Society of Cardiology/European Respiratory Society risk stratification improved the accuracy for predicting clinical worsening (pre vs. post area under the curve: 0.727 vs. 0.846, P < 0.001; net reclassification index: 0.852, 95% CI 0.372-1.332, P < 0.001; integrated discrimination index 0.133, 95% CI 0.031-0.235, P = 0.011).

CONCLUSIONS

The prognosis is poor for PAS-PH, and exercise intolerance and ventilation inefficiency are commonly observed. Peak O₂ pulse independently predicted the prognosis of these patients. A low peak O₂ pulse identified patients at high risk of clinical deterioration and served for risk stratification of PAS-PH.

Proximal interruption of the right pulmonary artery: A rare anomaly

We report a case of a 21-year-old woman with cyanosis where computed tomography (CT) angiography revealed a complete absence of the mediastinal part of the right pulmonary artery with the normal intrapulmonary vascular network, receiving supply from multiple collateral vessels. The case also highlights the various differential diagnoses and the role of CT angiography in arriving at the correct diagnosis.

Pulmonary Arteriovenous Malformation and Its Vascular Mimickers

Pulmonary arteriovenous malformation (AVM) is a congenital vascular disease in which interventional radiologists can play both diagnostic and therapeutic roles in patient management. The diagnosis of pulmonary AVM is simple and can usually be made based on CT images. Endovascular treatment, that is, selective embolization of the pulmonary artery feeding the nidus of the pulmonary AVM, and/or selectively either the nidus or draining vein, has become a first-line treatment with advances in interventional devices. However, some vascular diseases can simulate pulmonary AVMs on CT and pulmonary angiography. This subset can confuse interventional radiologists and referring physicians. Vascular mimickers of pulmonary AVM have not been widely known and described in detail in the literature, although some of these require surgical correction, while others require regular follow-up. This article reviews the clinical and radiologic features of pulmonary AVMs and their mimickers.

Proximal interruption of the pulmonary artery: A review of radiological findings

OBJECTIVES

Proximal interruption of the pulmonary artery (PIPA) has various clinical manifestations. This review focused on and summarized the clinical and radiological features of PIPA, based on relevant literature studies.

METHODS

The study included a total of 25 PIPA cases in the Guangzhou Women and Children's Medical Center between January 2015 and December 2021. Conventional chest photographs and chest computed tomography angiography (CCTA) of patients with PIPA were analyzed and summarized.

RESULTS

The radiological results showed that 17 cases were right-sided and 8 cases were left-sided PIPA. Additionally, the percentage of pulmonary hypoplasia on the affected side was 44%, 36% for pulmonary hypertension, 28% for the mosaic sign, 20% for subpleural cystic lucency shadow, 20% for subpleural serrated shadow, 20% for collateral vessel thickening, 16% for subpleural band-like parenchyma, 12% for pneumonia, and 56% for patent ductus arteriosus.

CONCLUSION

The clinical manifestations of PIPA are non-specific. Awareness of this anomaly, based on radiological manifestations, particularly those observed on CCTA images, is important for ruling out alternative diagnoses and implementing appropriate management.

Congenital cystic adenomatoid malformation associated with right aortic arch with mirror image branching and absence of left pulmonary artery in an adult

Background

Congenital cystic adenomatoid malformation is an uncommon developmental anomaly that is diagnosed prenatally or during early childhood and is rare to present in adulthood. Type 2 congenital cystic adenomatoid malformation is often associated with other anomalies such as congenital cardiac anomalies. We present a case of type 2 congenital cystic adenomatoid malformation in an adult male associated with absence of left pulmonary artery and right aortic arch with mirror image branching. To our knowledge, this is the first case report with the combination of all three anomalies.

Case presentation

A 33-year-old male presented to the Department of Pulmonary Medicine with high-grade fever, chills and rigor, breathlessness, and productive cough for a duration of one week. He had multiple similar self-limiting episodes in the past which did not require hospitalization. The plain radiograph showed right aortic arch and a small left hilum. CT thorax showed multiple cystic lesions of size 0.5–2.0 cm in the apico-posterior segment of the left upper lobe; anterior, posterior, and lateral segments of the left lower lobe; and the apical segment of the right upper lobe with a maximal cyst wall thickness of 2 mm. Volume of left lung was reduced with trans-thoracic herniation of the medial segment of the right middle lobe; bronchiectatic changes were seen in the apical, anterior, and posterior segments of the right upper lobe; and fibrotic strands were seen in the apical segment of the right lower lobe and the apico-posterior segment of the right upper lobe. Mediastinal window showed right-sided aortic arch with mirror image branching. The pulmonary trunk was seen to continue as the right pulmonary artery with absent left pulmonary artery.

Conclusions

Though congenital cystic adenomatoid malformation is a disease of infancy and childhood, it should also be considered in adults presenting with recurrent lower respiratory tract infections and/or pneumothorax. Radiologists must be aware of the types of congenital cystic adenomatous malformation (CCAM) and their associations, as type 2 CCAM has a high association with congenital cardiac disease. Proximal interruption of pulmonary artery should be considered if the pulmonary trunk continues as either right or left pulmonary artery.

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.

Added value of hyperdense lumen sign in prediction of acute central and peripheral pulmonary embolism on non-contrast CT chest

Background

Pulmonary embolism (PE) is a common condition with considerable morbidity and mortality; it is more often diagnosed post-mortem by pathologists than in vivo by clinicians. Prompt and accurate diagnosis is difficult because PE may be clinically silent, the symptoms are vague and nonspecific, and in addition, there is no definitive, non-invasive diagnostic test to establish its diagnosis. The aim of this study is to assess the reliability of detection of acute central and peripheral pulmonary embolism (PE) on non-contrast CT especially when no possible alternative is available as in allergic cases or emergency, patients with history of renal disease, or in cases where PE is not the leading diagnosis. CT pulmonary angiography study served as our gold standard.

Results

Eighty adult patients were included in our study; 44 were females and 36 males most of which were complaining of dyspnea and chest pain. Acute central pulmonary embolism was confirmed by CTPA. They all underwent a pre-contrast study just prior to the CTPA. Presence of high attenuation emboli in any of the main pulmonary vessels was our key for diagnosis of acute embolism. Non-contrast CT chest diagnosed 26 of the 47 cases confirmed by CTPA. The hyperdense lumen sign had an overall sensitivity of 55.3%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value of 61.1%. The accuracy of non-contrast CT chest study was evaluated using CTPA as our gold standard.

Conclusion

Non-contrast CT chest is a good indicator in predicting central and peripheral pulmonary embolism, particularly in cases of emergency, those unable to take intravenous contrast for angiography, or in cases where pulmonary embolism is not the leading diagnosis.

Pulmonary artery pseudoaneurysms: endovascular management after adequate imaging diagnosis

Pulmonary artery pseudoaneurysms (PAPs) are rare serious vascular abnormalities mostly due to infections and trauma, although other conditions such as vasculitis, neoplasms, or inflammatory lung diseases can also predispose to this entity. Endovascular techniques such as embolization or covered stent placement have mostly substituted surgical approaches, for their lower invasiveness and greater security, mainly in patients with life-threatening hemoptysis. The purpose of this manuscript is to describe the imaging findings of pulmonary artery pseudoaneurysms and their endovascular management including tips to help interventional radiologists. PAP should be diagnosed as accurately and early as possible in order to prompt endovascular management of further life-threatening hemoptysis. KEY POINTS: • Pulmonary artery pseudoaneurysms (PAPs) are rare serious vascular abnormalities that may represent a life-threatening condition, mainly due to Staphylococcus, Streptococcus, or Mycobacterium tuberculosis. • Radiologists should know the imaging findings of PAP in order to make an accurate and early diagnosis to prompt endovascular management of further life-threatening hemoptysis.

Multiple pulmonary artery aneurysms in a young female with patent ductus arteriosus on CT pulomnary angiography

Aneurysms of lobar branches of pulmonary artery are extremely rare with few reported cases in literature. The exact etiopathogenesis of pulmonary artery aneurysms is not clearly understood and no clear guidelines on their management is available. Aneurysms of the secondary and tertiary branches appear to be even more uncommon than those of the trunk and primary branches.

Here we report an unusual case of young female with multiple pulmonary artery aneurysms in bilateral lungs with fusiform dilation of main pulmonary trunk and a small patent ductus arteriosus.

Three-dimensional printing in a patient with pulmonary artery pseudoaneurysm and complex congenital heart disease-A case report

3D-printing is a powerful tool in patients with complex anatomy undergoing cardiac surgery.

Congenital central pulmonary artery anomalies: Part 1

There is a broad spectrum of congenital anomalies of the central pulmonary arteries including abnormalities of development, origin, course and caliber. These anomalies incorporate simple lesions such as isolated pulmonary valve stenosis to very complex anomalies with many associated abnormalities. Part 1 and Part 2 of this review describe the range of anatomical variations that are encountered as well as important aspects of anatomy, physiology and surgical correction. The authors summarize and illustrate well-recognized as well as more complex anomalies to provide a broad and comprehensive understanding of these lesions and their appearances on CT and MR imaging. Part 1 covers anomalous development or origin of the main pulmonary artery.

Congenital central pulmonary artery anomalies: Part 2

There is a broad spectrum of congenital anomalies of the central pulmonary arteries including abnormalities of development, origin, course and caliber. These anomalies incorporate simple lesions such as isolated pulmonary valve stenosis to very complex anomalies with many associated abnormalities. Part 1 and Part 2 of this review describe the range of anatomical variations that are encountered as well as important aspects of anatomy, physiology and surgical correction. The authors summarize and illustrate both well-recognized and more complex anomalies to provide a broad and comprehensive understanding of these lesions and their appearances on CT and MR imaging. In Part 2 the authors review abnormalities in development, origin and course of the central branch pulmonary arteries as well as abnormal pulmonary artery caliber.

Pulmonary intimal sarcoma involving the pulmonary valve and right ventricular outflow tract: A case report and literature review

INTRODUCTION

Pulmonary artery intimal sarcoma (PAIS) is a rare and highly aggressive tumor, and approximately 80% of pulmonary cases occur in the pulmonary trunk. We report herein a case of retrograde extension of the sarcoma to the pulmonary valve and right ventricle, which is an uncommon manifestation of this lethal tumor.

PATIENT CONCERNS

A 41-year-old woman was initially diagnosed with pulmonary thromboembolism (PTE) and transferred to our hospital.

DIAGNOSIS

Computed tomographic pulmonary angiography (CTPA) showed that there are low-density filling defects in both pulmonary arteries, and the patient was diagnosed with PTE. However, the ultrasonographers considered that the lesion is a space-occupying type that involves the right ventricular outflow tract and pulmonary valve instead of PTE. Postoperative pathology confirmed the diagnosis of PAIS.

INTERVENTIONS

The patient underwent resection of pulmonary artery sarcoma and endarterectomy.

OUTCOMES

During the follow-up via telephone 1 month after discharge, the patient reported to have been feeling well.

CONCLUSION

Owing to the rarity of the disease and its non-specific clinical manifestations, approximately half of the PAIS cases are misdiagnosed or have a delayed diagnosis. Thus, improving our understanding of the disease and facilitating its early diagnosis are essential.

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.

MDCT angiographic findings of various congenital pulmonary artery anomalies in pediatric patients

Background

Congenital pulmonary artery anomalies are variable and need proper diagnosis and treatment. CT angiography with multiplanar reconstruction has the main role in the assessment of these anomalies and this non-invasive method should be the method of choice for preoperative planning and postoperative follow up.

The aim of the study is to assess the value of MDCT in the detection of pulmonary arteries anomalies in the pediatric population with complex congenital heart disease in conjunction with echocardiography as an alternative to conventional angiography and to determine the superiority of MDCT in the assessment of other abnormalities such as airway anomalies.

Results

In our retrospective study, 52 patients (28 male and 24 females, aged 1 day to 4 years: mean age 2 years) were examined with contrast-enhanced CT. CT examinations were done using a 128-section CT scanner (Siemens Somatom Definition AS) using non-ionic iodinated contrast media. 2D and 3D reconstructions were performed. The correlation was made with echocardiograms. All imaging studies were reviewed. The echo was done to all patients. Surgery and/or catheter angiography performed to all patients, their findings were reviewed and compared to CTA findings. Other abnormalities such as congenital airway anomalies are detected using axial MDCT images and reconstructed imaging techniques.

MDCT was accurate in revealing pulmonary artery anomalies. The commonest pulmonary artery anomaly was atresia, stenosis then hypoplasia. These anomalies may be isolated or associated with other congenital heart diseases. In the current study, MDCT could diagnose all cases of pulmonary arterial anomalies with 96% sensitivity, 100% specificity, 98% accuracy, 100% positive, and 94% negative predictive values. CT scans provide accurate information to assess complex spatial relationships of vascular airway compression frequently associated with CHD in the pediatric population.

Conclusion

MDCT scanner can be an alternative to diagnostic conventional angiography for the non-invasive assessment of the pulmonary artery. Higher quality multiplanar and 3D reconstruction achieved by the MDCT scanners offer a rapid, reliable and non-invasive technique that can be used for the evaluation and preoperative assessment of thoracic vascular and extra-vascular anatomy in infants and children with suspected congenital heart disease. CT technologies are constantly developing collaboration between radiologists, pediatric cardiologists, and anesthesiologists, which is essential for improving CT performance.

Successful Conservative Treatment of Mycotic Pulmonary Artery Aneurysms Caused by MRSA Bacteremia

Mycotic pulmonary artery aneurysms (MPAAs) are rare and life-threatening with currently no recommended treatment strategies. In this report, we describe a successfully treated case of ventricular septal defect in an 11-month-old girl who developed bacteremia, infective endocarditis, and MPAA caused by methicillin-resistant Staphylococcus aureus (MRSA). We first started vancomycin, gentamycin, and panipenem-betamipron for infective endocarditis but switched to teicoplanin and arbekacin on day 3 after initiating treatment because bacteremia persisted, and vancomycin minimum inhibitory concentration was relatively high at 2 mg/L. Although we added clindamycin on day 5 and fosfomycin on day 7, MRSA bacteremia persisted, and we finally added daptomycin at 10 mg/kg per day on day 8, whereupon the bacteremia subsided within a day. Although the bacteremia subsided, the patient developed septic pulmonary embolisms and septic arthritis on her left knee. We continued daptomycin but switched the concomitant drug to linezolid, trimethoprim-sulfamethoxazole, and rifampicin on day 11. After several repeats of puncture and lavage of her knee joint, she became afebrile on day 16. Computed tomography scans taken on day 32 revealed right pulmonary artery MPAAs. She was treated with long-term multidrug therapy, and MPAAs were absent on subsequent computed tomography scans on day 184. Multidrug therapy mainly based on daptomycin could be a possible salvage therapy for refractory MRSA bacteremia with high vancomycin minimum inhibitory concentration. Conservative treatment should be selectively considered as a treatment option for clinically stable MPAA instead of surgical and endovascular treatment.

Systemic Artery-to-Pulmonary Artery Fistula Mimics Pulmonary Embolus

Systemic artery-to-pulmonary artery fistula (SA-PAF) is a rare phenomenon that can resemble a filling defect on computed tomography angiography (CTA). SA-PAF can be due to congenital or acquired etiologies and can alter the hemodynamics of the pulmonary circulation, with the most serious reported complication being hemoptysis, requiring embolization. We describe a case of an unusual SA-PAF between the right inferior phrenic artery and the right lower lobe pulmonary artery that mimicked an unprovoked pulmonary embolus (PE) on standard CTA in a patient with cardiomyopathy. This SA-PAF was interpreted on CTA as PE due to the presence of a filling defect, revealing that not all filling defects are PE. SA-PAF should always be considered when the clinical context or the imaging findings are atypical, specifically with an isolated filling defect visualized in the inferior lower lobe pulmonary artery. The false-positive PE was the result of mixing of systemic non-opacified blood with opacified pulmonary arterial blood.

Pulmonary arteries: imaging of pulmonary embolism and beyond

The pulmonary arteries are not just affected by thrombus. Various acquired and congenital conditions can also affect the pulmonary arteries. In this review we discuss cross sectional imaging modalities utilized for the imaging of the pulmonary arteries. Acquired pulmonary artery entities, including pulmonary artery sarcoma (PAS), vasculitis, aneurysm, and arteriovenous malformations, and congenital anomalies in adults, including proximal interruption of the pulmonary artery, pulmonary sling, pulmonary artery stenosis, and idiopathic dilatation of the pulmonary trunk, are also discussed. An awareness of these entities and their imaging findings is important for radiologists interpreting chest imaging.

Cross-sectional imaging of congenital pulmonary artery anomalies

Congenital pulmonary artery (PA) anomalies comprise a rare and heterogeneous spectrum of disease, ranging from abnormal origins to complete atresia. They may present in early infancy or more insidiously in adulthood, often in association with congenital heart disease such as tetralogy of Fallot or other syndromes. In recent years, cross-sectional imaging, including computed tomography (CT) and magnetic resonance imaging (MRI), has become widely utilized for the noninvasive assessment of congenital PA diseases, supplementing echocardiography and at times supplanting invasive angiography. In this article, modern CT and MRI techniques for imaging congenital PA disorders are summarized. The key clinical features, cross-sectional imaging findings, and treatment options for the most commonly encountered entities are then reviewed. Emphasis is placed on the ever-growing role of cross-sectional imaging options in facilitating early and accurate diagnosis and tailored treatment.

Intraluminal Arterial Filling Defects Misdiagnosed as Pulmonary Emboli: What Else Could They Be?

Pulmonary artery filling defects can be observed in various pathologic processes other than pulmonary embolism, for example, nonthrombotic pulmonary embolism with biological and nonbiological materials and intrinsic pulmonary artery lesions. They have also been described in rare conditions, such as fibrosing mediastinitis and congenital absence or stenosis of pulmonary artery, and some pulmonary parenchymal and airway malignancies. Misdiagnosis is common owing to the relative rarity of these conditions. Correct diagnosis is based on the appropriate clinical suspicion considering the unique clinical features, laboratory findings, and additional radiologic clues inferring a pathology other than pulmonary embolism.

Proximal Interruption of the Pulmonary Artery

Proximal interruption of the pulmonary artery (PIPA) is an uncommon developmental anomaly resulting in underdevelopment of the proximal portion of the pulmonary artery with preservation of the intrapulmonary segments. Clinical presentation ranges between an asymptomatic incidental finding to massive hemoptysis. When findings suggestive of PIPA are present radiographically, the diagnosis of PIPA can be definitively diagnosed with computed tomography or magnetic resonance pulmonary angiography. Other imaging modalities, such as nuclear perfusion scan and catheter angiography can help in the diagnosis.

Pictorial review of the pulmonary vasculature: from arteries to veins

Pathology of the pulmonary vasculature involves an impressive array of both congenital and acquired conditions. While some of these disorders are benign, disruption of the pulmonary vasculature is often incompatible with life, making these conditions critical to identify on imaging. Many reviews of pulmonary vascular pathology approach the pulmonary arteries, pulmonary veins and bronchial arteries as individual topics. The goal of this review is to provide an integrated overview of the high-yield features of all major disorders of the pulmonary vasculature. This approach provides a more cohesive and comprehensive conceptualisation of respiratory pathology. In this review, we present both the salient clinical and imaging features of congenital and acquired disorders of the pulmonary vasculature, to assist the radiologist in identifying pathology and forming a robust differential diagnosis tailored to the presenting patient. TEACHING POINTS: • Abnormalities of the pulmonary vasculature are both congenital and acquired. • Pathology of a single pulmonary vascular territory often affects the entire pulmonary vasculature. • Anomalous pulmonary venous flow is named as a function of its location and severity. • Bronchial arteries often undergo dilatation secondary to cardio-respiratory pathology.

A Rare Combination of Congenitally Corrected Transposition of the Great Arteries with Pulmonary Artery Aneurysm

•ccTGA can be unnoticed until advanced age. •ccTGA is rarely associated with an ASD and a large PA aneurysm. •Mesocardia may accompany this complex congenital heart disease. •SAVV regurgitation is a common finding.

Congenital anomalies of the pulmonary arteries: an imaging overview

Congenital pulmonary artery anomalies represent a diverse group of abnormalities, ranging from asymptomatic incidental findings to causes of sudden cardiac death. While some may be recognized in childhood, others may be found incidentally in adulthood. We review the clinical and imaging findings in patients with congenital anomalies of the pulmonary arteries, including valvular and perivavular anomalies as well as abnormal narrowing, course and communications of the pulmonary arteries. We also discuss the role of various imaging modalities in the evaluation of these patients. It is vital to be aware of the key radiologic manifestations and associated haemodynamic consequences in these conditions in order to facilitate accurate diagnosis and prognostic stratification.

Prevalence and prognostic significance of pulmonary artery aneurysms in adults with congenital heart disease

BACKGROUND

Prevalence and prognostic significance of pulmonary artery (PA) dilatation in congenital heart disease (CHD) have never been studied systematically.

METHODS

Chest X-rays of 1192 consecutive adults with CHD were reviewed. Major diameter of the PA was determined by imaging techniques in those with PA dilatation. A value >29 mm was considered abnormal. Data on anatomy, hemodynamics, residual lesions and outcomes were retrospectively collected.

RESULTS

Overall prevalence of PA dilatation was 18%. A minority of patients (5.5%) reached 40 mm (aneurysm; PAA) and 1.8% exceeded 50 mm. The most common PAA underlying malformations were pulmonary stenosis (21%), and shunts (55%). Significantly larger diameters were observed in hypertensive shunts (40 mm; IQR 36.7-45 mm vs. 34 mm; IQR 32-36 mm) (p < 0.0001). However, the largest diameters were found in cono-truncal anomalies. There was no significant correlation between PA dimensions and systolic pulmonary pressure (r = -0.196), trans-pulmonary gradient (r = -0.203), pulmonary regurgitation (PR) (r = 0.071) or magnitude of shunt (r = 0.137) (p > 0.05 for all). Over follow-up, 1 sudden death (SD) occurred in one Eisenmenger patient. Complications included coronary (3), recurrent laryngeal nerve (1) and airway (1) compressions, progressive PR (1), and PA thrombosis (1). Coronary compression and SD were strongly associated (univariate analysis) with pulmonary hypertension (120 vs. 55 mm Hg; p = 0.002) but not with extreme PA dilatation (range: 40-65 mm).

CONCLUSIONS

PA dilatation in CHD is common but only a small percentage of patients have PAA. Clinical impact on outcomes is low. Complications occurred almost exclusively in patients with pulmonary hypertension whereas PA diameter alone was not associated with adverse outcomes.

Pulmonary artery aneurysms: diagnosis & endovascular therapy

Pulmonary artery aneurysms (PAAs) and pseudoaneurysms are rare entities in the spectrum of pulmonary arterial diseases. The etiology of these aneurysms is varied and patients present with nonspecific symptoms which make their diagnosis both difficult and less often considered. In this review, we will discuss the clinical manifestations, etiologies, methods of detection, imaging features, and the current role of endovascular treatment in the management of PAAs.

Acquired peripheral pulmonary artery aneurysms: morphological spectrum of disease and multidetector computed tomography angiography findings-cases series and literature review

BACKGROUND

Acquired peripheral or intraparenchymal pulmonary artery aneurysms (PPAA) are rare entities but are important to recognize because of the associated morbidity. Hemoptysis is their principal complication and is a potentially fatal condition.

PURPOSE

To illustrate the causes, multidetector CT angiography (MDCTA) findings and differential diagnosis of acquired PPAA.

MATERIALS AND METHODS

The institutional review boards approved this study. We conducted a retrospective review of the demographic data and the results of clinical and laboratory examinations, and imaging studies of patients managed between January 2012 and January 2017 in two institutions.

RESULTS

A total of 19 patients had acquired PPAA that were detected at MDCTA, 9 patients with normal pulmonary artery pressures and 10 with pulmonary hypertension. Nine patients developed PPAA-related acute symptoms. MDCTA features of PPAA include: a lobulated vascular mass, an indistinct irregular arterial wall, aneurysmal thrombosis or wall calcification, findings of impending rupture including perianeurysmal edema, gas or a soft tissue mass.

CONCLUSION

PPAA are rare. In our series, endocarditis and pulmonary hypertension are the PPAA leading causes. The treatment modality preferred is embolization, especially as surgery poses a very high risk for patients with severe pulmonary hypertension. Further clarification of the natural history of these rare arterial aneurysms is needed.

ACR Appropriateness Criteria® Suspected Pulmonary Hypertension

Pulmonary hypertension may be idiopathic or related to a large variety of diseases. Various imaging examinations that may be helpful in diagnosing and determining the etiology of pulmonary hypertension are discussed. Imaging examinations that may aid in the diagnosis of pulmonary hypertension include chest radiography, ultrasound echocardiography, ventilation/perfusion scans, CT, MRI, right heart catheterization, pulmonary angiography, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Embolization of congenital intercostobronchial trunk-pulmonary artery fistula using Amplatzer vascular plugs

We present the case of a 54-year-old male patient diagnosed with a right upper lobe lung cancer and was referred for resection. Positron emission tomography-computed tomography scan showed a prominent vascular structure in the right lung, suspicious for vascular malformation. A computed tomography angiography was done, demonstrating an intercostobronchial trunk-pulmonary artery fistula. There was also non-tapering dilated wandering pulmonary artery coursing through the right lower lung without any abnormal connection with pulmonary veins and were supplying normal lung parenchyma. Amplatzer vascular plugs were used for the treatment of the intercostobronchial trunk-pulmonary artery fistula. Our case highlights these very rare vascular anomalies, and their management.

Approach to Pulmonary Hypertension: From CT to Clinical Diagnosis

Pulmonary hypertension (PH) is a condition characterized by increased pressure in the pulmonary circulation. It may be idiopathic or arise in the setting of other clinical conditions. Patients with PH tend to present with nonspecific cardiovascular or respiratory symptoms. The clinical classification of PH was recently revised at the World Health Organization symposium in Nice, France, in 2013. That consensus statement provided an updated classification based on the shared hemodynamic characteristics and management of the different categories of PH. Some features seen at computed tomography (CT) can suggest a subtype or probable cause of PH that may facilitate placing the patient in the correct category. These features include findings in the pulmonary arteries (peripheral calcification, peripheral dilatation, eccentric filling defects, intra-arterial soft tissue), lung parenchyma (centrilobular nodules, mosaic attenuation, interlobular septal thickening, bronchiectasis, subpleural peripheral opacities, ground-glass opacities, diffuse nodules), heart (congenital lesions, left heart disease, valvular disease), and mediastinum (hypertrophied bronchial arteries). An approach based on identification of these CT features in patients with PH will allow the radiologist to play an important role in diagnosis and help guide the clinician in management of PH. ^©RSNA, 2018.

Infectious and Non-Infectious Diseases Causing the Air Crescent Sign: A State-of-the-Art Review

Aspergilloma, also known as mycetoma or fungus ball, is characterized by a round or oval mass with soft-tissue attenuation within a preexisting lung cavity. The typical computed tomography (CT) aspect of an aspergilloma is a mass separated from the wall of the cavity by an airspace of variable size and shape, resulting in the air crescent sign, also known as the meniscus sign. This CT feature is non-specific and can be simulated by several other entities that result in intracavitary masses. This review describes the main clinical and imaging aspects of the infectious and non-infectious diseases that may present with fungus-ball appearance, including pulmonary hydatid cyst, Rasmussen aneurysm, pulmonary gangrene, intracavitary clot, textiloma, lung cancer, metastasis, and teratoma, focusing on the differential diagnosis.

Robot-assisted lobectomy for lung cancer in the presence of intraoperatively discovered broncho-vascular anomalies affecting right upper and middle lobes

Anatomical variations of the pulmonary bronchi and vessels can lead to serious intraoperative complications during minimally invasive surgery if overlooked. We describe the intraoperative management of an exceptional bronco-vascular variation of the right upper and middle lobe revealed during robotic lobectomy.

An intimal sarcoma of pulmonary artery mimicking pulmonary embolism: a case report and literature review

Pulmonary artery intimal sarcoma is a highly aggressive disease, and is most often misdiagnosed as pulmonary thromboembolism (PTE) due to the similar clinical symptoms and its rarity, which leads to the use of inappropriate treatments such as prolonged anticoagulant therapy. We reported a case of pulmonary artery intimal sarcoma in a patient who was misdiagnosed as having PTE. Pathology after surgery confirmed malignant disease. We concluded that when a patient presents with mild clinical manifestations yet with strong imaging manifestations, pulmonary artery malignancy should be suspected.