Elena Pena

ALCAPA Syndrome: Not Just a Pediatric Disease

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) syndrome is a rare congenital coronary artery anomaly. There are two types of ALCAPA syndrome: the infant type and the adult type, each of which has different manifestations and outcomes. Infants experience myocardial infarction and congestive heart failure, and approximately 90% die within the 1st year of life. Rarely, ALCAPA syndrome manifests in adults; it may be an important cause of sudden cardiac death. Historically, ALCAPA syndrome was diagnosed at conventional angiography. However, the development of electrogardiographically gated multidetector computed tomographic (CT) angiography and magnetic resonance (MR) imaging enables accurate noninvasive imaging. At MR imaging and multidetector CT angiography, findings include direct visualization of the left coronary artery arising from the main pulmonary artery. Reversed flow from the left coronary artery into the main pulmonary artery may be seen at steady-state free-precession cine and fast cine phase-contrast MR imaging. Because of its ability to assess myocardial viability, which can be used as a prognostic factor to direct the need for surgical repair, MR imaging plays an important role in patient treatment. Restoration of a dual-coronary-artery system is the ideal surgical treatment for ALCAPA syndrome.

Pulmonary Hypertension: How the Radiologist Can Help

Pulmonary hypertension is defined as an abnormal elevation of pressure in pulmonary circulation, with a mean pulmonary arterial pressure higher than 25 mmHg, regardless of the underlying mechanism. The clinical classification system for pulmonary hypertension was updated at the fourth World Symposium on Pulmonary Hypertension in Dana Point, California, in 2008. In patients with suspected pulmonary hypertension, the diagnostic approach includes four stages: suspicion, detection, classification, and functional evaluation. It is crucial to understand the advantages and disadvantages of the different imaging tools available for the diagnostic work-up and follow-up of patients with pulmonary hypertension. Many conditions that cause pulmonary hypertension have suggestive findings at multidetector computed tomography or magnetic resonance imaging; some causes may be surgically treatable, whereas others may demonstrate adverse reactions to vasodilator therapies used during the course of treatment. Therefore, the radiologist plays an important role in evaluating patients with this disease. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.321105232/-/DC1.

Shifts in myocardial fatty acid and glucose metabolism in pulmonary arterial hypertension: a potential mechanism for a maladaptive right ventricular response.

AIMS We investigated the role of metabolic alterations in the development of a maladaptive right ventricular (RV) response in pulmonary arterial hypertension (PAH), which has not previously been undertaken. This study evaluated relationships between glucose and fatty acid metabolism obtained using PET with invasive pulmonary haemodynamics, RV measurements, and RV function to gain insight into the mechanism of RV maladaptation. METHODS AND RESULTS Seventeen consecutive PAH patients (mean age 56 ± 15) who underwent right heart catheterization [mean pulmonary arterial pressure (mPAP) 43 ± 12 mmHg] had cardiac 18F-fluoro-2-deoxyglucose (FDG) and (18)F-fluoro-6-thioheptadecanoic acid (FTHA) PET imaging. RV and left ventricular (LV) FDG and FTHA uptake standard uptake values (SUVs) were measured. The SUV was corrected for the partial volume effect (SUVPVE) based on cardiac magnetic resonance imaging (CMR). Right ventricular ejection fraction (RVEF) was determined by CMR. There was a significant positive correlation between mPAP and RV/LV FDG SUVPVE (r = 0.68, P = 0.003), and the ratio of RV/LV FDG SUV : RV/LV FTHA SUV (r = 0.60, P = 0.02). RVEF was negatively correlated with RV/LV FDG SUVPVE uptake (r = -0.56, P = 0.02) and RV/LV FTHA SUVPVE (r = -0.62, P = 0.019). CONCLUSION Increased pulmonary arterial pressures are associated with increases in the ratio of FDG/FTHA uptake in the RV. Inverse correlation between the uptake of the metabolic tracers and RV function may reflect a shift towards increased fatty acid oxidation and glycolysis associated with RV failure in maladaptive remodelling.

Acute and chronic pulmonary embolism: an in-depth review for radiologists through the use of frequently asked questions.

In this article, the authors review the role of the different imaging modalities in the diagnostic workup of patients with suspected acute or chronic pulmonary embolism (PE). The authors also discuss the current guidelines for the diagnosis of acute PE based on the pretest probability clinical assessment and outline the current recommendations for special patient populations. The recent guidelines from the American Thoracic Society/Society of Thoracic Radiology for the assessment of suspected PE in pregnancy are also reviewed. Finally, the imaging findings in acute and chronic PE are illustrated.

Noninfectious Pulmonary Complications after Hematopoietic Stem Cell Transplantation: Practical Approach to Imaging Diagnosis

Hematopoietic stem cell transplantation (HSCT) is a widely available treatment for a variety of malignant and nonmalignant disorders. The treatment outcome is affected by the type of transplant and is limited by complications secondary to immunosuppression and treatment-related toxicity. Pulmonary complications are very common and follow a predictable timeline that reflects the immunologic status of the patient in the peritransplant period. Until recently, pulmonary complications were largely attributed to infectious causes. However, advances in diagnosis and treatment have led to a shift, and noninfectious complications have emerged as a major cause of morbidity and mortality in this population. With the increasing number of centers that perform HSCT, knowledge of posttransplant noninfectious pulmonary complications has become increasingly relevant. The basic principles of and indications for HSCT are described, and a timeline for the clinical, radiologic, and pathologic manifestations of noninfectious pulmonary complications is presented. Emphasis is given to high-resolution computed tomographic findings and the role of imaging in management of complications. A practical approach is provided to guide imaging interpretation and diagnosis of noninfectious pulmonary complications after HSCT.

Anomalous Coronary Arteries That Need Intervention: Review of Pre- and Postoperative Imaging Appearances

Coronary artery anomalies constitute a diverse group of abnormalities, ranging from anatomic variants to those having hemodynamic consequences. This review focuses on major anomalies that have clinical implications requiring treatment, including anomalous origin of the coronary artery from the opposite sinus with interarterial course specifically with an intramural course, coronary artery origin from the pulmonary artery, and coronary artery fistula. Comprehensive imaging evaluation is necessary to precisely delineate the anatomy as well as pathophysiologic aspects of the anomaly before determining treatment options for a specific patient. Coronary computed tomographic angiography provides elegant depiction of coronary arterial anatomy and the relationship of the vessel to the adjacent structures, with the ability to perform three-dimensional reconstructions. Magnetic resonance (MR) imaging is emerging as an alternative noninvasive imaging strategy, particularly in young individuals, due to the lack of ionizing radiation and avoidance of iodinated contrast agents. This review describes the roles and recent technical advancements in computed tomography and MR imaging pertinent to coronary artery imaging. Additionally, this article will familiarize readers with the cross-sectional imaging appearance of clinically relevant coronary anomalies, hemodynamic considerations, and complex decision making. The different management strategies used for these anomalies, such as coronary unroofing, reimplantation, bypass grafting, Takeuchi repair, and surgical and interventional closure of fistulas, as well as specific posttreatment complications, are also discussed. ©RSNA, 2017.

Scar-based catheter ablation for persistent atrial fibrillation.

Purpose of review Percutaneous catheter ablation can be an effective treatment for paroxysmal atrial fibrillation. However, catheter ablation for the treatment of persistent atrial fibrillation or long-standing persistent atrial fibrillation is associated with success rates of 45–50% at 1 year. To address the challenge of ablating patients with persistent atrial fibrillation, several approaches have been proposed. Atrial scar-based catheter ablation is a promising strategy for ablation of persistent atrial fibrillation. Recent findings In this review, we outline the role of atrial scar/fibrosis in the pathophysiology of atrial fibrillation and how this encouraged clinical studies assessing the atrial substrate using scar-based mapping. We highlight current approaches to voltage mapping of atrial scar in patients with atrial fibrillation. The characteristics, techniques, and outcomes of recently published studies evaluating scar-based catheter ablation strategies for the treatment of atrial fibrillation are discussed. Finally, we explore the role of noninvasive tools such as delayed enhancement MRI to assess the atrial fibrillation substrate. Summary In summary, the optimal catheter ablation strategy for persistent atrial fibrillation remains unknown. Current data highlight the need for a better understanding of the substrate and mechanisms of arrhythmia maintenance in this population. Atrial scar-based catheter ablation has recently emerged as a promising strategy for ablation of atrial fibrillation. However, the available data have limitations that preclude definitive conclusions regarding the utility of this strategy. Further research is needed to assess the role of scar-based ablation for persistent atrial fibrillation.

Quantitative texture features as objective metrics of enhancement heterogeneity in hypertrophic cardiomyopathy

Background Hypertrophic cardiomyopathy (HCM) results in myocardial disarray, hypertrophy and fibrosis. Late gadolinium enhanced MRI (LGE) can assess the presence and extent of fibrosis, which is associated with the development of arrhythmias and sudden cardiac death. However, enhancement may not always be present or only sparsely distributed. Thus, one of the challenges is how best to describe heterogeneous LGE patterns in an objective fashion that informs clinical decision making. Quantitative texture features may provide clinicians with an objective means of describing the heterogeneity of LGE patterns in HCM. We hypothesized that hypertrophied segments would exhibit greater grey-level heterogeneity than both (a) non-hypertrophied segments in HCM patients, and (b) healthy volunteers.

Pericardial Lymphangiohemangioma Multimodality Imaging Features and Pathologic Correlation

A 42-year-old woman presented to the emergency department with recurrent episodes of palpitation. The physical examination and the ECG were unremarkable. Echocardiographic examination revealed a solid mass compressing the right cardiac chambers (Movie I in the online-only Data Supplement). A contrast-enhanced computed tomography of the thorax confirmed the presence of a soft tissue mass measuring 8×6×9 cm in transverse × anteroposterior × craniocaudal dimensions, in the right atrioventricular groove (Figure 1). It contained no calcifications, and no vascular connection with adjacent structures was identified. There was no pericardial effusion. Figure 1. Contrast-enhanced multidetector computed tomography image demonstrates a well-circumscribed soft-tissue mass in the right atrioventricular groove. The mass causes significant compression of the right atrium (RA) and right ventricle (RV). Cardiac magnetic resonance imaging confirmed an intrapericardial mass in the right atrioventricular groove surrounding the right coronary artery. The mass was isointense to myocardium on T1-weighted imaging (Figure 2) and hyperintense on …

Nonthrombotic Pulmonary Embolism: A Radiological Perspective

In this review, the authors highlight the clinical setting, symptoms, and imaging findings in nonthrombotic pulmonary embolism that radiologists may encounter in their clinical practice. We illustrate the imaging features based on the inciting agent with an emphasis on computed tomography. The diagnosis of nonthrombotic pulmonary embolism usually requires a high index of clinical suspicion and knowledge of the typical radiological findings.