Epicardial Space: Comprehensive Anatomy and Spectrum of Disease.

The epicardial space (ES) is the anatomic region located between the myocardium and the pericardium. This space includes the visceral pericardium and the epicardial fat that contains the epicardial coronary arteries, cardiac veins, lymphatic channels, and nerves. The epicardial fat represents the main component of the ES. This fat deposit has been a focus of research in recent years owing to its properties and relationship with coronary gossypiboma plaque and atrial fibrillation. Although this region is sometimes forgotten, a broad spectrum of lesions can be found in the ES and can be divided into neoplastic and nonneoplastic categories. Epicardial neoplastic lesions include lipoma, paraganglioma, metastases, angiosarcoma, and lymphoma. Epicardial nonneoplastic lesions encompass inflammatory infiltrative disorders, such as immunoglobulin G4-related disease and Erdheim-Chester disease, along with hydatidosis, abscesses, coronary abnormalities, pseudoaneurysms, hematoma, lipomatosis, and gossypiboma. Initial imaging of epicardial lesions may be performed with echocardiography, but CT and cardiac MRI are the best imaging modalities to help characterize epicardial lesions. Due to the nonspecific onset of signs and symptoms, the clinical history of a patient can play a crucial role in the diagnosis. A history of malignancy, multisystem diseases, prior trauma, myocardial infarction, or cardiac surgery can help narrow the differential diagnosis. The diagnostic approach to epicardial lesions should be made on the basis of the specific location, characteristic imaging features, and clinical background. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Duodenal tumors on cross-sectional imaging with emphasis on multidetector computed tomography: a pictorial review.

Duodenal tumours are uncommon, but they can cause significant morbidity and mortality. As stomach and colon are a more common site of gastrointestinal malignancies, radiologists sometimes neglect the duodenum. Multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) can accurately locate and characterize mass-forming duodenal lesions, making them invaluable for the differential diagnosis and determining management strategies such as biopsy or surgery. Although conventional endoscopy continues to play an important role in the diagnosis of duodenal tumors, MDCT and MRI are very useful for evaluating the duodenal wall, extraduodenal space, and surrounding viscera, as well as the intraluminal content seen on endoscopy. This pictorial review aims to illustrate the most common benign and malignant mass-forming duodenal lesions and to focus on the imaging features that are most helpful in reaching the correct diagnosis.

Imaging of non-neoplastic duodenal diseases. A pictorial review with emphasis on MDCT.

A wide spectrum of abnormalities can affect the duodenum, ranging from congenital anomalies to traumatic and inflammatory entities. The location of the duodenum and its close relationship with other organs make it easy to miss or misinterpret duodenal abnormalities on cross-sectional imaging. Endoscopy has largely supplanted fluoroscopy for the assessment of the duodenal lumen. Cross-sectional imaging modalities, especially multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI), enable comprehensive assessment of the duodenum and surrounding viscera. Although overlapping imaging findings can make it difficult to differentiate between some lesions, characteristic features may suggest a specific diagnosis in some cases. Familiarity with pathologic conditions that can affect the duodenum and with the optimal MDCT and MRI techniques for studying them can help ensure diagnostic accuracy in duodenal diseases. The goal of this pictorial review is to illustrate the most common non-malignant duodenal processes. Special emphasis is placed on MDCT features and their endoscopic correlation as well as on avoiding the most common pitfalls in the evaluation of the duodenum. TEACHING POINTS: • Cross-sectional imaging modalities enable comprehensive assessment of duodenum diseases. • Causes of duodenal obstruction include intraluminal masses, inflammation and hematomas. • Distinguishing between tumour and groove pancreatitis can be challenging by cross-sectional imaging. • Infectious diseases of the duodenum are difficult to diagnose, as the findings are not specific. • The most common cause of nonvariceal upper gastrointestinal bleeding is peptic ulcer disease.

A diagnostic approach to the mediastinal masses.

BACKGROUND: Multiple different types of mediastinal masses may be encountered on imaging techniques in symptomatic or asymptomatic patients. The location and composition of these lesions are critical to narrowing the differential diagnosis. METHODS: Radiological compartmentalisation of the mediastinum helps in focusing the diagnosis of masses on the basis of their site. Some diseases, however, do not occur exclusively in any specific compartment and can spread from one compartment to another. RESULTS: Tissular components of the mass, the degree of vascularisation and the relationships with mediastinal structures assessed by computed tomography (CT) or magnetic resonance imaging (MRI) are a leading edge of the radiological diagnosis. Special applications at MRI have been developed over the recent years in order to identify accurately tissular components of the mediastinal masses. The likelihood of malignancy of the mediastinal masses is influenced by the symptomatology and the age of the patient. This article reviews the most commonly encountered mediastinal masses considering clinical history and manifestations, anatomical position and certain details seen on different imaging modalities that allow correct diagnosis in many cases. CONCLUSION: Familiarity with the radiological features of mediastinal masses facilitates accurate diagnosis, differentiation from other mediastinic processes and, thus, optimal patient treatment. TEACHING POINTS: • CT and MRI are important for the diagnosis of mediastinal masses. • The location and tissue characteristics on imaging studies are critical to narrow down the differential diagnosis of mediastinal masses. • Symptomatology and patient age affect the likelihood of malignancy.

Imaging of breast implants-a pictorial review.

The number of women with breast implants is increasing. Radiologists must be familiar with the normal and abnormal findings of common implants. Implant rupture is a well-known complication after surgery and is the main cause of implant removal. Although mammography and ultrasonography are the standard first steps in the diagnostic workup, magnetic resonance imaging (MRI) is the most useful imaging modality for the characterisation of breast implants because of its high spatial resolution and contrast between implants and soft tissues and absence of ionising radiation. MRI has the highest sensitivity and specificity for implant rupture, thanks to its sequences that can suppress or emphasise the signal from silicone. Regardless of the technique used, the overall aim of imaging breast implants is to provide essential information about tissue and prosthesis integrity, detect implant abnormalities and detect breast diseases unrelated to implants, such as breast cancer.