Imaging Patterns of Pneumonia.

Imaging findings of pneumonia are diverse, with frequent overlap between the various infectious etiologies of pneumonia, as well as various other disease conditions, including inflammatory conditions, vasculitis, and malignancy. In the appropriate clinical context, a number of imaging findings and the patterns that they form on imaging may provide clues that enable radiologists and clinicians to narrow the differential diagnostic considerations. Although a definite diagnosis can rarely be provided based on imaging findings alone, the combination of clinical, imaging, and laboratory findings are usually sufficient for accurate diagnosis and management decisions.

Imaging of the Anterior/Prevascular Mediastinum.

Prevascular mediastinal masses include a wide range of benign and malignant entities. Localization of mediastinal masses to specific compartments together with characteristic imaging findings and demographic and clinical information allows formulation of a focused differential diagnosis. Radiologists may use these methods to distinguish between surgical and nonsurgical cases and thus inform patient management and have an impact on outcomes.

Uncommon thoracic manifestations from extrapulmonary tumors: Computed tomography evaluation - Pictorial review.

Although metastasis can occur at a variety of sites, pulmonary involvement is common in patients with cancer. Depending on the source and type of tumor, pulmonary metastases present with a wide range of radiologic appearances. Hematogenous dissemination through the pulmonary arteries to the pulmonary capillary network is the most common form of spread in pulmonary metastases.

Multimodality Imaging of Focal and Diffuse Fibrosing Mediastinitis.

Fibrosing mediastinitis is a rare benign but potentially life-threatening process that occurs because of proliferation of fibrotic tissue in the mediastinum. The focal subtype is more common and typically is associated with an abnormal immunologic response to infection. Affected patients are typically young at presentation, but a wide age range has been reported, without a predilection for either sex.

Evaluation after Orthotopic Heart Transplant: What the Radiologist Should Know.

Orthotopic heart transplant (OHT) is the treatment of choice for end-stage heart disease. As OHT use continues and postoperative survival increases, multimodality imaging evaluation of the transplanted heart will continue to increase. Although some of the imaging is performed and interpreted by cardiologists, a substantial proportion of images are read by radiologists.

IASLC/ITMIG Staging System and Lymph Node Map for Thymic Epithelial Neoplasms.

Thymic epithelial neoplasms are rare malignancies that arise from the thymus and include thymoma, thymic carcinoma, and thymic neuroendocrine tumors. At least 15 different stage classifications have been proposed for thymic epithelial neoplasms and used to varying degrees in clinical practice, many of which have been constructed from small groups of patients. Traditionally, the Masaoka and Masaoka-Koga staging systems have been the schemes most commonly employed, and the latter has been recommended for use by the International Thymic Malignancy Interest Group (ITMIG).

Bronchiolitis: A Practical Approach for the General Radiologist.

Radiologists consciously or unconsciously encounter bronchiolitis on images frequently. The purpose of this article is to simplify the concept of bronchiolitis to facilitate the formulation of a succinct and accurate differential diagnosis and suggest potential causes for the imaging findings. Direct and indirect signs of bronchiolitis that are seen on computed tomographic images are detailed.

ITMIG Classification of Mediastinal Compartments and Multidisciplinary Approach to Mediastinal Masses.

Division of the mediastinum into specific compartments is beneficial for a number of reasons, including generation of a focused differential diagnosis for mediastinal masses identified on imaging examinations, assistance in planning for biopsies and surgical procedures, and facilitation of communication between clinicians in a multidisciplinary setting. Several classification schemes for the mediastinum have been created and used to varying degrees in clinical practice. Most radiology classifications have been based on arbitrary landmarks outlined on the lateral chest radiograph.

Emerging Concepts in Intramural Hematoma Imaging.

Intramural hematoma (IMH) is included in the spectrum of acute aortic syndrome and appears as an area of hyperattenuating crescentic thickening in the aortic wall that is best seen at nonenhanced computed tomography. IMH is historically believed to originate from ruptured vasa vasorum in the aortic media without an intimal tear, but there are reports of small intimomedial tears identified prospectively at imaging or found at surgery in some cases of IMH. These reports have blurred the distinction between aortic dissection and IMH and raise questions about what truly distinguishes the entities that compose acute aortic syndrome.

Thoracic Metastases From Primary Hepatobiliary and Pancreatic Malignancies: Predictable Patterns of Metastatic Spread.

This article reviews common and uncommon patterns of thoracic metastatic disease in primary hepatobiliary and pancreatic malignancies that are often overlooked or improperly diagnosed because of atypical location or imaging appearance. An understanding of the pathophysiology and routes of tumor spread aids in tailoring a search pattern allowing for more accurate evaluation of disease activity.

Bronchial arteries: anatomy, function, hypertrophy, and anomalies.

The two main sources of blood supply to the lungs and their supporting structures are the pulmonary and bronchial arteries. The bronchial arteries account for 1% of the cardiac output but can be recruited to provide additional systemic circulation to the lungs in various acquired and congenital thoracic disorders. An understanding of bronchial artery anatomy and function is important in the identification of bronchial artery dilatation and anomalies and the formulation of an appropriate differential diagnosis.

A modern definition of mediastinal compartments.

Division of the mediastinum into compartments is used to help narrow the differential diagnosis of newly detected mediastinal masses, to assist in planning biopsy and surgical procedures, and to facilitate communication among clinicians of multiple disciplines. Several traditional mediastinal division schemes exist based upon arbitrary landmarks on the lateral chest radiograph. We describe a modern, computed tomography-based mediastinal division scheme, which has been accepted by the International Thymic Malignancy Interest Group as a new standard.

Imaging manifestations of mediastinal fat necrosis.

Mediastinal fat necrosis (MFN) or epipericardial fat necrosis, as it is commonly referred to in the literature, is a rare self-limiting cause of chest pain of unclear etiology. MFN affects previously healthy individuals who present with acute pleuritic chest pain. Characteristic computed tomography (CT) findings include a fat attenuation lesion with intrinsic and surrounding increased attenuation stranding.

Spectrum of pulmonary neuroendocrine proliferations and neoplasms.

Neuroendocrine neoplasms are ubiquitous tumors found throughout the body, most commonly in the gastrointestinal tract followed by the thorax. Neuroendocrine cells occur normally in the bronchial and bronchiolar epithelium and may be solitary or may occur in clusters. Although neuroendocrine cell proliferations may be found in association with chronic lung disease, a broad range of neuroendocrine proliferations and neoplasms may occur and exhibit variable biologic behavior.

Partial anomalous pulmonary venous return through a left subaortic vein.

We present an unusual case of partial anomalous pulmonary venous return draining a subsegmental area of the left upper lobe into the superior vena cava. To our knowledge, this type of partial anomalous pulmonary venous return has not been described previously. We briefly describe embryologic considerations that we believe could help explain the origin of this rare anomaly.

Role of imaging in the diagnosis, staging, and treatment of thymoma.

Thymoma is a rare mediastinal neoplasm but is the most common primary neoplasm of the anterior mediastinum. There have been only a few published reports assessing this disease. Furthermore, many of these reports are from a single institution and span several decades, which may lead to potentially misleading conclusions related to diagnosis, staging, and treatment.

Imaging findings in human Bordetella bronchiseptica pneumonia.

Bordetella bronchiseptica is a gram-negative coccobacillus, which causes respiratory infection in dogs, rabbits, and pigs, and is rarely a human pulmonary pathogen. We present 2 immunocompromised patients diagnosed with B. bronchiseptica pneumonia.

Right-sided oropharyngeal cervical aortic arch.

We present a rare case of cervical aortic arch with associated spontaneously ruptured thoracic aortic aneurysm. Our case is unique in that the apex of the arch was at the level of the second cervical vertebra, the most cranial location of all reported cases. To our knowledge, this case represents the first "oropharyngeal cervical aortic arch" ever described.

Imaging of small airways disease.

Small airways disease includes a spectrum of inflammatory and fibrotic pulmonary diseases centered on the small conducting airways. High-resolution computed tomography plays a key role in the detection and classification of small airways disease and, when combined with relevant clinical and pathologic findings, leads to a more accurate diagnosis. The imaging manifestations of small airways disease on high-resolution computed tomography may be direct or indirect signs of small airway involvement and include centrilobular nodules and branching nodular (tree-in-bud) opacities, or the demonstration of mosaic attenuation that is typically exaggerated on expiratory computed tomography.