Faculty Bibliography

Extracardiac nonsurgical vascular shunts in the thorax are a group of well-recognized heterogeneous conditions, frequently symptomatic, in which there is diversion of blood flow from one vessel to another or from a vessel to a cardiac chamber. The authors describe and classify many of these nonsurgical extracardiac shunts or fistulas according to their source and endpoint (eg, systemic-to-systemic, systemic-to-pulmonic, pulmonic-to-systemic, and pulmonic-to-pulmonic) and to whether the oxygenated blood mixes with deoxygenated systemic venous flow (left-to-right shunts), deoxygenated blood bypasses the pulmonary capillary bed (right-to-left shunts), or oxygenated blood recirculates (left-to-left shunts). Clinical manifestations and imaging appearances of these conditions are highlighted.

OBJECTIVE:Lipoid pneumonia results from accumulation of lipids in the alveoli and can be either exogenous or endogenous in cause based on the source of the lipid. Exogenous lipoid pneumonia is caused by inhalation or aspiration of animal fat or vegetable or mineral oil. Endogenous lipoid pneumonia is usually associated with bronchial obstruction. The purpose of this article is to review the pathogenesis and clinical and radiologic manifestations of exogenous and endogenous lipoid pneumonia. CONCLUSION/CONCLUSIONS:The ability to recognize the radiologic manifestations of lipoid pneumonia is important because, in the appropriate clinical setting, these findings can be diagnostic.

OBJECTIVE:The purpose of this article is to review open thoracic aortic surgical techniques and to describe the range of postoperative findings on CT angiography (CTA). CONCLUSION/CONCLUSIONS:An understanding of surgical thoracic aortic procedures will allow appropriate differentiation of normal from abnormal CTA findings on postoperative imaging.

Cocaine is the second most commonly abused illicit drug in the US and the most common one involved in emergency department visits, the majority of which are related to the cardiovascular system. Cardiovascular complications related with cocaine abuse include myocardial ischemia and infarction, myocarditis, hypertrophic cardiomyopathy, dilated cardiomyopathy, aortic dissection, thrombosis, stroke and cerebral hemorrhage, and different forms of visceral ischemia, among others. In an era where cocaine use has reached epidemic proportions, it is necessary for the radiologist to understand the pathophysiology, clinical presentation, and imaging characteristics of its cardiovascular complications.

OBJECTIVE:The objective of our study was to review expected findings and complications after thoracic endovascular aortic repair on CT angiography (CTA). CONCLUSION/CONCLUSIONS:Luminal and extraluminal changes to the thoracic aorta occur after endovascular stent-grafting. The radiologist can facilitate appropriate management by detecting and differentiating expected CTA findings from complications.

The sternum and sternoclavicular joints--critical structures of the anterior chest wall--may be affected by various anatomic anomalies and pathologic processes, some of which require treatment. Pectus excavatum and pectus carinatum are common congenital anomalies that are usually benign but may warrant surgical treatment if they cause compression of vital internal structures. By contrast, developmental variants such as the sternal foramen are asymptomatic and do not require further evaluation or treatment. Arthritides of the sternoclavicular joint (osteoarthritis, septic arthritis, and seronegative arthropathies) are common and must be differentiated before an appropriate management method can be selected. The recognition of complications of sternotomy (eg, sternal dehiscence, secondary osteomyelitis) is critical to avoid life-threatening sequelae such as acute mediastinitis. Likewise, the detection of sternal fractures and sternoclavicular dislocations is important, especially where they impinge on vital structures. In addition, sternal malignancies (most commonly, metastases and chondrosarcoma) must be distinguished from benign neoplasms. To achieve accurate and timely diagnoses that facilitate appropriate treatment, radiologists must be familiar with the appearances of these normal anatomic variants and diseases of the sternum.

OBJECTIVE:To assess patient outcome and imaging findings of patients with pulmonary embolism of fluid silicone. METHODS:Medical records and imaging examinations of 10 patients with respiratory distress after illicit injection of fluid silicone were reviewed. Population consisted of 8 male (6 male-to-female transsexuals) and 2 female subjects. RESULTS:Average age was 29 years. Most common injection sites were gluteal and trochanteric. Respiratory symptoms developed between 15 minutes and 2 days after silicone injection. Five referred fever, 6 developed adult respiratory distress syndrome, and 2 subsequently died. Alveolar hemorrhage was demonstrated on pathological examination in 6, with silicone vacuoles in the lung parenchyma in 3. Computed tomography demonstrated peripheral ground glass opacities with interlobular septal thickening in all and peripheral airspace disease in 7. CONCLUSIONS:Illicit injection of large volumes of fluid silicone for cosmetic purposes is associated with pulmonary embolism and acute alveolar hemorrhage and is associated with a significant mortality.

Mucoid impaction is a relatively common finding at chest radiography and computed tomography (CT). Both congenital and acquired abnormalities may cause mucoid impaction of the large airways that often manifests as tubular opacities known as the finger-in-glove sign. The congenital conditions in which this sign most often appears are segmental bronchial atresia and cystic fibrosis. The sign also may be observed in many acquired conditions, include inflammatory and infectious diseases (allergic bronchopulmonary aspergillosis, broncholithiasis, and foreign body aspiration), benign neoplastic processes (bronchial hamartoma, lipoma, and papillomatosis), and malignancies (bronchogenic carcinoma, carcinoid tumor, and metastases). To point to the correct diagnosis, the radiologist must be familiar with the key radiographic and CT features that enable differentiation among the various likely causes. CT is more useful than chest radiography for differentiating between mucoid impaction and other disease processes, such as arteriovenous malformation, and for directing further diagnostic evaluation. In addition, knowledge of the patient's medical history, clinical symptoms and signs, and predisposing factors is important.

The retrocrural space (RCS) is a small triangular region within the most inferior posterior mediastinum bordered by the two diaphragmatic crura. Multiplanar imaging modalities such as computed tomography and magnetic resonance imaging allow evaluation of the RCS as part of routine examinations of the chest, abdomen, and spine. Normal structures within the retrocrural region include the aorta, nerves, the azygos and hemiazygos veins, the cisterna chyli with the thoracic duct, fat, and lymph nodes. There is a wide range of normal variants of the diaphragmatic crura and of structures within the RCS. Diverse pathologic processes can occur within this region, including benign tumors (lipoma, neurofibroma, lymphangioma), malignant tumors (sarcoma, neuroblastoma, metastases), vascular abnormalities (aortic aneurysm, hematoma, azygos and hemiazygos continuation of the inferior vena cava), and abscesses. An understanding of the anatomy, normal variants, and pathologic conditions of the diaphragmatic crura and retrocrural structures facilitates diagnosis of disease processes within this often overlooked anatomic compartment.