Vascular malformations and arteriovenous fistulas of the kidney

Vascular malformations of the kidney are disease processes that involve renal veins and arteries and include congenital arteriovenous malformations (AVMs) and arteriovenous fistulas. AVMs are congenital communications between arteries and veins with a vascular nidus that bypass the capillary bed. Congenital AVMs are rare and subclassified in cirsoid, angiomatous, and aneurysmal types. Congenital AVMs are different from iatrogenic or traumatic arteriovenous fistulas (AVF), which are characterized by a single direct communication between an artery and a vein without an intervening vascular nidus. These lesions may present with a wide range of signs and symptoms that vary from hypertension to renal masses. Imaging is valuable in the detection and characterization of AVM and AVF. The presence of arteriovenous shunting characterizes AVM and AVF. These lesions represent an important group of entities for diagnostic consideration, and understanding the vascular anatomy helps in guiding for proper treatment. This article describes the imaging features of each lesion that help to differentiate it from the others and the endovascular therapies to treat these vascular processes and their possible complications.

Arteriovenous malformations of the uterus

Arterial venous malformations (AVM) of the uterus are uncommon entities and should be considered in patients who present with profuse genital bleeding. There are two types of uterine AVM: acquired and congenital. Acquired uterine AVMs are conformed by communications between the uterine arteries and the myometrial veins, and are caused by an iatrogenic event or a pathological condition. Congenital AVMs are the result of abnormal development of primitive vessels that result in connections between pelvic arteries and veins in the uterus without an interconnecting capillary bed. Ultrasonography is a noninvasive diagnostic method able to demonstrate and characterize AVMs of the uterus. AVM in the pelvis may be noted incidentally by computed tomography (CT) of the pelvis, and magnetic resonance imaging (MRI) is frequently used to confirm and further characterize the sonographic findings of uterine AVM. Catheter angiography and embolization are very effective in defining the vascular anatomy and treating uterine vascular abnormalities.

Diagnostic and interventional radiology for Budd-Chiari syndrome

Budd-Chiari syndrome is a heterogeneous group of disorders characterized by hepatic venous outflow obstruction that involves one or more draining hepatic veins. Its occurrence in populations in the western hemisphere is commonly associated with hypercoagulative states. Clinical manifestations in many cases are nonspecific, and imaging may be critical for early diagnosis of venous obstruction and accurate assessment of the extent of disease. If Budd-Chiari syndrome is not treated promptly and appropriately, the outcome may be dismal. Comprehensive imaging evaluations, in combination with pathologic analyses and clinical testing, are essential for determining the severity of disease, stratifying risk, selecting the appropriate therapy, and objectively assessing the response. The main goal of treatment is to alleviate hepatic congestion, thereby improving hepatocyte function and allowing resolution of portal hypertension. Various medical, endovascular, and surgical treatment options are available. Percutaneous and endovascular procedures, when performed in properly selected patients, may be more effective than medical treatment methods for preserving liver function and arresting disease progression in the long term. In addition, such procedures are associated with lower morbidity and mortality than are open surgical techniques.

Midaortic syndrome associated with fetal alcohol syndrome

Midaortic syndrome (MAS) is an uncommon condition characterized by progressive narrowing of the abdominal aorta and its branches and impressive formation of collateral circulation. It affects children and young adults and presents predominantly as untreatable hypertension. Fetal alcohol syndrome (FAS) refers to a constellation of physical, behavioral, and cognitive abnormalities secondary to alcohol exposure in utero. The authors present an unusual association between a hypoplastic abdominal aorta and fetal alcohol syndrome. The patient discussed in this article presented with severe hypertension that was successfully treated with renal angioplasty.

Pulmonary meningioma: false-positive positron emission tomography for malignant pulmonary nodules

An intraparenchymal lung tumor exhibiting the histopathologic and immunophenotypic characteristics of an intracranial meningioma is described. The tumor presented as a solitary asymptomatic pulmonary nodule with increased fluorodeoxyglucose uptake on positron emission tomography. After right upper lobectomy, benign psammomatous meningioma was diagnosed. There was no clinical or radiographic evidence of a central nervous system tumor, suggesting that this was a primary lung tumor. The authors describe a benign tumor that can present as a false-positive finding of positron emission tomography performed to evaluate a possible malignant pulmonary nodule.