Renovascular Hypertension Etiology The most common cause of renovascular hypertension is renal artery stenosis, which may be caused by atherosclerosis (70% to 90%) or less commonly by fibromuscular dysplasia (10% to 30%). Rare causes of renal artery stenosis include arteritis,…
Renal failure may be classified as prerenal when secondary to a reduction in the renal perfusion pressure gradient, renal when the result of intrinsic disease of the renal parenchyma, and postrenal when secondary to an abnormality of urine outflow. Prerenal…
This chapter discusses benign and malignant renal lesions ( Box 63-1 ) with a separate note on cystic lesions based on the Bosniak classification. Box 63-1 Benign and Malignant Focal Renal Lesions Benign Lesions Simple renal cyst Oncocytoma Angiomyolipoma Leiomyoma…
Anatomy Overview The Kidney The kidneys are paired retroperitoneal organs that primarily function in the excretion of metabolic waste. They are bean shaped with a convex lateral border and a concave medial surface known as the renal hilum. On intravenous…
Lymph Node Imaging Techniques Imaging evaluation of lymph nodes forms an integral component of staging of various malignancies, including lymphomas, and is also helpful in the evaluation of certain infective and inflammatory processes within the abdomen. This has special relevance…
Normal Variants and Congenital Anomalies The spleen begins to develop during the fifth week of embryogenesis when mesenchymal cells aggregate between the two leaves of the dorsal mesogastrium to form a lobulated embryonic spleen. Rotation of the stomach and growth…
Splenic Cysts Non-Neoplastic and Nonparasitic Splenic Cysts Etiology Non-neoplastic and nonparasitic splenic cysts are classified into primary (i.e., epithelial, true) and secondary (i.e., pseudocysts, false) cysts, depending on the presence or absence of the internal epithelial lining. Primary or epithelial…
Technical Aspects Functional imaging of the gallbladder and bile ducts is a valuable tool, providing critical information for the management of conditions of the biliary system. Modern functional techniques are noninvasive and can permit earlier and improved disease characterization resulting…
Focal gallbladder wall thickening is often an imaging diagnosis and encompasses a wide variety of differential diagnoses. Polypoid lesions of the gallbladder form an important group of conditions that are included in the differential diagnosis of focal gallbladder wall thickening…
Diffuse gallbladder wall thickening is commonly encountered in diagnostic settings. The ability of ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) to directly visualize the thickened gallbladder wall ascertains the importance of this condition. Ultrasound is the initial imaging…