Radiology of Cystic Kidneys

Abstract

Radiographic techniques that may be used in the evaluation of cystic kidneys include excretory urography, radionuclide scintigraphy, ultrasound, computed tomography (CT), magnetic resonance imaging and renal angiography. Of these, CT and ultrasound have had a most dramatic effect on diagnosis of renal cystic disease and these techniques are emphasized in this chapter. Many types of cystic kidneys demonstrate similar CT and sonographic features. Meticulous attention to subtle radiographic finding is, therefore, essential for reaching a correct diagnosis. Also, radiographic findings should always be carefully correlated with clinical features such as patient age, family history, symptoms, physical findings and renal functional status before a diagnosis is attempted. Radiographic features that require analysis include whether cysts are unilateral or bilateral, renal size and functional status, cyst distribution in the kidneys, and presence of hemorrhagic and calcified renal cysts, solid renal masses, extraparenchymal renal cysts and cysts in adjacent organs. We describe the most common radiographic patterns of the various disorders and an optimal imaging approach for each type of cystic disorder is suggested. Conditions described include renal cortical cysts, multicystic dysplastic kidney, hereditary polycystic kidney disease, cystic kidneys in hereditary syndromes, renal medullary cystic disorders, acquired renal cystic disease, cystic renal neoplasms, unilateral renal cystic disease and extraparenchymal renal cysts.