CT OF RENAL INFLAMMATORY DISEASE

Although computed tomography (CT) is not routinely indicated in uncomp licated renal infection, it is of value in establishing the diagnosis in equivocal cases, in evaluating high-risk patients, and in determini ng the extent of disease, Unenhanced CT is useful in demonstrating gas , calculi, parenchymal calcifications, hemorrhage, and inflammatory ma sses, However, a contrast material-enhanced study is essential for com plete evaluation of patients with renal inflammatory disease to demons trate alterations in renal excretion of contrast material that occur a s a result of the inflammatory process, In severe acute pyelonephritis , enhanced CT scans obtained during the cortical nephrographic phase t ypically demonstrate solitary or multifocal areas of hypoattenuation w ith loss of the corticomedullary interface, Delayed CT scans obtained during the excretory phase are frequently more helpful than early CT s cans in defining the extent of the disease process, identifying compli cations such as renal abscess, and confirming the presence of urinary obstruction.