Role of CT in Evaluation of Pyelonephrirtis

CT is the imaging modality of choice for the diagnosis of acute pyelonephritis and its associated complications due to its wide availability and accurate depiction of the features, extent and severity of the disease. Unenhanced CT is mostly sufficient to rule out some of the causes and extent of the disease such as the presence of calculi, perinephric fat stranding, presence of hydronephrosis, presence of air foci within the renal parenchyma or the collecting system or the presence of fluid collections around the kidney. contrast enhanced CT scan is required in all cases of suspected pyelonephritis, to look for hypoenhancing areas of renal parenchyma or striations within the renal parenchyma. It helps in the early detection of suspected pyelonephritis leading to early management and decreased morbidity and decreased incidence of complications, limiting the extent of progression of the disease. Contrast enhanced CT scan is confirmatory to assess the diffuse/focal extent of the disease. CT is particularly useful for evaluating the complications of pyelonephritis such as abscesses and emphysematous pyelonephritis. It helps in defining theextent and severity of these complications. It also plays an important role not only in the diagnosis of these complications but also in the management, wherein CT guided procedures . CT plays a critical role in patient management by suggesting the correct diagnosis based on characteristic imaging findings, identifying the complications especially in critically ill patients and reducing the morbidity and mortality by immediate percutaneous nephrostomy or nephrectomy in cases of complications of pyelonephritis