Imaging-of-Urinary-system--精品医学课件.ppt

Unenhanced CT scan demonstrates multiple, scattered, round and oval hyperattenuation foci within the left kidney, ?ndings indicative of hemorrhagic acute bacterial pyelonephritis. Multifocal acute bacterial pyelonephritis Most affected patients are young or middle-aged women. Infection usually begins in the bladder and ascends to involve the ureters, intrarenal collecting systems, and then the kidneys. Acute bacterial pyelonephritis CT scan shows the enlarged kidney with global decreased uptake of contrast material and multiple small low-attenuation foci from abscess pockets. CT scan demonstrates peripheral low-attenuation lesions (arrowheads) that are maturing into small abscess cavities. Renal abscess The mass is predominantly hypodense with multiple enhancing septations, and it contains an irregularly thickened and enhancing wall. Renal abscesses form in most patients as a result of inadequate treatment of an ascending infection Perinephric stranding, found commonly in the setting of inflammatory processes, is usually present and an important clue to the diagnosis. The mass has a thick enhancing wall and a nonenhancing, hypodense central portion. CT urogram demonstrate a large, low-attenuation collection along the lateral aspect of the right kidney; the renal parenchyma is severely compressed. There is bilateral moderate caliectasis and multifocal renal parenchymal loss on the left, likely due to chronic pyelonephritis or reflux nephropathy. Emphysematous pyelonephritis Necrosis + gas replacement of renal parenchyma with little or no pus (emphysematous type) Occurs almost exclusively in poorly controlled diabetics Due to infarction infection with gas forming organisms Usually requires urgent nephrectomy Unenhanced CT scan demonstrates a large area of air that has completely destroyed and distorted the right kidney. Note the absence of ?uid within or around the kidney. Emphysematous pyelitis. CT images of the abdomen and pelvis demonstrate bilate