Acute pyelonephritis is a severe form of bacterial infection in the kidneys. The clinical presentation of this disease includes fevers and chills. The patient may also suffer from lower abdominal pain and flank pain. Although during the first few stages, it would be difficult to relate the infection to acute pyelonephritis.
The acute pyelonephritis infection may typically result from an ascending retrograde spread initiating from the collecting ducts and gradually spreading to the renal parenchyma. In case the doctor suspects an acute pyelonephritis infection he may recommend a CT scan of the kidneys in order to diagnose the disease. In most cases the symptoms are poorly localized and if unidentified it may lead to various complications.
A CT scan of the acute pyelonephritis kidneys will show many focal areas that are striated with wedge shaped hypo perfusion that results from characteristic striated nephrogram. In most cases, the infected kidneys will appear to be enlarged in size and one may also observe stranding in the surrounding fat. In recurrent infections one may also observe a nephrogram with highly increased attenuation.
The various striations that are observed a CT scan of the infected kidneys are as s result of stasis of the contrast material with the associated tubules. This gives an enhanced level of attenuation over a period of time.