الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Urinary tract infections are the most common urologic diseases, considered as the most common cause of renal infection through the ascending route. Kidney infection (upper UTI) is typically more severe than lower UTI because bacteria may also infect the blood stream (bacteremia) from kidneys resulting in a more severe illness if not early diagnosed.
Although upper urinary tract infections are usually straightforward or ”uncomplicated”, they can potentially be serious if there is an obstruction or if they develop in patients who are at risk of complications.
Renal infections range from mild to severe, acute to chronic and may be associated with predisposing risk factors like diabetes mellitus, human immunodeficiency virus (HIV), leukemia, vesico-ureteric reflux , recurrent UTI and calculi.
Traditionally, imaging of renal infections was largely a multimodality approach. Excretory urography, ultrasonography, nuclear scintigraphy and computed tomography scans have all played major roles; however in recent years, CT has increased in prominence in the imaging and evaluation of renal infection. The reason for this trend includes improvement in the quality of CT scanners which provide excellent resolution of the tissues and their easy accessibility. Most uncomplicated cases of renal infection in adults do not require imaging for diagnosis and treatment. When imaging is indicated plain and contrast enhanced CT is always the study of choice.
MDCT is of value in establishing the diagnosis in equivocal cases, in evaluating high risk patients, and in determining the extent of the disease. In complicated cases, an urgent CT scan is necessary.
Unenhanced CT is useful in demonstrating gas (emphysematous pyelonephritis), calculi, parenchymal calcifications, wall calcifications, hemorrhage, and inflammatory masses.
CT scanning is essential for diagnosis and evaluation of cases by detecting parenchymal abnormalities, accurate assessment of the pelvicalyceal system and its mucosal linning, defining the extent of disease and detecting perinephric fluid collections and abscesses, presence of gas, hemorrhage inflammatory masses as well as retroperitoneal extensions and any other complication.
Furthermore, it is essential that the radiologist is aware of unusual and rare forms of pyelonephritis, especially pseudotumoural forms, so that clinicians can be pointed towards the appropriate treatment, avoiding unnecessary and invasive interventions.
Acute pyelonephritis is the most common renal infection but a variety of other infections could be seen including renal abscesses, xanthogranulomatous pyelonephritis (XGP), emphysematous pyelonephritis (EP), tubulointerstitial nephritis, tuberculosis, pyonephrosis, chronic pyelonephritis and upper tract fungal infection. These entities require urgent management and treatment as soon as possible to prevent permanent kidney damage and spread to other parts of the body causing more serious complications.