Imaging pyelonephritis : part 1

Abstract

Urinary tract infection typically originates in the urinary bladder (lower urinary tract); when it migrates to the kidney via the ureter or is seeded there haematogenously, a tubulointerstitial inflammatory reaction ensues, involving the renal pelvis and parenchyma. The condition is characterized as pyelonephritis. Classic symptoms of pyelonephritis include an abrupt onset of chills, fever (temperature of 100°F or greater), and unilateral or bilateral flank pain with posterior costovertebral Crenal angle") tenderness. These "upper tract signs" are often accompanied by dysuria and urinary frequency and urgency. Furthermore, acute pyelonephritis may cause gastrointestinal symptoms, such as abdominal pain, nausea, vomiting, and diarrhoea, which confound the diagnosis. Laboratory findings include pyuria, granular or leukocytic casts, bacteriuria, and a positive urine culture. Blood tests may show leukocytosis with a neutrophilic shift, elevated erythrocyte sedimentation rate, elevated C-reactive protein levels, and occasionally positive blood cultures that grow the same organism as cultured from the urine.