Ultrasound of Upper Urinary Tract Infections

Urinary tract infection (UTI) is the most common bacterial infection. It accounts for 8.6 million visits in the ambulatory care setting in the United States. Women are at higher risk for UTI, with a self-reported annual incidence of 12%, and by the age of 32, half of them have suffered at least one UTI. Moreover UTI recurrence is high. Luckily acute pyelonephritis is much less common than cystitis, with a peak annual incidence of 25 cases per 10,000 women 15–34 years of age [1]. Infection is initiated when potential pathogens migrate from the bowel lumen to urethra and ascend to the kidneys. Accurate differentiation between uncomplicated UTI (episodes of acute cystitis and pyelonephritis in healthy premenopausal, non-pregnant woman, with no history suggesting abnormalities of urinary tract) and complicated UTI (all the other cases) is mandatory. Imaging helps in disease detection, definition its extent, reveal predisposing conditions and complications. Ultrasound is iexpensive, immediate, painless, widely available and radiation-free, so it should represents he first line imaging modality in the majority of patients. However uncomplicated UTI usually do not require imaging for diagnosis and treatment.