[Imaging of urinary tract infection in children]

Urinary tract infection is very common in children. Its diagnosis, management and treatment have led to abundant literature and many controversies. The main challenges are to identify patients at risk of infection and those at risk of complicated infections. Long-term complications include reflux nephropathy, renal hypertension and stage renal disease. Imaging has a triple role: to confirm the diagnosis in patients with equivocal clinical symptoms; to determine patients at risk of recurrence; prevention of infection by detecting already in utero patients with congenital malformation. During the acute phase, Ultrasound has an important role in detecting favouring conditions such as urinary tract dilatation. The use of color Doppler increases the sensibility and specificity of ultrasound. To date, DMSA scan is the key examination for demonstrating the parenchymal lesions. CT-scan and MRI are rarely used in this acute phase. Retrograde voiding cystography (RVC) will be used whenever vesico-ureteric reflux is suspected. A decision algorithm can be proposed bases on US and DMSA; RVC will be performed whenever one of them is positive. CT or MRI will be used to look for abscesses complicating the UTI. DMSA scan is the gold standard for detecting renal scanning, sequellae of the infection. In the future, the role of MRI will surely increase for the demonstration of uropathy acute and sequelae of the renal involvement.