Lithiasis-induced acute kidney injury: Is ultrasonography enough?

Obstructive acute kidney injury(AKI) is relatively common, reported in 8% to 17% of cases presenting with community-acquired AKI. It is more frequent in males of advanced age, usually from bladder outlet obstruction. Guidelines recommend imaging, namely a renal tract ultrasound (US), within 24 hours from admission to rule-out obstruction and guarantee recovery of renal function. Lithiasis is not a common cause of AKI (1–2% of obstructive cases) and it is reported that only 0.72% of patients with urinary calculi develop AKI from stones. It is known that US may have difficulties in demonstrating stones-related obstructionand that unenhanced CT ismost sensitive and specific for this purpose. We report therefore the imaging findings in a series of patients with lithiasis-induced AKI to understand the respective roles of these techniques.