Imaging manifestations of lithiasis. Radiological evaluation was performed with IVU following a KUB. A. KUB before the intravenous injection of contrast. B. KUB 30s after the intravenous injection of contrast. A 2.5 cm × 1.0 cm high-density mass was shown in the right ureter at the L3 level (A and B, black arrows). Right renal pelvis was enlarged (B, red arrow). Lithiasis was diagnosed on the basis of the imaging features after excluding other diseases.