A method of diagnosing a condition of a living subject that uses gadoxeate disodium as a contrast agent for making images such as CT scans of the biliary tree and related anatomical structures. The method uses x-ray radiation generated with excitation voltages in the range of 70 KV to 140 KV. The x-ray radiation is preferably filtered to suppress or practically remove x-rays having energy lower than 50.2 KeV.