CT evaluation of urinary lithiasis.

Unenhanced CT has been demonstrated to be the most accurate and efficient diagnostic imaging means to evaluate urinary lithiasis, with capability of directing management, and has become well accepted by radiologists, urologists, and emergency department physicians such that it is now the standard of practice. It is the duty of the radiologist to be aware of proper technique and the details of interpretation. The radiologist also has a duty to be aware of the limitations of unenhanced CT for detection and evaluation of various nonstone disorders, particularly with poor patient selection, and to extend the examination if appropriate. Controversies and future developments include cost containment with care for the selection of patients. Further attempts to reduce radiation exposure should be made. Optimal CT technique is not needed in general merely to detect urinary lithiasis. A consensus should be developed regarding use of CT in pregnant patients. Further improvements in the digital scout view would be useful for following patients.