CT urography: Review of technique and spectrum of diseases

The American Urological Association Best Practices Policy guidelines recommend IV or CT urography as the initial imaging test for patients with asymptomatic microscopic hematuria.1 Likewise, the American College of Radiology rated CTU as the most appropriate imaging procedure in the evaluation of hematuria.1 Furthermore, extraurinary findings, some of them clinically important, can be found in a percentage of patients undergoing CTU.1 Contraindications to CTU are generally limited to those patients who cannot receive iodinated contrast because of renal insufficiency, prior severe reaction, or pregnancy. A recent study evaluating low-dose noncontrast CT for the evaluation of stone disease suggests that significant dose reductions can be realized in certain patient populations without sacrificing accuracy. 9 Nonetheless, at this time, most authors report radiation doses associated with CTU to be greater than those with IVU, and continued refinement of patient selection criteria and imaging protocols should be performed to avoid unnecessary exposure.