Computed tomography-urography for upper urinary tract imaging: is it required for all patients who present with hematuria?

PURPOSE

To define in which patients who present with microscopic or macroscopic hematuria CT urography (CTU) is indicated as an imaging mode for the upper urinary tract (UUT).

PATIENTS AND METHODS

We conducted a prospective study on consecutive patients who attended a modern protocol-driven hematuria clinic from January 2006 to February 2010. Standard tests (history taking, physical examination, urinalysis via dipstick method, ultrasonography of kidneys and bladder performed by urologists, cystoscopy, and cytology) were directed to all patients, whereas the mode of additional UUT imaging (ultrasonography by a radiologist or four-phase CTU/magnetic resonance (MR) urography (MRU) when CTU was contraindicated) was selected according to a risk factor-based management algorithm. The added value of cross-sectional urography (CTU/MRU) supplementary to ultrasonography (by urologists) to detect renal masses, UUT tumors, and stones was assessed. Univariate and multivariate analysis on predictive factors for cross-sectional urography result were performed.

RESULTS

From the total of 841 patients, lesions that might account for hematuria could not be identified in 462 (54.9%), whereas in 250 (29.7%) and 124 (14.7%) patients, hematuria was from benign and malignant disease, respectively. Cross-sectional urography revealed relevant UUT lesions in 73 of 525 (13.9%) patients. Only result of ultrasonography (odds ratio [OR] 7.7, 95% confidence interval [CI] 4.0-14.9), P<0.001) and type of hematuria (OR 2.6, 95% CI 1.3-5.1, P=0.01) were significant predictors for cross-sectional urography result. In 44 of 456 (9.6%) patients with no abnormalities on ultrasonography, CTU/MRU revealed that these were false negatives, with most lesions missed being stones. In 253 of 309 (81.9%) patients with macroscopic hematuria, no lesions were detected in the UUT on CTU/MRU, in contrast to 199 of 216 patients (92.1%) with microscopic hematuria.

CONCLUSION

For patients who present with microscopic hematuria, ultrasonography is sufficient to exclude significant UUT disease. For patients with macroscopic hematuria, the likelihood of finding UUT disease is higher, and a CTU as a first-line test seems justified.