Yecies T, et al. - A PUBMED-based literature search was done to recognize model inputs in order to model the risk of radiation-induced malignancy from CT urography (CTU) in the assessment of gross hematuria and compare this with the advantages of urinary tract cancer detection when contrasted with renal ultrasound. Male gender and age over 50 years were related to a relative risk of upper tract malignancy of 2.04 and 2.95, respectively. The risk of upper tract malignancy missed by renal ultrasound varied from 0.055% in females under 50 to 0.51% in males over 50. The risk of CTU-induced malignancy with correlated loss of life expectancy varied from 0.25% and 0.027 years in females under 50 to 0.08% and 0.0054 years in males over 50. An undiagnosed upper tract malignancy would have to carry a loss of life expectancy of 49.2 years in females under 50, 13.4 years in males under 50, 2.6 years in females over 50, and 1.1 years in males over 50, for CTU to be better to renal ultrasound. Thus, in low-risk patients, CTU for assessment of gross hematuria may carry an important risk of radiation-induced secondary malignancy in relation to the diagnostic advantage offered over renal ultrasound.