Diagnostic Values of Urothelial Carcinomas: Single-bolus Versus Split-bolus Computed Tomography Urography

This study will enroll 352 patients. The calculation of sample size is according to the following equation: n2=〖(Z∝+Zβ/2)〗\^2/〖(δ-\|ε\|)〗\^2 \[p1(1-p1)/k+p1(1-p2)\] ∝=0.05, β=0.2, δ=0.05, p1=0.96, p2=0.80 Then, the number of each arm patient should be ≥ 141 patients. However, if 20 % of the enrolled patients by fitting inclusion criteria are excluded by fitting exclusion criteria, the number of each arem should be ≥ 176 patients. Thus, this study plans to enroll 352 patients (for two arms). The enrolled patients are randomized to two groups (using single-bolus CTU versus using split-bolus CTU) using permuted block method.