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

Single-bolus computed tomography urography (CTU)is a recently developed one-stop imaging examination for diagnosis of urinary tract diseases, including urinary malignancies. However, single-bolus CTU uses two post- contrast phases (i.e.: nephrographic and excretory phases) for diagnosis of urinary tract diseases. A further-developed split-bolus CTU uses solitary post-contrast phase containing mixed information of nephrographic and excretory phases for diagnosis of urinary tract disease; however, whether split-bolus CTU has similar high diagnostic values for urinary malignancies remains unaddressed. Thus, the aim of this study is to compare the diagnostic performance between single-bolus and split-bolus CTU for diagnosing urinary malignancies. This study will enroll 352 patients from two hospitals if they fit the including criteria including aged \> 40 years old, presenting with gross hematuria or having urinary malignancies histories, normal renal function (i.e.: estimated glomerular filtration rate \> 60 mL/min/1.73 m2, no allergic history to iodinated contrast medium and no pregnancy). All enrolled patients will be randomized to undergo split-bolus and single-bolus CTU in 1: 1 manner. Two radiologists will read CTU images independently using a standardized recording sheet with Likert scales 1-5 representing higher probabilities of presence of urinary malignancies for larger number). The diagnostic values of split-bolus and single-bolus CTU will analyzed using reference standards by final diagnoses of urinary malignancies (i.e.: presence of urinary malignancies based on histological examinations of cytology examinations, biopsies or surgical specimens). The diagnostic performance of split-bolus CTU and single- bolus CTU for urinary malignancies will be compared using areas under receiver operating curve (ROC) to determine whether there is presence of significant difference .