Which imaging study is used to visualize the urinary tract without contrast dye?

• A. Kidney, Ureter, Bladder (KUB)
• B. Hysteroscopy
• C. Hysterosalpingography
• D. Glucose tolerance test

Answer: (A)

Visualizing the urinary tract without contrast is accomplished with a plain abdominal X-ray called a kidney-ureter-bladder (KUB) study. This single-film exam focuses on the outline of the kidneys, ureters, and bladder without injecting dye, making it useful for a quick survey to detect radiopaque stones, gross hydronephrosis, or bladder distension. It’s inexpensive, fast, and noninvasive, which is why it’s chosen when you need information about the urinary tract without contrast. The other options involve examining the uterus or using contrast to map anatomy, or in the case of a glucose tolerance test, assess metabolic function rather than imaging.