Evaluation of the upper urinary tract using transureteric ultrasound--a review of the technique and typical imaging appearances.

Ureteric strictures and pelviureteric junction obstruction often present a diagnostic conundrum to radiologists, particularly after the first-line investigations have failed to provide a definitive answer. Transureteric ultrasonography (TUU) is a relatively novel technique performed by the radiologist, which uses a miniature endoluminal ultrasound probe to interrogate the ureteric anatomy and peri-ureteric soft tissues. In this review, we discuss how TUU is performed, and the normal imaging appearances of the ureter and surrounding anatomical structures. We also focus on the various pathological processes that can be accurately evaluated or diagnosed using TUU including lymphadenopathy, calculi, ureteric neoplasms, ureteritis, crossing vessels and aneurysms. As TUU is not well established in UK practice as yet, we suggest possible indications for its use in the diagnostic work-up of urological patients and future applications.