Poster Session 9: Miscellaneous| Volume 8, ISSUE 8, P652, September 2009

S136 CT urography: clinical indications, limitations and radiation dose: a proposed approach

      Introduction and Objectives

      In our exhibit we will demonstrate a proposed protocol that we use at our institution, based on the most frequent present-day clinical indications and the possible limitations of the examination.

      Material and Methods

      Computed tomography urography (CTU) is a relatively new diagnostic imaging modality providing comprehensive evaluation of the upper and lower urinary tract. As multidetector CT has become more widely available, CTU has begun to replace other imaging techniques, especially intravenous urography (IVU).
      CTU is defined as a diagnostic examination optimized for imaging the kidneys, ureters, and bladder. The examination involves the use of multidetector CT with thin-slice imaging, intravenous administration of a contrast medium and imaging in arterial, corticomedullary and excretory phases. Two and Three-dimensional images of the targeted organs can be then obtained through digital image reconstruction.


      CTU is justified as a first-line test for patients with macroscopic haematuria at high-risk for urothelial cancer. Renal tumors and their vascular structures can be imaged in high detail with CTU. CTU can also be useful in the investigation of urinary diversion procedures following cystectomy, hydronephrosis, chronic symptomatic urolithiasis including planning of percutaneous nephrolithotomy (PCNL), traumatic and iatrogenic ureteral injury, complex urinary tract infections and in the diagnosis of bladder tumours.
      The relatively high radiation dose of multiphase CTU is a significant limitation of the widespread acceptance of this technique. Strict indications for multiphase CTU are important tools to manage this relatively high-dose examination.


      CT Urography is a non-invasive and relatively safe method for the imaging of the entire urinary tract. Its use in selected cases greatly increases the diagnostic possibilities of urinary tract imaging methods. As multidetector CT scanners become more widely available, this imaging method will supplant older imaging techniques. Surprisingly, in many reviews only one CTU technique is suggested to encompass all clinical indications. Therefore we propose a differential approach used in different patient populations as the next logical step in the evolution of CTU as a powerful yet dose-efficient test for urinary tract assessment.