Review of Technique and Spectrum of Diseases

Skip M. Alderson, MD; Susan Hilton, MD; Nicholas Papanicolaou, MD


Appl Radiol. 2011;40(7):6-13. 

In This Article

Abstract and Introduction


Imaging of the upper urinary tract has traditionally been the purview of intravenous (IV) urography, but over the last decade, computed tomography urography (CTU) has become the modality of choice in imaging the urinary tract. With few exceptions, most notably that of the unenhanced CT performed for acute flank pain and stone disease, many urological symptoms and conditions are now investigated with CTU. Continuing improvements in the spatial resolution and speed of newer CT scanners, combined with advanced multiplanar and volume-rendered image reconstruction, have made CTU a comprehensive examination whereby the kidneys and upper collecting system, ureters, and urinary bladder can be evaluated in one setting.

Indications for CTU continue to evolve. Conditions commonly referred for CTU include urinary calculus disease, hematuria, flank and abdominal pain, suspected renal or urothelial neoplasm, a variety of inflammatory conditions, and congenital anomalies of the kidneys and ureters. Experience with patients who have undergone cystectomy with urinary diversion, most often for treatment of bladder carcinoma,continues to increase, and CTU is commonly used for surveillance of the urothelium in at-risk patients. Currently, CT urographic evaluation of the urinary bladder generally is not considered accurate enough to exclude small superficial urothelial tumors, and cystoscopy is indicated for complete bladder evaluation. The ability to biopsy and resect lesions are added benefits of cystoscopy.

The American Urological Association Best Practices Policy guidelines recommend IV or CT urography as the initial imaging test for patients with asymptomatic microscopic hematuria.[1] Likewise, the American College of Radiology rated CTU as the most appropriate imaging procedure in the evaluation of hematuria.[1] Furthermore, extraurinary findings, some of them clinically important, can be found in a percentage of patients undergoing CTU.[1] Contraindications to CTU are generally limited to those patients who cannot receive iodinated contrast because of renal insufficiency, prior severe reaction, or pregnancy.