Computed Tomographic Urography Update: An Evolving Urinary Tract Imaging Modality

Optimization of Split-Bolus CT Urography: Effect of Differences in Allocation of Contrast Medium and Prolongation of Imaging Delay

“…CTU provides a comprehensive evaluation with high sensitivity and specificity for diseases of the renal collecting system, ureters, and bladder [1][2][3][4][5][6][7][8][9][10][11][12][13]. Many institutions are advocating split-bolus CTU for the evaluation of patients with hematuria and urinary tract diseases because of its lower radiation dose compared with single-bolus three-phase imaging [5, 10-14, 16, 19-23, 25-28], especially in patients younger than 40 years [10][11][12]16].…”

“…Many institutions are advocating split-bolus CTU for the evaluation of patients with hematuria and urinary tract diseases because of its lower radiation dose compared with single-bolus three-phase imaging [5, 10-14, 16, 19-23, 25-28], especially in patients younger than 40 years [10][11][12]16]. Over the years, CTU techniques have improved [7,23] in terms of optimal opacification and distention of the urinary collecting system, which are important factors for the evaluation of disease [3,14,29]. The fundamental problem of imaging the entire collecting system is ureteral peristalsis, which causes inadequate ureteral opacification [3,29].…”

Urinary bladder: normal appearance and mimics of malignancy at CT urography

“…Excretory phase images are considered essential in the evaluation of the urothelium [ 3 , 4 , 10 ] . We obtain an unenhanced CT scan of the abdomen and pelvis to identify calculi, including those in the bladder, that could be masked by excreted contrast material.…”

“…Furosemide increases urinary flow rate, thereby increasing both distention and mixing of the contrast material, the latter likely via an increased ureteral jet phenomenon [ 11 ] . Others have used a log-rolling technique to promote mixing of contrast material and urine in the bladder [ 3 ] . Wide window settings may be required, particularly if CTU is not supplemented with furosemide, as dense contrast material may obscure small urothelial masses [ 12 ] (Fig.…”

“…CT urography (CTU) is defined as a CT examination of the urinary tract that is performed both before and after intravenous (IV) contrast material, and includes excretory phase images [ 3 ] . CTU is emerging as the imaging test of choice for the evaluation of the urinary tract for a variety of disorders, including hematuria [ 4 , 5 ] .…”