Computed Tomography Urography for Diagnosis of Calyceal Diverticulum Complicated by Urolithiasis: The Accuracy and the Effect of Abdominal Compression and Prolongation of Acquisition Delay

Abstract

To evaluate the accuracy of computed tomography urography (CTU) in the detection of caliceal diverticulum (CD) complicated with urolithiasis and the effect of compression and prolongation of acquisition delay. All data were collected from a previous research between 2002 and 2011 at 3 hospitals. A total of 182 patients with evidence of renal parenchymal cystic lesion with calcific density were evaluated by CTU. Excretory phase imaging was acquired at 10 minutes and 60 minutes for each patient. Eighty-three patients received abdominal compression intervention during 10-minutes delay. CDs with stones were finally diagnosed in 41 patients (22.5%). Opacification within an apparent cyst was found in 31 patients (75.6%) when excretory phase images were acquired at 10 minutes and 38 patients (92.7%) at 60 minutes. The sensitivity and accuracy were significantly better with 60-minutes delay than with 10-minutes delay (92.7% vs 75.6%, P= .016 and 97.8% vs 94.0%, P= .016, respectively). The diagnostic results of compression group had significantly higher sensitivity and accuracy than that of the noncompression group (94.4% vs 60.9%, P= .025 and 98.8% vs 90.9%, P= .023, respectively). It is important to distinguish CD from other diseases such as complex cyst when diagnosing a renal parenchymal cystic lesion with wall calcification. CTU has high sensitivity and accuracy in the detection of CD. Abdominal compression and longer imaging delay can significantly improve the diagnostic effect of CTU.