Effect of Prone and Supine Positioning on Computed Tomography Urography Examination.

OBJECTIVES

The aim of this study is to evaluate the effects of performing computed tomography (CT) urogram in the prone position in terms of diagnosis.

METHODS

CT urograms of 208 patients imaged randomly in the prone and supine positions were included in this study. A total of 199 patients and 370 collecting systems were examined in total. Axial raw data and reconstructed coronal thin and thick MIP images with a slice thickness of 5 mm were evaluated by 2 independent radiologists blinded to the initial diagnosis. Renal collecting system, ureters, and bladder were included in radiological evaluation. Anatomically, the renal collecting system was separated into 7 regions. Filling and dilatation of collecting systems were evaluated via images at urogram phase by scoring.

RESULTS

Filling in lower pole infundibulum (p = 0.006), distal ureter (p = 0.006); and highly dilated lower pole calyx (p = 0.020), pelvis (p = 0.006), and bladder (p < 0.001) were determined to be better in images in the prone position compared to the supine position. There were no statistical differences in other regions.

CONCLUSION

Better contrast material filling is achieved in dilated or non-dilated lower pole collecting system, dilated renal pelvis, non-dilated distal ureter of kidney, and in the bladder only by imaging the urogram phase in the prone position compared to the supine position. Additionally, presence of dilatation is a factor that could adversely affect filling. Studies in the future may investigate the contribution of prone positioning to CT urogram with larger series comparing it with other methods and modalities.