Presentation Authors: John Sung*, Francis Jefferson, Lauren Drysch, Peter Ghamarian, Zhamshid Okhunov, Roshan Patel, Shlomi Tapiero, Chandana Lall, Ralph Clayman, Jaime Landman, Orange, CA
Introduction: Non-contrast computed tomography (NCCT) is the imaging modality of choice in evaluating patients with urolithiasis. In the absence of hydronephrosis or a delayed contrast phase, delineation of the collecting system is not possible. Thus, the surgical plan may not be fully devised until a retrograde pyelogram is performed at the time of surgery. The combination of hydration and furosemide has been shown to improve visualization of the upper urinary tract during contrast-enhanced CT imaging. We evaluated the effect of the DRINK protocol (pre-imaging oral hydration and a single oral dose of furosemide) on delineation of the collecting system during NCCT.
Methods: In this prospective, non-randomized study, each participant&[prime]s pre-existing NCCT scan served as a control. For the study NCCT, each patient was instructed to drink one liter of water and take 20 mg of oral furosemide within the hour prior to their study. A distension score was given for three segments (upper, middle, and lower infundibula) in the axial, coronal, and sagittal views of the nonaffected kidney. Scores (0-3) were based on the percentage of the segment that was distended compared to the prior non-DRINK NCCT (0=0%; 1= < 50%; 2=50-99%; 3=100%). Images were scored by a radiologist and two fellowship trained endourologists. Distension scores for both the control and DRINK hydration protocol were compared. The nonparametric Wilcoxon signed-rank test was used to test for statistical change.
Results: Among 15 study patients, collecting system distension scores were significantly higher after the hydration and lasix protocol when compared to the images from their past non-DRINK NCCT scans (p < 0.05) (Table 1). This pattern of statistically significant change extended across all image views (axial, coronal, and sagittal) and all infundibula (upper, middle, and lower).
Conclusions: Hydration and furosemide given an hour prior to NCCT (i.e. DRINK protocol) result in a measurably increased distension of the collecting system.