PD4-03 A COMPARISON OF CALCULATED ABSORBED RADIATION ORGAN DOSES AND IMAGE QUALITY FOR ITERATIVE VERSUS FILTERED BACK PROJECTION CT IN KIDNEY STONE PATIENTS

Abstract

You have accessJournal of UrologyImaging/Radiology: Uroradiology I1 Apr 2015PD4-03 A COMPARISON OF CALCULATED ABSORBED RADIATION ORGAN DOSES AND IMAGE QUALITY FOR ITERATIVE VERSUS FILTERED BACK PROJECTION CT IN KIDNEY STONE PATIENTS Rishi Modh, Akira Yamamoto, James Mason, Elizabeth Vorhis, Lori Deitte, Cyrus Monroe, Anna Mench, Rebecca H. Lamoureux, Izabella Lipnharski, Jacob Batson, Derek Lee, Carl Henriksen, Manuel Arreola, and Benjamin Canales Rishi ModhRishi Modh More articles by this author , Akira YamamotoAkira Yamamoto More articles by this author , James MasonJames Mason More articles by this author , Elizabeth VorhisElizabeth Vorhis More articles by this author , Lori DeitteLori Deitte More articles by this author , Cyrus MonroeCyrus Monroe More articles by this author , Anna MenchAnna Mench More articles by this author , Rebecca H. LamoureuxRebecca H. Lamoureux More articles by this author , Izabella LipnharskiIzabella Lipnharski More articles by this author , Jacob BatsonJacob Batson More articles by this author , Derek LeeDerek Lee More articles by this author , Carl HenriksenCarl Henriksen More articles by this author , Manuel ArreolaManuel Arreola More articles by this author , and Benjamin CanalesBenjamin Canales More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.315AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Methods commonly used to reduce patient radiation exposure, such as standard Filtered Back Projection CT (FBP CT), may still result in significant image noise and decreased image quality. Adaptive Iterative Dose Reduction (AIDR), a CT image reconstruction algorithm, has been touted to lower patient radiation dose while maintaining adequate diagnostic quality. Our group recently developed a validated method to estimate CT patient absorbed dose based on statistical modeling and post-mortem dosimetry. The purpose of this study is to determine absorbed dose in urinary stone patients undergoing FBP CT compared to AIDR CT and compare the quality of the scans. METHODS After IRB approval, we reviewed records of all patients who underwent stone protocol CT scan from 11/1/12 – 7/1/13 at our single institution which houses 2 ADR-capable and 4 FBP CT scanners, a modified form of random assignment. Clinical and radiological data was then recorded from patients found to have urinary tract stones. Two blinded, board-certified radiologists independently reviewed data sets for image quality (1–5), noise (1–3), and calculi (number, size, location),and discrepancies were resolved by a blinded third board-certified radiologist. Absorbed skin and internal abdominal organ doses were calculated using equations that utilize the scanner-reported CT dose Index (CTDI) and the patient central effective diameter. Statistical analysis was performed using Fisher's Exact and paired t tests. RESULTS Of the 54 patients who met inclusion criteria, 28 patients underwent FBP CT while 26 underwent AIDR. Both groups were similar in regard to gender, race, BMI(31.7 +/- 9.9), stone burden detected, image quality, and image noise. Absorbed skin dose was 42.9 ± 19.9 mGy for FBP CT and 27.4 ± 35.0 mGy (p<0.001) for AIDR CT, while mean internal organ doses were 20.12 ± 9.7 mGy (FBP CT) and 6.9 ± 3.8 mGy (p<0.001, ADIR). Mean CTDI for all stone protocol FBP CT studies was 31.4 ± 11.8 mGy compared to 15.4 ± 13.9 mGy (p<0.05) for AIDR CT. CONCLUSIONS In our random cohort and using a validated absorbed dose formula, urinary stone patients who underwent AIDR CT had 36% and 65% reduction in skin and internal organ dose (respectively) compared to FBP CT, without compromising scan readability. Measured CT output using CTDI did not correlate to calculated patient absorbed dose and should not be used as a valid patient dose parameter. AIDR technology decreases radiation doses in urinary stone formers undergoing stone protocol CT and may replace FBP CT as the standard of care in CT imaging. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e87 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Rishi Modh More articles by this author Akira Yamamoto More articles by this author James Mason More articles by this author Elizabeth Vorhis More articles by this author Lori Deitte More articles by this author Cyrus Monroe More articles by this author Anna Mench More articles by this author Rebecca H. Lamoureux More articles by this author Izabella Lipnharski More articles by this author Jacob Batson More articles by this author Derek Lee More articles by this author Carl Henriksen More articles by this author Manuel Arreola More articles by this author Benjamin Canales More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...