Dosimetric Characterization of a Tableside Fluoroscopy with Dynamic Flat Panel Detector
J Zhang*, A Fain, D DiSantis, University of Kentucky, Lexington, KYSU-E-I-29 Sunday 3:00PM - 6:00PM Room: Exhibit Hall
Purpose: A tableside fluoroscopy system with dynamic flat panel detector (FPD) has been recently introduced. Compared to conventional fluoroscopy system with image intensifier (II), the FPD fluoroscopy system has potential in dose reduction while improving image quality. As the first of its kind, radiation dose of the FPD system has yet to be investigated. This study is to investigate patient dose from a tableside FPD fluoroscopy and compare to those from a conventional II system.
Methods: A whole body anthropomorphic phantom was used for dose measurements with three common GI fluoroscopic procedures: Barium Swallow, Barium upper GI, and Cystogram. Radiation doses were obtained in the chest, the upper abdomen, and the pelvis, respectively. Different pulse fluoroscopy rates (15 and 7.5 frames/sec) were used for the FPD system, while continuous mode was used in II system. Entrance skin exposure, exposure rate, and fluoroscopy time were measured using an Unfors dosimeter (Unfors RaySafe, Inc., Hopkinton, MA) and with a radiography/fluoroscopy detector. Dose-area-product (DAP) was recorded from both systems. Image quality was evaluated by an attending radiologist and radiology resident.
Results: Radiation dose of the FPD system strongly depends on initial exposure setting for the pulse. With default protocols, the FPD system delivers more radiation than II system for chest imaging (700.4 mR/min vs. 549.2 mR/min). With pelvic imaging, both the 15 and 7.5 fps setting delivered less radiation dose compared to the II system (806.4 mR/min, 1195 mR/min vs. 1330 mR/min). The dose rate for abdominal imaging varied with pulse rate. Image quality was substantially improved on the FPD fluoroscopy system.
Conclusion: Compared to the II system, clinical protocols and dose reduction program of the tableside fluoroscopy system with dynamic FPD can be optimized, potentially reducing patient radiation dose with no loss or even improved image quality.