Abstract 16798: Impact of Very Low X-Ray Dose Levels on Imaging Quality in Electrophysiology Procedures
Introduction: Fluoroscopy is the basic imaging modality in the electrophysiological (EP) laboratory. Since fluoroscopic systems are technically optimized for high-resolution angiography, there may be room for additional dose reduction in EP interventions not requiring detailed resolution. Aim of this study was to determine the minimal X-Ray dose necessary to achieve adequate imaging quality in EP procedures.
Material & Methods: A phantom experiment was carried out involving a biplane angiography system and a realistic thoracic phantom. Standard EP catheters were placed inside the phantom heart. Detector entrance dose was varied from 6 nGy to 41 nGy per pulse. For each selected detector entrance dose, the tube voltage was varied from 70 kV to 125 kV. 8 EP specialists evaluated image quality. In addition a software algorithm using Gaussian noise was developed to simulate very low dose settings on clinical fluoroscopy images. These simulated very low dose clinical data were evaluated as well.
Results: Our experiment yielded a relationship between detector entrance dose and maximum tube voltage for acceptable image quality (Fig. 1). Very low dose settings were simulated on fluoroscopic images of n=20 right-atrial and n=20 PVI procedures. Image quality was still sufficient in right-atrial procedures after X-Ray dose reduction of 74%, resp. 65% in PVI procedures, as compared to the currently available clinical EP low dose protocol.
Conclusions: The lowest available clinical acquisition settings for EP procedures are operated at 23 nGy. Our findings suggest that a adequate image quality for normal-weight patients can be obtained at dose levels that are up to 74% lower than the current lowest settings. For obese patients, one may be able to save up to 57% of X-ray dose. In general a dose reduction of 74% seems possible for right-atrial procedures. Beyond the potential for dose savings, we also found that contrast visibility was still acceptable at tube voltages of up to 119 kV.
- © 2013 by American Heart Association, Inc.