Feasibility of optimized ultralow-dose pulsed fluoroscopy for upper gastrointestinal tract examinations: a phantom study with clinical correlation.

Abstract

To establish an optimized ultralow-dose digital pulsed fluoroscopy (FP) protocol for upper gastrointestinal tract examinations and to investigate the radiation dose and image quality. An Alderson-Rando-Phantom with 60 thermoluminescent dosimeters was used for dose measurements to systematically evaluate the dose-area product (DAP) and organ doses of the optimized FP protocol with the following acquisition parameters: 86.7kV; 77mA; 0.9mm3, automatic image noise and contrast adaption. Subjective image quality, depiction of contrast agent and image noise (5-point Likert scale; 5=excellent) were assessed in 41 patients, who underwent contrast-enhanced FP with the aforementioned optimized protocol by two radiologists in consensus. A conventional digital radiograph (DR) acquisition protocol served as the reference standard for radiation dose and image quality analyses. Phantom measurements revealed a general dose reduction of approximately 96% per image for the FP protocol as compared to the DR standard. DAP could be reduced by 97%. Significant dose reductions were also found for organ doses, both in the direct and scattered radiation beam with negligible orbital (FP 5.6×10-3 vs. DR 0.11; p=0.02) and gonadal dose exposure (female FP 2.4×10-3 vs. DR 0.05; male FP 8×10-4 vs. DR 0.03; p≤0.0004). FP provided diagnostic image quality in all patients, although reading scores were significantly lower for all evaluated parameters as compared to the DR standard (p<0.05). Ultralow-dose FP is feasible for clinical routine allowing a significant reduction of direct and scattered dose exposure while providing sufficient diagnostic image quality for reliable diagnosis.