Determining patient abdomen thickness from a single digital radiograph with a computational model: clinical results from a proof of concept study.

Abstract

A computational model has been created to estimate the abdominal thickness of a patient following an X-ray examination; its intended application is assisting with patient dose audit of paediatric X-ray examinations. This work evaluates the accuracy of the computational model in a clinical setting for adult patients undergoing anteroposterior (AP) abdomen X-ray examinations. The model estimates patient thickness using the radiographic image, the exposure factors with which the image was acquired, a priori knowledge of the characteristics of the X-ray unit and detector and the results of extensive Monte Carlo simulation of patient examinations. For 20 patients undergoing AP abdominal X-ray examinations, the model was used to estimate the patient thickness; these estimates were compared against a direct measurement made at the time of the examination. Estimates of patient thickness made using the model were on average within ±5.8% of the measured thickness. The model can be used to accurately estimate the thickness of a patient undergoing an AP abdominal X-ray examination where the patient's size falls within the range of the size of patients used to create the computational model. This work demonstrates that it is possible to accurately estimate the AP abdominal thickness of an adult patient using the digital X-ray image and a computational model.