Size-specific Dose Estimates for Chest Abdominal and Pelvic CT: Effectof Intrapatient Variability in Water-equivalent Diameter

摘要

Although water-equivalent diameter (Dw) can vary substantially along the z-axis within any given patient, using the mean volume CT dose index over the whole scan range and the Dw from the image located at the center of the scan range provides an accurate and easily obtained estimation of the size-specific dose estimate for the whole scan range, with a root mean square error of less than 1.4 mGy or 9% for a scan range of the complete chest, abdomen, and pelvis.