Emergency Medicine: Open Access
Open Access

Abstract

Cumulative Radiation Exposure from Medical Imaging in Two Hospital Systems – Implications for Medical Record Portability

Timothy B. Bullard, Jay L. Falk, Mark S. Smith, Audrey Wegst, David H. Roseman, James S. Jelinek, Mihail Stojanovski, Ashley Waplinger and Linda Papa

This study assessed the estimated cumulative effective ionizing radiation dose from diagnostic imaging studies performed on a sample of patients identified in two emergency departments (ED) from different hospital systems over 5 years. A random sample of patients was retrospectively identified from a cohort of patients receiving diagnostic imaging during their visit. All imaging diagnostic studies performed on the sample patients over a five year period were retrieved and assigned an effective radiation dose by a radiation physicist, using published reference tables. During the five year study period there were 13,387 radiological studies performed on 1,243 patients sampled from the two hospitals. The mean cumulative radiation dose per patient in milliseiverts (mSv) was 45.0 (SD ±71.4) (range 0.1-674.6) mSv. There were 150 patients (12%) exposed to over 100 mSv of ionizing radiation over 5 years. Although CT scans accounted for only 25.5% of tests performed, they contributed to over 53% of the entire estimated effective radiation dose to this population. Moreover, nuclear medicine tests accounted for 5.3% of all tests performed but contributed to 29.7% of the total estimated effective radiation. The study identified a substantial number of patients exposed to estimated cumulative effective doses of ionizing radiation that would put them at risk of developing cancer based on the Linear No-Threshold Model. The study demonstrates that it is important for physicians to know how much cumulative radiation exposure from medical imaging their patients have received. This is one more example of the urgent need for medical record portability and information sharing.