An approach for rapid establishment of patient effective dose during radiology and results for two large university hospitals

Patient dosimetry and assessment of effective dose was implemented under the condition that measurements involve commonly available instrumentation. Four categories of examination were distinguished: radiographs with manual techniques, radiographs with automatic exposure control (AEC), examinations involving fluoroscopy, and computed tomography (CT). For projection radiography the dose-area product (DAP) and for CT the computed tomography dose index were measured. Databases of conversion factors were consulted for the calculation of effective dose. Effective doses varied from less than 0.001 to over 100 mSv. Only 5-7% of the total examinations consist of CT scans, the contribution of CT to the collective effective dose for the patient population, however, was 40-50%. Whereas simple radiographs constitute almost 84-89% of the number of examinations the contribution to the collective dose was only 2-11%.