Patient dose reduction in diagnostic radiology

Dose reduction in double contrast barium enema by use of low fluoroscopic current

Under standard conditions double contrast barium enema (DCBE) was carried out on a selected patient cohort using either standard (1.5 mA) or low (0.5 mA) fluoroscopic current. A statistically significant (p < or = 0.01) reduction in total dose was achieved by use of low screening current. This reduction was of the order of 40%. Fluoroscopic image quality was analysed both objectively and subjectively, and was found not to be significantly degraded when the lower current was used. On blinded evaluation all examinations were found to be of diagnostic quality. The use of low fluoroscopic current results in a reduction in patient dose, without compromising fluoroscopic image quality or diagnostic standard of the examination. Low fluoroscopic current technique has been adopted as the standard in our department.

Coronary angiography: an analysis of radiographic practice in the UK

There is growing public and professional concern over the risks of medical ionizing radiation. It is therefore important to examine our procedures for ways in which we can reduce radiation dose to patients and staff. We surveyed 48 catheter laboratories nationwide to establish the range of practice in performing "routine" coronary angiography and left ventriculography. There were wide variations in the numbers of views obtained, mean ciné film lengths and mean fluoroscopy times. Despite the recommendation of the National Radiological Protection Board, only five of the 36 centres responding were able to provide estimates of patient radiation dose per procedure. Calculations of maximum and minimum patient doses, based on ciné film length and fluoroscopy time, show a fourfold variation between hospitals. Using the concept of estimated dose equivalent, the predicted lifetime fatal cancer risk for a routine examination ranges from 1/16,600 to 1/4300. As a preliminary step in radiation dose reduction we have used this survey data to suggest how a typical coronary angiogram and left ventriculogram might be performed.

Audit in action: significant reduction of double-contrast barium enema screening time with no loss of examination quality

The double-contrast barium enema is an examination of high radiation exposure to the patient. As part of a departmental audit, our own fluoroscopic screening times were being recorded. A study was undertaken to see if a determined effort could reduce the screening time without having a detrimental effect on the quality of the examinations. Methods of screening time reduction were identified and then implemented by two radiologists. In the period before the study the average screening time for radiologists A and B was 2.6 min and 3.2 min, respectively (over 56 examinations). After implementation of the changes, the average screening time for both was 0.9 min (over 50 examinations). This is a statistically significant reduction (p less than 0.01). The examinations were assessed independently by a gastroradiologist. No difference in the quality of the examinations was identified. We conclude that a significant reduction of screening time for the double-contrast barium enema can be achieved without loss of examination quality.