Abstract
Thermoluminescent dosimetry was used to study the dose received by 50 consecutive pediatric patients. The average thyroid exposure was 7.7 R and the average gonad exposure 0.35 R. The relative contribution of fluoroscopy and serial film radiography was calculated and over 70% of the thyroid dose comes from the use of the roll film changer. The significance of high thyroid dose was discussed. Serial film changers evidently no longer have a primary role in the study of congenital heart disease.