Organ doses from cardiac and carotid digital subtraction angiography

Estimates of mean organ doses from cardiac and carotid digital subtraction angiography (DSA) are obtained from measurements done using a Rando-Alderson tissue-equivalent phantom. Thermoluminescent dosemeter chips and discs were calibrated and used for all measurements in the primary and scattered radiation fields. Skin doses as well as mean doses received by the thyroid, lung, lens of the eye, breast, uterus and the ovaries were measured. A 30 degree right anterior oblique (RAO) cardiac DSA study produces a beam entrance dose of about 121 mGy at a rate of 0.48 mGy/frame. The highest mean organ dose from cardiac DSA was to the lung with a value of 14.4 mGy. The rest of the organs received doses below 1 mGy. In carotid DSA, the mean entrance doses resulted from the RAO, left anterior oblique, and the Towne's view projections give an average of 168 mGy at a rate of 8.4 mGy/frame. The highest mean organ dose from the three projections, 21 mGy, was received by the thyroid. The uterus and ovaries received the lowest doses from both procedures with values below 0.04 mGy. Patient and phantom surface exposures were compared using an exposure area product system. Hence, exposure conditions used for measuring organ doses on the phantom were adjusted to resemble those used for patients.