The Influence of DSA Examinations on Patient-absorbed Doses.

An exposure measurement experiment was performed to obtain frontal DSA, lateral DSA and fluoroscopic absorbed doses. In addition, the proportion of each dose to the total absorbed dose was obtained to estimate which influenced the patient-absorbed dose the most among the three in diagnostic DSA examinations for the head and neck. Three correlation coefficients were obtained to evaluate the relationship between any two doses. As a result, the following four findings were obtained: 1. The mean proportion of each absorbed dose reached a high value in the order of frontal DSA absorbed dose > lateral DSA absorbed dose > fluoroscopic absorbed dose. 2. A strongly negative correlation between the proportions of frontal DSA absorbed dose and fluoroscopic absorbed dose was observed (r = -0.864, P < 0.01). Also, a slightly negative correlation between the proportions of lateral DSA absorbed dose and fluoroscopic absorbed dose was observed (r = -0.375, P < 0.01). However, no correlation between the proportions of frontal DSA absorbed dose and lateral DSA absorbed dose was observed (r = -0.143, P > 0.05). 3. The patient-absorbed doses, which were different from those of IVR examinations, were confirmed to be largely influenced by DSA radiographic doses. 4. The best method for the reduction of patient-absorbed doses was considered to be minimization of the frame number in DSA radiography required for diagnosis.