Radiation Protection in CT Fluoroscopy

This article discusses the dose to the operator and radiation protection in computed tomographic fluoroscopy (CTF)-guided intervention. One of the major limitations of CTF is excessive radiation exposure to the operator, in particular, to his or her hands. Therefore, we developed biopsy needle-holders that permit the operator to manipulate the needle without placing his or her hands in the direct X-ray beam and evaluated the effects of using a needle-holder on dose reduction. We also measured the exposure dose to the operator's body and evaluated the effects of using protective clothing on dose reduction. Imaging parameters were a tube voltage of 80 kVp and a tube current of 30 mA. The dose-equivalent rates for the operator's hands and entire body were 1 .150 mSv/s (H70m) and 1 .60 pSv/s, respectively. When a needle-holder and protective clothing were used, the corresponding values were 0.019 mSv/s and 0.052 .tSv/s. The use of a needle-holder and protective clothing is considered to be indispensable in performing nonvascular interventional radiology procedures under CTF guidance. It was confirmed that the exposure dose did not exceed the dose limit specified by the 1990 recommendation of the International Commission on Radiological Protection when adequate protective measures were taken.