Development of variable dose X-ray fluoroscopic system--aimed at reduction of X-ray exposure during interventional radiologic procedure.

Recent advancement in IVR by the catheterization technique has raised the problem of increased X-ray exposure dose. To minimize this problem, we developed an X-ray fluoroscopy system with which the operator can select the X-ray dose according to the required image quality. The optical system features an optical iris that adjusts the amount of light input to the camera tube (the optical iris is usually fixed). If a rough fluoroscopic image with low S/N is acceptable, the optical iris is opened and the fluoroscopic dose is automatically reduced. This reduces exposure dose to 30-60% of the conventional dose.