[Measurement of Head and Neck Exposure in CT Guided IVR].

In April 2011, the International Radiological Protection Committee recommended that "The equivalent dose of the crystalline lens should not exceed 20 mSv/year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv". Based on this recommendation, it is predicted that the equivalent dose limit of our crystalline lens can be lowered in the near future. Therefore, it is important to grasp the current situation of radiation exposure.

[The Measurement of X-ray Fluoroscopy Input-output Characteristics in Angiography System].

Purpose: Determination of X-ray fluoroscopy radiation dose and contrast with angiographic system automatically depending on the objects, and to control setting manually, which is difficult for the measurement of characteristics. Therefore, we examined the method to adjust the conditions of fluoroscopy and measured the input-output characteristics.

Method: To adjust and fix the condition of fluoroscopy, the exposure adjustment area at the center of the irradiation field was moved to the left side and attached the copper plates to regulate the exposure dose.

[The Time Sequence Noise Characteristics of the X- ray Fluoroscopic Image].

The role of the X-ray fluoroscopic image during interventional radiology (IVR) is not only the real-time dynamic image for the catheter operation but also to confirm the vascular anatomy using stored image, so that the importance increases more. For the purpose of measuring the time sequence characteristics of X-ray fluoroscopic image, we sampled the digital value of the same coordinate from each X-ray fluoroscopic image and calculated the frequency properties of the noise for the time sequence order as NPStime by performing Fourier transform on the digital value. The parameters, except k-factor which is the time sequence filter, did not influence NPStime.