[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.

[The protocol of dose reduction in liver perfusion computed tomography].

Cerebral perfusion computed tomography (CT) has been widespread, but abdominal perfusion CT has not been very popular because there has been a problem with regard to the limit of irradiation range and respiratory effects. Recently, it became easy to perform perfusion of abdominal organs because the use of multi detector row CT (MDCT) has been extensive. Along with it, the number of hospitals that perform liver perfusion CT has increased.

[Study of spatial resolution in three-dimensional rotational angiography].

In interventional radiology (IVR) of cerebral aneurysms, it is important to understand the form and physical relationships between the cerebral aneurysm and the surrounding vessels. However, because the vessels in the head area are highly complex, it can be difficult to comprehend the structure using conventional angiography. Therefore, three-dimensional rotational angiography (3D-RA) has been used in recent years.

[A design of the measuring chart for magnifying-power compensation in brain angiography].

Purpose: When brain angiography was performed, we devised the calculation theory for rectifying magnifying power, and produced the auxiliary tool.

Method: We produced the frame with a size of 300 x 300 x 15 mm from the thin board made from carbon. The frame is around arranged for every 1 cm in Pb-ball of the diameter of 1 mm.