[Investigation of the present management status of calibration source based on the law concerning prevention of radiation hazards due to radioisotopes].

An amendment concerning the enforcement of the law on the prevention of radiation hazards due to radioisotopes, etc., and the medical service law enforcement regulations were promulgated on June 1, 2005. This amendment concerned international basic safety standards and the sealing of radiation sources.

[Comparative evaluation of absorbed dose and image quality in X-ray head CT scanning for hospital facilities in Gunma.].

Recently, the number of scans for X-ray computed tomography (CT) examinations has been rising due to the wide-spread use of multi-slice CT (MSCT) scanners. There is a concern that the total medical exposures will be increased by these examinations. In order to lower exposures, routine parameters for head CT examinations done at several hospitals in Gunma were investigated.

[Registration of chest PET and CT images-fusion technique using the PET/Tr image by the respiration compensation].

Objective: The conventional registration of PET images of the chest with CT images is performed by rotating and shifting those images while used median lines and contours on axial images as the reference indexes. For the thoracic and the abdominal regions, therefore, the respiratory movements have prevented us from achieving satisfactory levels of registration reproducibility and accuracy. In order to solve this, we have analyzed respiratory movements of the chest and derived an image fusion method.

[Effect of the respiratory movements on the intensity of FDG accumulation in PET inspection image].

Purpose: With chest PET examination, expansion of an image showing a small accumulation and reduction in the radiation count due to breathing movements are anticipated. The purpose of this paper is to analyze movement in the chest region when breathing and to clarify effects of the movement on expansion of the image of a small accumulation and intensity of the radiation count.

Methods: Movements around the hilum of the lung under resting respiration are analyzed in X-rays, CT images and MR images.