抄録
A flying spot (random access) type x-ray microbeam system with the rating of 150 kV-2 mA has been constructed. By means of a new radiographic method using on-line computer control of x-ray beam scan, observations of the tongue movements have been performed. Also, some pilot experiment on the automatic identification of the bone outline has been conducted.
The method employed here makes it possible to track specific points on a moving organ or to trace outline of an object. The movements of the tongue during speech have been observed by tracking several metal pellets placed on the tongue. Up to 6 pellets have been tracked at the rate of 120 frames/sec. The effective exposure area per frame was 1 cm2 and the exposure rate within this area was 100 mR/min, approximately.
Also, identification of the bone outline with restricted scan of a narrow area along it has been successfully performed.
In these experiments, resulting spatial restrictions of exposures combined with the use of highly sensitive scintillation detector achieved a substantial reduction of x-ray dosage.
