EMISSION CT SYSTEM

• Main Author: KOUNO KAZUHIRO
• Format: Patent
• Language: English
• Published: 08.06.1984
• Subjects: MEASUREMENT OF NUCLEAR OR X-RADIATION; MEASURING; PHYSICS; TESTING

PURPOSE:To obtain a re-constituted image uniform in the detection of gamma rays regardless of the distance from a ray source thereof and excellent in distance resolving capacity, by a method wherein the original image to be re-constituted obtained from the projection data of gamma rays is subjected to Fourier transformation and each frame image is masked so as to remove regions other than the image region to which a filter is adapted while the original imge is corrected by the addition of each frame image. CONSTITUTION:An original image I is obscure at the center thereof and the circumferencial part thereof is sharp. When this image is subjected to Fourier transformation, the converted image is developed as an image II and the center part thereof is obscure much more. Therefore, a high pass filter is adapted (a process III) by the function as shown by a filter f1...fn to perform Fourier transformation (a process IV) to correct the obscurity at said part. By using obscurity correction filters f1...fn calculated corresponding to the obscure degree of the divided image region in each band, the n-frame images of an inverse Fourier image IV (an image 1- an image n) are obtained. With respect to these frame images, masks 1...n are applied to left hatching parts so as to take out only the image (a right hatching part) in each band corrected in obscurity (a process V).