| 摘要 |
PURPOSE:To enable absorption correction of an ECT tomographic image to be performed accurately by obtaining an absorption coefficient distribution by providing a line source covering a specimen near it, obtaining an ECT value for each picture cell, and then obtaining a projection data in each angle direction by performing projection while performing absorption and correction by using an absorption coefficient distribution and then performing its inverse projection. CONSTITUTION:A line source 4 is placed between a specimen 1 and a turbo fan collimator 3. The line source 4 is placed within a container 41 and is formed by mixing a radioactive isotope R1 into an aqueous solution. When the meter 3 rotates, radioactive radiation which is radiated and transmitted in a direction of the specimen 1 impinges on a detector 2 through the meter 3. Radioactive radiation in an opposite direction to the specimen 1 is shielded by a lead plate 42 and only a transmitted data is collected and then a transmission tomographic image according to an inverse projection, namely an absorption coefficient distribution image for each picture cell is reconfigured. Then, the line source 4 is excluded, RI is given to the specimen 1 and the ECT image is constituted by a projection data of normal emission data. It indicates distribution of ECT value for each picture cell but it is compensated and a true ECT value is obtained due to lack of absorption correction.
|
