| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a radiation tomograph which is improved in a detection sensitivity characteristic without increasing manufacturing cost by devising a radiation detector composing a detector ring. <P>SOLUTION: A first unit ring 12a and a third unit ring 12c are positioned at both ends in the direction z of the detector ring 12, and therefore, in the rings, it is more difficult to detect an annihilation radiation pair than for a second unit ring 12b positioned in the central part of the detector ring 12. However, the radiation detection sensitivity of a first radiation detector constituting the first unit ring 12a and the third unit ring 12c is made higher than that of a second radiation detector. Thus, this radiation tomograph suppresses positional nonuniformity in the radiation sensitivity of the detector ring 12 and can provide a more homogeneous tomographic image over the range of a tomographic field of the detector ring 12. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
