| 摘要 |
<p>PURPOSE:To measure the spatial distribution of a radiation dose with high sensitivity, by measuring the spatial distribution of the relaxation ratio of predetermined atomic uncleus spin in a specimen irradiated with radioactive rays and measuring the distribution of the radiation dose from said spatial distribution. CONSTITUTION:A substance of which the magnetic resonance characteristic is changed by irradiation with radioactive rays and a specimen (phantom) having a radiation increasing/decreasing agent almost uniformly distributed therein are prepared and the specimen is irradiated with radioactive rays and the spatial distribution of the relaxiation ratio of the predetermined atomic nucleus spin in the specimen irradiated with radioactive rays is measured by an NMR image forming apparatus and the distribution of the radiation does is measured from said spatial distribution. If this method is adapted, by using the radiation increasing/decreasing agent, the change in the relaxation ratio becomes larger than a case using said agent and high-sensitivity measurement is enabled. This is, values near to lines 11, 12 are obtained by this embodiment and it is cleared that the relaxation ratio larger than conventional ones shown by lines 13, 14 is obtained at the same dose.</p> |
