With left liver irradiated by 40Gy single-dosed X-rays

12 rabbits’ liver SPECT with 99mTc-Phy and SPIO-MR imaging were implemented in 3rd—4th day post-irradiation

and pathologic study was carried out at the same time. In our SPECT study

the radioisotope absorption of the irradiated livers decreased in 9 rabbits; and the positive rabbits demonstrated radioactive retention in 24-hour delayed observation. In early-phase SPIO enhanced MR imaging

the irradiated livers of 10 rabbits showed the positive appearance as high-signal region; however

the signal contrast of some rabbits’ livers became weak in 60min delayed-enhanced MRI. In pathologic investigation of livers 4th day post-irradiation

the number of Kupffer cells having swallowed SPIO in irradiated liver was less than that non-irradiated region. So we can conclude that both SPECT and MRI are effective in evaluating early effect of liver injury post-irradiations

i.e. dysfunction of reticuloendothelial system.