Experimental Correlative Study On ～1HMRS Findings And Their Pathologic Basis Of Early Changes After Whole Brain Irradiation In Rats

Objective: To analyze 1HMRS changes in radiation cerebrum damage in pathology.Methods: 25 maturity SD rats divide into 5 groups including matched control, 10Gy, 20Gy, 30Gy once irradiation group and 30Gy/3 times/3 weeks group. Whole cerebrum irradiation with 6MeV electric rays. Give these groups MRI and 1HMRS examination after 1 month. To analyze concentration changes of NAA , Cho and Cr, give a comparison with Integra area to calculate NAA/Cr , Cho/Cr and NAA/Cho. Cerebral hemisphere were taken respectively, one side examined with HE Staining and the other side with electron micrograph.Results: All cerebrums in MRI were no abnormality seen,NAA/Cr, Cho/Cr and NAA/Cr of all irradiation groups showed the maximal stimulating effect and marked difference appeared with dosage increase. Light edema in 30Gy once irradiation group by routine examination, light changes of myelin sheath and angio-endothelial cell injury by electron micrograph in 20Gy and30Gy many times irradiation groups, demyelination, pyknosis glial cell swelling and vessel milieu edema in 30Gy once irradiation group.Conclusions: We can detect metabolism abnormality of cerebrum constitution before morphology changes appeared and show earlier period ultrastructure changes of cerebrum constitution after irradiation by concentration monitoring to NAA, Cho and Cr. Correlation analysis showed the concentration changes had positive correlation with ultrastructure changes of rat cerebrum constitution.