Diagnostic Study Of Radiation Encephalopathy And The Related Factors In Low-Field-MRI

Objective: To investigate the features of radiation encephalopathy in low-field-MRI and the related factors of radiation encephalopathy(including sex, irradiation area, irradiation dose and the period of radiation therapy, associate with chemical medication), to discuss the diagnostic value of low-field-MRI in diagnoses of radiation encephalopathy. Materials and Methods: 154 patients post-radiation therapy were scanned by 0.3T AIRIS MRI, including 112 cases which with the first period of irradiation therapy and 42 cases that with both the first and the second period of irradiation therapy. The patients were performed MR scan with the head-loop coil in common scan and post administration of Gadopentetate Dimeglumine (0.1mmol/kg).Results : There are 41 cases (66 sites) who were diagnosed the radiation encephalopathy, the incidence of disease is 26.6%. Most of the sites distributing encircling the irradiation wild, especially in the white matter(83.3%). There are 32 lesions (48.5%) located in lobus tempororalis;22 lesions(33.3%) located in lobus frontalis and lobus parietalis;10 lesions(15.1%) located in truncus encephalicus and 2 lesions(3.0%) located in cerebellum. The shape of the lesions are multiplicate, most of them circled with edema. Their signal assume equal or lower at T1WI(92.4%), high at T2WI(95.5%) and FI FLAIR (89.4%) .Most the focus can be abnormal intensified, the focus in differ period assume differ intensified degree. The "garland" shape is the most characteristic intensified shape of radiation encephalopathy. Radiation encephalopathy have definite delitescence. Correlation chi-square test, and analysis of variance indicated that the re'ativity between the related factors (^uch as the irradiate area , irradiate dose,the period of treatment and associate with chemistry medication or not) and the abnormal intensification of radiation encephalopathy has statistically significance.Conclusion: The Low-Field-MRI representation of radiation encephalopathy has many character, analysis of manifold correlation factors show that there is no statistically significance between some factor (such as sex) and the abnormal intensification of radiation encephalopathy;while other factors (such as the irradiate area , irradiate dose, the period of treatment and associate with chemistry medication or not ) definitively affect the especial representation of MRI. Low-Field-MRI can provide information for accurately imaging diagnosis of radiation encephalopathy and even for moreclinical treatment.