Study On The Specific Feature Of Imaging Before And After Therapy

Purpose: To evaluate the effects of radiotherapy in patients with intracranial glioma by dynamic CT and MRI or MRS before and after therapy, and to study the specific feature of recurrent astro-glioma and radiate necrosis on CT or MRI. 1H magnetic resonance spectroscopy (1H MRS) in diagnosing delayed cerebral necrosis, Materials and Methods: We compared the CT or MRI change of glioma size, mass effect; edema; recurrent astro-glioma, radiation therapy-induced necrosis of brain and intracranial structure before and after radiotherapy, 26 patients of recurrent tumors and 5 patients of radiological necrosis were imaged on CT or MRI patients who had a clear clinical diagnosis of delayed cerebral necrosis underwent single voxel MR spectroscopy simultaneously both in the lesion region and the contrast lateral side, and proved by second operation and pathology evidences. Twenty-three cases of no recurrence verified by clinical course and follow-up CT or MRI were taken as contrast group. Result: The findings of postoperative and radiotherapy malignant gliomas on CT or MRI or dynamic contrast MRI were as follows: We found that the operative patients were closely related to the rate of tumor recurrence, but not related to recurrent type which classified as primary type, expanded type, and distant type. Radiological necrosis was found within 2 years of after operation. Recurrent tumor in this study showed post-operative active growing syndrome on CT or MRI; Fingering-like edema could be seen in radiological necrosis. Most recurrent tumors showed nodule ring-like contrast study while map-like enhancement or non-enhanced were considered as specific feature of radiological necrosis. Among 2 cases with delayed cerebral necrosis, one case exhibited decreased or absent Cho, NAA, Cr and abnormal Lipid, one case showed absent NAA, Cr, Cho with a flat curve. Conclusion: The findings of post-operative malignant gliomas on MRI are quite characteristic, and can be used as modality for evaluating the therapeutic effect and drawing up the next plan. It can objectively reflect the change of intracranial malignant gliomas before and after radiotherapy. 1H MRS is positively claimed for diagnosing delayed cerebral necrosis. It is a non-invasion and sensitive method for evaluation of the clinical state.