Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocamp...Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocampal formation （HF） in patients with medial temporal lobe epilepsy （MTLE）. Methods Fourteen patients with MTLE and 14 healthy subjects were evaluated. Mean diffusivity （MD） and fractional anisotropy （FA） from the symmetrical-voxel sampling regions of the anterior HF were calculated in all subjects. The MD and FA values were compared across the groups. Results No significant differences of MD and FA values were noted between right and left HF in the controls. In the patient group, MD significantly increased in the HF ipsilateral to the lesioned side [（9.27±1.09）×10^-4 mm^2/s], compared with the values in the contralateral HF [（8.20±0.59）×10^-4 min^2]s] （t = 4.479, P = 0.001） and healthy subjects [（7.58±0.51）×10^-4 mm^2/s] （P 〈 0.001）, but no significant differences were found in FA. When compared with the controls, patients had a significantly higher MD in the contralateral HF （P 〈 0.05）, but the difference in FA was not statistically significant. Conclusions DTI could detect hippocampal abnormality in patients with MTLE. This technique may be helpful for preoperative evaluation of such patients.展开更多
Objective To review the applications of magnetic resonance imaging （MRI） techniques in assessing treatment response to gamma knife radiosurgery for brain tumors. Data sources Published articles about assessing treat...Objective To review the applications of magnetic resonance imaging （MRI） techniques in assessing treatment response to gamma knife radiosurgery for brain tumors. Data sources Published articles about assessing treatment response to gamma knife radiosurgery for brain tumors were selected using PubMed. The search terms were ＂MRr＇, ＂gamma knife＂ and ＂brain tumors＂. Study selection Articles regarding the MRI techniques using for early assessment of treatment response of gamma knife were selected. Results MRI techniques, especially diffusion weighted imaging, perfusion weighted imaging, magnetic resonance spectroscopy, are useful for early assessment of treatment response of gamma knife by detecting the hemodynamic, metabolic, and cellular alterations. Moreover, they can also provide important information on prognosis. Conclusions Diffusion weighted imaging, perfusion weighted imaging and magnetic resonance spectroscopy can provide early assessment of treatment response of gamma knife for brain tumors, and also information of tumor progression or recurrence earlier than conventional MRI. But there are still many questions to be answered which should be based on the development and advancement of MRI and related disciplines.展开更多
文摘Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocampal formation （HF） in patients with medial temporal lobe epilepsy （MTLE）. Methods Fourteen patients with MTLE and 14 healthy subjects were evaluated. Mean diffusivity （MD） and fractional anisotropy （FA） from the symmetrical-voxel sampling regions of the anterior HF were calculated in all subjects. The MD and FA values were compared across the groups. Results No significant differences of MD and FA values were noted between right and left HF in the controls. In the patient group, MD significantly increased in the HF ipsilateral to the lesioned side [（9.27±1.09）×10^-4 mm^2/s], compared with the values in the contralateral HF [（8.20±0.59）×10^-4 min^2]s] （t = 4.479, P = 0.001） and healthy subjects [（7.58±0.51）×10^-4 mm^2/s] （P 〈 0.001）, but no significant differences were found in FA. When compared with the controls, patients had a significantly higher MD in the contralateral HF （P 〈 0.05）, but the difference in FA was not statistically significant. Conclusions DTI could detect hippocampal abnormality in patients with MTLE. This technique may be helpful for preoperative evaluation of such patients.
文摘Objective To review the applications of magnetic resonance imaging （MRI） techniques in assessing treatment response to gamma knife radiosurgery for brain tumors. Data sources Published articles about assessing treatment response to gamma knife radiosurgery for brain tumors were selected using PubMed. The search terms were ＂MRr＇, ＂gamma knife＂ and ＂brain tumors＂. Study selection Articles regarding the MRI techniques using for early assessment of treatment response of gamma knife were selected. Results MRI techniques, especially diffusion weighted imaging, perfusion weighted imaging, magnetic resonance spectroscopy, are useful for early assessment of treatment response of gamma knife by detecting the hemodynamic, metabolic, and cellular alterations. Moreover, they can also provide important information on prognosis. Conclusions Diffusion weighted imaging, perfusion weighted imaging and magnetic resonance spectroscopy can provide early assessment of treatment response of gamma knife for brain tumors, and also information of tumor progression or recurrence earlier than conventional MRI. But there are still many questions to be answered which should be based on the development and advancement of MRI and related disciplines.
