Diffusion-tensor imaging can be used to observe the microstructure of brain tissue. Fractional ani- sotropy reflects the integrity of white matter fibers. Fractional anisotropy of a young adult brain is low in gray ma...Diffusion-tensor imaging can be used to observe the microstructure of brain tissue. Fractional ani- sotropy reflects the integrity of white matter fibers. Fractional anisotropy of a young adult brain is low in gray matter, high in white matter, and highest in the splenium of the corpus callosum. Thus, we selected the anterior and posterior limbs of the internal capsule, head of the caudate nucleus, semioval center, thalamus, and corpus callosum （splenium and genu） as regions of interest when using diffusion-tensor imaging to observe fractional anisotropy of major white matter fiber tracts and the deep gray matter of healthy rhesus monkeys aged 4-8 years. Results showed no laterality dif- ferences in fractional anisotropy values. Fractional anisotropy values were low in the head of cau- date nucleus and thalamus in gray matter. Fractional anisotropy values were highest in the sple- nium of corpus callosum in the white matter, followed by genu of the corpus callosum and the pos- terior limb of the internal capsule. Fractional anisotropy values were lowest in the semioval center and posterior limb of internal capsule. These results suggest that fractional anisotropy values in major white matter fibers and the deep gray matter of 4-8-year-old rhesus monkeys are similar to those of healthy young people.展开更多
Magnetic resonance imaging (MRI) has significantly contributed to our capabilities of diagnosis multiple sclerosis (MS) since it is able to detect demyelinating lesions in almost 100% of patients. However, there are m...Magnetic resonance imaging (MRI) has significantly contributed to our capabilities of diagnosis multiple sclerosis (MS) since it is able to detect demyelinating lesions in almost 100% of patients. However, there are modest correlations between irreversible disability and white matter lesion load, as measured by T2-weighted MRI scans, which represents the clinicoradiological paradox of MS. We report the case of a patient with MS and few neurological manifestations despite extensive T2 visible morphologic abnormalities. The use of non-conventional MRI techniques, which are more specific in the analysis of the pathological substrate of demyelinating lesions and normal appearing brain matter (both white and gray matter), might assist us to overcome this limitation of conventional MRI.展开更多
基金supported by the National Natural Science Foundation of China,No.30960398,81260213the Forty-Seventh Batch of China Postdoctoral Science Foundation,No.20100470376
文摘Diffusion-tensor imaging can be used to observe the microstructure of brain tissue. Fractional ani- sotropy reflects the integrity of white matter fibers. Fractional anisotropy of a young adult brain is low in gray matter, high in white matter, and highest in the splenium of the corpus callosum. Thus, we selected the anterior and posterior limbs of the internal capsule, head of the caudate nucleus, semioval center, thalamus, and corpus callosum （splenium and genu） as regions of interest when using diffusion-tensor imaging to observe fractional anisotropy of major white matter fiber tracts and the deep gray matter of healthy rhesus monkeys aged 4-8 years. Results showed no laterality dif- ferences in fractional anisotropy values. Fractional anisotropy values were low in the head of cau- date nucleus and thalamus in gray matter. Fractional anisotropy values were highest in the sple- nium of corpus callosum in the white matter, followed by genu of the corpus callosum and the pos- terior limb of the internal capsule. Fractional anisotropy values were lowest in the semioval center and posterior limb of internal capsule. These results suggest that fractional anisotropy values in major white matter fibers and the deep gray matter of 4-8-year-old rhesus monkeys are similar to those of healthy young people.
文摘Magnetic resonance imaging (MRI) has significantly contributed to our capabilities of diagnosis multiple sclerosis (MS) since it is able to detect demyelinating lesions in almost 100% of patients. However, there are modest correlations between irreversible disability and white matter lesion load, as measured by T2-weighted MRI scans, which represents the clinicoradiological paradox of MS. We report the case of a patient with MS and few neurological manifestations despite extensive T2 visible morphologic abnormalities. The use of non-conventional MRI techniques, which are more specific in the analysis of the pathological substrate of demyelinating lesions and normal appearing brain matter (both white and gray matter), might assist us to overcome this limitation of conventional MRI.
