Objective To detect the changes of cerebral perfusion in patients with MELAs syndrome by using MR perfusion technique.Methods Thirteen patients with MELAS syndrome and 13 controls with normal neurological conditions were scanned with the sequence of flow-sensitive alternating inversion recovery exempting separate T1 measurement(FAIREST).Their rCBF values were obtained in regions of bilateral basilar nuclei and thalami,as well as bilateral temporal lobes and occipital lobes.Regression analysis was carried out to determine the effect of location and side on the measurement of rCBF in controls.One-way ANOVA was conducted to compare rCBF values among the control group.the lesion ROIs and normal ROIs of the MELAS syndrome group.Results The values of rCBF were 0.83±0.23,1.17±0.30.0.93±0.28,and 1.11±0.25 for the left basilar ganglia,thalamus,temporal lobe,and occipital lobe respectively,while they were 0.77±0.15,1.03±0.34,1.06±0.23,and 1.09±0.23 for the right basilar ganglia,thalamus,temporal lobe.and occipital lobe respectively.Regression analysis revealed no effect of location and side on the rCBF (P＞0.05).The rCBF value for control group was 1.00±0.28,while it was 1.01±0.31 for the normal ROIs and 1.95±0.43 for the lesion ROIs in the MELAS syndrome group(F=54.99.P＜0.01).The rCBF of the lesion ROIs in the MELAS syndrome group was significantly higher than the normal ROIs and the control group.Conclusion CBF maps can reveal changes of cerebral blood flow in patients with ietal MELAS,which suggests increased perfusion in the stroke-like lesions.

Objective To determine the MR phenotype of Leigh syndrome (IS) with SURF-1 gene mutation.Methods The cranial MR examination of eight patients with the diagnosis of Leigh syndrome associated with SURF-1 gene 604G→C mutations were reviewed retrospectively.Comparison was made with typical LS patients' MRI.Observation was made regarding lesions in basal ganglia,subthalamic nuclei,substantia nigra,and dentate nuclei,involvement of white matter,and brain atrophy.Results The MR findings of LS in the study included the following:3 cases exhibited involvement of brain stem and subthalamic nuclei,2 of these 3 cases also had basal ganglia abnormalities.3 cases showed abnormality in the white matter without any involvement of the deep nuclei.Cerebral atrophy was observed in all cases in the group,and was the only finding in two cases.Conclusion The imaging findings in LS with SURF-1 604G→C gene mutation were variable.