Objective To analyze the morphological alterations of corpus callosum in children with spastic cerebral palsy(SCP)using three-dimensional magnetization prepared rapid acquisition gradient echo(3D-MPRAGE)technology and to investigate the correlation between morphological indexes and gross motor function.Methods Sagittal T1WI 3D-MPRAGE data was collected from 136 children with SCP(SCP group)and 132 age-and gender-matched healthy controls(HC)(HC group),and the gross motor function measure-88(GMFM-88)was applied to assess the gross motor function.Independent sample t-test was used to compare the corpus callosum surface area,volume,maximum anterior-posterior diameter,median sagittal area(total area and area of Ⅰ-Ⅴ zone)between the two groups.Partial correlation analysis was performed to calculate the correlation between morphological indexes of the corpus callosum and GMFM-88 with age as a covariate.Results Children under 3 years old,the corpus callosum surface area of the SCP group(3 914.51 mm2±1 207.97 mm2)was lower than that of the HC group(5 725.51 mm2±1 412.66 mm2).The volume of the corpus callosum(6 108.46 mm3±2 803.97 mm3)in the SCP group was lower than that of the HC group(11 297.96 mm3±4 109.02 mm3).Also,the maximum anterior-posterior diameter of the corpus callosum in the SCP group(53.40 mm±6.31 mm)was lower than that of the HC group(57.74 mm±6.04 mm)(all P<0.05).Children over 3 years old,the corpus callosum surface area of the SCP group(4 970.06 mm2±1 191.31 mm2)was lower than that of the HC group(6 372.55 mm2±1 445.59 mm2).The volume of the corpus callosum(8 330.20 mm3±2 888.20 mm3)in the SCP group was lower than that of the HC group(13 599.82 mm3±3 429.81 mm3)(all P<0.05).Partial correlation analysis showed significant correlation between corpus callosum volume,median sagittal area and gross motor score(P<0.01)with age as a covari-ate.Conclusion The 3D-MPRAGE technology can be useful for the comprehensive assessment of morphological alterations of the corpus callosum in SCP.The corpus callosum volume,and median sagittal area may become neuroimaging references for the assess-ment of motor development in cerebral palsy(CP).