Abstract:Objective To explore the value of high-resolution 3-dimensional T1-weighted imaging (3D-T1WI) in children with focal cortical dysplasia (FCD) of type Ⅰ. Methods The MRI data of 26 pathologically confirmed FCD type I children admitted from July 2016 to July 2018 were retrospectively analyzed, and the 3D-T1WI sequence was compared with other sequences for the main MRI signs of FCD type I children (blurred gray-white matter junction, focal cortical structure abnormalities and abnormal signal focus in white matter) detection status and the occurrence rate of different MRI signs among FCD I subtypes. The number of cases and the number of consecutive layers with local blurred gray-white matter junctions and cortical structural abnormalities detected by 3D-T1WI sequence in each plane calculated. Results The detection rates of blurred gray-white matter junction by 3D-T1WI (92.3%)were obviously higher than those by 3D-T2 FLAIR(61.5%)and by T1WI(42.3%)respectively(all P＜0.017), and the detection rate of abnormal cortical stracture by 3D-T1WI(69.2%)was obvionsly higher than that by T1WI(26.9%)(P<0.017),but there was no significant difference in the detection rate of abnormal signal foci in white matter among the three sequences(P>0.05).There was no significant difference in the occurrence rate of different MRI signs in subtypes of FCD I(all P>0.05). In axial,coronal and sagittal sections,3D-T1WI showed that the continuous layers of blurred gray-white matter junction were all≥3 layers,and the continuous layers of focal cortical structural abnormalities were all≥2 layers. Conclusion 3D-T1WI could improve the detection rate in children with FCD type I and can be used as the preferred MRI sequence.