Diffusion Tensor Imaging (DTI)

In L-CID, participants watched a self-chosen child-friendly movie while undergoing a structural connectivity scan called Diffusion Tensor Imaging (DTI). The MRI scans were conducted on a Philips Ingenia 3.0 T MRI system, using a standard whole-head coil. To ensure minimal head motion, foam inserts were placed around the children's heads. Two transverse Diffusion Weighted Imaging (DWI) scans were obtained with specific parameter settings which remained constant throughtout the waves: There were 30 diffusion-weighted volumes acquired with different noncollinear diffusion directions and a b-factor of 1000 s/mm². Additionally, 5 diffusion-unweighted volumes were acquired with a b-factor of 0 s/mm². The scans used an anterior-posterior phase encoding direction and a parallel imaging SENSE factor of 3. The flip angle was set at 90°, and 75 slices were obtained with a slice thickness of 2 mm and no slice gap. The reconstruction matrix size was 128 × 128, and the Field of View (FOV) was 240 × 240 mm. The echo time (TE) was 69 ms, and the repetition time (TR) was 7315 ms. For the second DWI set, the parameter settings were identical to the first set, except that it was acquired with a reversed k-space readout direction (posterior-anterior phase encoding direction). This change allowed for the removal of susceptibility artifacts during post-processing, resulting in improved image quality and reduced distortions caused by susceptibility effects.