94 Chapter 6 MATERIAL AND METHODS The Institution Research Ethics Board at the Erasmus University Medical Center, Rotterdam, The Netherlands approved this study (MEC-2014-461), which is part of ongoing work at the Dutch Craniofacial Center involving protocolized care, brain imaging, clinical assessment and data summary and evaluation. Subjects MRIs from non-operated children with genetically confirmed diagnosis of syndromic craniosynostosis aged under 2 years were included. The cohort consisted of patients with Apert syndrome (mutation in the fibroblast growth factor receptor (FGFR) 2 gene), patients with Crouzon-Pfeiffer (mutation in FGFR 1 or FGFR 2 gene), patients with Muenke syndrome (mutation in FGFR 3 gene) and patients with Saethre-syndrome (mutation or deletion in the twist related protein (TWIST1 gene). Patients with 2 or more affected sutures, but for whom a responsible gene mutation has not been found, were named complex craniosynostosis patients. Controls with the same age range were identified from a historic hospital MRI database of children who had undergone MRI brain studies for clinical reasons between 2010-2020. Patients were considered a control if any cerebral and/or skull pathology was absent. Scans of potential controls were reviewed by an expert pediatric radiologist and a neurosurgeon to ensure the absence of any cerebral pathology and/or skull pathology. MRI Acquisition All brain MRI data were acquired with a 1.5 Tesla unit (General Electric Healthcare, Milwaukee, Wisconsin), including three-dimensional (3D) T1-weighted fast spoiled gradient-recalled sequence, high-resolution 3D T2- weighted spin echo sequence, and DTI sequences. DTI was obtained using a multi repetition single-shot echo-planar sequence with a section thickness of 3 mm without a gap. Images were obtained in 25 gradient directions with the following parameters: sensitivity, b: 1000s/mm2; TR: 15,000ms; TE: 82.1ms; FOV: 240 x 240 mm2; and matrix: 128 x 128, resulting in a voxel size of 1.8 x 1.8 x 3.0 mm. This protocol was identical in both sCS patients and controls and kept equal throughout the entire study period. DTI Data Collection DTI processing was performed using ExploreDTI (http:// exploredti.com/). The processing consisted of correction of subject motion and eddy current distortions, and a weighted linear least-squares estimation of the diffusion tensor with the robust extraction of kurtosis indices with linear estimation (REKINDLE) approach.15, 16 White matter tracts for fiber tractography included projection fibers (corticospinal tract), commissural fibers (corpus callosum), tracts of the brain stem (medial cerebellar peduncle) and the tracts of the limbic system (fornix and cingulated bundle).
RkJQdWJsaXNoZXIy MTk4NDMw