14800-DvRappard

109 Quantitative MR spectroscopic imaging in metachromatic leukodystrophy 7 For five additional patients, MRI scans at diagnosis were obtained with a different protocol at another scanner or in another hospital. For these patients, only follow-up data after HCT or diagnosis were available, (median interval 3.3 y (range 11 months -14.8 years) until first follow-up, median age at first follow-up 8.1 years, range 6.4-28.8 years). Two adult patients (eligible and treated) had good outcome at latest follow-up, two juvenile patients (eligible and treated) had moderate outcome and one juvenile patient (non-eligible and untreated) had poor outcome (now deceased). Clinical status Motor function was scored by the MLD Gross Motor Function (MLD-GMF). 13 Cognitive function was determined through developmental or IQ testing and clinically estimated in evidently non-eligible patients. Depending on age and proficiencies, cognitive function was assessed using theWechsler Intelligence Scale for Children-III (6–18 years), the Wechsler Nonverbal Scale of Ability (4–22 years) or the Wechsler Adult Intelligence Scale-III (≥ 18 y). 7 Median follow-up of surviving transplanted patients was 7.7 years (range 4-16.9 years), of surviving non-transplanted patients 4.1 years (range 2.7-7.8 years). Clinical outcome at latest follow-up was defined as good (MLD-GMF ≤1, IQ deterioration ≤5 points), moderate (MLD-GMF 2-4, IQ deterioration >5 points) or poor (MLD-GMF ≥5 or deceased). While peripheral neuropathy contributed to a suboptimal outcome in two patients, their classification was not influenced by this. Accordingly, classification reflected central nervous system (CNS) involvement for all patients. MR Data Acquisition All subjects were examined at 1.5T (Siemens Sonata) with an eight-channel phased-array head-coil. MR imaging included axial T2-weighted fast spin-echo images (repetition time (TR) 2450 ms, echo times (TE) 24/85 ms, 4 mm slice thickness, in-plane resolution 1 mm), axial fluid attenuated inversion recovery (FLAIR) images (TR/TE/ inversion time (TI) 9000/108/2500 ms, 5 mm slice thickness, in-plane resolution 1 mm), and sagittal 3D T1-weighted images using a 3D magnetization prepared rapid acquisition gradient echo sequence (TR/TE/TI 2700/5/950 ms, 1 mm isotropic voxels). MRSI was obtained with point resolved spectroscopy localization (TR/TE 3000/30 ms, 6 acquisitions with weighted phase-encoding) on a single 15 mm slice (field of view 160x160 mm 2 , volume of interest (VOI) 80x100 mm 2 , 16x16 phase-encodings, voxel size 10 x10x15 mm 3 ) centered onto the corpus callosum (Figure 1A). Unsuppressed water reference scans were obtained with head and body coil. 14