Proton MR spectroscopy in children with acute brain injury: comparison of short and long echo time acquisitions.

The aim of this study was to evaluate comparatively the information given by proton magnetic resonance spectroscopy (MRS) with short echo time (TE 20 msec) stimulated echo acquisition mode and long TE (270 msec) point-resolved spectroscopy in predicting long-term outcome in children suffering from acute brain injury. At 1.5 T, we performed single-voxel proton MRS with both methods in occipital gray matter of 70 children. A linear discriminant analysis used to predict outcomes based on MRS variables was compared with actual neurologic outcome assigned at least 6 months after injury by a pediatric neurologist. Using peak area metabolite ratios and lactate presence, the short and long TE methods were equally predictive in children over 1 month of age. In neonates less than 1 month of age, the long TE method produced a higher percentage of correct outcome predictions (91%) than the short TE method (79%). The long TE method detected lactate more often in all age groups.