Magnetic resonance imaging (MRI) has made important contributions toward the study of the developing pediatric brain. In addition to morphological information, advanced MRI methodologies are being relied on to interrogate non-invasively brain chemistry, physiology, and microstructure. Altogether, the application of such advanced MR methodologies, including spectroscopy (MRS), perfusion imaging, and diffusion tensor imaging (DTI) in the pediatric population has the potential for providing more in-depth information in the daily pediatric radiology practice. In an ideal world, one should be able to apply all these techniques together to differentiate more appropriately between several pathologies. However, despite the obvious advantages of the combination of such techniques, most of these procedures are actually applied separately. The main reason for this partitioning comes from the prolonged acquisition times associated with each of these techniques. Furthermore, most of these methods are by their very nature sensitive to motion and can be challenging to apply to difficult patient populations, such as unsedated children with disabilities or developmental delay.
Recently, however, the incorporation of fast spatial-encoding methods, such as those provided by parallel imaging,[1,2] has made standard use of advanced MRI for the evaluation of the pediatric brain more feasible and has allowed the routine implementation of isotropic, high-spatial-resolution three-dimensional morphological imaging. Furthermore, the greater availability of high-field (>3 T) MR scanners and phased-array receiver coils designed for brain imaging has permitted the trade-off of high image signal-to-noise ratio (SNR) for faster acquisition time. Finally, other new developments have emerged, allowing uncooperative patients to be scanned using motion-insensitive techniques such as PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction). These improvements should allow comprehensive physiological MR studies to be performed in children in the future with clinically acceptable scan times.