Myelin Imaging Changes In Patients With Neurosurgical Diseases

While a number of advanced imaging techniques, notably magnetization transfer, diffusion tensor and quantitative T1 and T2 imaging (MTI, DTI, qT1 and qT2, respectively), have been used previously to study white matter in neurosurgical diseases, these methods provide only indirect, non-specific information related to myelin content. For example, these modalities can tell when there is swelling that is affecting the movement of water, which may be indicative of a process that would affect myelin, but they cannot tell us specific information about the amount of myelin surrounding a nerve. The investigators propose using a MRI sequence, mcDESPOT (multicomponent driven equilibrium potential of T1 and T2) that utilizes a computer model that takes T1 and T2 sequences and derives a quantitative value for the myelin content in the myelin sheath. In the present program, the investigators propose adding the mcDESPOT sequence to the MRI scanner in accordance with the MRI manufacturer's technical requirements. When this sequence is added, the normal sequences are done first and mcDESPOT is done last. Although the sequences obtained for mcDESPOT are sequences used in clinical practice, the flip-angles are changed so that they cannot be read like a traditional image. Rather, the data have to be post-processed by a computer in order to be able to derive myelin information. McDESPOT is a 10 minute sequence that can be added to any MRI scanner. It is a obtained from standard T1 and T2 sequences.