In order to run a source analysis on the MEG data it is necessary to have an accurate head model describing the shape of the scalp, skull, and cortical surface. The best way to calculate a subject-specific head model is to use a high resolution anatomical MRI scan of the subject. Information about collecting MRI, such as scheduling and fees, can be found at the CIR Website.
Recommended MRI Protocols
The MRI protocol will depend on how much time you have available for data collection. At the very least, a T1-weighted scan, such as an SPGR or MPRAGE, is necessary. In addition, we currently recommend collecting a T2-weighted scan with the same resolution as the T1 scan. If there is additional time available then the protocol could include: additional T1 scans, a resting state fMRI scan, a proton density (PD) scan, or a diffusion (DTI) scan. It is VERY important that the scan covers the entire scalp surface including the ears. If some of the head is cut off than this will decrease the accuracy of the head model.
The T1 scan is used to identify the gray matter cortical surface, as well as the boundary of the scalp, skull, and dura. Several T1 scans can be collected and averaged together; however, because of alignment error, averaging may not provide much benefit unless there are at least three scans.
Proton Density (optional)
Resting State (optional)
If the subject has metal implants, check the nanufacturer name and see if it is listed as safe in this website. http://www.mrisafety.com/TheList_search.asp