MRI is the primary neuroimaging modality used for monitoring the effects of the PBTC therapeutic protocols. MRI has become sufficiently mature to allow for a standardization of imaging protocols between sites despite disparities between MRI manufacturers. The NIC staff provides each site with a minimum set of MRI sequences, which must be performed for inclusion into the database including T1, T2, FLAIR, and gradient sequences. Standardization of all pulse sequence parameters including slice plane selection, slice thickness, in-plane matrices, spatial resolution, repetition times, echo times, and echo train lengths is mandated among the sites.
Data analysis of standard MR images includes tumor location, tumor signal characteristics, and presence of hemorrhage. Tumor volume analysis is done from FLAIR or T2 sequences and T1 gadolinium sequences (enhancing and nonenhancing, cyst/necrosis) using the Vitrea workstation(Vital Images, Plymouth, MN.