NOrmalized MAgnetization Ratio (NOMAR) filtering for creation of tissue selective contrast maps.

TitleNOrmalized MAgnetization Ratio (NOMAR) filtering for creation of tissue selective contrast maps.
Publication TypeJournal Article
Year of Publication2013
AuthorsLiu G, Chan KWY, Song X, Zhang J, Gilad AA, Bulte JWM, van Zijl PCM, McMahon MT
JournalMagnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine
Volume69
Issue2
Pagination516-23
Date Published2013 Feb
Abstract

An MRI segmentation technique based on collecting two additional saturation transfer images is proposed as an aid for improved detection of chemical exchange saturation transfer agents. In this approach, the additional images are acquired at saturation frequencies of -12.5 and -50 ppm. Use of the ratio of these images allows differentiation of voxels with low magnetization transfer contrast (such as fat, cerebrospinal fluid, edema, or blood) from target tissue voxels using a global threshold determined by histogram analysis. We demonstrate that this technique can reduce artifacts, in vitro, in a phantom containing tubes with chemical exchange saturation transfer contrast agent embedded in either crosslinked bovine serum albumin or buffer, and in vivo for detecting diamagnetic CEST (DIACEST) liposomes injected into mice.

DOI10.3174/ajnr.A3505
Alternate JournalMagn Reson Med