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An efficient chemical shift imaging scheme for magnetic resonance‐guided neurosurgery
Author(s) -
Liu Haiying,
Hall Walter A.,
Martin Alastair J.,
Truwit Charles L.
Publication year - 2001
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.1143
Subject(s) - imaging phantom , scanner , magnetic resonance imaging , signal (programming language) , computer science , nuclear magnetic resonance , materials science , nuclear medicine , radiology , physics , medicine , artificial intelligence , programming language
An efficient magnetic resonance spectroscopic imaging (MRSI) or chemical shift imaging (CSI) technique based on multiple spin echoes (MSE) has been implemented, validated, and used in both phantom and in vivo MR‐guided neurosurgical applications. The key concept of the method is to employ MSE to significantly speed up the data collection rate for mapping hydrogen‐containing metabolites. Using an echo train length (ETL) of three per excitation to simultaneously fill three consecutive k‐space areas, the total scan time for a spectroscopic image matrix size of 32 × 32 has been shortened to approximately 11 minutes. An interecho spacing time of 273 msec was used to null the phase anomalies of lactate double peaks due to the J‐coupling. This allowed a sufficient long data sampling time to achieve 4 Hz spectral resolution. Performing CSI intraopertively during an MR‐guided neurosurgical procedure was shown to be feasible at 1.5 T. More importantly, it was shown that more relevant information can be obtained regarding neurochemistry about a targeted lesion, in addition to conventional MR morphological imaging noninvasively. In 25 MR‐guided neurosurgical cases, the alleviated choline signal has been found to be consistent with the existence of rapid tumor cell proliferation in the corresponding area. The actual neurobiopsy guided by the spectroscopic imaging method demonstrated that it could provide valuable information in specifying the optimal site in a biopsy procedure, especially in the case involving a nonenhancing tumor. The multiecho scheme has made the CSI technique efficient enough to be routinely used in MR‐guided surgical procedures at 1.5 T and also allows the possibility of taking full advantage of MRI capability. J. Magn. Reson. Imaging 2001;14:1–7. © 2001 Wiley‐Liss, Inc.