Abstract
Purpose
To describe and evaluate a fast, fluid‐suppressed 2D multislice steady‐state free precession (SSFP) neuroimaging sequence.
Materials and Methods
We developed a fast fluid‐attenuated inversion‐recovery SSFP sequence for use in neuroimaging. The inversion time (TI) was optimized to yield good cerebrospinal fluid (CSF) suppression while conserving white matter (WM)/lesion contrast across a broad range of flip angles. Multiple SSFP acquisitions were combined using the sum‐of‐squares (SOS) method to maximize SNR efficiency while minimizing SSFP banding artifacts. We compared our fluid‐attenuated inversion‐recovery (FLAIR) SSFP sequence with FLAIR fast spin‐echo (FSE) in both normal subjects and a volunteer with multiple sclerosis. SNR measurements were performed to ascertain the SNR efficiency of each sequence.
Results
Our FLAIR SSFP sequence demonstrated excellent CSF suppression and good gray matter (GM)/WM contrast. Coverage of the entire brain (5‐mm slices, 24‐cm FOV, 256 × 192 matrix) was achieved with FLAIR SSFP in less than half the scan time of a corresponding FLAIR FSE sequence with similar SNR, yielding improvements of more than 50% in SNR efficiency. Axial scans of a volunteer with multiple sclerosis show clearly visible plaques and very good visualization of brain parenchyma.
Conclusion
We have demonstrated the feasibility of a very fast fluid‐suppressed neuroimaging technique using SSFP. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.