MPnRAGE: A technique to simultaneously acquire hundreds of differently contrasted MPRAGE images with applications to quantitative T-1 mapping

作者：Kecskemeti Steven; Samsonov Alexey; Hurley Samuel A; Dean Douglas C; Field Aaron; Alexander Andrew L

来源：Magnetic Resonance in Medicine, 2016, 75(3): 1040-1053.

DOI：10.1002/mrm.25674

• MPRAGE
• inversion recovery
• T-1 mapping
• T-1 weighted imaging
• Look-Locker
• segmentation

PurposeTo introduce a new technique called MPnRAGE, which produces hundreds of images with different T-1 contrasts and a B1 corrected T-1 map.
Theory and MethodsAn interleaved three-dimensional radial k-space trajectory with a sliding window reconstruction is used in conjunction with magnetization preparation pulses. This work modifies the SNAPSHOT-FLASH T-1 fitting equations for radial imaging with view-sharing and develops a new rapid B-1 correction procedure. MPnRAGE is demonstrated in phantoms and volunteers, including two volunteers with eight scans each and eight volunteers with two scans each. T-1 values from MPnRAGE were compared with those from fast spin echo inversion recovery (FSE-IR) in phantoms and a healthy human brain at 3 Tesla (T).
ResultsThe T-1 fit for human white and gray matter was T1(MPnRAGE) = 1.00 T1(FSE-IR) + 24 ms, r(2) = 0.990. Voxel-wise coefficient of variation in T-1 measurements across eight time points was between 0.02 and 0.08. Region of interest-based T-1 values were reproducible to within 2% and agree well with literature values.
ConclusionIn the same amount of time as a traditional MPRAGE exam (7.5 min), MPnRAGE was shown to produce hundreds of images with alternate T-1 contrasts as well as an accurate and reproducible T-1 map that is robust to B-1 errors. Magn Reson Med 75:1040-1053, 2016.

• 出版日期2016-3