Reconstruction for 7T high-resolution whole-brain diffusion MRI using two-stage N/2 ghost correction and L1-SPIRiT without single-band reference

Ziyi Pan, Xiaodong Ma, Erpeng Dai, Edward J. Auerbach, Hua Guo, Kâmil Uğurbil, Xiaoping Wu

Research output: Contribution to journalArticlepeer-review


Purpose: To combine a new two-stage N/2 ghost correction and an adapted L1-SPIRiT method for reconstruction of 7T highly accelerated whole-brain diffusion MRI (dMRI) using only autocalibration scans (ACS) without the need of additional single-band reference (SBref) scans. Methods: The proposed ghost correction consisted of a 3-line reference approach in stage 1 and the reference-free entropy method in stage 2. The adapted L1-SPIRiT method was formulated within the 3D k-space framework. Its efficacy was examined by acquiring two dMRI data sets at 1.05-mm isotropic resolutions with a total acceleration of 6 or 9 (i.e., 2-fold or 3-fold slice and 3-fold in-plane acceleration). Diffusion analysis was performed to derive DTI metrics and estimate fiber orientation distribution functions (fODFs). The results were compared with those of 3D k-space GRAPPA using only ACS, all in reference to 3D k-space GRAPPA using both ACS and SBref (serving as a reference). Results: The proposed ghost correction eliminated artifacts more robustly than conventional approaches. Our adapted L1-SPIRiT method outperformed 3D k-space GRAPPA when using only ACS, improving image quality to what was achievable with 3D k-space GRAPPA using both ACS and SBref scans. The improvement in image quality further resulted in an improvement in estimation performances for DTI and fODFs. Conclusion: The combination of our new ghost correction and adapted L1-SPIRiT method can reliably reconstruct 7T highly accelerated whole-brain dMRI without the need of SBref scans, increasing acquisition efficiency and reducing motion sensitivity.

Original languageEnglish (US)
Pages (from-to)1915-1930
Number of pages16
JournalMagnetic resonance in medicine
Issue number5
StatePublished - May 2023

Bibliographical note

Funding Information:
XM, EJA, KU, and XW were supported in part by National Institutes of Health (U01 EB025144 and P41 EB027061). The authors thank Dr. Zhe Zhang for the helpful discussion.

Publisher Copyright:
© 2023 International Society for Magnetic Resonance in Medicine.


  • HCP
  • L1-SPIRiT
  • N/2 ghost correction
  • diffusion imaging
  • simultaneous multislice

Center for Magnetic Resonance Research (CMRR) tags

  • BFC
  • IRP
  • P41

PubMed: MeSH publication types

  • Journal Article
  • Research Support, N.I.H., Extramural


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