Selective Inversion Recovery Quantitative Magnetization Transfer Brain MRI at 7T: Clinical and Postmortem Validation in Multiple Sclerosis

Francesca Bagnato, Simon Hametner, Giulia Franco, Siddharama Pawate, Subramaniam Sriram, Hans Lassmann, John Gore, Seth E. Smith, Richard Dortch

Research output: Contribution to journalArticlepeer-review

Abstract

BACKGROUND AND PURPOSE: An imaging biomarker of myelin integrity is an unmet need in multiple sclerosis (MS). Selective inversion recovery (SIR) quantitative magnetization transfer imaging (qMT) provides assays of myelin content in the human brain. We previously translated the SIR method to 7T and incorporated a rapid turbo field echo (TFE) readout for whole-brain imaging within clinically acceptable scan times. We herein provide histological validation and test in vivo feasibility and applicability of the SIR-TFE protocol in MS. METHODS: Clinical (T1- and T2-weighted) and SIR-TFE MRI scans were performed at 7T in a postmortem MS brain and MRI data were acquired in 10 MS patients and 14 heathy volunteers in vivo. The following parameters were estimated from SIR data: the macromolecular-to-free water pool-size-ratio (PSR), the spin-lattice relaxation rate of water (R1f), and the MT exchange rate (kmf). Differences in SIR parameters across tissue types, eg, white matter lesions (WM-Ls) and normal appearing WM (NAWM) in patients, and normal white matter (NWM) in heathy volunteers were evaluated. Associations between SIR parameters and disability scores were assessed. RESULTS: For postmortem scans, correspondence was observed between WM-Ls and NAWM from histology and PSR/R1f values. In vivo differences were detected for PSR, R1f, and kmf between WM-Ls and NWM (P ≤.041). Associations were seen between WM-Ls/ NAWM PSR and disability scores (r ≤ –.671, P ≤.048). CONCLUSIONS: SIR-qMT at 7T provides sensitive, quantitative measures of myelin integrity for clinical and research applications.

Original languageEnglish
Pages (from-to)380-388
Number of pages9
JournalJournal of Neuroimaging
Volume28
Issue number4
DOIs
Publication statusPublished - Jul 1 2018
Externally publishedYes

Keywords

  • magnetic resonance imaging
  • multiple sclerosis
  • Myelin
  • quantitative magnetization transfer imaging

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Clinical Neurology

Fingerprint Dive into the research topics of 'Selective Inversion Recovery Quantitative Magnetization Transfer Brain MRI at 7T: Clinical and Postmortem Validation in Multiple Sclerosis'. Together they form a unique fingerprint.

Cite this