# Robust 3D MR spectroscopic imaging through multi-coil magnetic field shaping

> **NIH NIH R01** · YALE UNIVERSITY · 2020 · $406,504

## Abstract

PROJECT SUMMARY
MR spectroscopic imaging (MRSI) is a powerful, non-invasive method to map the metabolic profile of human
brain. The intrinsic chemical specificity of MRSI can reveal altered metabolism in regions that would appear
non-pathologic on standard MRI. MRSI has successfully been used for brain tumor classification and
infiltration, planning of radiation therapy and surgery and has helped to characterize a range of
neurodegenerative diseases such as multiple sclerosis, Alzheimer's disease and epilepsy. Despite its merits
and successes, MRSI is not a widespread imaging modality because the method is hampered by the long-
standing problem of magnetic field inhomogeneity, which leads to lower-quality and thus less-reproducible
data. Incomplete water and lipid suppression can compromise data quality even further. Over the last decade
we have developed multi-coil (MC) shimming as an alternative to conventional spherical harmonics based
shimming. By controlling the current in a matrix of generic, circular DC coils the magnetic field homogeneity
can be improved to less than 0.1 ppm across the entire human brain. In this renewal application we propose to
apply our extensive experience with MC field manipulation and the superior performance of MC shimming to
achieve consistent and reliable MRSI performance across the human brain. Aim 1 is focused on the
implementation of MC shimming and its integration with ultra-fast, EPI-based MRSI. The MC technology will be
modified and extended to generate local crusher gradients for effective lipid suppression. Aim 2 is concerned
with the validation of MC-augmented MRSI on the human brain. Besides comparisons between MC and
conventional shimmed MRSI, Aim 2 will also establish intra- and inter-subject, as well as test-retest
reproducibility. In addition, the MC setup optimized at 4 T will be transferred to 3 T and 7 T, without
modifications, to demonstrate compatibility of MC-based shimming with clinical MR systems. The
implementation and validation of MC-augmented MRSI is considered complete when >90% of MRSI voxels on
all slices, all subjects and all scanners adhere to stringent data quality requirements. While all neurological
disorders and pathologies can benefit from high-fidelity MRSI, Aim 3 focuses on obtaining high-quality, reliable
MRSI on tumor patients. The presence of metallic implants in many post-surgery tumor patients, in addition to
tumor-related pathology, compromises the magnetic field homogeneity. MC shimming will be used to
demonstrate that high-fidelity MRSI can be achieved on a challenging, clinical subject population.

## Key facts

- **NIH application ID:** 9923655
- **Project number:** 5R01EB014861-08
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** ROBIN A DE GRAAF
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $406,504
- **Award type:** 5
- **Project period:** 2012-04-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9923655

## Citation

> US National Institutes of Health, RePORTER application 9923655, Robust 3D MR spectroscopic imaging through multi-coil magnetic field shaping (5R01EB014861-08). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9923655. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*