Strategies for shimming the breast

Nimrod Maril, Christopher M. Collins, Robert L. Greenman, Robert E. Lenkinski

Research output: Contribution to journalArticle

40 Scopus citations

Abstract

There is evidence in the literature indicating a significant static field inhomogeneity in the human breast. A nonhomogenous field results in line broadening and frequency shifts in MRS and can cause intensity loss and spatial errors in MRI. Thus, there is a clear rationale for determining the regional variations in the static field homogeneity in the breast and providing strategies to correct them. Herein, the nature and extent of the static magnetic field at 3 T were measured in central planes of the human breast using both phase maps and multivoxel MRS techniques. In addition, the effect of first- and high-order shimming and of spatial saturation pulses on the static field inhomogeneity was evaluated. Both the theoretical and the measured field were found to be primarily linear in nature, with a reduction of 300 Hz from the nipple to the chest wall. First-order shimming reduced this inhomogeneity by 65%. Interestingly, the combination of spatial saturation pulses and first-order shimming was more effective than high-order shim alone. Since many clinical scanners do not have either higher-order shim or automated higher shimming algorithms that work in the presence of fat, the suggested combination provides an effective means to correct inhomogeneities in the breast.

Original languageEnglish (US)
Pages (from-to)1139-1145
Number of pages7
JournalMagnetic resonance in medicine
Volume54
Issue number5
DOIs
StatePublished - Nov 1 2005

Keywords

  • Breast
  • CSI
  • Field homogeneity
  • High field
  • Phase map

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Fingerprint Dive into the research topics of 'Strategies for shimming the breast'. Together they form a unique fingerprint.

  • Cite this

    Maril, N., Collins, C. M., Greenman, R. L., & Lenkinski, R. E. (2005). Strategies for shimming the breast. Magnetic resonance in medicine, 54(5), 1139-1145. https://doi.org/10.1002/mrm.20679