Usefulness of SWI for the Detection of Iron in the Motor Cortex in Amyotrophic Lateral Sclerosis

J Neuroimaging. May-Jun 2015;25(3):443-51. doi: 10.1111/jon.12127. Epub 2014 Jun 3.


Purpose: The purpose of the present retrospective study was to evaluate the sensitivity of susceptibility-weighted imaging (SWI) compared to conventional spin-echo T2-weighted and T2*-weighted images in detecting iron deposition in the motor cortex of amyotrophic lateral sclerosis (ALS) patients in comparison with age-matched normal controls. We also investigated the etiology of the low signal referring to the pathology of one autopsy case.

Methods: This retrospective magnetic resonance (MR) study included 23 ALS patients and 28 age-matched normal controls. The signal intensity of the motor cortex was scored by SWI, conventional T2-weighted images and T2*-weighted images. A postmortem study of one patient was also performed.

Results: On SWI, there was a significant difference between the precentral cortical signal intensity scores in the ALS patients and the controls (P < .0001). The total scores of signal intensities of the precentral cortex were positively correlated with age in the normal controls (r = .494), but no correlation was observed in the ALS patients. The postmortem study showed intensely stained microglias and macrophages after antiferritin antibody staining in the precentral cortices.

Conclusions: Decreased signal intensity of the motor cortex on SWI may serve a useful role in ALS diagnoses, particularly in young patients. MR images were also helpful for speculating on the etiology of ALS.

Keywords: alprostadil; erectile dysfunction; prostate cancer; validation.

MeSH terms

  • Adult
  • Aged
  • Amyotrophic Lateral Sclerosis / metabolism*
  • Amyotrophic Lateral Sclerosis / pathology
  • Biomarkers / metabolism
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Iron / metabolism*
  • Iron Overload / metabolism*
  • Iron Overload / pathology
  • Male
  • Middle Aged
  • Molecular Imaging / methods
  • Motor Cortex / metabolism*
  • Motor Cortex / pathology
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spin Labels
  • Tissue Distribution


  • Biomarkers
  • Spin Labels
  • Iron