title: Detection of corticospinal tract compromise in amyotrophic lateral sclerosis with brain MR imaging: relevance of the T1-weighted spin-echo magnetization transfer contrast sequence.
abstract: OBJECTIVE
  Hyperintensity in the posterior limb of the internal capsule at T2-weighted MR imaging, consistent with corticospinal tract (CST) degeneration, is described in amyotrophic lateral sclerosis (ALS). However, the lack of specific tests or biological markers hinders confirmation of the diagnosis, especially in the early stages. We investigated the CST in ALS with MR imaging.
  
  
  METHODS
  We examined 25 patients (14 men, 11 women; mean age, 49.1 years; range, 29-68 years) and 21 age- and sex-matched control subjects without upper motor neuron signs. According to the revised El Escorial criteria, 22 patients had definite ALS; two, probable ALS; and one, suspected ALS. Fluid-attenuated inversion recovery (FLAIR; TR/TE/TI, 11,000/140/2600) and T1-weighted spin-echo (SE)/magnetization transfer contrast-enhanced (MTC; TR/TE, 510/12) imaging was performed at 1 T. Two experienced neuroradiologists blinded to the patients' history independently evaluated the CST.
  
  
  RESULTS
  T1-weighted SE MTC imaging allowed visualization of the CST in both patients and control subjects. T1-weighted SE MTC images showed hypointensity along the CST and bilateral subcortical regions of the precentral gyri in all control subjects and hyperintensity in 80% of patients with ALS (P < .05). FLAIR images showed hyperintensity in these areas in both groups, with no significant difference.
  
  
  CONCLUSIONS
  T1-weighted SE MTC imaging is sensitive and accurate in depicting CST lesions in ALS, whereas FLAIR imaging is not. T1-weighted SE MTC imaging is useful in diagnosing ALS by showing hyperintense areas along the CST, which separates patients from control subjects. This sequence should be included in the workup of patients with weakness and pyramidal signs.
authors.affiliation: Section of Radiology, Santa Casa de Misericordia de Sao Paulo, Brazil.
authors.forename: Antônio J
authors.initials: AJ
authors.lastname: da Rocha
authors.forename: Acary S B
authors.initials: AS
authors.lastname: Oliveira
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Fonseca
authors.forename: Antônio C M
authors.initials: AC
authors.lastname: Maia
authors.forename: Renata P
authors.initials: RP
authors.lastname: Buainain
authors.forename: Henrique M
authors.initials: HM
authors.lastname: Lederman
mesh_terms: D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000473:pathology; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D020772:Internal Capsule / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000175:diagnosis*; D009410:Nerve Degeneration / Q000175:diagnosis*; D011712:Pyramidal Tracts / Q000473:pathology*; D012680:Sensitivity and Specificity