title: High-Resolution 7T MR Imaging of the Motor Cortex in Amyotrophic Lateral Sclerosis.
abstract: OBJECTIVE
  Amyotrophic lateral sclerosis is a progressive motor neuron disorder that involves degeneration of both upper and lower motor neurons. In patients with amyotrophic lateral sclerosis, pathologic studies and ex vivo high-resolution MR imaging at ultra-high field strength revealed the co-localization of iron and activated microglia distributed in the deep layers of the primary motor cortex. The aims of the study were to measure the cortical thickness and evaluate the distribution of iron-related signal changes in the primary motor cortex of patients with amyotrophic lateral sclerosis as possible in vivo biomarkers of upper motor neuron impairment.
  
  
  METHODS
  Twenty-two patients with definite amyotrophic lateral sclerosis and 14 healthy subjects underwent a high-resolution 2D multiecho gradient-recalled sequence targeted on the primary motor cortex by using a 7T scanner. Image analysis consisted of the visual evaluation and quantitative measurement of signal intensity and cortical thickness of the primary motor cortex in patients and controls. Qualitative and quantitative MR imaging parameters were correlated with electrophysiologic and laboratory data and with clinical scores.
  
  
  RESULTS
  Ultra-high field MR imaging revealed atrophy and signal hypointensity in the deep layers of the primary motor cortex of patients with amyotrophic lateral sclerosis with a diagnostic accuracy of 71%. Signal hypointensity of the deep layers of the primary motor cortex correlated with upper motor neuron impairment (r = -0.47; P < .001) and with disease progression rate (r = -0.60; P = .009).
  
  
  CONCLUSIONS
  The combined high spatial resolution and sensitivity to paramagnetic substances of 7T MR imaging demonstrate in vivo signal changes of the cerebral motor cortex that resemble the distribution of activated microglia within the cortex of patients with amyotrophic lateral sclerosis. Cortical thinning and signal hypointensity of the deep layers of the primary motor cortex could constitute a marker of upper motor neuron impairment in patients with amyotrophic lateral sclerosis.
authors.affiliation: From the Department of Translational Research and New Technologies in Medicine and Surgery (M.Cosottini) and Neurology Unit mircocosottini@libero.it.
authors.forename: M
authors.identifier: http://orcid.org/0000-0001-9400-6574
authors.initials: M
authors.lastname: Cosottini
authors.affiliation: Neuroradiology Unit (G.D., I.P.), Department of Diagnostic and Interventional Radiology, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy.
authors.forename: G
authors.identifier: http://orcid.org/0000-0002-5325-0746
authors.initials: G
authors.lastname: Donatelli
authors.affiliation: IMAGO7 Foundation (M.Costagli), Pisa, Italy.
authors.forename: M
authors.identifier: http://orcid.org/0000-0001-9073-1082
authors.initials: M
authors.lastname: Costagli
authors.affiliation: Department of Clinical and Experimental Medicine (E.C.I., D.F., G.S.), University of Pisa, Pisa, Italy.
authors.forename: E
authors.identifier: http://orcid.org/0000-0003-0134-5062
authors.initials: E
authors.lastname: Caldarazzo Ienco
authors.affiliation: Department of Clinical and Experimental Medicine (E.C.I., D.F., G.S.), University of Pisa, Pisa, Italy.
authors.forename: D
authors.identifier: http://orcid.org/0000-0002-4049-7424
authors.initials: D
authors.lastname: Frosini
authors.affiliation: Neuroradiology Unit (G.D., I.P.), Department of Diagnostic and Interventional Radiology, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy.
authors.forename: I
authors.identifier: http://orcid.org/0000-0002-6361-7169
authors.initials: I
authors.lastname: Pesaresi
authors.affiliation: IRCCS Stella Maris (L.B., M.T.), Pisa, Italy.
authors.forename: L
authors.identifier: http://orcid.org/0000-0003-2159-439X
authors.initials: L
authors.lastname: Biagi
authors.affiliation: Department of Clinical and Experimental Medicine (E.C.I., D.F., G.S.), University of Pisa, Pisa, Italy.
authors.forename: G
authors.identifier: http://orcid.org/0000-0001-8555-6013
authors.initials: G
authors.lastname: Siciliano
authors.affiliation: IRCCS Stella Maris (L.B., M.T.), Pisa, Italy.
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-2515-7560
authors.initials: M
authors.lastname: Tosetti
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007501:Iron / Q000032:analysis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology*; D009046:Motor Neurons / Q000473:pathology; D059906:Neuroimaging / Q000379:methods*
chemical_list: D007501:Iron