title: Detection of changes in the locus coeruleus in patients with mild cognitive impairment and Alzheimer's disease: high-resolution fast spin-echo T1-weighted imaging.
abstract: OBJECTIVE
  Neuronal degeneration in the locus coeruleus occurs in the early phase of Alzheimer's disease, similar to mild cognitive impairment. The locus coeruleus produces norepinephrine, a deficiency of which causes both memory disturbance and psychological symptoms. Thus, we evaluated signal alterations in the locus coeruleus of patients with Alzheimer's disease and mild cognitive impairment using a high-resolution fast spin-echo T1-weighted imaging.
  
  
  METHODS
  A total of 22 patients with Alzheimer's disease, 47 patients with mild cognitive impairment and 26 healthy controls were prospectively examined by high-resolution fast spin-echo T1-weighted imaging at 3 Tesla. Signal intensities in the locus coeruleus were manually measured and expressed relative to those in the adjacent white matter structures as contrast ratios.
  
  
  RESULTS
  Locus coeruleus contrast ratios were significantly reduced in patient groups with Alzheimer's disease, mild cognitive impairment that converted to Alzheimer's disease and mild cognitive impairment that did not convert to Alzheimer's disease (1.80-16.09% [median, 9.30%], 3.45-14.84% [median 6.87%] and 3.01-19.19% [median 7.72%], respectively) compared with the healthy control group (6.24-20.94% [median 14.35%]; P < 0.0001). The sensitivity and specificity for discriminating these diseases were 85.0% and 69.2%, respectively, which suggests that this measurement can be carried out reliably. There was no significant difference in the locus coeruleus contrast ratios among the Alzheimer's disease, mild cognitive impairment-converted and mild cognitive impairment-non-converted groups.
  
  
  CONCLUSIONS
  High-resolution fast spin-echo T1-weighted imaging can show signal attenuation in the locus coeruleus of patients with Alzheimer's disease or with mild cognitive impairment whose pathology may or may not eventually convert to Alzheimer's disease.
authors.affiliation: Department of Neurology and Gerontology, School of Medicine, Iwate Medical University, Morioka, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Takahashi
authors.forename: Toshihide
authors.initials: T
authors.lastname: Shibata
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.forename: Masako
authors.initials: M
authors.lastname: Kudo
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yanezawa
authors.forename: Satoko
authors.initials: S
authors.lastname: Obara
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Kudo
authors.forename: Kenji
authors.initials: K
authors.lastname: Ito
authors.forename: Fumio
authors.initials: F
authors.lastname: Yamashita
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terayama
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000175:diagnosis / Q000523:psychology; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology; D018450:Disease Progression; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008125:Locus Coeruleus / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D013997:Time Factors
keywords: Alzheimer's disease; locus coeruleus; magnetic resonance imaging; mild cognitive impairment; neuromelanin