title: Diagnostic imaging of dementia with Lewy bodies by susceptibility-weighted imaging of nigrosomes versus striatal dopamine transporter single-photon emission computed tomography: a retrospective observational study.
abstract: BACKGROUND
  The characteristics of dementia with Lewy bodies (DLB), Alzheimer's disease (AD) and amnestic mild cognitive impairment (a-MCI) overlap but require different treatments; therefore, it is important to differentiate these pathologies. Assessment of dopamine uptake in the striatum using dopamine transporter (DaT) single-photon emission computed tomography (SPECT) is the gold standard for diagnosing DLB; however, this modality is expensive, time consuming and involves radiation exposure. Degeneration of the substantia nigra nigrosome-1, which occurs in DLB, but not in AD/a-MCI, can be identified by 3T susceptibility-weighted imaging (SWI). Therefore, the aim of this retrospective observational study was to compare SWI with DaT-SPECT for differentiation of DLB from AD/a-MCI.
  
  
  METHODS
  SWI data were acquired for patients with clinically diagnosed DLB (n = 29), AD (n = 18), a-MCI (n = 13) and healthy controls (n = 26). Images were analysed for nigrosome-1 degeneration. Diagnostic accuracy was evaluated for DLB, AD and a-MCI compared with striatal dopamine uptake using DaT-SPECT.
  
  
  RESULTS
  SWI achieved 90% diagnostic accuracy (93% sensitivity, 87% specificity) for the detection of nigrosome-1 degeneration in DLB and not in AD/a-MCI as compared with 88.3% accuracy (93% sensitivity, 84% specificity) using DaT-SPECT.
  
  
  CONCLUSIONS
  SWI nigrosome-1 evaluation was useful in differentiating DLB from AD/a-MCI, with high accuracy. This less invasive and less expensive method is a potential alternative to DaT-SPECT for the diagnosis of DLB.
authors.affiliation: Department of Radiology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan. kkamagat@juntendo.ac.jp.
authors.forename: Koji
authors.identifier: http://orcid.org/0000-0001-5028-218X
authors.initials: K
authors.lastname: Kamagata
authors.affiliation: Department of Radiology, Toho University Sakura Medical Center, 564-1 Shimoshizu, Sakura, Sakura, 285-8741, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Nakatsuka
authors.affiliation: Department of Neurology, Toho University Sakura Medical Center, 564-1 Shimoshizu, Sakura, Sakura, 285-8741, Japan.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Sakakibara
authors.affiliation: Department of Neurology, Toho University Sakura Medical Center, 564-1 Shimoshizu, Sakura, Sakura, 285-8741, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Tsuyusaki
authors.affiliation: Department of Radiology, University of Yamanashi, 1111 Shimokato, Chuo-shi, Yamanashi, 409-3898, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Takamura
authors.affiliation: Department of Radiology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Radiology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
authors.forename: Michimasa
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Radiology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hori
authors.affiliation: Department of Radiology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
authors.forename: Kanako K
authors.initials: KK
authors.lastname: Kumamaru
authors.affiliation: Department of Radiology, Toho University Sakura Medical Center, 564-1 Shimoshizu, Sakura, Sakura, 285-8741, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Inaoka
authors.affiliation: Department of Radiology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Aoki
authors.affiliation: Department of Radiology, Toho University Sakura Medical Center, 564-1 Shimoshizu, Sakura, Sakura, 285-8741, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Terada
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013378:Substantia Nigra / Q000000981:diagnostic imaging* / Q000473:pathology*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
keywords: Alzheimer’s disease; Dementia; Dopamine; Lewy bodies; Parkinson disease