title: A Comparison of Substantia Nigra T1 Hyperintensity in Parkinson's Disease Dementia, Alzheimer's Disease and Age-Matched Controls: Volumetric Analysis of Neuromelanin Imaging.
abstract: Neuromelanin loss of substantia nigra (SN) can be visualized as a T1 signal reduction on T1-weighted high-resolution imaging. We investigated whether volumetric analysis of T1 hyperintensity for SN could be used to differentiate between Parkinson's disease dementia (PDD), Alzheimer's disease (AD) and age-matched controls.
  
  
  
  This retrospective study enrolled 10 patients with PDD, 18 patients with AD, and 13 age-matched healthy elderly controls. MR imaging was performed at 3 tesla. To measure the T1 hyperintense area of SN, we obtained an axial thin section high-resolution T1-weighted fast spin echo sequence. The volumes of interest for the T1 hyperintense SN were drawn onto heavily T1-weighted FSE sequences through midbrain level, using the MIPAV software. The measurement differences were tested using the Kruskal-Wallis test followed by a post hoc comparison.
  
  
  
  A comparison of the three groups showed significant differences in terms of volume of T1 hyperintensity (p < 0.001, Bonferroni corrected). The volume of T1 hyperintensity was significantly lower in PDD than in AD and normal controls (p < 0.005, Bonferroni corrected). However, the volume of T1 hyperintensity was not different between AD and normal controls (p = 0.136, Bonferroni corrected).
  
  
  
  The volumetric measurement of the T1 hyperintensity of SN can be an imaging marker for evaluating neuromelanin loss in neurodegenerative diseases and a differential in PDD and AD cases.
authors: Department of Radiology, Konkuk University School of Medicine, Seoul 05030, Korea.
authors: Won-Jin
authors: WJ
authors: Moon
authors: Department of Radiology, Konkuk University School of Medicine, Seoul 05030, Korea.
authors: Ju-Yeon
authors: JY
authors: Park
authors: Department of Radiology, Konkuk University School of Medicine, Seoul 05030, Korea.
authors: Won-Sung
authors: WS
authors: Yun
authors: Department of Radiology, Konkuk University School of Medicine, Seoul 05030, Korea.; Department of Radiology, Asan Medical Center, Seoul 05505, Korea.
authors: Ji Yeong
authors: JY
authors: Jeon
authors: Department of Neurology, Konkuk University School of Medicine, Seoul 05030, Korea.
authors: Yeon Sil
authors: YS
authors: Moon
authors: Department of Neurology, Konkuk University School of Medicine, Seoul 05030, Korea.
authors: Heejin
authors: H
authors: Kim
authors: Department of Biomedical Engineering, Hanyang University, Seoul 04763, Korea.
authors: Ki-Chang
authors: KC
authors: Kwak
authors: Department of Biomedical Engineering, Hanyang University, Seoul 04763, Korea.
authors: Jong-Min
authors: JM
authors: Lee
authors: Department of Neurology, Konkuk University School of Medicine, Seoul 05030, Korea.
authors: Seol-Heui
authors: SH
authors: Han
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging; D015415:Biomarkers / Q000378:metabolism; D003704:Dementia / Q000000981:diagnostic imaging* / Q000209:etiology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008543:Melanins / Q000378:metabolism*; D008875:Middle Aged; D015588:Observer Variation; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000523:psychology; D012189:Retrospective Studies; D012984:Software; D013378:Substantia Nigra / Q000000981:diagnostic imaging* / Q000378:metabolism
chemical_list: D015415:Biomarkers; D008543:Melanins; C014121:neuromelanin
keywords: Alzheimer disease; Dementia; High-resolution T1-weighted imaging; Magnetic resonance; Neuromelanin; Parkinsonian disorders; Substantia nigra