title: MR image texture in Parkinson's disease: a longitudinal study.
abstract: BACKGROUND
  Few of the structural changes caused by Parkinson's disease (PD) are visible in magnetic resonance imaging (MRI) with visual inspection but there is a need for a method capable of observing the changes beyond the human eye. Texture analysis offers a technique that enables the quantification of the image gray-level patterns.
  
  
  OBJECTIVE
  To investigate the value of quantitative image texture analysis method in diagnosis and follow-up of PD patients.
  
  
  METHODS
  Twenty-six PD patients underwent MRI at baseline and after 2 years of follow-up. Four co-occurrence matrix-based texture parameters, describing the image homogeneity and complexity, were calculated within clinically interesting areas of the brain. In addition, correlations with clinical characteristics (Unified Parkinson's Disease Ranking Scales I-III and Mini-Mental State Examination score) along with a comparison to healthy controls were evaluated.
  
  
  RESULTS
  Patients at baseline and healthy volunteers differed in their brain MR image textures mostly in the areas of substantia nigra pars compacta, dentate nucleus, and basilar pons. During the 2-year follow-up of the patients, textural differences appeared mainly in thalamus and corona radiata. Texture parameters in all the above mentioned areas were also found to be significantly related to clinical scores describing the severity of PD.
  
  
  CONCLUSIONS
  Texture analysis offers a quantitative method for detecting structural changes in brain MR images. However, the protocol and repeatability of the method must be enhanced before possible clinical use.
authors.affiliation: Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland minna.sikio@tut.fi.
authors.forename: Minna
authors.initials: M
authors.lastname: Sikiö
authors.affiliation: Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland.
authors.forename: Kirsi K
authors.initials: KK
authors.lastname: Holli-Helenius
authors.affiliation: Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland Department of Anaesthesia, Tampere University Hospital, Tampere, Finland.
authors.forename: Lara C V
authors.initials: LC
authors.lastname: Harrison
authors.affiliation: Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland.
authors.forename: Pertti
authors.initials: P
authors.lastname: Ryymin
authors.affiliation: Tampere Medical School, University of Tampere, Tampere, Finland Department of Neurology and Rehabilitation, Tampere University Hospital, Tampere, Finland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Ruottinen
authors.affiliation: Department of Neurology and Rehabilitation, Tampere University Hospital, Tampere, Finland.
authors.forename: Tiia
authors.initials: T
authors.lastname: Saunamäki
authors.affiliation: Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland.
authors.forename: Hannu J
authors.initials: HJ
authors.lastname: Eskola
authors.affiliation: Tampere Medical School, University of Tampere, Tampere, Finland Department of Neurology and Rehabilitation, Tampere University Hospital, Tampere, Finland.
authors.forename: Irina
authors.initials: I
authors.lastname: Elovaara
authors.affiliation: Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland Tampere Medical School, University of Tampere, Tampere, Finland.
authors.forename: Prasun
authors.initials: P
authors.lastname: Dastidar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Parkinson’s disease; follow-up; image analysis; magnetic resonance imaging (MRI); texture analysis