title: Differential diagnosis of parkinsonism: a metabolic imaging study using pattern analysis.
abstract: BACKGROUND
  Idiopathic Parkinson's disease can present with symptoms similar to those of multiple system atrophy or progressive supranuclear palsy. We aimed to assess whether metabolic brain imaging combined with spatial covariance analysis could accurately discriminate patients with parkinsonism who had different underlying disorders.
  
  
  METHODS
  Between January, 1998, and December, 2006, patients from the New York area who had parkinsonian features but uncertain clinical diagnosis had fluorine-18-labelled-fluorodeoxyglucose-PET at The Feinstein Institute for Medical Research. We developed an automated image-based classification procedure to differentiate individual patients with idiopathic Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy. For each patient, the likelihood of having each of the three diseases was calculated by use of multiple disease-related patterns with logistic regression and leave-one-out cross-validation. Each patient was classified according to criteria defined by receiver-operating-characteristic analysis. After imaging, patients were assessed by blinded movement disorders specialists for a mean of 2.6 years before a final clinical diagnosis was made. The accuracy of the initial image-based classification was assessed by comparison with the final clinical diagnosis.
  
  
  RESULTS
  167 patients were assessed. Image-based classification for idiopathic Parkinson's disease had 84% sensitivity, 97% specificity, 98% positive predictive value (PPV), and 82% negative predictive value (NPV). Imaging classifications were also accurate for multiple system atrophy (85% sensitivity, 96% specificity, 97% PPV, and 83% NPV) and progressive supranuclear palsy (88% sensitivity, 94% specificity, 91% PPV, and 92% NPV).
  
  
  CONCLUSIONS
  Automated image-based classification has high specificity in distinguishing between parkinsonian disorders and could help in selecting treatment for early-stage patients and identifying participants for clinical trials.
  
  
  BACKGROUND
  National Institutes of Health and General Clinical Research Center at The Feinstein Institute for Medical Research.
authors.affiliation: Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: Chris C
authors.initials: CC
authors.lastname: Tang
authors.forename: Kathleen L
authors.initials: KL
authors.lastname: Poston
authors.forename: Thomas
authors.initials: T
authors.lastname: Eckert
authors.forename: Andrew
authors.initials: A
authors.lastname: Feigin
authors.forename: Steven
authors.initials: S
authors.lastname: Frucht
authors.forename: Mark
authors.initials: M
authors.lastname: Gudesblatt
authors.forename: Vijay
authors.initials: V
authors.lastname: Dhawan
authors.forename: Martin
authors.initials: M
authors.lastname: Lesser
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Vonsattel
authors.forename: Stanley
authors.initials: S
authors.lastname: Fahn
authors.forename: David
authors.initials: D
authors.lastname: Eidelberg
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism; D001931:Brain Mapping; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000145:classification / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D010363:Pattern Recognition, Automated / Q000379:methods; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D019275:Radiopharmaceuticals / Q000378:metabolism; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18