title: Discriminating among degenerative parkinsonisms using advanced (123)I-ioflupane SPECT analyses.
abstract: (123)I-ioflupane single photon emission computed tomography (SPECT) is a sensitive and well established imaging tool in Parkinson's disease (PD) and atypical parkinsonian syndromes (APS), yet a discrimination between PD and APS has been considered inconsistent at least based on visual inspection or simple region of interest analyses. We here reappraise this issue by applying advanced image analysis techniques to separate PD from the various APS. This study included 392 consecutive patients with degenerative parkinsonism undergoing (123)I-ioflupane SPECT at our institution over the last decade: 306 PD, 24 multiple system atrophy (MSA), 32 progressive supranuclear palsy (PSP) and 30 corticobasal degeneration (CBD) patients. Data analysis included voxel-wise univariate statistical parametric mapping and multivariate pattern recognition using linear discriminant classifiers. MSA and PSP showed less ioflupane uptake in the head of caudate nucleus relative to PD and CBD, yet there was no difference between MSA and PSP. CBD had higher uptake in both putamen relative to PD, MSA and PSP. Classification was significant for PD versus APS (AUC 0.69, p < 0.05) and between APS subtypes (MSA vs CBD AUC 0.80, p < 0.05; MSA vs PSP AUC 0.69 p < 0.05; CBD vs PSP AUC 0.69 p < 0.05). Both striatal and extra-striatal regions contain classification information, yet the combination of both regions does not significantly improve classification accuracy. PD, MSA, PSP and CBD have distinct patterns of dopaminergic depletion on (123)I-ioflupane SPECT. The high specificity of 84-90% for PD versus APS indicates that the classifier is particularly useful for confirming APS cases.
authors.affiliation: Neurology Division, Department of Clinical Neurosciences (NEUCLI), Geneva University Hospitals, Switzerland; Neurophysiology Unit, Department of Medicine, University of Fribourg (CH), Switzerland; Faculty of Medicine, University of Geneva, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Badoud
authors.affiliation: Department of Imaging and Medical Informatics, University Hospitals of Geneva, Faculty of Medicine, University of Geneva, Switzerland; Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Switzerland.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Van De Ville
authors.affiliation: Neurology Division, Department of Clinical Neurosciences (NEUCLI), Geneva University Hospitals, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Nicastro
authors.affiliation: Faculty of Medicine, University of Geneva, Switzerland; Nuclear Medicine and Molecular Imaging Division, Department of Imaging and Medical Informatics, University Hospitals of Geneva, Switzerland.
authors.forename: Valentina
authors.initials: V
authors.lastname: Garibotto
authors.affiliation: Neurology Division, Department of Clinical Neurosciences (NEUCLI), Geneva University Hospitals, Switzerland; Faculty of Medicine, University of Geneva, Switzerland.
authors.forename: Pierre R
authors.initials: PR
authors.lastname: Burkhard
authors.affiliation: Faculty of Medicine, University of Geneva, Switzerland; Affidea Centre de Diagnostic Radiologique de Carouge CDRC, Geneva, Switzerland; Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden; Department of Neuroradiology, University Hospital Freiburg, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Haller
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D004298:Dopamine / Q000378:metabolism; D059290:Dopaminergic Neurons / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009662:Nortropanes; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D007457:Iodine Radioisotopes; D009662:Nortropanes; C519528:ioflupane; D004298:Dopamine
keywords: APS, atypical parkinsonian syndromes; Atypical parkinsonism; CBD, corticobasal degeneration; MSA, multiple system atrophy; MVPA, Multi Voxel Pattern Analysis; Multi vector pattern analysis (MVPA); PD, Parkinson's disease; PSP, progressive supranuclear palsy; Parkinson's disease; ROI, region of interest; SPECT, single photon emission computed tomography; SVM, support vector machines; Single photon emission computed tomography (SPECT)