MRI supervised and unsupervised classification of Parkinson's disease and multiple system atrophy

Abstract

This study demonstrates that multimodal MRI is able to discriminate patients with PD from those with MSA with high accuracy. The combination of different MR biomarkers could be a great tool in early stage of disease to help diagnosis. © 2018 International Parkinson and Movement Disorder Society.

Morphometric MRI profiles of multiple system atrophy variants and implications for differential diagnosis

“…By applying a support vector machine to classify regional volumetric MRI data, a multicenter study achieved sensitivity ranging from 79% to 87% and specificity from 87% to 96% for the diagnosis of PD, PSP, and MSA (combining MSA‐P and MSA‐C into 1 group) . Another approach used mean values of gray‐mater density, diffusion tensor, and r2* signal within voxel‐clusters obtained from previous group analysis of patients with PD and MSA (including patients with MSA‐P and MSA‐C) and reported >95% discrimination accuracy of fractional anisotropy clusters of the cerebellum, brain stem, and white‐matter bilateral superior corona radiate combined with another mean diffusivity cluster of the right superior frontal gyrus . In the present study, monomodal volumetric measurements were harmonized by z transformation to rank affected brain areas according to their volume loss in individual patients.…”

“…16 Another approach used mean values of gray-mater density, diffusion tensor, and r2* signal within voxel-clusters obtained from previous group analysis of patients with PD and MSA (including patients with MSA-P and MSA-C) and reported >95% discrimination accuracy of fractional anisotropy clusters of the cerebellum, brain stem, and white-matter bilateral superior corona radiate combined with another mean diffusivity cluster of the right superior frontal gyrus. 15 In the present study, monomodal volumetric measurements were harmonized by z transformation to rank affected brain areas according to their volume loss in individual patients. Furthermore, in an attempt to avoid the inclusion of volumes from brain areas within the normal range into the diagnostic algorithm, only measurements that showed a reduction of more than 2 standard deviations from the mean of the healthy control sample were considered.…”

“…So far, diagnostic imaging studies in MSA have focused on the validation of either 2‐dimensional distance measures, calculation of indices, or whole‐brain voxel‐based analysis to identify disease characteristic patterns of atrophy . Although such approaches have the potential to reveal disease‐related signal alterations, efforts to rank patterns of atrophy by their severity at the single‐subject level and hence disentangle the dimensions’ “signal distribution” and “signal quantity” are sparse . Advances in MRI postprocessing algorithms including automated compartmentalization of the brain into multiple anatomic regions, volume calculation, and z transformation have provided an opportunity to localize and grade disease‐specific brain atrophy patterns in relation to age‐ and sex‐matched healthy control cohorts .…”

“…13,14 Although such approaches have the potential to reveal disease-related signal alterations, efforts to rank patterns of atrophy by their severity at the single-subject level and hence disentangle the dimensions' "signal distribution" and "signal quantity" are sparse. 15,16 Advances in MRI postprocessing algorithms including automated compartmentalization of the brain into multiple anatomic regions, volume calculation, and z transformation have provided an opportunity to localize and grade disease-specific brain atrophy patterns in relation to age-and sex-matched healthy control cohorts. 17,18 Recently, such an approach was shown to reliably differentiate progressive supranuclear palsy Richardson type and MSA-P from Parkinson's disease.…”

Catechol neurochemistry in the autonomic clinic: helpful but not absolutely required

“…Is this run-of-the-mill Parkinson disease (PD), dementia with Lewy bodies (DLB), or multiple system atrophy (MSA)? This question can sometimes be answered with the help of neuroimaging [6], cardiac metaiodobenzylguanidine scintigraphy [8], or autonomic reflex screen and thermoregulatory sweat test [5] data, but these diagnostic tools are not always available or the results revealing. Enter plasma catechol testing.…”