The utility of quantitative MRI parameters in discriminating progressive supranuclear palsy from Parkinson’s disease

Abstract

ABSTRACT Objective We sought tore-evaluate the utility of all the quantitative neuroimaging parametersattributed to progressive supranuclear palsy (PSP) in discrimination betweenPSP and Parkinson’ s disease (PD) subjects in our cohort. We aimed to proposesome practical clinical remarks in this field. Methods In our retrospective study, 19 patients with‘probable’ PSP and 37 patients with PD were enrolled. The radiological measurements of PSP, describedin the previous reports, have been calculated in all subjects. The comparisonsbetween the groups were performed and the measures regarding the accuracy ofthese parameters in the differentiation of PSP from PD subjects were analyzed. Results We found that the values of magnetic resonance parkinsonism index-2 (MRPI-2), pontine-to-midbrain area (P/M) ratio, P/M 2 ratio, and 3rdV/bifrontal width ratio had high AUC values and very good discriminative powers. The analyses revealed that; for the discrimination of PSP from PD subjects, a 3rdvent/bifrontal width cut-off value of 0.30 had 42.1 % sensitivity and 97.3 % specificity; a P/M cut-off value of 6.03 had a 52.6 % sensitivity and 97.3 % specificity; and an MRPI-2 cut-off value of 7.43 had 57.9 % sensitivity and 97.3 % specificity. Remarkably, we also found that the presence of high values for both P/M and 3rdV/bifrontal ventricle rate had a positive predictive value of 100% for the diagnosis of PSP. Conclusion Our study results support the utility of previously defined neuroimaging parameters in distinguishing PSP and PD subjects. Besides, combined use of a high P/M ratio and 3rdV/bifrontal width may be practical and present strictly high evidence for the diagnosis of PSP.