Anatomically standardised 99m Tc-ECD brain perfusion SPET allows accurate differentiation between healthy volunteers, multiple system atrophy and idiopathic Parkinson's disease

Abstract

The clinical differentiation between typical idiopathic Parkinson's disease (IPD) and atypical parkinsonian disorders such as multiple system atrophy (MSA) is complicated by the presence of signs and symptoms common to both forms. The goal of this study was to re-evaluate the contribution of brain perfusion single-photon emission tomography (SPET) with anatomical standardisation and automated analysis in the differentiation of IPD and MSA. This was achieved by discriminant analysis in comparison with a large set of age- and gender-matched healthy volunteers. Technetium-99m ethyl cysteinate dimer SPET was performed on 140 subjects: 81 IPD patients (age 62.6+/-10.2 years; disease duration 11.0+/-6.4 years; 50 males/31 females), 15 MSA patients (61.5+/-9.2 years; disease duration 3.0+/-2.2 years; 9 males/6 females) and 44 age- and gender-matched healthy volunteers (age 59.2+/-11.9 years; 27 males/17 females). Patients were matched for severity (Hoehn and Yahr stage). Automated predefined volume of interest (VOI) analysis was carried out after anatomical standardisation. Stepwise discriminant analysis with cross-validation using the leave-one-out method was used to determine the subgroup of variables giving the highest accuracy for this differential diagnosis. Between MSA and IPD, the only regions with highly significant differences in uptake after Bonferroni correction were the putamen VOIs. Comparing MSA versus normals and IPD, with putamen VOI values as discriminating variables, cross-validated performance showed correct classification of MSA patients with a sensitivity of 73.3%, a specificity of 84% and an accuracy of 83.6%. Additional input from the right caudate head and the left prefrontal and left mesial temporal cortex allowed 100% discrimination even after cross-validation. Discrimination between the IPD group alone and healthy volunteers was accurate in 94% of the cases after cross-validation, with a sensitivity of 91.4% and a specificity of 100%. The three-group classification (MSA, IPD and healthy volunteers) resulted in an overall accuracy of 86% post hoc, with 98% of normals, 78% of IPD and 93% of MSA correctly classified. These values were slightly lower after cross-validation: 96% for healthy volunteers, 77% for IPD and 67% for MSA. In conclusion, using age- and gender-matched healthy volunteer data and anatomical standardisation, it is possible to differentiate between IPD and MSA with high discriminating power in clinically relevant circumstances.

Combined Striatal Binding and Cerebral Influx Analysis of Dynamic 11C-Raclopride PET Improves Early Differentiation Between Multiple-System Atrophy and Parkinson Disease

“…To our knowledge, there is no existing study that has directly compared these influx values with regional perfusion imaging for 11 C-raclopride. However, the regional pattern of significant changes in 11 C-raclopride R 1 closely matched that observed in other perfusion studies and implies striatum, pons, and cerebellum as the most significant discriminators between MSA and PD (22,28). Finally, the number of patients in our study was relatively small.…”

Recent developments in multiple system atrophy

“…Finally, brain perfusion SPECT shows striatal hypoperfusion in MSA-P that distinguishes this disorder from PD [20,36,105,183]. Perfusion SPECT, when coupled with classic MRI, shows high sensitivity and specificity in differentiating MSA from PD [36].…”

Quantitative Analysis in Functional Brain Imaging

“…72 Metabolic or perfusion brain imaging is useful in the differential diagnosis of extrapyramidal disorders due to the application of anatomical standard-ization. 166,167 Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are neurodegenerative disorders that may be accompanied by dementia and Parkinsonism as clinical symptoms. Measurement of glucose metabolism by PET and a voxel-based analysis is useful to understand the pathophysiology and differentiate IPD and corticobasal degeneration with cognitive impairments.…”