Detecting Primary Progressive Aphasia Atrophy Patterns: A Comparison of Visual Assessment and Quantitative...

There are now clinically available automated MRI analysis software programs that compare brain volumes of patients to a normative sample and provide z-score data for various brain regions. These programs have yet to be validated in primary progressive aphasia (PPA).

To address this gap in the literature, we examined Neuroreader^™ z-scores in PPA, relative to visual MRI assessment. We predicted that Neuroreader^™ 1) would be more sensitive for detecting left > right atrophy in the cortical lobar regions in logopenic variant PPA clinical phenotype (lvPPA), and 2) would distinguish lvPPA (n = 11) from amnestic mild cognitive impairment (aMCI; n = 12).

lvPPA or aMCI patients who underwent MRI with Neuroreader^™ were included in this study. Two neuroradiologists rated 10 regions. Neuroreader^™ lobar z-scores for those 10 regions, as well as a hippocampal asymmetry metric, were included in analyses.

Cohen's Kappa coefficients were significant in 10 of the 28 computations (k = 0.351 to 0.593, p≤0.029). Neuroradiologists agreed 0% of the time that left asymmetry was present across regions. No significant differences emerged between aMCI and lvPPA in Neuroreader^™ z-scores across left or right frontal, temporal, or parietal regions (ps > 0.10). There were significantly lower z-scores in the left compared to right for the hippocampus, as well as parietal, occipital, and temporal cortices in lvPPA.

Overall, our results indicated moderate to low interrater reliability, and raters never agreed that left asymmetry was present. While lower z-scores in the left hemisphere regions emerged in lvPPA, Neuroreader^™ failed to differentiate lvPPA from aMCI.