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Quantifying the degree of atrophy is done clinically by neuroradiologists following established visual rating scales. For these assessments to be reliable the rater requires substantial training and experience, and even then the rating agreement between two radiologists is not perfect. We have developed a model we call AVRA (Automatic Visual Ratings of Atrophy) based on machine learning methods and trained on 2350 visual ratings made by an experienced neuroradiologist. It provides fast and automatic ratings for Scheltens' scale of medial temporal atrophy (MTA), the frontal subscale of Pasquier's Global Cortical Atrophy (GCA-F) scale, and Koedam's scale of Posterior Atrophy (PA). We demonstrate substantial inter-rater agreement between AVRA's and a neuroradiologist ratings with Cohen's weighted kappa values of kappa(w) = 0.74/0.72 (MTA left/right), kappa(w) = 0.62 (GCA-F) and kappa(w) = 0.74 (PA). We conclude that automatic visual ratings of atrophy can potentially have great scientific value, and aim to present AVRA as a freely available toolbox., QC 20191004

BACKGROUND/AIMS: Dementia biomarkers that are accessible and easily applicable in nonspecialized clinical settings are urgently needed. Quantitative electroencephalography (qEEG) is a good candidate, and the statistical pattern recognition (SPR) method has recently provided promising results. We tested the diagnostic value of qEEG-SPR in comparison to cognition, structural imaging, and cerebrospinal fluid (CSF) biomarkers.METHODS: A total of 511 individuals were recruited from the multicenter NORD EEG study [141 healthy controls, 64 subjective cognitive decline, 124 mild cognitive impairment, 135 Alzheimer's disease (AD), 15 dementia with Lewy bodies/Parkinson's disease with dementia (DLB/PDD), 32 other dementias]. The EEG data were recorded in a standardized way. Structural imaging data were visually rated using scales of atrophy in the medial temporal, frontal, and posterior cortex.RESULTS: qEEG-SPR outperformed structural imaging, cognition, and CSF biomarkers in DLB/PDD diagnosis, outperformed structural imaging in AD diagnosis, and improved the differential diagnosis of AD. In addition, qEEG-SPR allowed differentiation of two clinically different AD subtypes.CONCLUSION: Adding qEEG to the diagnostic workup substantially increases the detection of AD pathology even in pre-dementia stages and improves differential diagnosis. EEG could serve as a good complement to currently established dementia biomarkers since it is cheap, noninvasive, and extensively applied outside academic centers.

BACKGROUND: Atrophy in the medial temporal lobe, frontal lobe and posterior cortex can be measured with visual rating scales such as the medial temporal atrophy (MTA), global cortical atrophy - frontal subscale (GCA-F) and posterior atrophy (PA) scales, respectively. However, practical cut-offs are urgently needed, especially now that different presentations of Alzheimer's disease (AD) are included in the revised diagnostic criteria. AIMS: The aim of this study was to generate a list of practical cut-offs for the MTA, GCA-F and PA scales, both for diagnosis of AD and determining prognosis in mild cognitive impairment (MCI), and to evaluate the influence of key demographic and clinical factors on these cut-offs. METHODS: AddNeuroMed and ADNI cohorts were combined giving a total of 1147 participants (322 AD patients, 480 MCI patients and 345 control subjects). The MTA, GCA-F and PA scales were applied and a broad range of cut-offs was evaluated. RESULTS: The MTA scale showed better diagnostic and predictive performances than the GCA-F and PA scales. Age, apolipoprotein E (ApoE) ε4 status and age at disease onset influenced all three scales. For the age ranges 45-64, 65-74, 75-84 and 85-94 years, the following cut-offs should be used. MTA: ≥1.5, ≥1.5, ≥2 and ≥2.5; GCA-F, ≥1, ≥1, ≥1 and ≥1; and PA, ≥1, ≥1, ≥1 and ≥1, respectively, with an adjustment for early-onset ApoE ε4 non-carrier AD patients (MTA: ≥2, ≥2, ≥3 and ≥3; and GCA-F: ≥1, ≥1, ≥2 and ≥2, respectively). CONCLUSIONS: If successfully validated in clinical settings, the list of practical cut-offs proposed here might be useful in clinical practice. Their use might also (i) promote research on atrophy subtypes, (ii) increase the understanding of different presentations of AD, (iii) improve diagnosis and prognosis and (iv) aid population selection and enrichment for clinical trials. This article is protected by copyright. All rights reserved.

Ökad kunskap om demenssjukdomar leder till att de diagnostiska kriterierna förändras. Diagnostiken kan förbättras med hjälp av hjärnavbildningsfynd. Med datortomografi (DT) och magnetisk resonanstomografi (MRT) kan medial temporallobsatrofi, global cerebral atrofi och förändringar i vit substans visualiseras och kvantifieras. För att ge optimal information om dessa förändringar krävs ett strukturerat radiologiskt DT-/MR-utlåtande. Imaging Cognitive Impairment Network (ICINET) har som huvudmål att föreslå ett standardiserat MRT-protokoll och kliniska utvärderingsverktyg (visuella skattningsskalor för MRT och DT)., New guidelines on care in dementia from the Swedish National Board of Health and Welfare emphasize that brain imaging should be included in the standard diagnostic evaluation. Evidence supports the importance of regional/global atrophy and white matter changes in dementia. However, the use of imaging in dementia evaluation is often sub-optimal, urging optimization of clinical imaging practice. Imaging Cognitive Impairment Network (ICINET) is a network between some of the largest Swedish and Norwegian university hospitals. The network’s aims are to standardize the radiological evaluation and reporting of structural MRI/CT and to propose a suitable MRI protocol, which has the potential to be harmonized across sites. The importance of efficient clinical imaging practice in dementia will continue to increase with increasing numbers of dementia investigations. To maximize the gain from clinical imaging assessments, an optimized MRI/CT protocol and a structured radiological assessment and report are required.

Background: Medial temporal lobe atrophy (MTA) has been found to be an early sign of Alzheimer’s disease (AD). Visual assessment of MTA (vaMTA) is a rapid, cost-efficient and clinically adaptable visual interpretation method for rating MTA, based on coronal magnetic resonance imaging (MRI) scans. The method was developed by Scheltens et al in the 1990s. Purpose: The aim of this thesis was to investigate the reliability of vaMTA using the Scheltens rating scale: on a long-term basis, compared with volumetric calculation, compared with multivariate analyses and, finally, tested in a clinical situation. In Study I, MRI scans of 100 patients were visually assessed six times over a 1-year period. Two radiologists, with different backgrounds, performed the assessments independently of each other. The results showed a high degree of reproducibility when performed by an experienced investigator. The reproducibility drops when assessment is rarely performed. Study II was a comparison between vaMTA and measurement of hippocampal volume in 544 non-demented elderly individuals from the SwedishNational Study of Ageing and Care in Kungsholmen (SNAC-K). A significant correlation was found between the two methods. Cut-off values for MTA scores in normal ageing were also suggested. In Study III the reliability of Scheltens’ visual assessment rating scale for assessing MTA was compared with that of a multivariate MRI classification method, orthogonal projections to latent structures (OPLS), and manually measured hippocampal volumes to distinguish between subjects with AD and healthy elderly controls (CTL). A comparison between the different techniques was also performed in predicting future developments from mild cognitive impairment (MCI) to AD. The prediction accuracies in distinguishing between AD patients and CTL were high for all three modalities. All three methods were also highly accurate in identifying subjects who converted from MCI to AD at 1-year follow-up. Finally, in Stu

Background It is important to have a replicable easy method for monitoring atrophy progression in Alzheimer's disease. Volumetric methods for calculating hippocampal volume are time-consuming and commonly used in research. Visual assessments of medial temporal lobe atrophy (vaMTA) is a rapid method for clinical use. This method has not been tested in a large non-demented population in comparison with volumetry mesurements. Since hippocampal volume decreases with time even in normal aging there is also a need to study the normal age differences of medial temporal lobe atrophy. Purpose To compare visual assessment of medial temporal lobe atrophy (vaMTA) with hippocampal volume in a healthy, non-demented elderly population. To describe normal ageing using vaMTA. Material and Methods Non-demented individuals aged 60, 66, 72, 78, 81, 84, and ≥87 years old were recruited from the Swedish National study on Ageing and Care in Kungsholmen (SNAC-K), Sweden. Standard magnetic resonance imaging (MRI) scans, vaMTA, and calculations of hippocampal volumes were performed in 544 subjects. Results Significant correlation (rs = −0.32, P < 0.001, sin; and rs = −0.26, P < 0.001, dx) was found between hippocampal volume measurements and vaMTA. In normal ageing, almost 95% of ≤66-year-olds had a medial temporal lobe atrophy (MTA) score ≤1, with possible scores ranging from 0 to 4. Subjects aged 72, 78, and 81 years scored ≤2, while the two oldest age groups had scores ≤3. Conclusion There was a highly significant correlation between volumetric measurements of the hippocampus and MTA scoring. In normal ageing, there is increasing MTA score. For non-demented elderly individuals ≤70 years, an MTA score of 0–1 may be considered normal, compared with MTA ≤2 for 70–80-years and MTA 3 for >80-year-old individuals.