Lesion Explorer: A Video-guided, Standardized Protocol for Accurate and Reliable MRI-derived Volumetrics in Alzheimer's Disease and Normal Elderly

Obtaining in vivo human brain tissue volumetrics from MRI is often complicated by various technical and biological issues. These challenges are ...

Sunnybrook Health Sciences Centre

&#xC778;&#xC9C0; &#xC7A5;&#xC560;&#xB294; &#xB2E4; &#xBC1C;&#xC131; &#xACBD;&#xD654; &#xC99D; (MS) &#xD658;&#xC790;&#xC5D0;&#xC11C; &#xC9C8;&#xBCD1;&#xC758; &#xBD80;&#xB2F4;&#xC73C;&#xB85C; &#xCD94;&#xAC00;&#xD560; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. &#xC774; &#xC5F0;&#xAD6C;&#xC758; &#xBAA9;&#xD45C;&#xB294; &#xD655;&#xC0B0; &#xD150;&#xC11C; &#xC601;&#xC0C1; (DTI) &#xC778;&#xB371;&#xC2A4; &#xC815;&#xC0C1; &#xB098;&#xD0C0;&#xB098;&#xB294; &#xBC31;&#xC0C9; &#xC9C8; (NAWM) &#xBC0F; MS &#xD658;&#xC790;&#xC5D0;&#xC11C; &#xC778;&#xC9C0; &#xAE30;&#xB2A5; &#xC7A5;&#xC560;&#xB97C; &#xACB0;&#xC815; &#xD68C;&#xC0C9; &#xBB3C;&#xC9C8; (NAGM)&#xC5D0;&#xC11C; &#xD30C;&#xC0DD; &#xB41C;&#xC758; &#xC0C1;&#xB300;&#xC801; &#xC911;&#xC694;&#xB3C4; &#xD3C9;&#xAC00; &#xD588;&#xB2E4;.

&#xD655;&#xC0B0; &#xD150;&#xC11C; &#xC601;&#xC0C1; &#xC774;&#xC0C1;&#xC740; cognitively &#xB2E4; &#xBC1C;&#xC131; &#xACBD;&#xD654; &#xC99D; &#xD658;&#xC790; &#xC7A5;&#xC560;.

El deterioro cognitivo puede agregar a la carga de enfermedad en pacientes con esclerosis m&#xFA;ltiple (EM). El objetivo de este estudio fue evaluar la importancia relativa de tensor de difusi&#xF3;n (DTI) los &#xED;ndices derivados de la materia normal que aparece de color blanco (NAWM) y la materia gris (NAGM) en la determinaci&#xF3;n de la disfunci&#xF3;n cognitiva en pacientes con esclerosis m&#xFA;ltiple.

Anomal&#xED;as tensor de difusi&#xF3;n de imagen en pacientes con deterioro cognitivo Esclerosis M&#xFA;ltiple

&#x8BA4;&#x77E5;&#x529F;&#x80FD;&#x969C;&#x788D;&#x53EF;&#x4EE5;&#x6DFB;&#x52A0;&#x7684;&#x591A;&#x53D1;&#x6027;&#x786C;&#x5316; (MS) &#x60A3;&#x8005;&#x7684;&#x75BE;&#x75C5;&#x8D1F;&#x62C5;&#x3002;&#x8FD9;&#x9879;&#x7814;&#x7A76;&#x7684;&#x76EE;&#x7684;&#x662F;&#x8BC4;&#x4F30;&#x5F25;&#x6563;&#x5F20;&#x91CF;&#x6210;&#x50CF; (DTI) &#x6307;&#x6570;&#x6765;&#x81EA;&#x6B63;&#x5E38;&#x51FA;&#x73B0;&#x767D;&#x8272;&#x7269;&#x8D28; (NAWM) &#x548C;&#x5728;&#x786E;&#x5B9A; MS &#x60A3;&#x8005;&#x7684;&#x8BA4;&#x77E5;&#x529F;&#x80FD;&#x969C;&#x788D;&#x7684;&#x7070;&#x8272;&#x7269;&#x8D28; (NAGM) &#x7684;&#x76F8;&#x5BF9;&#x91CD;&#x8981;&#x6027;&#x3002;

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Cognitive impairment can add to the burden of disease in patients with multiple sclerosis (MS). The aim of this study was to assess the relative importance of diffusion tensor imaging (DTI) indices derived from normal appearing white matter (NAWM) and grey matter (NAGM) in determining cognitive dysfunction in MS patients.

Diffusion tensor imaging abnormalities in cognitively impaired multiple sclerosis patients.

Les troubles cognitifs peuvent ajouter &#xE0; la charge de morbidit&#xE9; chez les patients atteints de scl&#xE9;rose en plaques (MS). Le but de cette &#xE9;tude &#xE9;tait d&#x26;#39;&#xE9;valuer l&#x26;#39;importance relative de tenseur de diffusion d&#x26;#39;imagerie (DTI) des indices d&#xE9;riv&#xE9;s de la normale de la substance blanche appara&#xEE;t (NAWM) et de mati&#xE8;re grise (Nagm) dans la d&#xE9;termination de dysfonctionnement cognitif chez les patients atteints de SEP.

Anomalies de diffusion imagerie du tenseur de troubles cognitifs dans la scl&#xE9;rose en plaques

Kognitiver Beeintr&auml;chtigung kann Krankheiten bei Patienten mit multipler Sklerose (MS) hinzuf&uuml;gen. Ziel dieser Studie war die relative Bedeutung der Diffusion Tensor imaging (DTI) Indizes aus den normalen erscheinenden wei&szlig;en Substanz (NAWM) und graue Substanz (NAGM) bei der Bestimmung der kognitive Dysfunktion bei MS-Patienten zu beurteilen.

Diffusion Tensor imaging Anomalien im beeintr&auml;chtigt kognitiv Patienten mit multipler Sklerose.

Deterioramento cognitivo pu&ograve; aggiungere per il carico di malattia in pazienti con sclerosi multipla (SM). Lo scopo di questo studio era di valutare l&#39;importanza relativa di diffusion tensor imaging indici (DTI) derivati dalla normale materia bianca comparente (NAWM) e materia grigia (Antonio) nel determinare le disfunzioni cognitive nei pazienti affetti da MS.

Diffusion tensor imaging anomalie nella compromessa cognitivamente pazienti con sclerosi multipla.

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Lesion Explorer (LE) is a reliable and comprehensive MRI-derived tissue segmentation and brain region parcellation processing pipeline for obtaining intracranial tissue and subcortical hyperintensity (SH) volumetrics. The processing pipeline segments: gray (GM) and white matter (WM); sulcal (sCSF) and ventricular cerebrospinal fluid (vCSF); periventricular (pvSH) and deep white subcortical hyperintensities (dwSH); and cystic fluid filled lacunar-like infarcts (Lacunar); into 26 regions of interest. A short-term scan-rescan reliability test was performed on 20 healthy volunteers: 10 older (mean = 77.7 years, SD = 11.1) and 10 younger (mean = 29.4 years, SD = 7.1). Each participant was scanned twice with an average interscan interval of 15.4 days (range: 29 min-50 days). Results suggest low technique-related error as indicated by excellent intraclass correlation coefficient (ICC) results, with ICCs above 0.90 (p < 0.05) for GM, WM, and CSF, in all 26 regions of interest (13 per hemisphere). Ventricular and lesion sub-type (pvSH, dwSH, and Lacunar) volumes also showed high scan-rescan reliability (dwSH = 0.9998, pvSH = 0.9998, Lacunar = 0.9859, p < 0.01). As indicated by the results of this short-term scan-rescan study, the LE structural MRI processing pipeline can be applied for longitudinal volumetric analyses with confidence.

A short-term scan-rescan reliability test measuring brain tissue and subcortical hyperintensity volumetrics obtained using the lesion explorer structural MRI processing pipeline.

We studied behavioral variant frontotemporal dementia (bvFTD) using object alternation (OA) as a novel probe of cognition. This task was adopted from animal models and is sensitive to ventrolateral-orbitofrontal and medial frontal function in humans. OA was administered to bvFTD patients, normal controls, and a dementia control group with Alzheimer disease (AD). Two other frontal lobe measures adopted from animal models were administered: delayed response (DR) and delayed alternation (DA). Brain volumes were measured using the semiautomatic brain region extraction method. Compared with the normal controls, bvFTD patients were significantly impaired on OA and DR. For OA and DR, sensitivities and specificities were 100% and 51.5% (cutoff=22.5 errors) and 9.5% and 98% (cutoff=1.5 errors), respectively. Negative predictive value (NPV) for OA was 100% at all prevalence rates. Comparing AD with bvFTD, there were no significant differences on OA, DR, or DA. Nevertheless, positive predictive value (PPV) and NPV were good at all prevalence rates for OA (cutoff=36.5 errors) and DA (cutoff=6 errors); PPV was good for DR (cutoff=9 errors). Error scores above cutoffs favored diagnosis of AD. Performance on OA was significantly related to medial frontal gray matter atrophy. OA, together with DR and DA, may facilitate assessment of bvFTD as a novel probe of medial frontal function.

Object alternation: a novel probe of medial frontal function in frontotemporal dementia.

We report a single-case study of a female patient (VL) who exhibited frequent episodes of erroneous recollections triggered by everyday events. Based on neuropsychological testing, VL was classified as suffering from mild to moderate dementia (MMSE=18) and was given a diagnosis of probable Alzheimer׳s disease. Her memory functions were uniformly impaired but her verbal abilities were generally well preserved. A structural MRI scan showed extensive areas of gray matter atrophy particularly in frontal and medial-temporal (MTL) areas. Results of experimental recognition tests showed that VL had very high false alarm rates on tests using pictures, faces and auditory stimuli, but lower false alarm rates on verbal tests. We provide a speculative account of her erroneous recollections in terms of her MTL and frontal pathology. In outline, we suggest that owing to binding failures in MTL regions, VL׳s recognition processes were forced to rely on earlier than normal stages of analysis. Environmental features on a given recognition trial may have combined with fragments persisting from previous trials resulting in erroneous feelings of familiarity and of recollection that were not discounted or edited out, due to her impaired frontal processes.

Christopher J.M. Scott

LC Campbell Cognitive Neurology Research Unit,
Heart & Stroke Foundation Canadian Partnership for Stroke Recovery,
Brain Sciences Research Program,
LC Campbell Cognitive Neurology Research Unit, Heart & Stroke Foundation Canadian Partnership for Stroke Recovery, Brain Sciences Research Program

Sunnybrook Health Sciences Centre

Lesion Explorer: A Video-guided, Standardized Protocol for Accurate and Reliable MRI-derived Volumetrics in Alzheimer's Disease and Normal Elderly