Quantitative Gradient Echo MRI Identifies Dark Matter as a New Imaging Biomarker of Neurodegeneration that Precedes Tisssue Atrophy in Early Alzheimer's Disease.

Autor:	Kothapalli SVVN; Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA., Benzinger TL; Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA.; Knight Alzheimer Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA., Aschenbrenner AJ; Knight Alzheimer Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA.; Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA., Perrin RJ; Knight Alzheimer Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA.; Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO, USA.; The Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, USA., Hildebolt CF; Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA., Goyal MS; Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA., Fagan AM; Knight Alzheimer Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA.; Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA.; The Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, USA., Raichle ME; Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA.; The Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, USA., Morris JC; Knight Alzheimer Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA.; Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA., Yablonskiy DA; Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA.; Knight Alzheimer Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA.; The Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, USA.
Jazyk:	angličtina
Zdroj:	Journal of Alzheimer's disease : JAD [J Alzheimers Dis] 2022; Vol. 85 (2), pp. 905-924.
DOI:	10.3233/JAD-210503
Abstrakt:	Background: Currently, brain tissue atrophy serves as an in vivo MRI biomarker of neurodegeneration in Alzheimer's disease (AD). However, postmortem histopathological studies show that neuronal loss in AD exceeds volumetric loss of tissue and that loss of memory in AD begins when neurons and synapses are lost. Therefore, in vivo detection of neuronal loss prior to detectable atrophy in MRI is essential for early AD diagnosis. Objective: To apply a recently developed quantitative Gradient Recalled Echo (qGRE) MRI technique for in vivo evaluation of neuronal loss in human hippocampus. Methods: Seventy participants were recruited from the Knight Alzheimer Disease Research Center, representing three groups: Healthy controls [Clinical Dementia Rating® (CDR®) = 0, amyloid β (Aβ)-negative, n = 34]; Preclinical AD (CDR = 0, Aβ-positive, n = 19); and mild AD (CDR = 0.5 or 1, Aβ-positive, n = 17). Results: In hippocampal tissue, qGRE identified two types of regions: one, practically devoid of neurons, we designate as "Dark Matter", and the other, with relatively preserved neurons, "Viable Tissue". Data showed a greater loss of neurons than defined by atrophy in the mild AD group compared with the healthy control group; neuronal loss ranged between 31% and 43%, while volume loss ranged only between 10% and 19%. The concept of Dark Matter was confirmed with histopathological study of one participant who underwent in vivo qGRE 14 months prior to expiration. Conclusion: In vivo qGRE method identifies neuronal loss that is associated with impaired AD-related cognition but is not recognized by MRI measurements of tissue atrophy, therefore providing new biomarkers for early AD detection.
Databáze:	MEDLINE
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