@article{4cbc174dd6b64a77a7dc41f5cd119fc3,
title = "Application of machine learning methods to describe the effects of conjugated equine estrogens therapy on region-specific brain volumes",
abstract = "Use of conjugated equine estrogens (CEE) has been linked to smaller regional brain volumes in women aged ≥65 years; however, it is unknown whether this results in a broad-based characteristic pattern of effects. Structural magnetic resonance imaging was used to assess regional volumes of normal tissue and ischemic lesions among 513 women who had been enrolled in a randomized clinical trial of CEE therapy for an average of 6.6 years, beginning at ages 65-80 years. A multivariate pattern analysis, based on a machine learning technique that combined Random Forest and logistic regression with L1 penalty, was applied to identify patterns among regional volumes associated with therapy and whether patterns discriminate between treatment groups. The multivariate pattern analysis detected smaller regional volumes of normal tissue within the limbic and temporal lobes among women that had been assigned to CEE therapy. Mean decrements ranged as high as 7% in the left entorhinal cortex and 5% in the left perirhinal cortex, which exceeded the effect sizes reported previously in frontal lobe and hippocampus. Overall accuracy of classification based on these patterns, however, was projected to be only 54.5%. Prescription of CEE therapy for an average of 6.6 years is associated with lower regional brain volumes, but it does not induce a characteristic spatial pattern of changes in brain volumes of sufficient magnitude to discriminate users and nonusers.",
keywords = "Hormone therapy, MRI, Random forest, WHIMS",
author = "Ramon Casanova and Espeland, {Mark A.} and Goveas, {Joseph S.} and Christos Davatzikos and Gaussoin, {Sarah A.} and Maldjian, {Joseph A} and Brunner, {Robert L.} and Kuller, {Lewis H.} and Johnson, {Karen C.} and Mysiw, {W. Jerry} and Benjamin Wagner and Resnick, {Susan M.}",
note = "Funding Information: WHIMS-MRI Clinical Centers: Albert Einstein College of Medicine: Sylvia Wassertheil-Smoller; Medical College of Wisconsin, Milwaukee: Jane Morley Kotchen; Stanford Center for Research in Disease Prevention: Marcia L. Stefanick; The Ohio State University: Rebecca Jackson; University of California at Davis: John Robbins; University of California at Los Angeles: Lauren Nathan; University of Florida: Marian Limacher; University of Iowa: Jennifer Robinson; University of Massachusetts: Judith Ockene; University of Minnesota: Karen Margolis; University of Nevada: Robert Brunner; University of North Carolina, Chapel Hill: Carol Murphy; University of Pittsburgh: Lewis Kuller. WHIMS-MRI Clinical Coordinating Center: Wake Forest University Health Sciences: Sally Shumaker. WHIMS-MRI Quality Control Center: University of Pennsylvania: Nick Bryan. US National Institutes of Health: National Institute on Aging: Neil Buckholtz, Susan Molchan, Susan Resnick; National Heart, Lung, and Blood Institute: Jacques Rossouw, Linda Pottern. Funding: The Women's Health Initiative is funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health, US Department of Health and Human Services. WHIMS was funded in part by Wyeth Pharmaceuticals, St. Davids, PA, USA. S.M.R. is supported by the Intramural Research Program, NIA, National Institutes of Health. ",
year = "2011",
month = may,
doi = "10.1016/j.mri.2010.12.001",
language = "English (US)",
volume = "29",
pages = "546--553",
journal = "Magnetic Resonance Imaging",
issn = "0730-725X",
publisher = "Elsevier Inc.",
number = "4",
}