Effect of intrinsic and extrinsic factors on global and regional cortical thickness.
Global and regional cortical thicknesses based on T1-weighted magnetic resonance images acquired at 1.5 T and 3 T were measured on a relatively large cohort of 295 subjects using FreeSurfer software. Multivariate regression analysis was performed using Pillai's trace test to determine significant differences in cortical thicknesses measured at these two field strengths. Our results indicate that global cortical thickness is not affected by the field strength or gender. In contrast, the regional cortical thickness was observed to be field dependent. Specifically, the cortical thickness in regions such as parahippocampal, superior temporal, precentral and posterior cingulate is thicker at 3 T than at 1.5 T. In contrast regions such as cuneus and pericalcarine showed higher cortical thickness at 1.5 T than at 3 T. These differences appear to be age-dependent. The differences in regional cortical thickness between field strengths were similar in both genders. Further, male vs. female differences in regional cortical thickness were observed only at 1.5 T and not at 3 T. Our results indicate that magnetic field strength has a significant effect on the estimation of regional, but not global, cortical thickness. In addition, the pulse sequence, scanner type, and spatial resolution do not appear to have significant effect on the measured cortical thickness.
Department of Diagnostic and Interventional Imaging, The University of Texas - Health Sciences Center, Houston, Texas, United States of America.
Koushik A
KA
Govindarajan
Department of Diagnostic and Interventional Imaging, The University of Texas - Health Sciences Center, Houston, Texas, United States of America.
Leorah
L
Freeman
Division of Clinical and Translational Sciences, Department of Internal Medicine, University of Texas Medical School at Houston, The University of Texas - Health Sciences Center, Houston, Texas, United States of America.
Chunyan
C
Cai
Division of Clinical and Translational Sciences, Department of Internal Medicine, University of Texas Medical School at Houston, The University of Texas - Health Sciences Center, Houston, Texas, United States of America; Division of Epidemiology, Human Genetics and Environmental Sciences, School of Public Health, The University of Texas - Health Sciences Center, Houston, Texas, United States of America.
Mohammad H
MH
Rahbar
Department of Diagnostic and Interventional Imaging, The University of Texas - Health Sciences Center, Houston, Texas, United States of America.
Ponnada A
PA
Narayana
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002540:Cerebral Cortex / Q000033:anatomy & histology*; D005260:Female; D006179:Gyrus Cinguli / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009778:Occipital Lobe / Q000033:anatomy & histology; D020534:Parahippocampal Gyrus / Q000033:anatomy & histology; D012044:Regression Analysis; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult