Anterior cingulate cortex: an MRI-based parcellation method.
OBJECTIVE
The anterior cingulate cortex (ACC) is an important part of the limbic system involved in emotions, cognition and executive function. The ACC has structurally distinct subregions, both microscopically and functionally, that have been implicated in several major psychiatric disorders. However, a structural analysis of these subregions with magnetic resonance imaging (MRI) has not been done. Our main purpose was to develop an MRI-based parcellation method of the ACC that permits us to explore plausible abnormalities in 4 functionally relevant subregions: dorsal, rostral, subcallosal and subgenual.


METHODS
The reliability study for gray matter volume and surface area of each subregion was performed on 14 randomly selected MR scans by 3 different raters. Our method posits to conserve the topographic uniqueness of individual brains and is based on our ability to visualize both the 3-dimensional rendered brain and the 3 orthogonal planes simultaneously with BRAINS2 software. We developed rules to hand-trace regions of interest (ROI) to surround contiguous areas of gray matter for dorsal, rostral, subcallosal and subgenual regions. The ACC was then parcellated into these 4 distinct subregions (8 when both right and left hemispheres were measured).


CONCLUSIONS
The intraclass R coefficients for gray matter volume of each subregion ranged between 0.85 and 0.93. The current study describes a new highly reliable and reproducible topography-based parcellation method of the ACC into its dorsal, rostral, subcallosal and subgenual regions.


CONCLUSIONS
This new parcellation method provides a new means of exploring the role of the functionally and structurally distinct subregions of the ACC in schizophrenia, depression and various other brain illnesses.
McCormick
Laurie M
LM
Department of Psychiatry, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, 200 Hawkins Drive, W268 GH, Iowa City, IA 52242, USA. laurie-mccormick@uiowa.edu
Ziebell
Steven
S
Nopoulos
Peggy
P
Cassell
Martin
M
Andreasen
Nancy C
NC
Brumm
Michael
M
D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000473:pathology; D003337:Corpus Callosum / Q000033:anatomy & histology / Q000473:pathology; D007839:Functional Laterality / Q000502:physiology; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015588:Observer Variation; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000473:pathology; D012984:Software