Location of the central sulcus via cortical thickness of the precentral and postcentral gyri on MR.
OBJECTIVE
To determine whether relative cortical thickness measurements of the precentral and postcentral gyri can be used to differentiate the central sulcus from adjacent cortical sulci.


METHODS
Turbo inversion-recovery MR imaging of the entire brain was done with scans parallel to the anterior commissure-posterior commissure line. Cortical thickness was measured in each hemisphere with a jeweler's eyepiece with 0.1-mm gradations. Three measurements were obtained perpendicular to the central, precentral, and superior frontal sulci, as determined by means of established anatomic methods. The ratios of cortical thickness on both sides of the central, precentral, and superior frontal sulci were calculated and compared.


RESULTS
The mean ratio of precentral/postcentral gyri was 1.64 for the right hemisphere and 1.53 for the left hemisphere. The mean cortical thickness ratios were as follows: 1.01 for the right hemisphere and 3.01 for the left hemisphere across the precentral sulcus, and 1.03 for the right hemisphere and 0.99 for the left hemisphere across the superior frontal sulcus.


CONCLUSIONS
Cortical thickness measurements across the central sulcus provide a method for locating the primary motor (precentral gyri) and primary somatosensory (postcentral gyri) cortices. The higher mean cortical thickness ratio across the central sulcus corresponds with known cytoarchitectonic relationships.
Department of Radiology, Northwestern University Medical School, Chicago, III., USA.
J R
JR
Meyer
S
S
Roychowdhury
E J
EJ
Russell
C
C
Callahan
D
D
Gitelman
M M
MM
Mesulam
D000328:Adult; D002540:Cerebral Cortex / Q000033:anatomy & histology*; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology; D012016:Reference Values; D013003:Somatosensory Cortex / Q000033:anatomy & histology