Differential Cortical Thickness across the Central Sulcus: A Method for Identifying the Central Sulcus in the Presence of Mass Effect and Vasogenic Edema
T.J. Biegaa,
R.R. Lonserb and
J.A. Butmanc
a Department of Neuroradiology, George Washington University Medical Center, Washington DC
b Surgical Neurology Branch, National Institutes of Health, Bethesda, Md
c National Institute of Neurologic Disorders and Stroke and Diagnostic Radiology Department, Clinical Center, National Institutes of Health, Bethesda, Md
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Fig 1. Axial T2-weighted images showing edema surrounding the central sulcus (asterisks A–D) in 2 patients (A and C). Magnification of the boxed regions (B and D) demonstrate thickness measurements across the central sulcus (asterisks in B and D), across a neighboring parietal sulcus (a ramus of the intraparietal sulcus [white arrow]) and across a neighboring frontal sulcus (precentral sulcus [black arrow]). Only one measurement is shown for clarity. Up to 8 measurements were made along the length of the sulcus on each axial image. Note that measurements were performed perpendicular to the sulcus, ensuring that the ratio will not be affected by section orientation.
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Fig 2. A metastasis adjacent to the motor strip (arrow), confirmed by intraoperative cortical mapping. The motor cortex is thicker than the sensory cortex on T2-weighted imaging (A). This is not apparent on T1-weighted precontrast (B) and postcontrast (C) images in which the sulci are effaced.
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Fig 3. Contiguous axial T2-weighted (A–D) and corresponding T1- weighted (E–H) images in a patient with vasogenic edema. The T2-weighted images exquisitely demonstrate the cortical thickness difference between the precentral and postcentral gyrus (white arrows) because the vasogenic edema outlines the cortex. These findings are only partially visible on the T1-weighted images. There is no discernible difference in cortical thickness of the anterior and posterior bank of sulci in the frontal and parietal lobes (black arrows).
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Fig 4. Box plot demonstrates an approximate 2:1 ratio of precentral to postcentral sulcus cortical thickness. The ratio of anterior/lateral to posterior/medial bank cortex of frontal and parietal sulci approaches 1:1.
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