Al. Foundas et al., Morphology of the frontal operculum: A volumetric magnetic resonance imaging study of the pars triangularis, J NEUROIMAG, 11(2), 2001, pp. 153-159
Objective. Broca's area, which includes the pars triangularis (PTR), is a n
euroanatomical region important in speech and language production. Linear m
easures of the PTR have been found to be asymmetric, with the direction of
the asymmetry correlating with language dominance determined by Wada testin
g. It is unclear, however, whether these linear measurements correlate with
volumetric measures, and it is also unknown whether white matter and/or gr
ay matter contribute differentially to these asymmetries. To investigate th
ese issues, volumetric magnetic resonance imaging methodologies were used t
o measure the PTR in a group of healthy right-handed men (n = 12). There wa
s a significant leftward asymmetry of the PTR using linear and volumetric m
easures. Linear measures of the left and right hemispheres were highly corr
elated with volumetric measures. Underlying gray and white matter both cont
ributed to PTR asymmetry. Anatomical boundaries and four configurations (V,
U, Y, and J) are discussed with reference to potential interhemispheric di
fferences.