Influence of accessory sulci of the frontoparietal operculum on gray matter quantification

VALLEJO AZAR MARIANA; ALBA-FERRARA LUCIA; BOUZIGUES ARABELA; PRINCICH JUAN P; MARKOV MARTIN; BENDERSKY MARIANA; GONZALEZ PAULA N

Frontiers in Neuroanatomy

Frontiers

Año: 2022

1662-5129

The perisylvian region is the cortical core of language and speech. Several accessory Q8sulci have been described in this area, whose presence could modify the results ofthe automatic quantification of gray matter by popularly used software. This studyaimed to assess the expression of accessory sulci in the frontoparietal operculum(FPO) and to evaluate their influence on the gray matter volume estimated by anautomatic parcellation of cortical gyri and sulci. Brain MRI scans of 100 healthyadult volunteers were visually analyzed. The existence of the triangular and diagonalsulci, and the number of accessory sulci in the frontoparietal operculum, wereassessed on T1 images. Also, the gray matter volume of gyri and sulci was quantifiedby an automatized parcellation method. Interhemispheric differences in accessorysulci were evaluated with Chi-square and Wilcoxon paired tests. The effects of thehemisphere, sex, age, total intracranial volume, and accessory sulci on morphometricvariables were assessed by linear models. These sulci were found in more than halfof the subjects, mostly in the left hemisphere, and showed a significant effect on thegray matter content of the FPO. In particular, the volume of the inferior frontal sulcus,pars opercularis of the inferior frontal gyrus, horizontal ramus of the lateral sulcus,angular gyrus, and postcentral gyrus showed a significant influence on the presenceof accessory sulci. The prevalence of tertiary sulci in the FPO is high, although theirmeaning is not yet known. Therefore, they should be considered to reduce the riskof misclassifications of normal variation.