Morphological Aspects of the Inferior Frontal Gyrus and its Relations with Brain Hemispheres and Gender: A Study with in vivo Magnetic Resonance Imaging

Abstract

This study aims to evaluate the reliability of an anatomy-topographic location method for the anatomical references that form the inferior frontal gyrus and compare the findings of both studied brain hemisphere as well as the genre. Two different pulse sequences-gradient-echo T1 (T1 GRE) and reversal recovery gradient-echo T1 (T1 IR GRE) were used for such purpose. The sample consisted of 30 healthy individuals with a mean age 25.3±7.04 years, 16 women (53%) and 14 men (46%). A methodology adapted to identify the limits of the structure forming the inferior frontal gyrus was used. The reliability of the method was evaluated by the level of agreement on intra-examiner and inter-examiner analysis. There was a satisfactory degree of agreement-good, very good or excellent for most references evaluated both on intra-observer and inter-observer analysis. The only exception was the left orbital part on intra -examiner analysis in T1 IR GRE (Kappa test, p>0, 05). No differences were observed between the findings regarding gender. When evaluating the performance between sequences T1 GRE performed better in the independent identification of the structures of the analyzed hemispheres (Kappa test technique Jackniffe, p<0.05). The method proved to be reliable for identifying the structures that make up the inferior frontal gyrus. There was no difference between the morphological aspects related to brain hemisphere and gender. Comparing the performance of the sequences, T1 GRE functioned better. However, further studies are needed to confirm such findings.