Functional magnetic resonance imaging of auditory cortex in children

TO obtain images of auditory cortex activation in children by using functional magnetic resonance imaging (FMRI).

Seven healthy children (three girls and four boys), ages 6 to 10 years, were studied. Hearing evaluation was performed by puretone audiometry on the day of FMRI study. Brain imaging was performed on a commercial 1.5 T imager using a three-axis local gradient coil. During scanning the children were instructed to lie still and avoid any lip, eye, jaw, or other facial movements. Subjects were asked to listen to a standard text presented in on-off sequences. Functional images of the auditory cortex were acquired with FMRI technique. Functional imaging processing was done using cross-correlation techniques with a coefficient of 0.5 (P < .0001).

Functional correlation images of the auditory cortex activation were obtained in six of seven children after image processing. All children showed activation in the superior temporal gyrus, Heschl's gyrus, planum temporale, frontal lobe, and parietal regions. There was no significant difference in the number and percentage of activated pixels on right and left auditory cortices.

Functional images of auditory cortex activation were obtained in healthy children following binaural text presentation. Consistent activation was observed in primary and secondary auditory cortices with no hemispheric dominance. FMRI characteristics of the auditory cortex activation in healthy children should be established in order to study those with hearing impairment.