Datensatz

Zusammenfassung

The auditory pathway consist of several subcortical structures such as medial genicualte body (MGB), inferior
colliculi (IC), nuclei of lateral lemniscus (nuclei of LL), cochlear nuclei (CN) and superior olivary complex (SOC) and the acoustical cortex. MRI can easily be used to show activations within the acoustical cortex but the detection of other nuclei of the auditory pathway are rarely shown. The major problems in this case are brainstem motion relate to the heart beat and small size of the nuclei (CN is 3 x 3 x 7 mm, nuclei of LL is 2 x 2 x 5 mm, SOC is 2 x 2 x 5 mm and IC is 6 x 6 x 4 mm) [1]. Signal change due to motion can disturb functional images. The effect of pulsatile brainstem motion can be minimized using cardiac gated measurements, and measurements with high spatial resolution are recommended. This technique synchronizes image acquisitions in the same heart phase of cardiac cycle [2]. Additional analysis of functional connectivity can be also a useful tool which can describe the connections between functionally related regions. These regions can be visualized using
standard t-maps. Functional connectivity may provide the time-dependent cross-correlation function between each single pixel and the reference area what can characterize the relationship of the neural network in more detail. The aim of the study was investigate the auditory pathway using different technical parameters, cardiac gated measurements and analysis of functional connectivity.