[¹⁸F]FDG PET Imaging of the Inferior Colliculi in Asymmetric Hearing Loss

Abstract

Purpose: To evaluate the glucose metabolism of the inferior colliculi (IC) and primary auditory cortices (PAC) in patients with asymmetric hearing loss (AHL) using positron emission tomopgraphy (PET). Methods: Normalized regional [¹⁸F]FDG uptake of the IC and PAC (reference: cerebellum) was assessed in thirteen subjects with AHL using a fully digital clinical PET/CT system (Philips Vereos). Results: Regional metabolism of both, the IC and PAC was significantly reduced contralateral to the most hearing-impaired ear compared to the ipsilateral side. Duration of deafness correlated positively with metabolism of the contralateral PAC, but not that of the ipsilateral PAC or either of the IC. Conclusion: Fully digital, high-resolution clinical PET scanners allow for investigating small brainstem nuclei. AHL has a significant impact on regional glucose metabolism of the auditory pathway. Mitigation of this effect by longer duration of deafness might indicate reorganization at the cortical level.