An investigation into attenuation artefacts created by cochlear implants in positron emission tomography

Observed hypo-intensities in PET scans of patients with cochlear implants were investigated to establish whether they are due to inaccuracies in attenuation correction. Data from previously acquired scans were analysed and a number of phantom scans conducted on an HRRT and PET-CT scanner. For the HRRT similar hypo-intensities were observed but they were localised to the region around the implants. For the PET-CT scan artefacts extended further away and were due to artefacts in the CT scans used for attenuation correction.