ASSESSMENT OF ACTIVITY QUANTIFICATION ACCURACY IN PET/MR IMAGING

Abstract

QUANTITATIVE ACCURACY IN PET IMAGING IS USEFUL FOR RESEARCH AND CLINICAL APPLICATIONS. WHILE THE QUANTITATIVE ACCURACY OF ACTIVITY MEASUREMENTS HAS BEEN VALIDATED FOR PET/CT IMAGING, VALIDATION OF QUANTITATIVE PET/MR IMAGING HAS YET TO BE ACHIEVED. RECENT WORK COMPARING QUANTITATIVE MEASUREMENTS TYPICALLY SHOW SIGNIFICANTLY LOWER MEASURED ACTIVITY IN PET/MR DATA THAN PET/CT DATA. THIS THESIS AIMS TO ULTIMATELY IMPROVE QUANTIFICATION FOR PET/MR DATA. THE WORK IN THIS THESIS BEGINS BY INVESTIGATING THE DIFFERENCES IN ACTIVITY MEASUREMENTS BETWEEN THE PET/MR AND PET/CT SYSTEMS WITH PHANTOM AND PATIENT STUDIES. THE FINDINGS FROM BOTH STUDIES SUGGEST THAT ATTENUATION CORRECTION DIFFERENCES BETWEEN PET/MR AND PET/CT SYSTEMS IS A MAJOR CAUSE OF DIFFERENCES IN MEASURED ACTIVITY. DIFFERENCES IN SCATTER CORRECTION BETWEEN BOTH SYSTEMS ONLY ACCOUNT FOR A SMALL BUT SIGNIFICANT DIFFERENCE IN MEASURED ACTIVITY. A NOVEL APPROACH THAT MITIGATES THE EFFECT FROM METAL INDUCED ARTEFACTS ON THE ACCURACY