PET IMAGING OF LUNG AND MEDIASTINAL CANCER USING CT

University Of Michigan At Ann Arbor, Ann Arbor MI

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Abstract

DESCRIPTION (provided by applicant): The use of fluoro-deoxy-glucose (FDG) PET imaging for diagnosis of malignant cancer is growing rapidly. However, the detail obtained in PET thorax images is diminished by considerable noise introduced by poor attenuation correction factors derived from short transmission scans. Furthermore, limitations in image spatial resolution impair the contrast and quantitative accuracy of glucose metabolism values in small structures. This project will develop and evaluate methods that overcome these shortcomings by incorporating anatomical information from correlated X-ray CT images into the PET image reconstruction process. Improved methods for both transmission and emission reconstruction will be investigated. The structural information in X-ray CT images will be used to reconstruct improved PET attenuation maps from very short transmission scans; these attenuation maps will be reprojected to form more precise PET attenuation correction factors. Tumor boundary information from X-ray CT images will also be incorporated into the PET emission reconstruction algorithm to improve lesion contrast and accuracy of uptake estimates in small volumes of interest. The methods will be evaluated using computer simulations, phantom studies, and ROC studies based on retrospective reprocessing of scans from a pool of patients with nonspecific CT abnormalities (solitary pulmonary nodules) in the chest.