Correction of motion‐induced misalignment in co‐registered PET/CT and MRI (T1/T2/FLAIR) head images for stereotactic radiosurgery

摘要

The purpose was to evaluate and correct the co‐registration of diagnostic PET/CT and MRI/MRI images for stereotactic radiosurgery (SRS) using 3D volumetric image registration (3DVIR). The 3DVIR utilizes the homogeneity of color distribution over a volumetric anatomical landmark as the registration criterion with submillimeter accuracy. Fifty‐three PET/CT and MRI (T1, T2 and FLAIR) image sets of patients with brain lesions were acquired sequentially from a hybrid PET/CT or an MRI scanner with common diagnostic head holding devices. Twenty‐five sets of head images were scanned over a 10‐minute interval and 14 whole‐body sets were scanned over a 30‐minute interval. Fourteen sets of MRI images were acquired, and each 3‐modal image set (T1, T2 and FLAIR) was scanned in sequence at time 0, and minutes. The misalignments in these “co‐registered” images were evaluated and corrected using the 3DVIR. Using the head immobilization devices commonly found in diagnostic PET/CT and MRI/MRI imaging, 80%–100% of these “co‐registered” images were identified as misaligned. For PET/CT, the magnitude of misalignment was and for 10‐minute scans, and and for 30‐minute scans. For MRI/MRI, the magnitude was and for 5‐minute scan intervals, and and for 20‐minute intervals. Small, but significant, misalignment is present in the co‐registered diagnostic PET/CT and MRI/MRI images and can be corrected in SRS treatment planning using the volumetric image registration for improved target localization within the clinical error tolerance. PACS numbers: 87.53.Ly, 87.57.nj, 87.57.uk, 87.57.Q‐, 87.61.jc, 87.19.xc Conflict of Interest Statement: The authors do not have any conflict of interest on this research report.