FIGURE 5. Staging and evaluation of chemotherapy response in non-Hodgkin’s lymphoma with software registration. ¹⁸F-FDG PET examinations defined 2 lesions: hypermetabolic substernal, indicating continuing active disease, in what had been decrease in size noted on CT, and an additional small focal area in right paratracheal location. Lesions are shown on maximum intensity projection view (A, left) and corresponding transaxial slices (A, right). With image coregistration, extent of patent’s disease is defined as involving an osseous lesion not appreciated on CT alone. (B) Subsequent MR evaluation and MRI/PET fusion confirmed PET osseous lesion (arrow). PET with MRI coregistration confirmed osseous involvement and location that dramatically changed therapeutic approach. Images courtesy of John Vansant, MD, Providence Medical Center, Portland, OR.