Usefulness of MRI/MRS-CT-PET fusion imaging in diagnosis of brain, head and neck tumor

Forty-nine patients with Head and Neck tumor were studied using C-11 methionine with combined PET/CT scanner, Siemens Biograph, and precise fusion PET and CT images were acquired. We aligned CT images of PET/CT and MRI acquired on different scanners using a co-registration computer algorithm of Dr. View software on PC machine. And then we swapped CT images with MRI images to get MRI-PET fusion images. Due to the rich anatomical information of both CT and MRI images, our computer algorithm, AMIR, resulted in accurate MRI-CT fusion, and then precise MRI-PET fusion was successfully achieved by swapping CT images with MRI images. MRI-PET fusion images rather than PET fusion images showed clearly tumor extent or invasion into surrounding tissue, especially muscles and soft tissues, and it played a significant role in diagnosis, staging and treatment. We could get precisely co-registered MRI and PET images with the help of PET/CT fusion images. MRI-PET fusion images were useful especially for diagnosis tumor extent or invasion into muscles and soft tissues in Head and Neck. (author)