An Application of Combined PET/CT Images to Make MRI-PET Fusion Image in Head and Neck Region

PURPOSE:Precisely co-registered anatomical and functional images can be acquired using combined PET/CT scanner, offering the potential for increased diagnostic accuracy. The anatomical structures are very complicated especially in Head and Neck region. MRI is often much preferable to CT images to show anatomical structure in Head and Neck region, and MRI-PET fusions been desired to be available for clinical diagnosis and treatment in this region. We devised a new, simple, easy and precise method to co-regist MRI and PET images with the help of PET/CT fusion images.METHOD AND MATERIALS:Forty-five patients with Head and Neck cancer 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 (AMIR* Automatic Multimodality Image Registration Algorithm)on PC machine. And then we swapped CT images with MRI images to get MRI-PET fusion images.RESULTS:Precisely co-registered CT and PET images were acquired by PET/CT in all our cases. 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 CT-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.CONCLUSIONS: We could get precisely co-registered MRI and PET images with the help of PET/ CT fusion images were useful especially for diagnosis tumor extent or invasion into muscles and soft tissues in Head and Neck region.89th Scientific Assembly and Annual Meetin