“…There is increased interest in using fusion techniques to improve the imaging quality. The use of PET data in combination with some of the existing modalities using the image fusion techniques include MRI-CT-PET-SPECT-DSA-MEG [47,135], MRI-CT-PET [51,191,200,201,202], MRI-SPECT-PET [48], MRI/CT-PET-SPECT [190], MRI-PET [207,208,140,184,209,143,130,131], FDG-PET-CT [229,251,253], PET-CT [273,248,214,246,220,221,239,29,223,68,254,256,252,222,76,274,261], FDG-PET [272], and PET-CT-ultrasound [260].…”