《Fusion of PET and MRI for Hybrid Imaging》.pdfVIP

2 Fusion of PET and MRI for Hybrid Imaging Zang-Hee Cho, Young-Don Son, Young-Bo Kim, and Seung-Schik Yoo Summary. Recently, the development of the fusion PET-MRI system has been actively studied to meet the increasing demand for integrated molecular and anatom- ical imaging. MRI can provide detailed anatomical information on the brain, such as the locations of gray and white matter, blood vessels, axonal tracts with high res- olution, while PET can measure molecular and genetic information, such as glucose metabolism, neurotransmitter-neuroreceptor binding and affinity, protein–protein interactions, and gene trafficking among biological tissues. State-of-the-art MRI sys- tems, such as the 7.0 T whole-body MRI, now can visualize super-fine structures including neuronal bundles in the pons, fine blood vessels (such as lenticulostri- ate arteries) without invasive contrast agents, in vivo hippocampal substructures, and substantia nigra with excellent image contrast. High-resolution PET, known as High-Resolution Research Tomograph (HRRT), is a brain-dedicated system capable of imaging minute changes of chemicals, such as neurotransmitters and –receptors, with high spatial resolution and sensitivity. The synergistic power of the two, i.e., ultra high-resolution anatomical information offered by a 7.0 T MRI system com- bined with the high-sensitivity molecular information offered by HRRT-PET, will significantly elevate the level of our current understanding of the human brain, one of the most delicate, complex, and mysterious biological organs. This chapter intro- duces MRI, PET, and PET-MRI fusion system, and its algorithms are discussed in detail. 2.1 Introduction Among the modern medical imaging technologies, Positron Emission Tomog- raphy (PET) and Magnetic Resonance Imaging (MRI) are considered to be the most powerful diagnostic inventions. In t