ABSTRACT
This chapter presents the development of a second-generation small-animal Single-photon emission computed tomography (SPECT) - magnetic resonance (MR) insert that overcomes the shortcomings of the first-generation insert. Currently, the most exciting developments in multimodality imaging are dual-modality Positron emission tomography (PET)/magnetic resonance imaging (MRI) and SPECT/MRI. High-resolution MR images and their ability to differentiate between soft tissues can be exploited in quantitative PET and SPECT image reconstruction when partial volume effect from differential radioactivity uptake in adjacent tissues is important. Modern PET/CT and SPECT/CT scanners, in a coplanar configuration, share the same gantry and the scanning table transports the patient between the different modalities. The SPECT/MR insert demonstrated the feasibility of simultaneous SPECT/MRI with both phantom and small-animal studies. With collimator-detector response modeling, the SPECT image resolution exceeded the target system resolution of the multipinhole (MPH) collimators. Artifact-free high-quality MPH SPECT images were obtained from physical phantom studies and from small-animal studies using the SPECT/MR insert.
