The goal of this project is to overcome the difficulties related to space constraints and MR compatibility of collimator material and detectors.
Hybrid imaging of both function and anatomy of the human body has become the clinical standard for diagnosis and treatment monitoring. With multimodality imaging, medical doctors now have a tool to look inside the patient body. They are not only able to see what is happening but are also able to precisely locate where functional changes occur.
Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), two functional imaging modalities, have already been combined with Computed Tomography (CT), which looks at the anatomy.
PET has recently been combined with Magnetic Resonance Imaging (MRI). However, no simultaneous SPECT/MRI systems have been built so far. Benefits of SPECT/MRI over PET/MRI include better spatial resolution in small structures, better and cheaper tracer availability and the ability to longitudinally follow metabolism with long-lived isotopes.
Challenges for multimodal SPECT/MRI
The goal of this project is to overcome the difficulties related to space constraints and MR compatibility of collimator material and detectors. Furthermore, we will develop a hybrid SPECT/MRI demonstrator by integrating a SPECT gradient coil inside an MRI system.
Scaling down the SPECT component
The key component that enables us to scale down the SPECT system is a new production method of the collimator. Using pure tungsten additive manufacturing, virtually any geometry can be produced.
The SPECT system will be built using digital Silicon PhotoMultipliers (dSiPMs). These photodetectors will have to be characterized for use as a SPECT detector and for use in high magnetic and RF fields. Furthermore, the compatibility of the tungsten collimators with the MRI acquisition will be characterized.
In a final phase of the project, the SPECT camera and MRI coils will be integrated in the main magnet of the 3T MRI scanner. Simultaneous SPECT/MRI measurements will demonstrate the capabilities and benefits of simultaneous SPECT/MRI.