Imaging

Most of the research in the past has been focused on anatomical imaging, particularly using CT and MRI, which established radiology as an independent medical specialty. On the other hand, rapid understanding of cell and molecular biology has led to development of molecular and functional imaging techniques most often conducted using highly sensitive positron emission tomography (PET) and sometimes magnetic resonance imaging (MRI). However, molecular imaging is still facing challenges, particularly with adequate quantification, which often requires development of more sensitive and more reliable detection technologies. Similarly, molecular imaging technologies provide only better or worse surrogates of the underlying biological processes. Kinetic analysis is required to extract biological information of interest from dynamic imaging datasets.

The main imaging efforts of the will be focused on addressing these key problems through developments of:

  • Advanced detectors for PET/MRI: Even though PET is the workhorse imaging modality for molecular imaging its use is still sometimes compromised because of the inadequate image quality, which could be improved by using more capable detectors that would enable higher resolution imaging. We have shown that the use of semiconductor detectors, which enable detection at the 1 mm level, can significantly improve image quality. In addition, insensitivity of the semiconductor detectors to magnetic fields enables effective combination of PET with magnetic resonance imaging (MRI) to construct combined PET/MRI systems for improved diagnostic efficacy. Use of Cherenkov radiators, which enable time resolution under 100ps (FWHM) can further improve time resolution over the conventional scintillation detectors. The main goal of our research is to develop high-resolution PET sensors and assess their impact on diagnostics and treatment response assessment.
  • Advanced MRI sequence and probe design: There are numerous potential clinical MRI applications that can already be performed in vitro or ex vivo, but not in vivo due to present MRI hardware limitations or lack of appropriate MRI pulse sequences. Two examples of these are MRI in dentistry and MRI of blood clots. We aim to develop corresponding tools that would make in vivo application in these two areas closer to a clinical use.
  • Advanced kinetic analysis: Currently most of the comprehensive methods for kinetic analysis provide reliable results only for the whole region of interest (ROI), for example a tumor, as a single unit. This leads to significant loss of information on the spatial level, which is important for assessment of disease heterogeneity. The main goal of our research is to develop robust and convenient methods for voxel-based kinetic analysis, where each voxel represents its own, independent analytical region. We will apply these methods to concurrent assessment of proliferation and vasculature changes in response to novel molecular targeted anti-angiogenic therapies, such as VEGFR TKIs using dynamic 18F-fluorothymidine (FLT) PET/CT imaging.