The main research goal of our group is early detection of osteoarthritis through medical imaging.
Osteoarthritis is the most common chronic condition of the joints, affecting 27 million Americans, with an economic burden of $185 million per year. Osteoarthritis is caused by tissue degeneration or acute injury and manifests as joint pain and stiffness. It is a whole organ disease that causes cartilage loss, changes in the underlying bone (osteophytes, cysts and bone marrow lesions), and degeneration of menisci, synovium, ligaments, muscles and tendons. Due to increasing prevalence of osteoarthritis, there is a need to accurately evaluate early development in order to monitor disease progression and develop new treatments.
We develop new imaging methodologies to detect early biomarkers of osteoarthritis using Magnetic Resonance Imaging (MRI), simultaneous Positron Emission Tomography and MRI (PET/MRI), and cone beam Computed Tomography (CT). Specifically, we are working on the following research projects:
Quantitative 3D Imaging of Cartilage Using the Double-Echo Steady-State (DESS) Sequence
The DESS MRI sequence provides undistorted 3D images of the knee in short scan times. By comparing the image contrast to signal models, we can estimate parameters in the cartilage, such as T2 and diffusivity. These provide information about tissue structure and can help with early detection of osteoarthritis.
Quantitative and Morphological Imaging of the Whole Knee
UTEDESS is a pulse sequence that allows for rapid high-isotropic resolution imaging with multiple contrasts and very high SNR efficiencies. It also allows for simultaneous quantification of T2 relaxation times in short-T2 tissues.
Rapid Volumetric MRI of Cartilage GAG Content
GagCEST is a new imaging method which can detect, with high sensitivity, endogenous Glycosaminoglycan (GAG) content in cartilage without the need for invasive contrast injections or special hardware. This allows tracking of early cartilage degeneration prior to late-stage structural changes.
Visualization and Quantification of Quantitative MRI Cartilage Changes in the Knee
Identifying focal lesions of elevated quantitative MRI parameters can be important in quantifying and qualifying early OA changes. Our visualization and cluster analysis technique allows for the tracking of these changes over time in populations at risk of developing OA.
MR Imaging Of The Meniscal Radius Tie Sheaths
The radial tie sheaths of the meniscus are part of a collagenous network providing structural integrity to the meniscus. Degradation of the radial tie sheaths is believed to play a role in degenerative tears of the meniscus leading to osteoarthritis of the knee. MRI tools are being developed to image these radial tie sheaths.
PET/MR Imaging of Osteoarthritis
Integrated PET/MRI can simultaneously assess multiple early metabolic, biochemical and morphologic markers of knee OA across multiple tissues in the joint. This presents a new paradigm to study OA; allowing us to quantitatively detect and track early and reversible changes in OA and providing new insights into the spatiotemporal progression of the disease.
Dynamic PET/MR Imaging of Osteoarthritis
Our goal is to understand bone remodeling and function through kinetic modeling of dynamic PET tracer uptake over time. We quantify changes in bone metabolism and bone blood flow as new physiological biomarkers that probe the underlying mechanisms of OA pathology, and may reveal which lesions are active parts of the disease.
Weight-Bearing Imaging of the Knee Using C-Arm CT
The overarching goal of this research is to develop novel weight-bearing computed tomography (CT) imaging to expand our understanding of the mechanical stresses that affect cartilage and meniscus health and to provide a quantitative measure of knee joint health.