MRI Study of Musculoskeletal Function

This study will use magnetic resonance imaging (MRI) and ultrasound images to study how muscles, tendons, and bones work together to cause motion. The procedure is one of several tools being developed to characterize normal and impaired musculoskeletal function, with the goal of developing improved methods of diagnosis and treatment of movement disorders. Healthy normal volunteers must be age 5 to unlimited, with or without joint impairment, may be eligible for this study. Volunteers with joint impairment may not have serious injury to the joint being studied, previous surgery on the joint being studied, or extreme pain at the joint being studied. MRI uses a strong magnet and radio waves to create images of the inside of the body. The subject lies on a long narrow couch inside a metal cylinder (the scanner) for up to 3 hours while the scanner gathers data. Earplugs are worn to muffle loud noises caused by electrical switching of radiofrequency circuits used in the scanning process. A special pad or tube may be placed over or around the region being scanned to improve the quality of the data. The subject will be asked to repeatedly move a specific joint, such as the knee, for brief periods, usually less than 5 minutes. The subject can communicate via intercom with the person performing the study at all times during the procedure, and may request to stop the study at any time.

The overall goal of this technology development initiative is to greatly advance the clinical diagnosis and treatment of musculoskeletal impairments as they relate to joint function. The primary focus of this protocol is to initially develop and ultimately validate a combined set of tools (virtual functional anatomy - VFA) that will enable the accurate and precise measurement, analysis and visualization of three-dimensional (3D) static and dynamic musculoskeletal anatomy (e.g., bone shape, skeletal kinematics, tendon and ligament strain, muscle force, and joint space) from imaging data. We plan to merge and extend our existing MR imaging and analysis capabilities with ultrasound imaging and analysis for the development and implementation of a highly accurate, imaging-based measurement and analysis technique for the non-invasive quantification of complete joint anatomy and tissue dynamics during functional movements. In short, we plan to develop a method for creating 3D digital images of loaded and moving joint tissues (bone, cartilage, muscle, and connective tissues) that reveal joint contact patterns and tissue loads. In conjunction with building this tool, we will evaluate the variability of bone shape across subjects, the sensitivity of defined joint posture (translation and rotation of one bone relative to another) to osteo-based coordinate system definition, and the ability to ultimately use these tools to document and evaluate the function of normal and impaired joint structures (e.g., ACL rupture, patella tracking syndrome...) under simulated conditions experienced during activities of daily living. The principal investigator has previously developed and tested the primary component in the VFA package, cine-phase contrast and fast-phase contrast (fast-PC) MR imaging, demonstrating both to be highly accurate and precise in the measurement of normal 3D knee joint kinematics and biceps femoris strain. Additional investigators have previously developed techniques for imaging musculoskeletal structures using ultrasonography, demonstrating these techniques to be, likewise, highly accurate and precise in the measurement of biomechanical properties of the soft tissues surrounding the knee and the tendons of the quadriceps femoris. Under this protocol we propose to develop additional numerical reconstruction, image analysis, and display methods and test the applicability of fast-PC MR and ultrasound imaging to the study of various normal and impaired joints (e.g., ankle, wrist, and knee). This development process will require data from human volunteers obtained from both static and dynamic MR and ultrasound images. This development process will require data from human subjects obtained from both static and dynamic MR and ultrasound images. This development is being guided by our philosophy that impaired joint function likely occurs due to abnormal bone shape, abnormal musculoskeletal movements and forces, or both abnormal bone shape and musculoskeletal movements and forces. Thus, our long-term vision is to non-invasively quantify the in vivo 3D joint kinematics, bone shapes and tissue loads for both the impaired and normal volunteer populations, translate the methods and findings into interventional research and ultimately into common clinical practice.