When a patient injures his or her ankle or knee, the impact on the joint and surrounding tissue can be difficult for doctors to gauge. That’s because conventional CT and MRI scanners image patients while lying down, sometimes missing problems that are only evident when the joint is in a functional, weight-bearing state.
A newly available CT scanner addresses both of these limitations. It was developed by Johns Hopkins researchers in the departments of Biomedical Engineering, Radiology and Radiological Science, and Orthopaedic Surgery, and the Division of Rheumatology, in collaboration with Carestream.Called the OnSight 3D Extremity System, the scanner creates higher-quality images with low radiation exposure and allows a patient’s knees, ankles and feet to be imaged while the patient is standing.
The scanner design was based on mathematical models for 3-D image quality developed by Johns Hopkins researchers. This allowed them to understand and optimize trade-offs in resolution, contrast and dose.
“With this scanner, we see clear delineation of bone details as well as cartilage, tendons and ligaments sufficient for many radiological examinations,” says Jeff Siewerdsen, the biomedical engineering professor who led early development at Johns Hopkins. “The high level of image quality is a result of both rigorous system design and novel algorithms for artifact correction and 3-D image reconstruction.”
This means it’s easier to spot injuries that may have gone undetected, like damaged soft tissue or ligaments. Physicians could then provide more tailored treatment.
The scanner’s smaller size and cost also mean clinics could offer one-stop joint imaging and consultation.
The system won the 2016 Aunt Minnie Award for Best New Radiology Device and was approved by the Food and Drug Administration in September 2016. Johns Hopkins Technology Ventures is licensing the technology in partnership with Carestream.
Siewerdsen says the research has led to several new projects focusing on osteoarthritis and post-radiotherapy fracture risk, spearheaded by biomedical engineer Wojciech Zbijewski and clinical collaborators.