Visualizing Joint Trauma in the Knee

Expertise in imaging the musculoskeletal system is sought after by patients seeking medical care for problems related to the shoulder, elbow, wrist, foot, ankle, jaw, spine, hip, knee, hand, and other parts of the body.

The UC San Diego Musculoskeletal (MSK) Imaging Research Group, including its medical professionals affiliated with the Center for Translational Imaging and Precision Medicine (CTIPM), specializes in the evaluation of all major joints of the body through advanced magnetic resonance imaging (MRI) and innovative data processing.

One young athlete was recently the recipient of the university's expertise in MSK imaging. He first came to UC San Diego in 2009 after experiencing knee pain, and an initial MRI exam evaluated the patient for pathology of the meniscus (see the yellow arrow in the left image below), articular cartilage (triangles), subchondral bone (circle), and ligaments (curved arrow). The MRI revealed a torn medial collateral ligament, or MCL (also noted by the curved arrow).

In a follow-up MRI taken in 2014, the same regions evaluated five years earlier were initially difficult to match up precisely. However, physicians applied a 3D registration, in which datasets for the 2009 and 2014 images were superimposed for a more detailed view. Figure 1 shows the datasets superimposed, which allowed physicians to view details regardless of knee's position. The follow-up evaluation revealed a nicely healed MCL (curved arrow).

Figure 1

Registration is useful for following up with all types of image datasets, but it's especially useful for translational imaging, in which basic scientific discoveries in in imaging are applied in the clinic to benefit patients.

MRI Knee
Figure 2

Other advanced imaging techniques at CTIPM are illustrated in Figure 2. In the case of the human knee, the images compare a photograph of a knee section (A); a conventional MR image, which is unable to evaluate all layers of articular cartilage (B); and CTIPM's translational UTE MRI (C), which can depict the deepest layers of cartilage and the menisci with high signal intensity. UTE MRI, which stands for “ultra-short echo-time” MRI, enables the imaging of tissues and structures that are otherwise difficult to see. These include cortical bone, tendons, ligaments, menisci and other tissues. Finally, quantitative MRI analysis enables physicians to objectively evaluate subtle changes in tissue properties over time (D).