Eun-A Heo MD, Presenter: Nothing to Disclose

Kwon-Soo Chon PhD, Abstract Co-Author: Nothing to Disclose

Heon Su Kim, Abstract Co-Author: Nothing to Disclose

Kyong Woo Kim PhD, Abstract Co-Author: Nothing to Disclose

Seon-Kwan Jhung MD, PhD, Abstract Co-Author: Nothing to Disclose

Kwon-Ha Yoon MD, PhD, Abstract Co-Author: Nothing to Disclose

To demonstrate the feasibility of phase-contrast radiography using a micro-focus x-ray source for identification of articular cartilage lesions of the knee joints in rheumatoid arthritis mice model.

Rheumatoid arthritis was induced in 20 DBA/1J mice. Five mice were used for control group. Phase-contrast imaging was performed on knee joints of the mice on day 35 after intradermal bovine type II collagen injection. The imaging system for phase-contrast radiography was composed of an x-ray source with minimum focal spot size of 1μm, a detector with pixel size of 9μm, and an appropriate system geometry. The articular lesion were graded as 4 scales according to the appearance of articular surface on phase-contrast radiography and histopathology. The imaging findings were correlated with histopathology.

Correlation of grading of articular cartilage lesion between phase-contrast radiography and histopathology was moderately high (r=0.7) and statistically significant (p=0.001). For each specimen of articular cartilage lesions, phase-contrast images were reflective of their gross morphological appearance. The phase contrast radiography of the cartilage on the normal knee joint showed homogeniety, with an average height of 60 µm and moderate density. But, in the rheumatoid arthritis model, phase contrast radiography showed heterogeneities and irregularity of the articular cartilage displaying cartilage destruction.

This phase-contrast imaging with a compact x-ray source can allow the visualization of cartilage lesions on knee joints. Gross cartilage defects, even at early stages of development, can be visualized by this phase-contrast imaging technique.

Phase-contrast radiography with a compact x-ray source may be applicable to demonstrating articular cartilage lesions in patients with rheumatoid arthritis or osteoarthritis.

Heo, E, Chon, K, Kim, H, Kim, K, Jhung, S, Yoon, K, Articular Cartilage Imaging by Phase-contrast Radiography in Rheumatoid Arthritis Mice Model: Comparison with Histopathology.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5015188.html