무릎 연골 두께 아틀라스를 통한 손상 평가 기법

Abstract

Abstract: Osteoarthritis is the most common chronic joint disease in the world. With its progression, cartilage thick-ness tends to diminish, which causes severe pain to human being. One way to examine the stage of osteoarthritisis to measure the cartilage thickness. When it comes to inter-subject study, however, it is not easy task to comparecartilage thickness since every human being has different cartilage structure. In this paper, we propose a methodto assess cartilage defect using MRI inter-subject thickness comparison. First, we used manual segmentation methodto build accurate atlas images and each segmented image was labeled as articular surface and bone-cartilage interfacein order to measure the thickness. Secondly, each point in the bone-cartilage interface was assigned the measuredthickness so that the thickness does not change after registration. We used affine transformation and SyGN to getdeformation fields which were then applied to thickness images to have cartilage thickness atlas. In this way, it ispossible to investigate pixel-by-pixel thickness comparison. Lastly, the atlas images were made according to theirosteoarthritis grade which indicates the degree of its progression. The result atlas images were compared using theanalysis of variance in order to verify the validity of our method. The result shows that a significant difference isexisted among them with p < 0.001.Key words: osteoarthritis, Kellgren & Lawrence grade, cartilage thickness, magnetic resonance imaging, inter-sub-ject study, analysis of variance