Quantitative MRI analysis method for longitudinal assessment of knee OA

描述（由申请人提供）：磁共振成像（MRI）提供膝关节关节软骨的直接三维（3D）可视化。新型高场三特斯拉（3T） MRI扫描仪和专门的脉冲序列可以提供出色的空间分辨率和高对比度的图像，可以非常详细地显示膝关节软骨和其他结构。这些新技术非常适合应用图像处理软件在MRI切片上分割（识别和勾勒）软骨板，用于骨关节炎（OA）进展的定量评估。一些学术和工业附属的研究小组已经开发了软件工具来分割膝关节MRI扫描的软骨板。然而，从整个软骨板或甚至指定的子区域得出的测量结果可能对变化相对不敏感。我们建议验证这样一个假设，即基于比较膝关节软骨局部区域的分析将比软骨形态测量法的整体测量更能检测膝关节OA的变化。我们将使用我们实验室开发的软件工具来分割膝关节MRI图像集上的关节软骨。3D配准软件将用于对齐基线和后续分段扫描。一旦基线和后续分割图像被注册（对齐），该技术将测量靠近已知软骨变薄区域的区域的体积变化。我们还将开发和验证基于骨髓水肿（BME）、骨囊肿和骨赘体积测量的新的定量指标。我们的项目将使用来自骨关节炎倡议（OAI）的数据和图像，这是美国国立卫生研究院（NIH）的一项大型研究，约有4,800名入组受试者被细分为三组：发病率队列、进展队列和对照队列。来自进展队列的400名受试者将被用来检验我们的假设。我们会进一步发展现有的分析软件，以达到研究的目的。

DESCRIPTION (provided by applicant): Magnetic resonance imaging (MRI) offers direct three dimensional (3D) visualization of the articular cartilage in the knee joint. New high-field three-Tesla (3T) MRI scanners and specialized pulse sequences can provide images with excellent spatial resolution and high contrast, which show the cartilage and other structures of the knee in great detail. These new techniques are ideal for the application of image processing software to segment (identify and outline) cartilage plates on MRI slices for the quantitative assessment of osteoarthritis (OA) progression. Several academic and industry affiliated research groups have developed software tools to segment the cartilage plates on knee MRI scans. However measures derived from the full cartilage plate or even specified subregions can be relatively insensitive to change. We propose to test the hypothesis that an analysis based on comparing local regions of the knee cartilage will be more responsive than global measures of cartilage morphometry for detecting knee OA changes. We will use a software tool developed in our laboratory to segment the articular cartilage on knee MRI image sets. 3D registration software will be used to align baseline and follow-up segmented scans. Once the baseline and follow-up segmented images are registered (aligned) the technique will measure volume change in a region in close proximity to a known cartilage area of thinning. We will also develop and validate new quantitative metrics based on measurements of bone marrow edema (BME), bone cysts, and osteophyte volume. Our project will use data and images from the osteoarthritis Initiative (OAI), a large National Institutes of Health (NIH) study with approximately 4,800 enrolled subjects subdivided into three groups: the Incidence Cohort, the Progression Cohort, and the Control Cohort. A subset of 400 subjects from the Progression Cohort will be used to test our hypotheses. Our existing analysis software will be further developed to facilitate the aims of the study. PUBLIC HEALTH RELEVANCE: This project will address public health concerns by validating an improved technique for evaluating osteoarthritis of the knee. The work will contribute to the public health indirectly by assisting others in developing and evaluating OA therapies.