Early Diagnosis of Growth Disorders Uing MR Imaging

描述(申请人提供)：本研究的目的是检测 应用NOVICE预测骨痂缺血及其生长后遗症 非侵入性磁共振(MR)技术的出现。在动物模型中，我们建议 确定缺血的最早变化，区分早期和晚期 缺血导致缺血性坏死；并预测 增长停滞。除了常规MR测量(质子密度和T2 松弛)，我们将研究早期Gd的血流灌注相关变化 (Gd)增强成像；线扩散扫描的扩散相关改变 和扩散张量成像。我们还将评估 延迟发现包括糖胺聚糖在内的软骨基质耗竭 Gd增强成像，并通过磁化转移成像测定胶原含量。 主要的假设是MR参数可以1)发现早期的缺血，2) 鉴别早期和晚期导致后遗症的缺血，以及3)预测 通过反映组织结构和组织结构的MR参数显示生长畸形 未成熟骨骺的血管化。 骨骺缺血是许多常见儿科疾病的共同致病途径。 精神错乱。缺血导致股骨头缺血性坏死 经常导致儿童髋部畸形和残疾。长出的臀部 在成年人中，异常也容易患退行性关节疾病；超过 在所有患有髋关节骨性关节炎的成年人中，有一半患有髋关节疾病 孩子们。软骨疾病的成像有助于指导早期治疗， 防止或尽量减少畸形，并发现易早产的儿童 成年期软骨退变。 其具体目的是：1)确定正常人的MR组织特征 骨盆软骨。具体地说，我们希望测试更大的 未成熟的骨骺软骨的细胞化和血管化导致 不同的MR组织特征；2)早期缺血，确定颞叶 弥散成像、T2图和Gd增强图的空间差异 成像；3)在长时间的缺血中，确定哪些磁共振参数最能预测 不可逆转的损伤；以及4)在缺血性坏死的模型中，确定 磁共振参数可以预测异常生长。

DESCRIPTION (provided by applicant): The goal of this research is the detection of epiphyseal ischemia and prediction of its growth sequelae using novel non-invasive magnetic resonance (MR) approaches. In animal models, we propose to determine the earliest changes in ischemia, to differentiate early from late ischemia leading to avascular necrosis; and to predict the deverlopment of growth arrest. In addition to conventional MR measures (proton density and T2 relaxation), we will investigate perfusion-related changes by early gadolinum (Gd) enhanced imaging; and diffusion related changes by line diffusion scanning and diffusion tensor imaging. We will also evaluate disturbances of the cartilaginous matrix including glycosaminoglycan depletion revealed by delayed GD enhanced imaging, and collagen content by magnetization transfer imaging. The major hypotheses are that MR parameters can 1) detect early ischemia, 2) differentiate early from late ischemia leading to sequelae, and 3) predict growth deformity through MR parameters that reflect tissue structure and vascularization of the immature epiphysis. Epiphyseal ischemia is a pathogenic pathway shared by many common pediatric disorders. Ischemia leading to avascular necrosis of the femoral head frequently causes hip deformity and disability in childhood. A hip that grows abnormally also predisposes to degenerative joint disease in adult; more than half of all adults with osteoarthritis of the hip suffered hip diseases as children. Imaging of cartilaginous disorders serves to guide early therapy, prevent or minimize deformity, and detect children predisposed to premature cartilage degeneration in adulthood. The specific aims are to: 1) determine the MR tissue characteristics of normal epiphyseal cartilage. Specifically, we wish to test whether the greater cellularity and vascularization of immature epiphyseal cartilage result in different MR tissue characteristics; 2) in early ischemia, determine temporal and spatial differences between diffusion imaging, T2 maps and Gd-enhanced imaging; 3) in prolonged ischemia, determine which MR parameters best predict irreversible damage; and 4) in a model of avascular necrosis, determine which MR parameters predict abnormal growth.