EARLY DIAGNOSIS OF GROWTH DISORDERS USING MR IMAGING

骨端的特殊软骨结构，骨骺 和生长板（骨骺板）是儿童正常骨生长的部位。 四肢畸形是由于这种生长的软骨受到损伤而引起的。 提示 治疗骨骺和骨骺损伤可以防止或最小化 异常的骨骼生长 因为对生长软骨的损伤 通过X光直接检测， 在受伤后几个月，当骨骼异常发展时。 的假设 需要评估的是，磁共振（MR）允许更早和更长的时间 准确评估生长障碍，通过显示 生长软骨的组成和血管分布。 一个推论是， 生长扰动的可能性可以通过分析 生长软骨的损伤模式。 一、MR的特点 软骨骨骺的正常解剖和发育， 骨骺（包括信号特征和T2弛豫测量 时间）将与组织化学相关联。 软骨 将在两个实验中研究由于骺板直接损伤引起的异常。 动物模型来测试以下假设：a）在横向 骨折，骨折延伸至骨骺侧 可被MR检测到，并大大增加了生长停滞的可能性; B）在垂直骨折中，出现经骺端血管分布， 软骨组织的解体导致生长停滞。 异常 将在动物中研究由于对生长软骨的间接损伤 骨骺缺血模型，以确定是否有异常血流 未骨化骨骺的血管通道（通过对比可检测到， 增强的MR）导致骨骺和骨骺的缺血性损伤 软骨，并最终在异常骨化。 的队列研究 骨骺骨折的儿童将进行评估， MR成像预测骨桥形成的早期证据 骨骺软骨损伤的迹象 这项研究的最终目标是 （a）开发早期检测生长损害的方法 允许早期治疗和预防畸形的软骨，B） 为了更好地了解骨骼生长障碍， 体内软骨损伤的演变，以及c）验证模型 这可能有助于未来研究新的治疗生长停滞的方法。

Specialized cartilaginous structures at the ends of bones, the epiphysis and growth plate (physis), are the site of normal bone growth in children. Limb deformity results from damage to this growth cartilage. Prompt treatment of epiphyseal and physeal injuries can prevent or minimize abnormal bone growth. Because damage to the growth cartilage is not directly detectable radiographically, growth disturbances are discovered only months after injury, when bony abnormalities develop. The hypothesis to be evaluated is that Magnetic Resonance (MR) allows earlier and more accurate evaluation of growth disorders by showing alterations in the composition and vascularity of the growth cartilage. A corollary is that the likelihood of growth disturbance can be predicted by analyzing the pattern of injury to the growth cartilage. First, MR characteristics of the normal anatomy and development of the cartilaginous epiphysis and physis (including signal characteristics, and measurements of T2 relaxation times) will be correlated with histochemistry. The cartilaginous abnormalities due to direct injury to the physis will be studied in two animal models to test the following hypothesis: a) In transverse fractures, extension of the fracture to the epiphyseal side of the physis is detectable by MR and greatly increases the likelihood of growth arrest; b) In vertical fractures, development of a transphyseal vascularity and disorganization of the cartilage results in growth arrest. Abnormalities due to indirect injury to the growth cartilage will be studied in an animal model of epiphyseal ischemia to determine whether abnormal blood flow in the vascular channels of the unossified epiphysis (detectable by contrast- enhanced MR) results in ischemic damage to the epiphyseal and physeal cartilage and eventually in abnormal ossification. A cohort study of children with physeal fractures will be performed to evaluate the role of MR imaging in predicting bony bridge formation based on the early evidence of damage to the physeal cartilage. The ultimate goals of this research are; a) to develop methods of early detection of damage to the growth cartilage which will allow earlier therapy and prevention of deformity, b) to gain a better understanding of skeletal growth disturbances by seeing the evolution of cartilaginous injury in vivo, and c) to validate models which may serve for future research on new therapies for growth arrest.