Understanding Skeletal Growth Using Diffusion Tensor Imaging of the Physis and Metaphysis

项目总结 对纵向骨骼生长的主要器官生长板或生长板的系列评估，用一种新的 磁共振技术--生长板和干骺端的弥散张量成像(DTI-P/M)可以改善临床决策 导致儿童身材矮小的条件。生长激素治疗矮小 (GH)治疗导致的医疗费用每年可高达110亿美元。评估对GH的反应需要 高度速度的确定，目前依赖于不敏感的外部长度测量或 身高，并要求身高测量间隔至少1年。预测增长潜力，对 确定谁将从促进生长的治疗中受益，目前是通过评估生长激素来估计的 手部的变化只是间接反映了膝盖的变化，而膝盖是骨骼生长最多的地方。这 该提案解决了临床上尚未满足的需求，即需要一种更好的工具来确定身高速度和预测生长 潜力。我们开创了膝关节的DTI-P/M技术，这是一种基于各向异性产生束状结构的技术 测量骨束体积、骨束长度和通过骨赘和干骺端的水的扩散 分数各向异性(FA)，组织组织化的标志。我们的建议克服了目前在知识方面的差距 关于DTI-P/M随时间和对生长激素的反应而进行的测量。我们的具体目标将考验中央 股骨远端DTI-P/M可作为身高诊断和预测工具的假说 速度、生长潜力和生长激素反应：目的1)使用DTI-P/M参数预测身高速度 60名儿童的青春期生长突发期；目的2)预测青春期停止时的生长潜力 40名儿童的生长发育；以及目的3)根据DTI-P/M的早期变化评估生长激素治疗的反应 50例儿童生长激素治疗前和治疗后的束体积、长度和FA参数分析 临床随访4、8、12个月。实现这些目标将证明DTI-P/M是一种提高精度的工具 使用促进生长的药物和改善整形外科手术的时机进行治疗。

PROJECT SUMMARY Serial assessment of the main organ of longitudinal skeletal growth, the growth plate or physis, with a novel MR technique, diffusion tensor imaging of the physis and metaphysis (DTI-P/M), can improve clinical decision making for conditions that lead to short stature in children. Treatment of short stature using growth hormone (GH) therapy leads to healthcare costs that can rise to $11 billion per year. Assessing response to GH requires determination of height velocity, which currently relies on insensitive external measurements of length or stature and requires height measurements at least 1 year apart. Predicting growth potential, crucial to identifying who will benefit from growth-enhancing treatment, is currently estimated by assessing physeal changes on the hand that only indirectly reflect those of the knee, where most skeletal growth occurs. This proposal addresses an unmet clinical need for a better tool to determine height velocity and predict growth potential. We have pioneered DTI-P/M of the knee, a technique that generates tracts based on anisotropic diffusion of water through the physeal and metaphyseal columns, to measure tract volume, tract length, and fractional anisotropy (FA), a marker of tissue organization. Our proposal overcomes current gaps in knowledge regarding DTI-P/M measurements over time and in response to GH. Our specific aims will test the central hypothesis that DTI-P/M of the distal femur can be established as a diagnostic and predictive tool for height velocity, growth potential and GH response: Aim 1) Predict height velocity using DTI-P/M parameters during the adolescent growth spurt in 60 children; Aim 2) Predict growth potential during cessation of adolescent growth in 40 children; and Aim 3) Assess response to GH therapy based on early changes in DTI-P/M parameters by analyzing tract volume and length and FA in 50 children prior to initiation of GH therapy and at 4, 8, and 12 month clinical follow-ups. Achieving these aims will validate DTI-P/M as a tool for precision therapy with growth enhancing medications and improved timing of orthopedic procedures.