摘要目的证明分数阶微积分(FROC)扩散模型中的一套新参数(D、β和μ)可提高MRI在儿童高、低级别脑肿瘤鉴别诊断中的准确率。材料与方法本研究经医院执行审查委员会批准,患儿的法定监护人签署书面知情同意书。对67例脑肿瘤患儿行MR多b值扩散加权成像,将多b值扩散加权影像与FROC模型进行拟合,计算扩散系数D、分数阶参数β(与组织异质性)和微观结构数量μ。测定实体肿瘤的D、β、μ值,以正常灰质区为对照。使用Mann-Whitney U检验比较 Abstract Objective To prove that a new set of parameters (D, β and μ) in fractional calculus (FROC) diffusion model can improve the accuracy of MRI in the differential diagnosis of high and low grade brain tumors in children. Materials and Methods The study was approved by the Hospital Executive Review Board and the legal guardian of the child signed written informed consent. Sixty-seven children with brain tumors underwent MR multi-b diffusion weighted imaging. The multi-b diffusion weighted images were fitted with the FROC model to calculate the diffusion coefficient D, fractional parameter β (with tissue heterogeneity) and the number of microstructures μ. D, β, μ values ​​of solid tumors were measured and normal gray matter area was taken as control. Comparison using Mann-Whitney U test