O'Sullivan Finbarr, Roy Supratik, Eary Janet
The Statistical Laboratory, Department of Statistics, University College, Cork, Ireland.
Biostatistics. 2003 Jul;4(3):433-48. doi: 10.1093/biostatistics/4.3.433.
In vivo measurement of local tissue characteristics by modern bioimaging techniques such as positron emission tomography (PET) provides the opportunity to analyze quantitatively the role that tissue heterogeneity may play in understanding biological function. This paper develops a statistical measure of the heterogeneity of a tissue characteristic that is based on the deviation of the distribution of the tissue characteristic from a unimodal elliptically contoured spatial pattern. An efficient algorithm is developed for computation of the measure based on volumetric region of interest data. The technique is illustrated by application to data from PET imaging studies of fluorodeoxyglucose utilization in human sarcomas. A set of 74 sarcoma patients (with five-year follow-up survival information) were evaluated for heterogeneity as well as a number of other potential prognostic indicators of survival. A Cox proportional hazards analysis of these data shows that the degree of heterogeneity of the sarcoma is the major risk factor associated with patient death. Some theory is developed to analyze the asymptotic statistical behavior of the heterogeneity estimator. In the context of data arising from Poisson deconvolution (PET being the prime example), the heterogeneity estimator, which is a non-linear functional of the PET image data, is consistent and converges at a rate that is parametric in the injected dose.
通过正电子发射断层扫描（PET）等现代生物成像技术对局部组织特征进行体内测量，为定量分析组织异质性在理解生物学功能中可能发挥的作用提供了机会。本文基于组织特征分布与单峰椭圆轮廓空间模式的偏差，开发了一种组织特征异质性的统计量度。基于感兴趣体积区域数据，开发了一种计算该量度的高效算法。通过将该技术应用于人类肉瘤中氟脱氧葡萄糖利用的PET成像研究数据进行了说明。对一组74例肉瘤患者（有五年随访生存信息）进行了异质性以及其他一些潜在生存预后指标的评估。对这些数据进行的Cox比例风险分析表明，肉瘤的异质性程度是与患者死亡相关的主要风险因素。还发展了一些理论来分析异质性估计量的渐近统计行为。在泊松反卷积产生的数据背景下（PET是主要例子），作为PET图像数据的非线性泛函的异质性估计量是一致的，并且以与注射剂量相关的参数速率收敛。
