IEEE Trans Biomed Eng. 2019 Jun;66(6):1779-1790. doi: 10.1109/TBME.2018.2879362. Epub 2018 Nov 2.
Chronic kidney disease (CKD) is a serious medical condition characterized by gradual loss of kidney function. Early detection and diagnosis is mandatory for adequate therapy and prognostic improvement. Hence, in the current pilot study we explore the use of image registration methods for detecting renal morphologic changes in patients with CKD.
Ten healthy volunteers and nine patients with presumed CKD underwent dynamic T1 weighted imaging without contrast agent. From real and simulated dynamic time series, kidney deformation fields were estimated using a poroelastic deformation model. From the deformation fields several quantitative parameters reflecting pressure gradients, and volumetric and shear deformations were computed. Eight of the patients also underwent a kidney biopsy as a gold standard.
We found that the absolute deformation, normalized volume changes, as well as pressure gradients correlated significantly with arteriosclerosis from biopsy assessments. Furthermore, our results indicate that current image registration methodologies are lacking sensitivity to recover mild changes in tissue stiffness.
Image registration applied to dynamic time series correlated with structural renal changes and should be further explored as a tool for invasive measurements of arteriosclerosis.
Under the assumption that the proposed framework can be further developed in terms of sensitivity and specificity, it can provide clinicians with a non-invasive tool of high spatial coverage available for characterization of arteriosclerosis and potentially other pathological changes observed in chronic kidney disease.
慢性肾脏病(CKD)是一种严重的医学病症,其特征为肾功能逐渐丧失。为了进行充分的治疗和改善预后,早期发现和诊断是必要的。因此,在当前的初步研究中,我们探讨了使用图像配准方法来检测 CKD 患者的肾脏形态变化。
十名健康志愿者和九名疑似 CKD 患者接受了无造影剂的动态 T1 加权成像。从真实和模拟的动态时间序列中,使用多孔弹性变形模型估计肾脏变形场。从变形场中计算了反映压力梯度、体积和剪切变形的几个定量参数。其中八名患者还进行了肾脏活检作为金标准。
我们发现,绝对变形、归一化体积变化以及压力梯度与活检评估的动脉硬化显著相关。此外,我们的结果表明,当前的图像配准方法缺乏对组织硬度的轻微变化进行恢复的敏感性。
应用于动态时间序列的图像配准与结构肾脏变化相关,应进一步作为评估动脉硬化的侵入性测量工具进行探索。
假设所提出的框架在灵敏度和特异性方面可以进一步发展,那么它可以为临床医生提供一种非侵入性的、具有高空间覆盖范围的工具,用于表征动脉硬化以及可能在慢性肾脏病中观察到的其他病理变化。