Zhang Qihao, Luo Xianfu, Zhou Liangdong, Nguyen Thanh D, Prince Martin R, Spincemaille Pascal, Wang Yi
IEEE Trans Biomed Eng. 2023 Mar;70(3):980-990. doi: 10.1109/TBME.2022.3207057. Epub 2023 Feb 17.
We quantify liver perfusion using quantitative transport mapping (QTM) method that is free of arterial input function (AIF). QTM method is validated in a vasculature computational fluid dynamics (CFD) simulation and is applied for processing dynamic contrast enhanced (DCE) MRI images in differentiating liver with nonalcoholic fatty liver disease (NAFLD) from healthy controls using pathology reference in a preclinical rabbit model.
QTM method was validated on a liver perfusion simulation based on fluid dynamics using a rat liver vasculature model and the mass transport equation. In the NAFLD grading task, DCE MRI images of 7 adult rabbits with methionine choline-deficient diet-induced nonalcoholic steatohepatitis (NASH), 8 adult rabbits with simple steatosis (SS) were acquired and processed using QTM method and dual-input two compartment Kety's method respectively. Statistical analysis was performed on six perfusion parameters: velocity magnitude | u | derived from QTM, liver arterial blood flow LBF, liver venous blood flow LBF, permeability K, blood volume V and extravascular space volume V averaged in liver ROI.
In the simulation, QTM method successfully reconstructed blood flow, reduced error by 48% compared to Kety's method. In the preclinical study, only QTM |u| showed significant difference between high grade NAFLD group and low grade NAFLD group.
QTM postprocesses DCE-MRI automatically through deconvolution in space and time to solve the inverse problem of the transport equation. Comparing with Kety's method, QTM method showed higher accuracy and better differentiation in NAFLD classification task.
We propose to apply QTM method in liver DCE MRI perfusion quantification.
我们使用无需动脉输入函数（AIF）的定量传输映射（QTM）方法对肝脏灌注进行量化。QTM方法在血管计算流体动力学（CFD）模拟中得到验证，并应用于处理动态对比增强（DCE）MRI图像，以在临床前兔模型中使用病理学参考将非酒精性脂肪性肝病（NAFLD）肝脏与健康对照进行区分。
基于流体动力学，使用大鼠肝脏血管模型和质量传输方程，在肝脏灌注模拟中对QTM方法进行验证。在NAFLD分级任务中，分别使用QTM方法和双输入双室凯蒂方法获取并处理了7只成年兔的蛋氨酸胆碱缺乏饮食诱导的非酒精性脂肪性肝炎（NASH）、8只成年兔的单纯性脂肪变性（SS）的DCE MRI图像。对六个灌注参数进行统计分析：从QTM得出的速度大小|u|、肝脏动脉血流量LBF、肝脏静脉血流量LBF、渗透率K、血容量V和肝脏感兴趣区域（ROI）中平均的血管外空间体积V。
在模拟中，QTM方法成功重建了血流，与凯蒂方法相比误差降低了48%。在临床前研究中，只有QTM|u|在高等级NAFLD组和低等级NAFLD组之间显示出显著差异。
QTM通过时空反卷积自动对DCE-MRI进行后处理，以解决传输方程的反问题。与凯蒂方法相比，QTM方法在NAFLD分类任务中显示出更高的准确性和更好的区分能力。
我们建议将QTM方法应用于肝脏DCE MRI灌注量化。
