Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Lower Saxony, Germany.
Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Centre for Lung Research (DZL), Hannover, Lower Saxony, Germany.
Magn Reson Med. 2021 Sep;86(3):1482-1493. doi: 10.1002/mrm.28787. Epub 2021 Apr 9.
Contrast-free lung MRI based on Fourier decomposition is an attractive method to monitor various lung diseases. However, the accuracy of the current perfusion quantification is limited. In this study, a new approach for perfusion quantification based on voxel-wise proton density and median signal decay toward the steady state for Fourier decomposition-based techniques is proposed called Q (Q ).
Twenty patients with chronic obstructive pulmonary disease and 18 patients with chronic thromboembolic pulmonary hypertension received phase-resolved functional lung-MRI (PREFUL) and dynamic contrast-enhanced (DCE)-MRI. Nine healthy participants received phase-resolved functional lung-MRI only. Median values of Q were compared to a Fourier decomposition perfusion quantification presented by Kjørstad et al (Q ) and validated toward pulmonary blood flow derived by DCE-MRI (PBF ). Blood fraction maps determined by the new approach were calculated. Regional and global correlation coefficients were calculated, and Bland-Altman plots were created. Histogram analyses of all cohorts were created.
The introduced parameter Q showed only 2 mL/min/100 mL mean deviation to PBF in the patient cohort and showed less bias than Q . Significant increases of regional correlation with PBF were achieved (r = 0.3 vs. r = 0.2, P < .01*). The trend of global correlation toward PBF is not uniform, showing higher values for Q in the chronic obstructive pulmonary disease cohort than for Q and vice versa in the chronic thromboembolic pulmonary hypertension cohort. In contrast to Q , Q perfusion maps indicate a physiologic dorsoventral gradient in supine position similar to PBF with similar value distribution in the histograms.
We proposed a new approach for perfusion quantification of phase-resolved functional lung measurements. The developed parameter Q reveals a higher accuracy compared to Q .
基于傅里叶分解的无对比肺 MRI 是监测各种肺部疾病的一种很有吸引力的方法。然而，目前的灌注量化准确性有限。在这项研究中，我们提出了一种新的基于体素的质子密度和中值信号衰减的灌注量化方法，用于基于傅里叶分解的技术，称为 Q (Q)。
20 例慢性阻塞性肺疾病患者和 18 例慢性血栓栓塞性肺动脉高压患者接受了相位分辨功能肺 MRI (PREFUL) 和动态对比增强 (DCE)-MRI 检查。9 例健康受试者仅接受了相位分辨功能肺 MRI 检查。比较了新方法的 Q 与 Kjørstad 等人提出的傅里叶分解灌注量化方法 (Q) 以及与 DCE-MRI 衍生的肺血流 (PBF) 的相关性。计算了新方法确定的血液分数图。计算了局部和整体相关系数，并绘制了 Bland-Altman 图。对所有队列进行了直方图分析。
在患者队列中，引入的参数 Q 与 PBF 的平均偏差仅为 2 mL/min/100 mL，比 Q 具有更小的偏差。与 PBF 显著增加了局部相关性(r = 0.3 对 r = 0.2，P <.01*)。与 PBF 整体相关性的趋势并不一致，在慢性阻塞性肺疾病队列中，Q 的值高于 Q ，而在慢性血栓栓塞性肺动脉高压队列中则相反。与 Q 不同，Q 灌注图在仰卧位时显示出类似于 PBF 的生理背腹梯度，直方图中的值分布也相似。
我们提出了一种新的相位分辨功能肺测量灌注量化方法。与 Q 相比，新开发的 Q 参数具有更高的准确性。
