Renal Blood Oxygenation Level-Dependent Magnetic Resonance Imaging: A Sensitive and Objective Analysis.
Renal Blood Oxygenation Level-Dependent Magnetic Resonance Imaging: A Sensitive and Objective Analysis.
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DOI：
10.1097/rli.0000000000000190
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发表时间：
2015-12
影响因子：
6.7
通讯作者：
Prasad PV
中科院分区：
文献类型：
--
作者：
Thacker JM;Li LP;Li W;Zhou Y;Sprague SM;Prasad PV
确定一种用于分析肾血氧水平依赖性（BOLD）MRI数据的稳健（灵敏和客观）方法。47名受试者（30名慢性肾脏疾病患者和17名对照）在基线和呋塞米给药后使用多回波梯度回波序列进行成像。传统的分析包括区域分割（小皮质，大皮质和髓质），然后计算每个区域的平均值。此外，我们分割了整个实质，并计算了平均值（μ1）加上高阶矩（μ2、μ3和μ4）。两名评分员执行每个分割步骤，并使用类内相关系数（ICC）评估一致性。除了通常的统计学显著性测量（p值）外，我们还使用了效应量测量（科恩d值）来确定显著性结果。肾实质的平均值显示出评分者之间的最高一致性（ICC=0.99），较高的实质矩与大皮质ROI ICC相当。在健康受试者中，肾实质平均值对呋塞米给药后的变化也表现出显著的敏感性（p=0.002，d=0.84）;与髓质ROI一致（p=0.002，d=1.59）。当比较对照组和基线时患有CKD的受试者时，皮质ROI显示出显著差异（p=0.015，d=-0.69），而实质ROI没有显著差异（p=0.152，d=0.39）。所有区域的呋塞米给药后数据均产生显著差异（大皮质：p=0.026，d=-0.51;髓质：p=0.019，d=-0.61），肾实质ROI产生最大效应量（p=0.003，d=-0.75）。肾实质的高阶矩也显示出类似的显著差异。总体而言，我们的数据支持使用整个软组织来评价呋塞米给药后髓质的变化，呋塞米是一种广泛使用的药理学方法。高阶矩的变化表明，平均肾脏R2* 的变化不仅仅是变化，并且可以提供临床相关信息，而无需主观区域分割。为了评价对照组和基线CKD受试者之间的差异，大皮质ROI提供了最高的灵敏度和客观性。肾实质评估和大皮质ROI的组合可以提供评价肾BOLD MRI数据的最稳健方法。
To determine a robust (sensitive and objective) method for analyzing renal blood oxygenation level-dependent (BOLD) MRI data. 47 subjects (30 with Chronic Kidney Disease and 17 controls) were imaged at baseline and following furosemide with a multi-echo gradient recalled echo sequence. Conventional analysis consisted of regional segmentation (small-cortex, large-cortex and medulla), followed by computing the mean of each region. Additionally, we segmented the entire parenchyma and computed the mean (μ1) plus higher moments (μ2, μ3, and μ4). Two raters performed each of the segmentation steps and agreement was assessed with intra-class correlation coefficients (ICC). We used a measure of effect size (Cohen’s d value), in addition to the usual measure of statistical significance, p-values, for determining significant results. The mean of the renal parenchyma showed the highest agreement between raters (ICC=0.99), and the higher parenchyma moments were on par with large cortical ROI ICC. The renal parenchymal mean also exhibited significant sensitivity to changes post-furosemide in healthy subjects (p=0.002, d=0.84); in agreement with medullary ROIs (p=0.002, d=1.59). When comparing controls and subjects with CKD at baseline, cortical ROI showed a significant difference (p=0.015, d=−0.69) while the parenchyma ROI did not (p=0.152, d=0.39). Post-furosemide data in all regions resulted in a significant difference (large-cortex: p=0.026, d=−0.51; medulla: p=0.019, d=−0.61) with the renal parenchyma ROI resulting in the largest effect size (p=0.003, d=−0.75). Higher moments of the renal parenchyma showed similar significant differences as well. Overall, our data support the use of the entire parenchyma to evaluate changes in the medulla following administration of furosemide, a widely used pharmacological maneuver. Changes in higher moments indicate that there is more than just a shift in the mean renal R2* and may provide clinically relevant information without the need for subjective regional segmentation. For evaluating differences between controls and subjects with CKD at baseline; large cortical ROI provided the highest sensitivity and objectivity. A combination of renal parenchyma assessment and large cortical ROI may provide the most robust method of evaluating renal BOLD MRI data.