A Novel Semiautomatic Parenchyma Extraction Method for Improved MRI R2*Relaxometry of Iron Loaded Liver
A Novel Semiautomatic Parenchyma Extraction Method for Improved MRI R2*Relaxometry of Iron Loaded Liver
复制标题
一种改进载铁肝脏 MRI R2* 松弛测量的新型半自动实质提取方法
DOI：
10.1002/jmri.24331
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发表时间：
2014-07-01
影响因子：
4.4
通讯作者：
He, Taigang
中科院分区：
文献类型：
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作者：
Feng, Yanqiu;Feng, Meiyan;He, Taigang
目的：提出并评估一种自动的方法，从手动划定的整个肝脏提取实质的R2 * 测量的铁load.Materials和方法：在所有的，108输血依赖性患者的肝脏铁含量范围广泛的扫描与多回波梯度回波序列。通过将肝实质的平均信号拟合到噪声校正的单指数模型来测量R2 *，所述肝实质由所提出的半自动实质提取（SAPE）、传统的手动划定的多个感兴趣区域（mROI）和T2 * 阈值方法提取。通过模拟评估SAPE方法的R2 * 测量准确性;使用变异系数（CoV）从体内数据评估SAPE、mROI和T2 * 阈值的观察者内和观察者间重现性。结果：在模拟中，使用SAPE测量R2 * 的平均绝对百分比误差为0.23%（范围为0.01%-1.09%）。在体研究中，SAPE的观察者内和观察者间重复性的CoV分别为0.83%和1.39%，mROI的CoV分别为3.63%和6.28%，T2 * 阈值的CoV分别为1.62%和2.66%。使用SAPE方法改进的磁共振成像（MRI）R2 * 再现性可能导致更准确的组织表征和增加的诊断信心。
Purpose: To propose and evaluate an automatic method of extracting parenchyma from a manually delineated whole liver for the R2* measurement of iron load.Materials and Methods: In all, 108 transfusion-dependent patients with a wide range of hepatic iron content were scanned with a multiecho gradient-echo sequence. The R2* was measured by fitting the average signal of liver parenchyma, extracted by the proposed semiautomatic parenchyma extraction (SAPE), traditional manually delineated multiple regions-of-interest (mROIs), and T2* thresholding methods to the noise-corrected monoexponential model. The R2* measurement accuracy of the SAPE method was evaluated through simulation; the intra- and interobserver reproducibility of SAPE, mROI, and T2* thresholding were assessed from the in vivo data using coefficient of variation (CoV).Results: In the simulation, the mean absolute percentage error of R2* measurement using SAPE was 0.23% (range 0.01%-1.09%). In vivo study, the CoVs of intra- and interobserver reproducibility were 0.83%, 1.39% for SAPE, 3.63%, 6.28% for mROI, and 1.62%, 2.66% for T2* thresholding, respectively.Conclusion: The SAPE method provides an accurate and reliable approach to assessing the overall hepatic iron content. The improved magnetic resonance imaging (MRI) R2* reproducibility using the SAPE method may lead to more accurate tissue characterization and increased diagnostic confidence.