使用多光谱自回归滑动平均模型进行定量磁敏感图评估肝脏铁过载。
Quantitative Susceptibility Mapping Using a Multispectral Autoregressive Moving Average Model to Assess Hepatic Iron Overload.
机构信息
Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
Department of Biomedical Engineering, The University of Memphis, Memphis, Tennessee, USA.
出版信息
J Magn Reson Imaging. 2021 Sep;54(3):721-727. doi: 10.1002/jmri.27584. Epub 2021 Feb 26.
BACKGROUND
R2*-MRI is clinically used to noninvasively assess hepatic iron content (HIC) to guide potential iron chelation therapy. However, coexisting pathologies, such as fibrosis and steatosis, affect R2* measurements and may thus confound HIC estimations.
PURPOSE
To evaluate whether a multispectral auto regressive moving average (ARMA) model can be used in conjunction with quantitative susceptibility mapping (QSM) to measure magnetic susceptibility as a confounder-free predictor of HIC.
STUDY TYPE
Phantom study and in vivo cohort.
SUBJECTS
Nine iron phantoms covering clinically relevant R2* range (20-1200/second) and 48 patients (22 male, 26 female, median age 18 years).
FIELD STRENGTH/SEQUENCE: Three-dimensional (3D) and two-dimensional (2D) multi-echo gradient echo (GRE) at 1.5 T.
ASSESSMENT
ARMA-QSM modeling was performed on the complex 3D GRE signal to estimate R2*, fat fraction (FF), and susceptibility measurements. R2*-based dry clinical HIC values were calculated from the 2D GRE acquisition using a published R2*-HIC calibration curve as reference standard.
STATISTICAL TESTS
Linear regression analysis was performed to compare ARMA R2* and susceptibility-based estimates to iron concentrations and dry clinical HIC values in phantoms and patients, respectively.
RESULTS
In phantoms, the ARMA R2* and susceptibility values strongly correlated with iron concentrations (R ≥ 0.9). In patients, the ARMA R2* values highly correlated (R = 0.97) with clinical HIC values with slope = 0.026, and the susceptibility values showed good correlation (R = 0.82) with clinical dry HIC values with slope = 3.3 and produced a dry-to-wet HIC ratio of 4.8.
DATA CONCLUSION
This study shows the feasibility that ARMA-QSM can simultaneously estimate susceptibility-based wet HIC, R2*-based dry HIC and FFs from a single multi-echo GRE acquisition. Our results demonstrate that both, R2* and susceptibility-based wet HIC values estimated with ARMA-QSM showed good association with clinical dry HIC values with slopes similar to published R2*-biopsy HIC calibration and dry-to-wet tissue weight ratio, respectively. Hence, our study shows that ARMA-QSM can provide potentially confounder-free assessment of hepatic iron overload.
LEVEL OF EVIDENCE
3 TECHNICAL EFFICACY: Stage 2.
背景
R2*-MRI 临床上用于非侵入性地评估肝铁含量（HIC），以指导潜在的铁螯合治疗。然而，共存的病理学，如纤维化和脂肪变性，会影响 R2*的测量，从而可能干扰 HIC 的估计。
目的
评估多谱自动回归移动平均（ARMA）模型是否可与定量磁化率映射（QSM）结合使用，以测量磁化率作为无混杂因素的 HIC 预测因子。
研究类型
体模研究和体内队列研究。
受试者
9 个涵盖临床相关 R2*范围（20-1200/秒）的铁体模和 48 名患者（22 名男性，26 名女性，中位年龄 18 岁）。
磁场强度/序列：1.5T 下的三维（3D）和二维（2D）多回波梯度回波（GRE）。
评估
对复杂的 3D GRE 信号进行 ARMA-QSM 建模，以估计 R2*、脂肪分数（FF）和磁化率测量值。使用已发表的 R2*-HIC 校准曲线作为参考标准，从 2D GRE 采集计算基于 R2*的干临床 HIC 值。
统计学检验
对体模和患者的 ARMA R2*和基于磁化率的估计值与铁浓度和干临床 HIC 值进行线性回归分析。
结果
在体模中，ARMA R2和磁化率值与铁浓度强烈相关（R ≥ 0.9）。在患者中，ARMA R2值与临床 HIC 值高度相关（R = 0.97），斜率为 0.026，磁化率值与临床干 HIC 值具有良好的相关性（R = 0.82），斜率为 3.3，并产生 4.8 的干湿 HIC 比值。
数据结论
本研究表明，ARMA-QSM 可从单次多回波 GRE 采集同时估计基于磁化率的湿 HIC、基于 R2的干 HIC 和 FF，这是可行的。我们的结果表明，基于 ARMA-QSM 估计的 R2和基于磁化率的湿 HIC 值与临床干 HIC 值具有良好的相关性，斜率与已发表的 R2*-活检 HIC 校准和干-湿组织重量比相似。因此，本研究表明 ARMA-QSM 可以提供潜在无混杂因素的肝铁过载评估。
证据水平
3 级 技术功效：第 2 阶段。
Zotero 插件