Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.
Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA.
Magn Reson Med. 2023 Apr;89(4):1418-1428. doi: 10.1002/mrm.29529. Epub 2022 Nov 21.
To validate QSM-based biomagnetic liver susceptometry (BLS) to measure liver iron overload at 1.5 T and 3.0 T using superconducting quantum interference devices (SQUID)-based BLS as reference.
Subjects with known or suspected iron overload were recruited for QSM-BLS at 1.5 T and 3.0 T using eight different protocols. SQUID-BLS was also obtained in each subject to provide susceptibility reference. A recent QSM method based on data-adaptive regularization was used to obtain susceptibility and maps. Measurements of susceptibility and were obtained in the right liver lobe. Linear mixed-effects analysis was used to estimate the contribution of specific acquisition parameters to QSM-BLS. Linear regression and Bland-Altman analyses were used to assess the relationship between QSM-BLS and SQUID-BLS/ .
Susceptibility maps showed high subjective quality for each acquisition protocol across different iron levels. High linear correlation was observed between QSM-BLS and SQUID-BLS at 1.5 T (r range, [0.82, 0.84]) and 3.0 T (r range, [0.77, 0.85]) across different acquisition protocols. QSM-BLS and were highly correlated at both field strengths (r range at 1.5 T, [0.94, 0.99]; 3.0 T, [0.93, 0.99]). High correlation (r = 0.99) between 1.5 T and 3.0 T QSM-BLS, with narrow reproducibility coefficients (range, [0.13, 0.21] ppm) were observed for each protocol.
This work evaluated the feasibility and performance of liver QSM-BLS across iron levels and acquisition protocols at 1.5 T and 3.0 T. High correlation and reproducibility were observed between QSM-BLS and SQUID-BLS across protocols and field strengths. In summary, QSM-BLS may enable reliable and reproducible quantification of liver iron concentration.
使用基于超导量子干涉仪（SQUID）的 BLS 作为参考，验证基于 QSM 的生物磁肝磁化率（BLS）在 1.5T 和 3.0T 下测量肝铁过载的准确性。
招募已知或疑似铁过载的受试者，在 1.5T 和 3.0T 下使用八种不同的方案进行 QSM-BLS。每个受试者也进行了 SQUID-BLS 测量以提供磁化率参考。使用基于数据自适应正则化的最新 QSM 方法来获得磁化率和图像。在右肝叶测量磁化率和图像。使用线性混合效应分析来估计特定采集参数对 QSM-BLS 的贡献。使用线性回归和 Bland-Altman 分析来评估 QSM-BLS 与 SQUID-BLS/之间的关系。
在不同的铁水平下，每种采集方案的磁化率图都具有较高的主观质量。在不同的采集方案中，在 1.5T（r 范围，[0.82，0.84]）和 3.0T（r 范围，[0.77，0.85]）之间观察到 QSM-BLS 与 SQUID-BLS 之间具有高度的线性相关性。在两种场强下，QSM-BLS 和都具有高度相关性（1.5T 时 r 范围为[0.94，0.99]；3.0T 时 r 范围为[0.93，0.99]）。对于每个方案，都观察到 1.5T 和 3.0T QSM-BLS 之间的高相关性（r=0.99）和较窄的再现性系数（范围，[0.13，0.21]ppm）。
本研究评估了在 1.5T 和 3.0T 下，跨铁水平和采集方案的肝脏 QSM-BLS 的可行性和性能。在协议和场强之间，QSM-BLS 与 SQUID-BLS 之间观察到高度相关性和再现性。总之，QSM-BLS 可能实现对肝铁浓度的可靠和可重复的定量。
