绝经后女性腰椎骨密度不同时的磁化率和脂肪含量。
Magnetic Susceptibility and Fat Content in the Lumbar Spine of Postmenopausal Women With Varying Bone Mineral Density.
机构信息
Guangdong Provincial Key Laboratory of Medical Image Processing, School of Biomedical Engineering, Southern Medical University, Guangzhou, P.R. China.
Department of Radiology, Weill Medical College of Cornell University, New York, New York, USA.
出版信息
J Magn Reson Imaging. 2019 Apr;49(4):1020-1028. doi: 10.1002/jmri.26279. Epub 2018 Sep 25.
BACKGROUND
Osteoporosis is a systemic disease characterized by low bone mass with increased fracture risk. Quantitative imaging biomarkers are important for accurately predicting fracture risk in patients with osteoporosis.
PURPOSE
To prospectively study the changes of magnetic susceptibility and fat content in the lumbar spine of postmenopausal females with varying bone mineral density (BMD), and investigate their application to osteoporosis assessment.
STUDY TYPE
Cohort.
POPULATION
In all, 108 postmenopausal females (58.2 ± 6.7 [range 45-79] years old).
FIELD STRENGTH/SEQUENCE: Quantitative computed tomography (QCT) performed on a 64-detector CT scanner; quantitative susceptibility mapping (QSM) and mDixon quant MR imaging performed using a 3.0T imaging system with a 16-channel posterior coil.
ASSESSMENT
QCT, QSM, and mDixon were performed in 108 postmenopausal females to measure vertebral BMD, susceptibility, and proton-density fat fraction (PDFF). Mean vertebral QSM and PDFF were compared among three BMD cohorts (normal, osteopenic, and osteoporotic). Receiver operating characteristic analyses were performed to evaluate the performance of QSM, PDFF, and QSM+PDFF for assessing osteoporosis.
STATISTICAL TESTS
Parameters were compared using Kruskal-Wallis test and Pearson test.
RESULTS
Compared with that of the normal BMD group (-17.0 ± 43.6 ppb), vertebral QSM was significantly increased in osteopenia (30.8 ± 47.0 ppb, P < 0.001), and further increased in osteoporosis (82.0 ± 39.9 ppb, P < 0.001). QSM was negatively correlated with BMD (r = -0.70, P < 0.001) and positively correlated with PDFF (r = 0.64, P < 0.001). Compared with the area under the curve (AUC) of PDFF, the AUC of QSM was higher in differentiating between normal and osteoporosis (P = 0.44), and between osteopenia and osteoporosis (P = 0.13), but without statistical significance. The AUC of QSM+PDFF was significantly higher than that of PDFF for differentiating between osteopenia and osteoporosis (0.82 vs. 0.70, P = 0.039).
DATA CONCLUSION
The combination of vertebral susceptibility and fat content may be a promising marker for assessing postmenopausal osteoporosis.
LEVEL OF EVIDENCE
1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:1020-1028.
背景
骨质疏松症是一种以骨量低、骨折风险增加为特征的系统性疾病。定量影像学生物标志物对于准确预测骨质疏松症患者的骨折风险非常重要。
目的
前瞻性研究不同骨密度（BMD）绝经后女性腰椎的磁化率和脂肪含量变化，并探讨其在骨质疏松评估中的应用。
研究类型
队列研究。
人群
共 108 例绝经后女性（58.2±6.7[范围 45-79]岁）。
场强/序列：在 64 排 CT 扫描仪上进行定量 CT（QCT）；在配备 16 通道后线圈的 3.0T 成像系统上进行定量磁化率映射（QSM）和 mDixon quant MR 成像。
评估
对 108 例绝经后女性进行 QCT、QSM 和 mDixon 检查，以测量椎体 BMD、磁化率和质子密度脂肪分数（PDFF）。在三个 BMD 组（正常、骨量减少和骨质疏松）之间比较椎体 QSM 和 PDFF 的平均值。采用受试者工作特征分析评估 QSM、PDFF 和 QSM+PDFF 评估骨质疏松症的性能。
统计学检验
采用 Kruskal-Wallis 检验和 Pearson 检验比较参数。
结果
与正常 BMD 组（-17.0±43.6 ppb）相比，骨量减少组（30.8±47.0 ppb，P<0.001）和骨质疏松组（82.0±39.9 ppb，P<0.001）的椎体 QSM 显著增加。QSM 与 BMD 呈负相关（r=-0.70，P<0.001），与 PDFF 呈正相关（r=0.64，P<0.001）。与 PDFF 的曲线下面积（AUC）相比，QSM 的 AUC 在区分正常和骨质疏松症（P=0.44）以及骨量减少和骨质疏松症（P=0.13）方面更高，但无统计学意义。QSM+PDFF 的 AUC 显著高于 PDFF 在区分骨量减少和骨质疏松症（0.82 比 0.70，P=0.039）。
数据结论
椎体磁化率和脂肪含量的组合可能是评估绝经后骨质疏松症的一种很有前途的标志物。
证据水平
1 技术功效：第 2 阶段 J. Magn. Reson. Imaging 2019;49:1020-1028.
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