Metwally Maha Ibrahim, Almalki Yassir Edrees, Khalil Marwa Fathy, Alsowey Ahmed Mohamed, Tantawy Hazem Ibrahim Aly, Hamed Mohamed Gaber, Abdelmoneem Shimaa, Alduraibi Sharifa Khalid, Almushayti Ziyad A, Alshehri Shaker Hassan S, Basha Ahmed M Abdelkhalik, Basha Mohammad Abd Alkhalik
Department of Radio-diagnosis, Faculty of Human Medicine, Zagazig University, Zagazig, Egypt.
Division of Radiology, Department of Internal Medicine, Medical College, Najran University, Najran, Kingdom of Saudi Arabia.
Eur Radiol Exp. 2025 Sep 10;9(1):89. doi: 10.1186/s41747-025-00615-9.
Bone marrow (BM) lesion differentiation remains challenging, and quantitative magnetic resonance imaging (MRI) may enhance accuracy over conventional methods. We evaluated the diagnostic value and inter-reader reliability of Dixon-based signal drop (%drop) and fat fraction percentage (%fat) as adjuncts to existing protocols.
In this prospective two-center study, 172 patients with BM signal abnormalities underwent standardized 1.5-T MRI protocols, including Dixon sequences. Two musculoskeletal radiologists independently evaluated images and performed quantitative measurements of %drop and %fat. Final diagnoses were established through histopathology (n = 96) or imaging follow-up (n = 76). Diagnostic value was assessed using area under the receiver operating characteristic curve (AUROC), inter-reader reliability using Cohen's κ coefficient.
The consensus optimal cutoff was for %drop ≤ 19.8%, yielding 87.2% accuracy, 95.3% sensitivity, and 73.8% specificity, and that for %fat was ≤ 18.3%, achieving 86.6% accuracy, 96.3% sensitivity, and 70.8% specificity. Both metrics showed high diagnostic performance (AUROC 0.824-0.863) and excellent inter-reader reliability (κ > 0.93, p < 0.001). Multivariate analysis identified %drop ≤ 19.8% and %fat ≤ 18.3% as the strongest independent predictors of malignancy, with odds ratio (OR) being 9.38 and 8.85, respectively (p < 0.001). Signal characteristics on Dixon sequences provided additional diagnostic value, with signal voids on fat-only images (OR 7.14) and high signals on water-only images (OR 5.46).
Quantitative MRI Dixon imaging parameters demonstrated high diagnostic accuracy and excellent inter-reader reliability in differentiating benign and malignant BM lesions, supporting their implementation in clinical practice protocols as a reproducible adjunct to conventional MRI.
Quantitative Dixon MRI provides reproducible, noninvasive differentiation of bone marrow lesions with high diagnostic accuracy across anatomical sites, enhancing clinical decision-making with standardized thresholds while demonstrating excellent inter-center consistency.
Quantitative Dixon MRI thresholds of %drop ≤ 19.8% and %fat ≤ 18.3% were established as reliable predictors of malignancy in bone marrow lesions. Dixon metrics demonstrated superior diagnostic accuracy (86.6-87.2%), compared to conventional T1-weighted sequences (79.2%). Excellent inter-reader reliability (κ = 0.895-0.943) supports the reproducibility of quantitative Dixon MRI in clinical practice.
骨髓（BM）病变的鉴别诊断仍然具有挑战性，而定量磁共振成像（MRI）可能比传统方法提高准确性。我们评估了基于狄克逊法的信号下降率（%下降）和脂肪分数百分比（%脂肪）作为现有方案辅助手段的诊断价值和阅片者间可靠性。
在这项前瞻性双中心研究中，172例有骨髓信号异常的患者接受了标准化的1.5-T MRI检查方案，包括狄克逊序列。两位肌肉骨骼放射科医生独立评估图像并对%下降和%脂肪进行定量测量。最终诊断通过组织病理学（n = 96）或影像随访（n = 76）确定。使用受试者操作特征曲线下面积（AUROC）评估诊断价值，使用科恩κ系数评估阅片者间可靠性。
共识最佳截断值为%下降≤19.8%，准确率为87.2%，敏感性为95.3%，特异性为73.8%；%脂肪的最佳截断值为≤18.3%，准确率为86.6%，敏感性为96.3%，特异性为70.8%。两个指标均显示出较高的诊断性能（AUROC 0.824 - 0.863）和出色的阅片者间可靠性（κ>0.93，p<0.001）。多变量分析确定%下降≤19.8%和%脂肪≤18.3%是恶性肿瘤最强的独立预测因素，优势比（OR）分别为9.38和8.85（p<0.001）。狄克逊序列上的信号特征提供了额外的诊断价值，仅脂肪图像上的信号缺失（OR 7.14）和仅水图像上的高信号（OR 5.46）。
定量MRI狄克逊成像参数在鉴别良性和恶性骨髓病变方面显示出高诊断准确性和出色的阅片者间可靠性，支持将其作为传统MRI的可重复辅助手段纳入临床实践方案。
定量狄克逊MRI可对骨髓病变进行可重复、无创的鉴别诊断，在各解剖部位均具有高诊断准确性，通过标准化阈值增强临床决策，同时显示出出色的中心间一致性。
定量狄克逊MRI的%下降≤19.8%和%脂肪≤18.3%阈值被确定为骨髓病变恶性肿瘤的可靠预测指标。与传统T1加权序列（79.2%）相比，狄克逊指标显示出更高的诊断准确性（86.6 - 87.2%）。出色的阅片者间可靠性（κ = 0.895 - 0.943）支持定量狄克逊MRI在临床实践中的可重复性。
