Department of Radiology, Division of Musculoskeletal Radiology, Ajou University School of Medicine, 164, World cup-ro, Yeongtong-gu, Suwon, Gyeonggi-do, South Korea 16499.
Musculoskeletal Imaging Laboratory, Ajou University Medical Center, Suwon, South Korea.
AJR Am J Roentgenol. 2021 Mar;216(3):734-741. doi: 10.2214/AJR.19.22698. Epub 2021 Jan 6.
The purpose of this study was to evaluate the added value of proton density fat fraction (PDFF) in differentiating vertebral metastases from focal hematopoietic marrow depositions. The study included 44 patients with 30 vertebral metastases and 14 focal hematopoietic marrow depositions who underwent spinal MRI. The final diagnoses were based on histologic confirmation, follow-up MRI, or PET/CT. Two musculoskeletal radiologists with 1 and 15 years of experience independently interpreted both image sets (i.e., images from conventional MRI alone versus images from conventional MRI and PDFF combined). Using a 5-point scale, the readers scored their confidence in the malignancy of the vertebral lesions. The diagnostic performance (AUC) of the two image sets was assessed via ROC curve analyses. Sensitivities, specificities, and accuracies (for both image sets) were compared using the McNemar test. Kappa coefficients were calculated to assess interobserver agreement. Both readers showed improved diagnostic performance after PDFF was added (AUC, 0.840-0.912 and 0.805-0.895 for readers 1 and 2, respectively). However, adding PDFF did not significantly improve the sensitivity and specificity of either reader ( > .05). Interobserver agreement significantly improved from moderate (κ = 0.563) to excellent (κ = 0.947) after PDFF was added. The addition of PDFF to a conventional MRI protocol improved the diagnostic performance for differentiating vertebral metastases from focal hematopoietic marrow depositions but without resulting in significant improvement in sensitivity and specificity.
本研究旨在评估质子密度脂肪分数（PDFF）在区分椎体转移瘤和局灶性造血骨髓沉积中的附加价值。该研究纳入了 44 例患者，其中 30 例为椎体转移瘤，14 例为局灶性造血骨髓沉积，均行脊柱 MRI 检查。最终诊断基于组织学证实、随访 MRI 或 PET/CT。两位具有 1 年和 15 年经验的肌肉骨骼放射科医生分别独立解读了两组图像（即仅来自常规 MRI 的图像与常规 MRI 和 PDFF 组合的图像）。两位读者使用 5 分制对椎体病变恶性程度的置信度进行评分。通过 ROC 曲线分析评估两种图像集的诊断性能（AUC）。使用 McNemar 检验比较两种图像集的敏感性、特异性和准确性（均用于两种图像集）。计算kappa 系数以评估观察者间的一致性。两位读者在添加 PDFF 后均显示出诊断性能的提高（AUC 分别为 0.840-0.912 和 0.805-0.895）。然而，添加 PDFF 并未显著提高任何一位读者的敏感性和特异性（>0.05）。添加 PDFF 后，观察者间的一致性从中度（κ=0.563）显著提高到极好（κ=0.947）。将 PDFF 添加到常规 MRI 方案中可提高区分椎体转移瘤和局灶性造血骨髓沉积的诊断性能，但敏感性和特异性无显著提高。
