Department of Radiology, Division of Musculoskeletal Radiology, Ajou University School of Medicine, 164 World Cup-ro, Yeongtong-gu, Suwon, Gyeonggi-do, South Korea.
Musculoskeletal Imaging Laboratory, Ajou University Medical Center, Suwon, South Korea.
AJR Am J Roentgenol. 2020 May;214(5):1139-1145. doi: 10.2214/AJR.19.22177. Epub 2020 Feb 18.
The objective of our study was to assess the diagnostic utility of the "salt-and-pepper noise" sign on fat-fraction maps by chemical-shift-encoded MRI (CSE-MRI) compared with the halo sign on fat-suppressed T2-weighted imaging and mean attenuation on CT for differentiating bone islands from osteoblastic metastases. Twenty-nine patients with 43 sclerotic vertebral bone marrow lesions (26 osteoblastic metastases, 17 bone islands) were included retrospectively. All patients underwent CT and MRI, including a CSE-MRI sequence on a 1.5-T MRI system, from November 2016 to January 2019. The salt-and-pepper noise sign was defined as the speckled appearance of white and black pixels that is similar to the appearance of background air on a fat-fraction map. ROC curves were analyzed to compare the diagnostic performance of the salt-and-pepper noise sign, halo sign, and mean CT attenuation between the two groups. The salt-and-pepper noise sign was significantly associated with bone islands ( < 0.001). The sensitivity, specificity, and accuracy for discriminating bone islands from osteoblastic metastases were 92.31-96.15%, 100%, and 95.35-97.67% for the salt-and-pepper noise sign; 88.46-92.31%, 88.24-94.12%, and 90.70% for the halo sign; and 96.15%, 94.12-100%, and 95.35-97.67% for mean CT attenuation, respectively. There was no statistically significant difference of diagnostic performances among the imaging characteristics for differentiating between bone islands and osteoblastic metastases ( > 0.05). Interobserver agreement for the salt-and-pepper noise sign, halo sign, and mean CT attenuation was almost perfect (κ ≥ 0.953, κ = 0.905, and ICC = 0.966, respectively). The salt-and-pepper noise sign is present in bone islands on fat-fraction maps by CSE-MRI and can aid in differentiating bone islands from osteoblastic metastases.
我们的研究目的是评估化学位移编码 MRI (CSE-MRI) 上的“椒盐噪声”征象在区分成骨性骨岛和骨母细胞转移瘤中的诊断效用，与脂肪抑制 T2 加权成像上的晕征和 CT 平均衰减值进行比较。回顾性纳入 2016 年 11 月至 2019 年 1 月期间 29 例 43 个硬化性椎体骨髓病变患者（26 例骨母细胞转移瘤，17 例成骨性骨岛）。所有患者均行 CT 和 MRI 检查，包括在 1.5-T MRI 系统上行 CSE-MRI 序列。“椒盐噪声”征象定义为脂肪分数图上呈现的白色和黑色像素的斑点状外观，类似于背景空气中的外观。分析 ROC 曲线以比较两组之间“椒盐噪声”征象、晕征和 CT 平均衰减值的诊断性能。“椒盐噪声”征象与成骨性骨岛显著相关（<0.001）。用于区分成骨性骨岛和骨母细胞转移瘤的“椒盐噪声”征象的灵敏度、特异性和准确度分别为 92.31%-96.15%、100%和 95.35%-97.67%；晕征的为 88.46%-92.31%、88.24%-94.12%和 90.70%；CT 平均衰减值的为 96.15%、94.12%-100%和 95.35%-97.67%。区分成骨性骨岛和骨母细胞转移瘤的影像学特征之间的诊断性能无统计学差异（>0.05）。“椒盐噪声”征象、晕征和 CT 平均衰减值的观察者间一致性为几乎完美（κ≥0.953、κ=0.905 和 ICC=0.966）。CSE-MRI 上的“椒盐噪声”征象可见于成骨性骨岛的脂肪分数图中，有助于区分成骨性骨岛和骨母细胞转移瘤。
