超音波血流蝕骨徵象於評估類風濕性關節炎的潛在角色

The potential role of vascularity invasion bone sign in ultrasound assessment of rheumatoid arthritis

目的：闡明骨骼肌肉超音波之血侵蝕骨徵象於診斷類風濕性關節炎所扮演的角色。方法：本研究總共收集了四十八位符合2010年美國風濕病醫學會類風濕性關節炎診斷標準且有手腕疼痛的類風濕性關節炎病患做為實驗組，四十三位有手腕疼痛的非類風濕性關節炎病患做為對照組。每位病患接受超音波檢查一個腕關節。我們採用手腕背中線縱向掃描來評估每位病患的腕關節，並採用OMERACT標準來評估滑膜肥厚的程度和滑膜血流訊號的程度。血流蝕骨徵象定義為在超音波灰階影像中，基底滑膜之連續性的杜卜勒訊號侵入鄰近骨皮質，可以有或沒有相對應之灰階底下可見的骨頭侵蝕。並針對病患的基本資料，臨床表徵和檢查結果進行了統計分析。結果：腕關節血流蝕骨徵象出現在25/48（52.1%）類風濕性關節炎病患，2/43（4%）非類風濕性關節炎病患（p值<0.001）。血流蝕骨徵象對於類風濕性關節炎的特異性，陽性預測值和陰性預測值分別為95.3%，92.6%和64.1%。與血流蝕骨徵象陰性的類風濕性關節炎病患相較，血流蝕骨徵象陽性的病患有較高的比率會有高滑膜血流訊號（2.1 ± 0.5 vs. 0.9 ± 0.8, p值<0.001），較高的比率在灰階超音波影像中出現骨頭侵蝕（72.0% vs. 8.7%, p值<0.001），較高的比率在X影像中出現骨頭侵蝕（72.0% vs. 8.7%, p值<0.001），較高的C反應蛋白值（1.6 ± 2.0 vs. 0.7 ± 1.0, p值為0.04）。而在年齡，性別，病程，用藥史，滑膜肥厚的程度，紅血球沉降速率，類風濕因子和抗環瓜氨酸肽（CCP）抗體陽性率等方面，血流蝕骨徵象陽性和陰性的類風濕性關節炎患者之間並沒有顯著差異。結論：我們的研究顯示血流蝕骨徵象對類風濕性關節炎的評估扮演重要的角色。血流蝕骨徵象常見於類風濕性關節炎病患的手腕且具有診斷特異性，另外也會有較高的C反應蛋白值，較高的滑膜血流訊號和骨頭侵蝕的出現。

Objective: To clarify the role of vascularity invasion bone (VIB) sign in musculoskeletal ultrasound for RA diagnosis. Method: Forty-eight adult RA patients matching 2010 ACR classification criteria for RA with painful wrists were enrolled as the study group. Forty-three adult non-RA patients with painful wrists were enrolled as the control group. One wrist of each patient was examined by ultrasonography. The scoring of synovial hypertrophy and synovial vascularity followed OMERACT criteria. The VIB sign was defined as a continuous PD signal at the basal synovium invading adjacent bone cortex, with or without visible corresponding bone erosion on gray-scale image. Patients’ demographic data were reviewed. Results: The VIB sign was present in 25/48 (52.1%) of RA wrists and 2/43 (4.0%) of non-RA wrists (p <0.001). The specificity, positive predictive value, and negative predictive value of VIB sign for RA were 95.3%, 92.6%, and 64.1% respectively. In comparison with VIB-negative RA patients, VIB-positive RA patients had significantly higher risks for high synovial vascularity score (2.1 ± 0.5 vs. 0.9 ± 0.8, p <0.001), presence of bone erosion on gray-scale US (72.0% vs. 8.7%, p <0.001), presence of bone erosion on X-ray (62.5% vs. 23.8%, p <0.01), and higher level of CRP (1.6 ± 2.0 vs. 0.7 ± 1.0, p=0.04). There were no significant differences in age, sex, disease duration, medication history, synovial hypertrophy score, ESR, RF, and anti-CCP antibody between VIB-positive and VIB-negative RA patients. Conclusion: We demonstrated the important role of VIB sign for RA assessment. VIB sign is commonly seen in RA wrist and is specific to RA. It is significantly associated with higher CRP, higher synovial vascularity and bone erosions in RA patients.