台灣風濕科醫師對關節炎超音波靜態影像關節發炎程度評分之信度

Reliability of gray-scale and power Doppler ultrasound static image scoring for synovitis among Taiwanese rheumatologists

目的：檢驗台灣風濕科醫師於一天基礎肌肉骨骼超音波訓練課程前後對於關節超音波靜態影像發炎程度評分之可信度。方法：三十七位風濕科醫師完成了為期一天之基礎肌肉骨骼超音波訓練課程。於訓練課程進行前，所有參加者針對十四張關節整體超音波靜態影像以及十張關節能量都卜勒超音波靜態影像進行評分。於訓練課程後，相同參加者針對另外十四張關節灰階超音波靜態影像以及十張關節能量都卜勒超音波靜態影像進行評分。以Krippendorff's alpha （α） coefficient with 95% confidence interval （CI） 來評估觀察者間之可信度。結果：觀察者間對於關節超音波靜態影像評分之可信度差，無論在訓練課程前（α, 0.46; 95% CI, 0.37–0.55）或訓練課程後（α, 0.42; 95% CI, 0.33–0.50）。觀察者間對於關節能量都卜勒超音波靜態影像評分之可信度優於關節灰階超音波靜態影像評分之可信度，無論在訓練課程前（α, 0.66; 95% CI, 0.60–0.72）或訓練課程後（α, 0.62; 95% CI, 0.55–0.68）。在訓練課程前，具備大於三年超音波經驗之風濕科醫師中觀察者間之可信度（α, 0.65; 95% CI, 0.59–0.72）較一至三年超音波經驗之風濕科醫師（α, 0.48; 95% CI, 0.39–0.56）或小於三年超音波經驗之風濕科醫師（α, 0.49; 95% CI, 0.41–0.57）高。在所有關節區域中，灰階超音波靜態影像觀察者間之可信度以近端指間關節最低，但能量都卜勒超音波靜態影像觀察者間之可信度反而以近端指間關節最高。此基礎訓練課程只改善掌指關節以及蹠趾關節能量都卜勒超音波靜態影像評分之可信度。結論：台灣風濕科醫師對於灰階超音波靜態影像或能量都卜勒超音波評分之可信度差。仍需要安排一個進階訓練課程來改善對於超音波靜態影像評分之可信度，特別是針對具備小於三年超音波經驗之風濕科醫師對於灰階超音波靜態影像之評分。

Objective: To test the inter-observer reliability of gray-scale (GS) and power Doppler (PD) musculoskeletal ultrasound (MSUS) still images synovitis scoring among Taiwanese rheumatologists before and after a one-day basic MSUS training course. Methods: Thirty-seven rheumatologists completed the one-day basic MSUS training course. Before the training course, all participants scored synovitis semi-quantitatively for 14 GSUS and 10 PDUS still images. Likewise, all participants performed synovitis scoring for another sets of 14 GSUS and 10 PDUS still images after the training course. Inter-observer reliability was estimated by calculating the Krippendorff's alpha (α) coefficient with 95% confidence interval (CI). Results: Inter-observer reliability of US synovitis scoring was unacceptable, either before (α, 0.46; 95% CI, 0.37–0.55) or after (α, 0.42; 95% CI, 0.33–0.50) the training course. The inter-observer reliability of PDUS synovitis scoring was higher than that of GSUS synovitis scoring, both before (α, 0.66; 95% CI, 0.60–0.72) and after (α, 0.62; 95% CI, 0.55–0.68) the training course. Before the training course, the inter-observer reliability among sonographers with more than three years’ experience (α, 0.65; 95% CI, 0.59–0.72) was higher than that among those with 1-3 years’ experience (α, 0.48; 95% CI, 0.39–0.56) and those with less than one year’s experience (α, 0.49; 95% CI, 0.41–0.57). Among all joint regions, the interobserver reliability of GSUS synovitis scoring was the lowest in the proximal interphalangeal (PIP) joints, but the inter-observer reliability of PDUS synovitis scoring was the highest in the PIP joints. This basic training course only significantly improved the inter-observer reliability in the PDUS synovitis scoring of the metacarpophalangeal joints and the metatarsophalangeal joints. Conclusion: The inter-observer reliability of GUUS or PDUS still image synovitis scoring among Taiwanese rheumatologists was poor. There is an unmet need to conduct an intensive training course to improve the inter-observer reliability of semi-quantitative synovitis scoring of US images, especially for GSUS images and for rheumatologists with less than three years of MSUS experience.