Böttcher Peter, Armbrust Laura, Blond Laurent, Brühschwein Andreas, Gavin Patrick R, Gielen Ingrid, Hecht Silke, Jurina Konrad, Kneissl Sibylle, Konar Martin, Pujol Esteban, Robinson Andrew, Schaefer Susan L, Theyse Lars F H, Wigger Antje, Ludewig Eberhard
Department of Small Animal Medicine, University of Leipzig, Germany.
Vet Radiol Ultrasound. 2012 Nov-Dec;53(6):628-35. doi: 10.1111/j.1740-8261.2012.01967.x. Epub 2012 Aug 16.
Low-field MRI (lfMRI) has become increasingly accepted as a method for diagnosing canine meniscal tears in clinical practice. However, observer effects on diagnostic accuracy have not been previously reported. In this study, 50 consecutive stifle joints with clinical and radiologic evidence of cranial cruciate ligament insufficiency were investigated by lfMRI and arthroscopy. Fifteen observers who had varying levels of experience and who were unaware of arthroscopic findings independently reviewed lfMRI studies and recorded whether lateral and medial meniscal tears were present. Diagnostic accuracy (sensitivity, specificity, positive (PPV) and negative predictive value (NPV)) was determined for each observer and median values were calculated for all observers, using arthroscopy as the reference standard. Interrater agreement was determined based on intraclass correlation coefficient (ICC) analysis. Observer level of experience was compared with diagnostic sensitivity and specificity using correlation analysis. Based on pooled data for all observers, median sensitivity, specificity, PPV, and NPV for lfMRI diagnosis of lateral meniscal tears were 0.00, 0.94, 0.05, and 0.94, respectively. Median sensitivity, specificity, PPV, and NPV for medial meniscal tears were 0.74, 0.89, 0.83, and 0.79, respectively. Interrater agreement for all menisci was fair (0.51). Menisci were less consistently scored as having no tears (ICC = 0.13) than those scored as having tears (ICC = 0.50). No significant correlations between observer experience and diagnostic sensitivity/specificity were identified. Findings indicated that the accuracy of lfMRI for diagnosing canine meniscal tears was poor to fair and observer-dependent. Future studies are needed to develop standardized and widely accepted lfMRI criteria for diagnosing meniscal tears.
低场磁共振成像（lfMRI）在临床实践中已越来越被公认为是诊断犬半月板撕裂的一种方法。然而，此前尚未有关于观察者效应对诊断准确性影响的报道。在本研究中，对50个连续的膝关节进行了低场磁共振成像和关节镜检查，这些膝关节具有颅交叉韧带功能不全的临床和放射学证据。15名经验水平各异且不知晓关节镜检查结果的观察者独立审查了低场磁共振成像研究，并记录外侧和内侧半月板是否存在撕裂。以关节镜检查作为参考标准，确定每位观察者的诊断准确性（敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）），并计算所有观察者的中位数。基于组内相关系数（ICC）分析确定观察者间的一致性。使用相关分析比较观察者的经验水平与诊断敏感性和特异性。基于所有观察者的汇总数据，低场磁共振成像诊断外侧半月板撕裂的中位数敏感性、特异性、PPV和NPV分别为0.00、0.94、0.05和0.94。内侧半月板撕裂的中位数敏感性、特异性、PPV和NPV分别为0.74、0.89、0.83和0.79。所有半月板的观察者间一致性为中等（0.51）。半月板被评为无撕裂（ICC = 0.13）的一致性低于被评为有撕裂（ICC = 0.50）的情况。未发现观察者经验与诊断敏感性/特异性之间存在显著相关性。研究结果表明，低场磁共振成像诊断犬半月板撕裂的准确性较差至中等，且依赖于观察者。未来需要开展研究以制定标准化且被广泛接受的低场磁共振成像诊断半月板撕裂的标准。
