Zou Kelly H, Bhagwat Jui G, Carrino John A
Department of Radiology (L-2), Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
Acad Radiol. 2006 May;13(5):566-72. doi: 10.1016/j.acra.2006.01.052.
When diagnostic tests are repeated and combined, a number of schemes may be adopted. Guidelines for their interpretations are required.
Three combination schemes, "and" (A), "or" (O), and "majority" (M), are considered. To evaluate these schemes, dependency by specifying kappa values quantifying repeated test agreement was structured. In a pilot study, the combined accuracies of magnetic resonance imaging using six different pulse sequences of medial collateral ligaments of the elbows of 28 cadavers, with eight having lesions artificially created surgically, were examined. Images were evaluated simultaneously by using a five-point ordinal scale. For each pulse sequence, individuals for whom the diagnosis varied from once to three repetitions were considered.
Scheme M improves diagnostic accuracy when sensitivity and specificity of a single test exceed 0.5, with maximal improvement at 0.79. Under scheme A, sensitivity decreases to 0.38-0.59. Under scheme O, sensitivity increases to 0.53-0.79. Scheme M yields a small improvement, reaching 0.50-0.71. Under scheme A, specificity increases to 0.95-0.98. Under scheme O, specificity decreases to 0.91-0.98. Scheme M also yields a small improvement, reaching 0.94-0.98.
Scheme A is recommended for ruling in diagnoses, scheme O is recommended for ruling out diagnoses, and scheme M is neutral. Consequently, different schemes may be used to optimize the target diagnostic accuracy.
当重复并组合诊断测试时，可采用多种方案。需要对其解读制定指南。
考虑了三种组合方案，即“与”（A）、“或”（O）和“多数”（M）。为评估这些方案，通过指定量化重复测试一致性的kappa值来构建依赖性。在一项初步研究中，检查了使用28具尸体肘部内侧副韧带的六种不同脉冲序列进行磁共振成像的联合准确性，其中八具尸体的病变是通过手术人为制造的。使用五点有序量表同时对图像进行评估。对于每个脉冲序列，考虑诊断结果在一次到三次重复中有所变化的个体。
当单次测试的敏感性和特异性超过0.5时，方案M可提高诊断准确性，在0.79时提高最大。在方案A下，敏感性降至0.38 - 0.59。在方案O下，敏感性增至0.53 - 0.79。方案M有小幅提高，达到0.50 - 0.71。在方案A下，特异性增至0.95 - 0.98。在方案O下，特异性降至0.91 - 0.98。方案M也有小幅提高，达到0.94 - 0.98。
推荐方案A用于确诊，推荐方案O用于排除诊断，方案M为中性。因此，可使用不同方案来优化目标诊断准确性。
