Sonographic surveillance of abdominal aortic aneurysms: what is the smallest change in measured diameter that reliably reflects aneurysm growth?

摘要: OBJECTIVE The decision to repair an abdominal aortic aneurysm may be based on apparent increase in diameter seen successive sonographic examinations. However, true growth can diagnosed only if the measured exceeds variability inherent measurement. This study uses analysis of variance determine smallest change between 2 successive, independent measurements that reliably indicates growth. METHODS Pairs observers examined 63 patients with aneurysms. Each observer obtained a measurement anteroposterior transaxial and longitudinal scan planes, transverse plane. Analysis yielded total associated each type as well contributions made by among aneurysms, residual variance. These components were used estimate interobserver standard error measurement, reliability needed diagnose RESULTS Differences aneurysms largest contribution overall Interobserver was excellent, ranging from 0.89 0.94 (with perfect being 1.00). difference indicated at 95% confidence level 0.78 cm plane 0.92 same 1.05 cm. CONCLUSION Despite high reliability, changes greater than or equal indicate level. Smaller not real, but due