Ciasca Taízha C, David Frederic H, Lamb Christopher R
Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK.
Vet Radiol Ultrasound. 2013 May-Jun;54(3):207-11. doi: 10.1111/vru.12032. Epub 2013 Mar 15.
The ratio between maximal small intestinal (SI) diameter and the height of the body of the fifth lumbar vertebra (L5) in radiographs has been reported as a diagnostic test in dogs with suspected intestinal obstruction. In order to assess the effect of the SI/L5 ratio on the accuracy of radiographic diagnosis of intestinal obstruction, lateral abdominal radiographs of 37 dogs with small intestinal obstruction and 48 nonobstructed dogs were mixed and examined independently by six observers who were unaware of the final diagnosis and who represented a range of experience. Observers first examined radiographs subjectively and stated the likelihood of obstruction (definitely not, probably not, equivocal, probably, definitely). Observers subsequently reexamined the radiographs, determined the SI/L5 ratio, and again stated the likelihood of obstruction. The most frequent cause of obstruction was foreign body (29/37, 78%). Dogs with SI obstruction had a significantly larger median SI/L5 ratio than nonobstructed dogs (P = 0.0002). Using an SI/L5 ratio of 1.7 for diagnosis of intestinal obstruction, sensitivity and specificity were 66%. Use of the SI/L5 ratio was not associated with increased accuracy of diagnosis for any observer, regardless of experience, hence this test may have no diagnostic impact.
在怀疑患有肠梗阻的犬类中，X线片上小肠最大直径与第五腰椎（L5）椎体高度的比值已被报道作为一种诊断测试。为了评估小肠直径与第五腰椎高度比值（SI/L5比值）对肠梗阻X线诊断准确性的影响，将37只患有小肠梗阻的犬和48只无梗阻犬的腹部侧位X线片混合，由6名不了解最终诊断结果且经验各异的观察者独立进行检查。观察者首先主观检查X线片，并说明梗阻的可能性（肯定没有、可能没有、不明确、可能、肯定）。随后，观察者重新检查X线片，确定SI/L5比值，并再次说明梗阻的可能性。最常见的梗阻原因是异物（29/37，78%）。患有小肠梗阻的犬的SI/L5比值中位数显著高于无梗阻犬（P = 0.0002）。使用SI/L5比值1.7来诊断肠梗阻，敏感性和特异性均为66%。无论观察者经验如何，使用SI/L5比值均未提高任何观察者的诊断准确性，因此该测试可能没有诊断价值。
