In cases with duodenal obstruction due to intrinsic causes, the diameter of the dilated duodenum was 22± 6.5 mm; the sensitivity, specificity, positive and negative predictive value and accuracy of the "double bubble" sign were 87.5%, 90.1%, 87.6%, 90%, 88.8%, respectively.
Trong nhóm tắc tá tràng có xoắn ruột do RXBT, dấu Whirpool có độ nhạy, độ đặc hiệu, giá trị tiên đoán dương, giá trị tiên đoán âm 97,3%, 98,6%, 98,6%, 97,3%.