The indirect signs included dilatation of bowl loops (n=4), bowel wall thickening (n=6), the paper-thin wall sign (n=4), mesenteric stranding(n=5), mesenteric haziness(n=3), pneumatosis of bowel wall (n=2), portal veno gas(n=1) and ascites(n=3).

• 间接征象包括肠腔扩张积液(4例)、肠壁增厚(6例)、薄纸样肠壁(4例)、缆绳征(5例)、肠系膜积液(3例)、肠壁积气(2例)、门静脉积气(1例)及腹腔积液(3例)。