<prompt> Thumb print sign in plain x-ray is seen in:Ischeamic colitisUlcerative colitisPseudomembranous colitisAppendicitis  <response>: Ans: a Ischeamic colitisRef: Harrison, 17 ed. pg. 1091, 213; Grainger and Allison 5 ed. pg. 889.Thumb printing sign, i.e., bowel wall oedema seen as an early sign in ischaemic colitis. Also seen in: amoebic colitis and ulcerative colitisIschaemic colitis: Most common sites - Watershed areas of colon Splenic flexure Griffiths point Descendingsigmoid colon Sudecks pointRadiological signs in ischemic colitis:Early: Late :Thumb printing sign Pneumoperitoneum due to bowel wall oedema -perforation HallmarkPneumatosisintestinalis air in Luminal narrowing bowel wall Funneling of bowelOther specific radiological signs related to GIT:String sign : congenital hypertrophic pyloric stenosis String of kantor : Crohns disease Sawtooth appear- ance : DiverticulosisWhirlpool sign : Midgut volvulus Coffee bean sign : Sigmoid volvulus Claw signtarget signmeniscus sign:IntussusceptionBridgeThumb print sign in neck x-ray is seen in acute epiglotitis 