This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdominal Radiography, Subject name: Radiology
String sign of Kantor is seen in: 
Select and explain. 
A. Crohn's disease, B. Ulcerative colitis, C. Ca Colon, D. Typhoid colitis
A: Crohn's disease
Answer: A: Crohn's disease 
Explanation: Ans: A (Crohn's disease) Ref: http:www.uirlearning radiology.comExplanation:String Sign of KantorSeen in Crohn's diseaseFinding seen on contrast studies using primarily bariumIt is caused by severe spasm secondary to irritability of the loop producing the appearance of a frayed cotton stringAt first, edema and spasm narrow the loop but the narrow ing is at least partially distensibleEventually the wall of the ileum may become fibrotic and the lumen fixed in diameter.Imaging FindingsPersistently narrowed but potentially distensible terminal ileumFirst sign of Crohn's ileitis is usually shallow aphthous ulcersShort, linear ulcers along the mesenteric border may also be seen with Crohn's ileitisInduration of the surrounding fat may cause the loop to be separated from the other small bowel loops (Proud loop)