Question 1845
{"accessible":true,"alternatives":[{"id":9163,"text":"comb sign"},{"id":9164,"text":"fat halo sign"},{"id":9165,"text":"fistulous tracts"},{"id":9166,"text":"mesenteric lymphadenopathy"},{"id":9167,"text":"string sign (bowel)"}],"archived":false,"correctAlternativeId":9163,"explanation":"\u003cp\u003eFibrofatty proliferation and perivascular inflammatory infiltration outline the distended intestinal arcades. This forms linear densities on the mesenteric side of the affected segments of small bowel, which give the appearance of the teeth of a comb - known as comb sign.\u003c/p\u003e\u003cp\u003eComb sign can be seen on both CT and MRI, but is not pathognomonic\u0026nbsp;for Crohn disease. Other\u0026nbsp;acute inflammatory conditions of bowel and\u0026nbsp;\u003ca href=\"https://radiopaedia.org/articles/systemic-lupus-erythematosus?lang=gb\"\u003el\u003c/a\u003eupus\u0026nbsp;mesenteric vasculitis can give the same appearance,\u0026nbsp;however, in a known case of Crohn disease would suggest that the disease was extensive, advanced and active.\u003c/p\u003e\u003cp\u003eThe comb sign may be used to differentiate active inflammatory conditions from lymphoma and metastases, which tend to be hypovascular.\u003c/p\u003e","id":1845,"imageUrl":"https://prod-images-static.radiopaedia.org/multiple_choice_questions/335/crohn-disease-comb-sign-1_big_gallery.jpeg","imageAttribution":{"kind":"case","rID":6779},"imageAttributionCaseInfo":{"title":"Crohn disease - comb sign","contributor_name":"Natalie Yang","contributor_param":"yangnatalie","case_rid":6779,"case_param":"crohn-disease-comb-sign-1"},"firstQuestionPath":"/questions/2682","nextQuestionPath":"/articles/crohn-disease-1/questions/1843","relatedArticles":[{"id":1327,"title":"Fat halo sign (inflammatory bowel disease)","link":"/articles/fat-halo-sign-inflammatory-bowel-disease?lang=gb"},{"id":6781,"title":"Comb sign (mesentery)","link":"/articles/comb-sign-mesentery?lang=gb"},{"id":1375,"title":"String sign (bowel)","link":"/articles/string-sign-bowel?lang=gb"}],"alsoUsedIn":[],"stem":"\u003cp\u003ePatient with known Crohn disease. Which of the following features is shown on this selected post-contrast coronal CT image?\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/1845"}],"attemptsPercentages":[{"alternativeId":"9166","percentage":2},{"alternativeId":"9167","percentage":16},{"alternativeId":"9164","percentage":4},{"alternativeId":"9165","percentage":2},{"alternativeId":"9163","percentage":76}],"promptToLogin":false,"questionManager":false,"articleId":"crohn-disease"}