Question 2546
{"accessible":true,"alternatives":[{"id":12490,"text":"A"},{"id":12491,"text":"B"},{"id":12492,"text":"C"},{"id":12493,"text":"D"}],"archived":false,"correctAlternativeId":12493,"explanation":"\u003cp\u003eRadiograph D has prominent \u003ca href=\"/articles/mach-bands\" title=\"Mach effect\"\u003eMach effect\u003c/a\u003e resulting in apparent lucency around the mediastinum which is simulating pneumomediastinum. You can see the same effect occurring with the hemidiaphragms on this radiograph. Radiographs A, B and C all show typical appearances of pneumomediastinum with streaky lucencies and the mediastinal pleural margin evident.\u003c/p\u003e","id":2546,"imageUrl":"https://prod-images-static.radiopaedia.org/multiple_choice_questions/500/pneumo.001_big_gallery.jpeg","imageAttribution":{"kind":"external","attribution":"Radiopaedia case credits: Sally Ayesa rID: 98995, Julia Voitovich rID: 99439, Andrew Murphy rID: 49954, Andrew Dixon rID: 48424."},"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2546","nextQuestionPath":"/articles/pneumomediastinum/questions/2216","relatedArticles":[{"id":7804,"title":"Mach bands","link":"/articles/mach-bands?lang=us"},{"id":31401,"title":"Pneumomediastinum (summary)","link":"/articles/pneumomediastinum-summary?lang=us"}],"alsoUsedIn":[{"id":1411,"kind":"Course","title":"Emergency Radiology Course - page 1411","link":"https://radiopaedia.org/courses/emergency-radiology-course-online/pages/1411"},{"id":1411,"kind":"Course","title":"Emergency Radiology Course - Melbourne - page 1411","link":"https://radiopaedia.org/courses/emergency-radiology-course-melbourne-2022/pages/1411"},{"id":1411,"kind":"Course","title":"Emergency Radiology Course - Brisbane - page 1411","link":"https://radiopaedia.org/courses/emergency-radiology-course-brisbane-2022/pages/1411"}],"stem":"\u003cp\u003eWhich of the following chest radiographs does \u003cstrong\u003eNOT\u003c/strong\u003e show any evidence of pneumomediastinum?\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/2546"}],"attemptsPercentages":[{"alternativeId":"12490","percentage":25},{"alternativeId":"12493","percentage":51},{"alternativeId":"12491","percentage":9},{"alternativeId":"12492","percentage":15}],"promptToLogin":false,"questionManager":false,"articleId":"pneumomediastinum"}