Question 460
{"accessible":true,"alternatives":[{"id":2308,"text":"restricted compared to adjacent brain (~400-500)"},{"id":2309,"text":"similar to adjacent brain (~700-800)"},{"id":2310,"text":"somewhat facilitated compared to adjacent brain (~1000-1200)"},{"id":2311,"text":"similar to CSF (~2500-3000)"}],"archived":false,"correctAlternativeId":2309,"explanation":"\u003cp\u003eThis is an epidermoid cyst. ADC values, importantly, are only moderately low, similar to the\u0026nbsp;adjacent brain (~700-800 x 10\u003csup\u003e-6\u003c/sup\u003e mm\u003csup\u003e2\u003c/sup\u003e/s). They are not, as one might expect by looking at the DWI images, very low as one would encounter in infarction or lymphoma; much of the high DWI signal is due to T2 shine-through.\u0026nbsp;\u003c/p\u003e\u003cp\u003eIn addition to the related articles, the following Radiopaedia blog is worth reading: \u003ca href=\"https://radiopaedia.org/blog/why-routine-measurement-of-adc-values-is-important\"\u003eWhy routine measurement of ADC values is important\u003c/a\u003e.\u0026nbsp;\u003c/p\u003e","id":460,"imageUrl":"https://prod-images-static.radiopaedia.org/multiple_choice_questions/779/images-for-mcqs-1_big_gallery.jpeg","imageAttribution":{"kind":"case","rID":28770},"imageAttributionCaseInfo":{"title":"Epidermoid cyst (CP angle)","contributor_name":"Frank Gaillard","contributor_param":"frank","case_rid":28770,"case_param":"epidermoid-cyst-cp-angle"},"firstQuestionPath":"/questions/2260","nextQuestionPath":"/articles/intracranial-epidermoid-cyst/questions/459","relatedArticles":[{"id":21759,"title":"Apparent diffusion coefficient","link":"/articles/apparent-diffusion-coefficient-1?lang=us"}],"alsoUsedIn":[{"id":432,"kind":"Course","title":"Radiology Review Course - Melbourne - page 432","link":"https://radiopaedia.org/courses/radiology-review-course-melbourne-2019/pages/432"},{"id":432,"kind":"Course","title":"Radiology Review Course - Melbourne - page 432","link":"https://radiopaedia.org/courses/radiology-review-course-melbourne-2020/pages/432"},{"id":432,"kind":"Course","title":"Radiology Review Course - page 432","link":"https://radiopaedia.org/courses/radiology-review-course-online/pages/432"},{"id":462,"kind":"RestrictedPage","title":"Page 462 (in no courses)","link":"https://radiopaedia.org/admin/restricted_pages/462"},{"id":463,"kind":"RestrictedPage","title":"Page 463 (in no courses)","link":"https://radiopaedia.org/admin/restricted_pages/463"},{"id":619,"kind":"Course","title":"Neuroradiology Lectures - page 619","link":"https://radiopaedia.org/courses/neuroradiology-lectures/pages/619"},{"id":619,"kind":"Course","title":"Radiopaedia 2020 - Lectures Only - page 619","link":"https://radiopaedia.org/courses/radiopaedia-2020-exclusive/pages/619"},{"id":619,"kind":"Course","title":"2020 Virtual Conference Private Use - page 619","link":"https://radiopaedia.org/courses/2020-virtual-conference-private-use/pages/619"},{"id":619,"kind":"Course","title":"New test course - page 619","link":"https://radiopaedia.org/courses/new-test-course/pages/619"}],"stem":"\u003cp\u003eIf you were to review the apparent diffusion coefficient (ADC) maps of the adjacent study, what values (measured in units x 10\u003csup\u003e-6\u003c/sup\u003e mm\u003csup\u003e2\u003c/sup\u003e/s) would you expect to encounter in the area of abnormality?\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/460"}],"attemptsPercentages":[{"alternativeId":"2311","percentage":18},{"alternativeId":"2310","percentage":14},{"alternativeId":"2308","percentage":54},{"alternativeId":"2309","percentage":15}],"promptToLogin":false,"questionManager":false,"articleId":"intracranial-epidermoid-cyst"}