Question 345
{"accessible":false,"alternatives":[{"id":1698,"text":"prolonged mean transit time (MTT)"},{"id":1699,"text":"prolonged time to maximum (Tmax)"},{"id":1700,"text":"prolonged time to peak (TTP)"},{"id":1702,"text":"reduced cerebral blood flow (CBF)"},{"id":1701,"text":"reduced cerebral blood volume (CBV)"}],"archived":false,"correctAlternativeId":1701,"explanation":"\u003cp\u003eOn\u0026nbsp;\u003ca href=\"https://radiopaedia.org/articles/ct-perfusion-in-ischaemic-stroke\"\u003eCT perfusion\u003c/a\u003e\u0026nbsp;the ischemic penumbra has been variably defined using a combination of parameters. Generally, it should be conceptually thought of as \"the area of the brain with reduced perfusion\" minus the \"infarct core\". In practice, which parameters are used to define each component has varied. A fairly common definition for penumbra is the area of brain with:\u0026nbsp;\u003c/p\u003e\u003col\u003e\n\u003cli\u003eprolonged (increased) T-max, typically \u0026gt;6 seconds (or other measures of delayed arrival of contrast such as mean transit time (MTT) or time to peak (TTP)), and...\u003c/li\u003e\n\u003cli\u003enormal or increased cerebral blood volume (CBV) due to auto-regulation\u003c/li\u003e\n\u003c/ol\u003e\u003cp\u003eThis region will have only a moderate decreased cerebral blood flow (CBF). This is in contrast to the infarct core which will have marked decrease in CBF and also a decrease in CBV.\u0026nbsp;\u003c/p\u003e","id":345,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/345","nextQuestionPath":"/articles/ct-perfusion-in-ischaemic-stroke/questions/344","relatedArticles":[{"id":13437,"title":"Ischemic stroke","link":"/articles/ischaemic-stroke?lang=us"},{"id":24524,"title":"Ischemic penumbra","link":"/articles/ischaemic-penumbra?lang=us"}],"alsoUsedIn":[{"id":178,"kind":"Course","title":"Emergency Imaging in Stroke","link":"https://radiopaedia.org/courses/emergency-imaging-in-stroke"},{"id":984,"kind":"Course","title":"2021 Virtual Conference Private Use - page 984","link":"https://radiopaedia.org/courses/2021-virtual-conference-private-use/pages/984"},{"id":984,"kind":"Course","title":"Radiopaedia 2021 - isoCME - page 984","link":"https://radiopaedia.org/courses/radiopaedia-2021-isocme/pages/984"},{"id":984,"kind":"Course","title":"2022 Virtual Conference Private Use - page 984","link":"https://radiopaedia.org/courses/2022-virtual-conference-private-use/pages/984"},{"id":970,"kind":"RestrictedPage","title":"Page 970 (in no courses)","link":"https://radiopaedia.org/admin/restricted_pages/970"},{"id":955,"kind":"RestrictedPage","title":"Page 955 (in no courses)","link":"https://radiopaedia.org/admin/restricted_pages/955"},{"id":1,"kind":"LiveSchedule","title":"1","link":"https://radiopaedia.org/admin/live_schedules/1"},{"id":18,"kind":"LiveSchedule","title":"18","link":"https://radiopaedia.org/admin/live_schedules/18"},{"id":987,"kind":"Course","title":"2021 Virtual Conference Private Use - page 987","link":"https://radiopaedia.org/courses/2021-virtual-conference-private-use/pages/987"},{"id":987,"kind":"Course","title":"Radiopaedia 2021 - isoCME - page 987","link":"https://radiopaedia.org/courses/radiopaedia-2021-isocme/pages/987"},{"id":987,"kind":"Course","title":"2022 Virtual Conference Private Use - page 987","link":"https://radiopaedia.org/courses/2022-virtual-conference-private-use/pages/987"},{"id":20,"kind":"LiveSchedule","title":"20","link":"https://radiopaedia.org/admin/live_schedules/20"},{"id":908,"kind":"Course","title":"Neuroradiology Lectures - page 908","link":"https://radiopaedia.org/courses/neuroradiology-lectures/pages/908"},{"id":908,"kind":"Course","title":"2021 Virtual Conference Private Use - page 908","link":"https://radiopaedia.org/courses/2021-virtual-conference-private-use/pages/908"},{"id":908,"kind":"Course","title":"Radiopaedia 2021 - isoCME - page 908","link":"https://radiopaedia.org/courses/radiopaedia-2021-isocme/pages/908"},{"id":908,"kind":"Course","title":"New test course - page 908","link":"https://radiopaedia.org/courses/new-test-course/pages/908"},{"id":1192,"kind":"Course","title":"Neuroradiology Lectures - page 1192","link":"https://radiopaedia.org/courses/neuroradiology-lectures/pages/1192"},{"id":1192,"kind":"Course","title":"New test course - page 1192","link":"https://radiopaedia.org/courses/new-test-course/pages/1192"}],"stem":"\u003cp\u003eWhich of the following changes in CT perfusion parameters is\u0026nbsp;\u003cstrong\u003eNOT\u003c/strong\u003e consistent with an ischemic penumbra?\u0026nbsp;\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/345"}],"attemptsPercentages":[{"alternativeId":"1698","percentage":5},{"alternativeId":"1701","percentage":73},{"alternativeId":"1700","percentage":8},{"alternativeId":"1702","percentage":9},{"alternativeId":"1699","percentage":5}],"promptToLogin":false,"questionManager":false,"articleId":"ct-perfusion-in-ischemic-stroke"}