Question 2963
{"accessible":false,"alternatives":[{"id":14423,"text":"high radiofrequency transmit bandwidth"},{"id":14425,"text":"low amplitude slice selection gradient"},{"id":14424,"text":"long TE"},{"id":14426,"text":"short TR"},{"id":14427,"text":"small flip angle"}],"archived":false,"correctAlternativeId":14426,"explanation":"\u003cp\u003eShort TR times are required for saturation of stationary tissue. This will provide contrast with fresh unsaturated blood entering the slice.\u003c/p\u003e\u003cp\u003eSaturation of stationary tissue can also be achieved with larger flip angles. Short TE times provide high signal from unsaturated blood entering the slice (less transverse decay prior to readout).\u003c/p\u003e\u003cp\u003eIf the slice selected is too thick, blood can become saturated. A low amplitude slice selection gradient, in combination with a high RF transmit bandwidth, will increase slice thickness.\u003c/p\u003e","id":2963,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2968","nextQuestionPath":"/articles/echo-time/questions/2955","relatedArticles":[{"id":14588,"title":"Repetition time","link":"/articles/repetition-time?lang=us"},{"id":18476,"title":"MR angiography","link":"/articles/mr-angiography-2?lang=us"},{"id":18193,"title":"Time of flight angiography","link":"/articles/time-of-flight-angiography-1?lang=us"},{"id":21768,"title":"Gradient coils","link":"/articles/gradient-coils-1?lang=us"},{"id":22558,"title":"MRI physics","link":"/articles/mri-physics?lang=us"},{"id":61252,"title":"Radiofrequency transmitter","link":"/articles/radiofrequency-transmitter?lang=us"}],"alsoUsedIn":[{"id":1928,"kind":"Course","title":"Imaging Physics: MRI - page 1928","link":"https://radiopaedia.org/courses/imaging-physics-mri/pages/1928"}],"stem":"\u003cp\u003eWhich sequence parameter is required in time-of-flight magnetic resonance angiography (TOF MRA)?\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/2963"}],"attemptsPercentages":[{"alternativeId":"14426","percentage":46},{"alternativeId":"14424","percentage":12},{"alternativeId":"14427","percentage":24},{"alternativeId":"14425","percentage":6},{"alternativeId":"14423","percentage":11}],"promptToLogin":false,"questionManager":false,"articleId":"echo-time"}