Question 2959
{"accessible":false,"alternatives":[{"id":14406,"text":"30 seconds"},{"id":14407,"text":"1 minute"},{"id":14408,"text":"4 minutes"},{"id":14409,"text":"16 minutes"},{"id":14410,"text":"32 minutes"}],"archived":false,"correctAlternativeId":14406,"explanation":"\u003cp\u003eAcquisition time = (TR x # phase encoding steps x NEX x # of slices) / ETL\u003c/p\u003e\u003cp\u003eAcquisition time will decrease by a factor of 8\u003c/p\u003e\u003cp\u003e4 minutes / 8 = 30 seconds\u003c/p\u003e","id":2959,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2967","nextQuestionPath":"/articles/acquisition-time/questions/2953","relatedArticles":[{"id":14588,"title":"Repetition time","link":"/articles/repetition-time?lang=us"},{"id":22136,"title":"Spin echo sequences","link":"/articles/spin-echo-sequences?lang=us"},{"id":22558,"title":"MRI physics","link":"/articles/mri-physics?lang=us"},{"id":60745,"title":"Fast spin echo","link":"/articles/fast-spin-echo?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\u003eA single-echo conventional spin echo sequence takes 4 minutes to complete. Assuming resolution and TR remain constant, how long will a fast spin echo sequence with an echo train length (ETL) of 8 take to perform?\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/2959"}],"attemptsPercentages":[{"alternativeId":"14409","percentage":5},{"alternativeId":"14407","percentage":11},{"alternativeId":"14410","percentage":9},{"alternativeId":"14408","percentage":7},{"alternativeId":"14406","percentage":68}],"promptToLogin":false,"questionManager":false,"articleId":"acquisition-time"}