Question 2961
{"accessible":false,"alternatives":[{"id":14415,"text":"diffusion gradient amplitude"},{"id":14416,"text":"diffusion gradient duration"},{"id":14417,"text":"diffusion gradient orientation"},{"id":14418,"text":"diffusion gradient spacing"}],"archived":false,"correctAlternativeId":14417,"explanation":"\u003cp\u003eb value is a function of the diffusion gradient amplitude, duration and spacing (the period of time between the two diffusion gradients).\u003c/p\u003e\u003cp\u003eDiffusion gradient orientation is changed based on the orientation of the DWI source image being acquired. At a minimum, three orthogonal planes must be acquired.\u003c/p\u003e","id":2961,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2968","nextQuestionPath":"/articles/mri-physics/questions/2960","relatedArticles":[{"id":26733,"title":"b values","link":"/articles/b-values-1?lang=us"},{"id":16718,"title":"Diffusion-weighted imaging","link":"/articles/diffusion-weighted-imaging-2?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 of the following does NOT change the b value in diffusion weighted imaging?\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/2961"}],"attemptsPercentages":[{"alternativeId":"14416","percentage":15},{"alternativeId":"14417","percentage":57},{"alternativeId":"14415","percentage":7},{"alternativeId":"14418","percentage":21}],"promptToLogin":false,"questionManager":false,"articleId":"mri-physics"}