Question 2954
{"accessible":false,"alternatives":[{"id":14385,"text":"blood flow"},{"id":14386,"text":"magnetic field inhomogeneities"},{"id":14387,"text":"patient motion"},{"id":14388,"text":"spin-lattice interactions"},{"id":14389,"text":"spin-spin interactions"}],"archived":false,"correctAlternativeId":14386,"explanation":"\u003cp\u003eSpin echoes compensate for signal loss due to local magnetic field inhomogeneities.\u003c/p\u003e\u003cp\u003eSignal loss due to spin-spin and spin-lattice interactions cannot be compensated for. Signal loss due to blood flow requires modification of sequence parameters or specialized MR angiography sequences (such as phase contrast angiography). Patient motion leads to misregistration of signal. Spin echo plays no role in reversing this artifact.\u003c/p\u003e","id":2954,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2966","nextQuestionPath":"/articles/contrast-enhanced-mr-angiography-1/questions/2124","relatedArticles":[{"id":22136,"title":"Spin echo sequences","link":"/articles/spin-echo-sequences?lang=us"},{"id":16493,"title":"Free induction decay","link":"/articles/free-induction-decay?lang=us"},{"id":22024,"title":"Phase contrast imaging","link":"/articles/phase-contrast-imaging?lang=us"},{"id":6345,"title":"T2 weighted image","link":"/articles/t2-weighted-image?lang=us"},{"id":33838,"title":"Flow void","link":"/articles/flow-void?lang=us"},{"id":48589,"title":"Motion artifact","link":"/articles/motion-artifact-2?lang=us"},{"id":60745,"title":"Fast spin echo","link":"/articles/fast-spin-echo?lang=us"}],"alsoUsedIn":[{"id":1927,"kind":"Course","title":"Imaging Physics: MRI - page 1927","link":"https://radiopaedia.org/courses/imaging-physics-mri/pages/1927"}],"stem":"\u003cp\u003eWhat cause of signal loss does a spin echo sequence compensate for?\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/2954"}],"attemptsPercentages":[{"alternativeId":"14388","percentage":3},{"alternativeId":"14385","percentage":5},{"alternativeId":"14386","percentage":78},{"alternativeId":"14387","percentage":2},{"alternativeId":"14389","percentage":11}],"promptToLogin":false,"questionManager":false,"articleId":"contrast-enhanced-mr-angiography"}