Question 2828
{"accessible":false,"alternatives":[{"id":13802,"text":"an increase in blood velocity"},{"id":13803,"text":"increasing Doppler angle"},{"id":13804,"text":"increasing transducer frequency"},{"id":13805,"text":"using a thinner PZT crystal layer"}],"archived":false,"correctAlternativeId":13803,"explanation":"\u003cp\u003eDoppler shift is directly proportional to blood velocity, transducer frequency and cos(Doppler angle)\u003c/p\u003e\u003cp\u003eAn increase in blood velocity or an increase in transducer frequency will increase the Doppler shift value detected by the transducer.\u003c/p\u003e\u003cp\u003eAs the Doppler angle gets larger the value of cos(Doppler angle) gets smaller. Hence, an \u003cstrong\u003eincrease in Doppler angle will reduce the Doppler shift value\u003c/strong\u003e.\u003c/p\u003e\u003cp\u003eUsing a thinner PZT crystal will shorten the wavelength produced by the transducer, which will result in an increased transducer frequency (which, as we've discussed, will increase Doppler shift)\u003c/p\u003e","id":2828,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2830","nextQuestionPath":"/articles/doppler-shift/questions/2822","relatedArticles":[{"id":8661,"title":"Piezoelectric effect","link":"/articles/piezoelectric-effect?lang=us"},{"id":8664,"title":"Ultrasound frequencies","link":"/articles/ultrasound-frequencies?lang=us"},{"id":42049,"title":"Doppler waveforms","link":"/articles/doppler-waveforms?lang=us"},{"id":54038,"title":"Ultrasound transducer","link":"/articles/ultrasound-transducer?lang=us"},{"id":59274,"title":"Doppler angle correction","link":"/articles/doppler-angle-correction?lang=us"}],"alsoUsedIn":[{"id":1620,"kind":"RestrictedPage","title":"Page 1620 (in no courses)","link":"https://radiopaedia.org/admin/restricted_pages/1620"},{"id":1984,"kind":"Course","title":"Imaging Physics: Ultrasound Peer Review - page 1984","link":"https://radiopaedia.org/courses/imaging-physics-ultrasound-peer-review/pages/1984"},{"id":1984,"kind":"Course","title":"Imaging Physics: Ultrasound - page 1984","link":"https://radiopaedia.org/courses/imaging-physics-ultrasound/pages/1984"}],"stem":"\u003cp\u003eWhich change will result in a decrease in Doppler shift measured by the transducer?\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/2828"}],"attemptsPercentages":[{"alternativeId":"13804","percentage":13},{"alternativeId":"13802","percentage":7},{"alternativeId":"13803","percentage":69},{"alternativeId":"13805","percentage":10}],"promptToLogin":false,"questionManager":false,"articleId":"doppler-shift"}