کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10691705 1019604 2014 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The Delayed Onset of Subharmonic and Ultraharmonic Emissions from a Phospholipid-Shelled Microbubble Contrast Agent
ترجمه فارسی عنوان
آغاز تاخیر ناشی از انتشار گازهای سدیم هارمونیک و فوق العاده هارمونیک از نماینده کنتراست میکروببول فسفولیپید
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم آکوستیک و فرا صوت
چکیده انگلیسی
Characterizing the non-linear response of microbubble contrast agents is important for their efficacious use in imaging and therapy. In this article, we report that the subharmonic and ultraharmonic response of lipid-shelled microbubble contrast agents exhibits a strong temporal dependence. We characterized non-linear emissions from Targestar-p microbubbles (Targeson Inc., San Diego, CA, USA) periodically for 60 min, at 10 MHz excitation frequency. The results revealed a considerable increase in the subharmonic and ultraharmonic response (nearly 12-15 and 5-8 dB) after 5-10 min of agent preparation. However, the fundamental and the harmonic response remained almost unchanged in this period. During the next 50 min, the subharmonic, fundamental, ultraharmonic, and harmonic responses decreased steadily by 2-5 dB. The temporal changes in the non-linear behavior of the agent appeared to be primarily mediated by gas-exchange through the microbubble shell; temperature and prior acoustic excitation based mechanisms were ruled out. Further, there was no measurable change in the agent size distribution by static diffusion. We envisage that these findings will help obtain reproducible measurements from agent characterization, non-linear imaging, and fluid-pressure sensing. These findings also suggest the possibility for improving non-linear imaging by careful design of ultrasound contrast agents.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultrasound in Medicine & Biology - Volume 40, Issue 4, April 2014, Pages 727-738
نویسندگان
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