کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1762337 | 1019686 | 2009 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Characterization of Acoustic Properties of PVA-Shelled Ultrasound Contrast Agents: Linear Properties (Part I)
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
آکوستیک و فرا صوت
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Characterization of Acoustic Properties of PVA-Shelled Ultrasound Contrast Agents: Linear Properties (Part I) Characterization of Acoustic Properties of PVA-Shelled Ultrasound Contrast Agents: Linear Properties (Part I)](/preview/png/1762337.png)
چکیده انگلیسی
This work examines the linear acoustic behavior of ultrasound contrast agents made of three types of poly (vinyl alcohol) (PVA) shelled microbubbles manufactured at different pH and temperature conditions. Backscattered power, attenuation coefficient and phase velocity of ultrasonic waves propagating through suspensions of PVA contrast agents were measured at temperature values ranging between 24°C and 37°C in a frequency range from 3 MHz to 13 MHz. Enhancement of the backscattered power higher than 20 dB and displaying a weak dependence on temperature was observed. Attenuation and phase velocity, on the other hand, showed higher sensitivity to temperature variations. A modified version of the Church model, which accounts for the dispersion of the dynamic modulus of the PVA shells, was developed to simultaneously fit the attenuation and phase velocity data at 24°C. The frequency dependence of the storage modulus was found to be that of semiflexible polymeric networks. On the other hand, the frequency dependence of the dynamic loss modulus suggests that additional mechanisms, which may be related to the finite dimensions of the shell and/or to its inhomogeneity, may play a significant role in the dissipation of the acoustic energy. For the microbubbles of interest, this model predicts frequency dependent resonance frequency higher than 100 MHz. (E-mail: dmitryg@kth.se)
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultrasound in Medicine & Biology - Volume 35, Issue 7, July 2009, Pages 1127-1138
Journal: Ultrasound in Medicine & Biology - Volume 35, Issue 7, July 2009, Pages 1127-1138
نویسندگان
Dmitry Grishenkov, Claudio Pecorari, Torkel B. Brismar, Gaio Paradossi,