We propose a method to improve the diagnosis of infection in the paranasal sinuses, distinguishing between mucous and serous cases. The method utilizes a previously published method whereby the viscosity in a sealed container may be measured using an ultrasound Doppler method. As ultrasound propagates in a liquid medium, due to attenuation, the resulting pressure gradient will cause the liquid to move in the propagation direction - the wellknown effect of acoustic streaming. The streaming velocity will, for a given acoustic output, be proportional to the viscosity of the fluid. In this study, we verify that acoustic streaming can be induced in an anthropomorphic sinus phantom cast from a human cranium. The sinus phantom was made from agar with added graphite providing sound attenuation prior to the sinus cavity corresponding to an in vivo situation. A number of water-glycerol solutions with scattering particles, were prepared to mimic a clinically interesting range of viscosities (7-47 mPas). Using a 4.2 MHz continuous wave Doppler probe, clearly detectable mean Doppler shifts in the range of 6.5 to 20 Hz were recorded A linear relationship was found between the Doppler shifts and 1/viscosity (R<sup>2</sup>=0.94, corrected for the square-law dependence of sound speed variation due to varying glycerol concentration).
|Title of host publication||Proceedings - IEEE Ultrasonics Symposium|
|Publisher||IEEE--Institute of Electrical and Electronics Engineers Inc.|
|Publication status||Published - 2005|
|Event||IEEE Ultrasonics Symposium, 2005 - Rotterdam, Netherlands|
Duration: 2005 Sep 18 → 2005 Sep 21
|Conference||IEEE Ultrasonics Symposium, 2005 |
|Period||2005/09/18 → 2005/09/21|