| 1. |
- Cinthio, Magnus, et al.
(författare)
-
New non-invasive method for intima-media thickness and intima-media compression measurements
- 2005
-
Ingår i: Proceedings - IEEE Ultrasonics Symposium. - 1051-0117. - 0780393821 ; 1, s. 389-392
-
Konferensbidrag (refereegranskat)abstract
- Intim a-media thickness (IMT) is considered as a valuable marker of early atherosclerosis. We suggest a new algorithm for simultaneous measurements of absolute diameter at diastole, distension (diameter change), IMT at diastole and the intima-media compression (IMC) with a new fast, robust, high-resolution, and automatic algorithm utilizing the ultrasonic gray-scale information. The new algorithm is evaluated in a limited in vivo study on the common carotid artery of 5 healthy volunteers. The standard deviation within an investigation was (8 ± 4 μm; range 4-14 μm) during IMC measurements, (8 ± 5 μm; range 4-16 μm) during the measurements of the IMT at diastole, (30 ±36 μm; range 6-92 μm) during the distension measurements and (48 ±49 μm; range 15-134 μm) during the measurements of the lumen diameter at diastole. The evaluation shows that the algorithm is fast and that the reproducibility and resolution are more than sufficient for in vivo studies. © 2005 IEEE.
|
|
| 2. |
- Jansson, Tomas, et al.
(författare)
-
Ultrasound Doppler for improved diagnosis of disease in the paranasal sinuses
- 2005
-
Ingår i: Proceedings - IEEE Ultrasonics Symposium. - 1051-0117. - 0780393821 ; 2, s. 839-841
-
Konferensbidrag (refereegranskat)abstract
- 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 (R2=0.94, corrected for the square-law dependence of sound speed variation due to varying glycerol concentration).
|
|
