Velocity and attenuation of sound in arterial tissues

Abstract

The velocity and attenuation of sound has been determined for freshly excised human and canine arterial tissues using a time delay spectrometer (TDS) technique. Frequency was swept from 0 to 10 MHz with data being taken in the range from 2 to 10 MHz. The velocity was determined using a comparison of the time delay for the received signal between a water path and a sample tissue of measured thickness. The velocity of sound was measured for various pathologies and related to biochemical assays of tissue. It was found to increase with increasing ultrasound attenuation of the tissue. The velocity was shown to increase with increased collagen, C, expressed as a percentage of wet weight of the tissue, [V = 17.8* C + 1561 m/s at 37 degrees C, r = 0.77] but was strongly dependent on tissue cholesterol or low levels of calcium. For highly calcified lesions, the velocity of sound was found to be approximately 2000 m/s at 37 degrees C.

Time domain echo pattern evaluations from normal and atherosclerotic arterial walls: a study in vitro.

“…ULTRASONIC tissue characterization of atherosclerosis has been attempted in several studies in vitro. [1][2][3][4][5][6][7][8][9][10][11][12] The purpose of these studies has been twofold: (1) to test new variables of potential diagnostic use, and (2) to provide basic information for a better definition of limits and applicability of clinical echocardiography.Findings in vitro show that, in predominantly fatty samples of aortic wall, the values of the internal backscatter tend to overlap with those found in normal walls.9 In this previous study, the value of the specular echoes of aqueous phase-tissue interface -which is supposed to be strongly angle dependent -was purportedly "gated out." However, the detection of specular reflections is fundamental for the border identification with conventional echocardiographic instruments.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] The purpose of these studies has been twofold: (1) to test new variables of potential diagnostic use, and (2) to provide basic information for a better definition of limits and applicability of clinical echocardiography.…”

Speed of Sound

“…The same was found to apply within brain tissue, where differences in water content provide reasonable explanations for the differences in the speed of sound between adult and infant or foetal brain (Kremkau et al 1981;Wladimiroff et al 1975; see also Figure 5.5). This is not apparently so for arterial tissue, where speed of sound correlates positively with collagen content and negatively with percentage cholesterol, and the collagen content is a major determinant of the speed (Rooney et al 1982).…”

Multi-Frequency Processing for Lumen Enhancement with Wideband Intravascular Ultrasound

“…This incident was observed by Rooney et al as they report a velocity as high as 2000 m/s in diseases arteries with high level of collagen and cholesterol [67]. Attenuation in the arteries has been reported by [67][68][69]. The average attenuation for all three layers of the artery is 11 ± 4 db/cm/MHz, higher in calcified regions, and lower in lipid regions.…”

“…Due to the physics of ultrasound, as the media in which the ultrasound is propagating in becomes more dense, the beam will propagate faster through the media. This incident was observed by Rooney et al as they report a velocity as high as 2000 m/s in diseases arteries with high level of collagen and cholesterol [67]. Attenuation in the arteries has been reported by [67][68][69].…”