Evaluation of frequency dependence of backscatter coefficient in normal and atherosclerotic aortic walls

Measurement of the ultrasonic properties of human coronary arteries in vitro with a 50-MHz acoustic microscope

“…Ultrasonic characterization of vascular tissue has evolved from the use of frequencies between 4 and 15 MHz, (6)(7)(8) to the 20-to 27-MHz range (9,10), and more recently between 25 and 65 MHz (11)(12)(13). The benefits of using higher frequencies are the improvement of image quality as well as of the characterization of the layered structure of the vessel wall and consequently of the atherosclerotic plaque.…”

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.…”

Arterial Plaque Characterization Using IVUS Radio-Frequency Time Echoes

“…Despite the accurate differentiation between all plaque types (calcification, mixed lesion, fibrous tissue, lipid core and thrombus) using IB IVUS, the angle dependency between ROI's and catheter axis makes this classification unstable and sensitive (Urbani et al, 1993;Picano et al, 1983;Sarnelli et al,1986;Landini et al, 1986;Barzilai et al, 1987;De Kroon et al, 1991;Picano et al, 1994). Moreover the high resolution dictated for plaque detection necessitates high frequency ultrasound signals which affect the penetration depth of these transmitted ultrasonic pulses.…”