Abstract
PURPOSE: The aim of the proposed study was to conduct a feasibility study using a flat rectangular (2 × 10 mm(2)) transducer operating at 4.0 MHz for creating thermal lesions in an arterial atherosclerotic plaque phantom. The proposed method can be used in the future for treating atherosclerotic plaques in human arteries. MATERIALS AND METHODS: The flat rectangular transducer was firstly assessed in agar/silica evaporated milk phantom, polyacrylamide phantom and freshly excised turkeytissue phantom. Then, the same transducer was assessed in an arterial atherosclerotic plaque phantom which was created in the laboratory with a very low cost. The recipe of the atherosclerotic plaque phantom was 4% w/v agar, 1% w/v gypsum, 2% w/v butter and 93% water. The amount of plaque removal was evaluated visually and using an X-Ray system. RESULTS: It was shown that the flat rectangular transducer can create thermal lesions on the agar/silica evaporated milk phantom, polyacrylamide phantom and in excised tissue. The size of the lesions matches the geometry of the transducer. Moreover, this transducer destroyed 27.1% of the atherosclerotic plaque phantom with 8 W acoustical power and 30 s duration. CONCLUSIONS: This feasibility study demonstrated that atherosclerotic plaque can be destroyed using a very small flat rectangular (2 × 10 mm(2)) transducer in a very small time interval of 30 s. In future clinical trials the transducer will be incorporated in a catheter which will be inserted intravascular (1-3 mm) wide and can be used to treat atherosclerotic plaques in the coronary arteries.