A Large Aperture Real-Time Equipment for Vascular Imaging
A reflective scanning pulse-echo technique has been utilized to provide real-time imaging in conjunction with large aperture transducers. The larger apertures have been employed to provide sub-millimeter resolutions in all three space directions. Use of reflecting scanning mechanism provides real-time operation without sacrificing portability. To improve equipment repeatability, a novel technique termed the Interactive Gain Compensation (IGC) is used to preprocess the RF signals. This also enhances equipment detectability together with simplification to the conventional TGC arrangements. The input dynamic range is also favorably affected by the new IGC processing, Preliminary utilization of this equipment has been in the in-vivo imaging of the human carotid artery with planned subsequent applications for the coronaries, Atherosclerotic plaques less than lmm in size have been detected in the carotid. These present less than 5% occlusion in the artery and may not be readily identified by X-ray angiography. Because of greater gray scale repeatability and higher resolutions, it has also been possible to visualize the generally complex plaque topography and the relative “hardness” of the plaque in a consistent and repeatible manner. The accompanying presentation includes typical real-time videotaped data of images obtained in the carotid arteries of normals and patients with known atherosclerotic lesions
KeywordsCholesterol Attenuation Lution Reso
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