Research On The Processing Of Fog Artifacts In Ultrasonic Imaging For HIFU Therapeutic Monitoring

B-mode imaging is a significant way for real-time monitory and therapeutic evaluation in HIFU therapy due to its characteristics of low-cost, convenience and real-time imaging. However, a real image of tissue components is always covered by fog artifacts resulting from the ultrasonic imaging in HIFU therapeutic system. Fog artifacts have a bad effect on focus location and HIFU therapy. In this paper, the forming mechanism of fog artifacts is analyzed and the mathematical model is established. Thus, the fog artifacts in clinic images can be located and characterized based on the model. According to the different features between the fog artifacts and the tissue images, a differential- method for reducing fog artifacts is proposed. The experiments on clinic images show that the differential method improves the quality of B-mode imaging.Firstly, the paper studies the artifacts in B-mode imaging of HIFU therapeutic system. By analyzing the forming mechanisms and the clinical manifestations of all kinds of artifacts in ultrasonic diagnostic images, this paper indicates that a new kind of artifacts called "fog artifact" appear in the B-mode images acquired by HIFU therapeutic system. Then the forming mechanism of fog artifacts which differs from tradition artifacts is explained combined with the operating environment of a B-mode probe in HIFU therapeutic system. Suppression methods for speckle and reverberation are introduced and their advantages and drawbacks are also discussed.According to the forming mechanism of fog artifacts, the mathematical model is established. Simulation experiments under different imaging conditions are done based on the model and features of fog artifacts are also summarized. The model is used to locate the fog artifacts in clinic images. The experimental results verify the correctness of mechanism analysis and mathematical model.Based on the different characteristics between the fog artifacts and the tissue images, a differential method for removing fog artifacts is proposed. The method regards the image obtained from the probe's position close to skin as a reference image, which has a clear appearance of the tissue. The reference image is registered and...