Accession Number : ADA321817

Title :   A Study of Ultrasonic Wavefront Distortion Compensation.

Descriptive Note : Annual rept. 1 Sep 95-31 Aug 96,

Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA

Personal Author(s) : Zhu, Qing

PDF Url : ADA321817

Report Date : SEP 1996

Pagination or Media Count : 83

Abstract : The objective of this research is to develop ultrasonic wavefront distortion compensation methods to improve ultrasound resolution in the detection and classification of small breast lesions. A novel ultrasonic wavefront compensation technique which we call Toward Inverse Filtering (TIF) has been experimentally demonstrated last year and further analyzed since then. The well Known Inverse Filtering technique is optimal for imaging fidelity but unstable. TIF approaches the performance of Inverse Filtering while demonstrates adequate stability. Experiments with breast specimens have shown that TIF represents a substantial improvement over other compensation algorithms, offering the potential for better visualization of small breast lesions. Last year, our major effects have been devoted to the understanding of TIF and further experimentation with TIF. First, the relationship of TIF with Inverse Filtering has been established, and comparisons of TIF with other compensation algorithms have been made. Second, further experimentation with TIF is in progress. In addition to TIF, another novel compensation approach which we call modified CLEAN algorithm (MCLEAN), although it has limitations in its application to breast imaging, has also been exploited. MCLEAN has shown to improve image quality by canceling coherent multipath image artifacts. The strengths and limitations of MCLEAN have been investigated.

Descriptors :   *ULTRASONICS, *COMPENSATION, *DISTORTION, *WAVEFRONTS, *BREAST CANCER, ALGORITHMS, STABILITY, DETECTION, RESOLUTION, IMAGES, VISIBILITY, CLASSIFICATION, INVERSION, FILTERS, ARTIFACTS, MULTIPATH TRANSMISSION, LESIONS, MAMMARY GLANDS, FILTRATION.

Subject Categories : Medicine and Medical Research
      Acoustics
      Optics
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE