Detection of defects in the liver using ultrasonograms and 3D images
Raman V. Kumar · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2001
Ultrasound scan of liver is performed and a total of 22 2-D images are obtained using mechanical jig each at every 10 degree interval. Each image slice is the projection of the liver in a vertical plane. These images are digitized into bitmaps and are averaged using a spatial filter to make them noiseless. To enhance the noiseless image, contrast stretching is also performed using Histogram Equalization. The Detection and Localization is done with a Sobel Compass Operator. The Sobel Compass Operator detects edges of the individual noiseless and enhanced image slices. Subsequently, Tissue Characterization is done using the property of Differential Absorption of Ultrasound waves. Thus the attributes of the image are extracted. Finally defects are localized and stored for future reference. The stored 2-D images are then interpolated to develop 3-D images. The default position of the viewer of the 3-D image is the center of the liver, which is movable according to viewer's interest. The goal of this paradigm is to provide explicit view of the liver at any mentioned depth from the center, thus providing a distinctive advantage over the existing methods. The 3D images are made more comprehensive by pseudocoloring and Perspective Zooming.