Search Contact information
University of Cambridge Home Department of Engineering
University of Cambridge > Engineering Department > Machine Intelligence Lab

Abstract for rohling_firstyear

Cambridge University Engineering Department 1st year PhD progress report


Robert Rohling

May 1996

A drawback of conventional 2-D ultrasound imaging is the requirement that the physician mentally reconstruct 3-D anatomy given multiple 2-D image slices. This report reviews attempts to overcome this problem using 3-D ultrasonic imaging. It is argued that free-hand imaging holds the most promise for effective and inexpensive 3-D ultrasound. In the free-hand paradigm, the physician is allowed to move the probe freely over the region of interest, while a sensing device records the position of each 2-D image slice. The set of 2-D images and position data are subsequently used to reconstruct a 3-D data set which can be rendered on a computer monitor or used for volumetric data analysis. Initial tests show that measurement errors, including image artifacts, are significant enough to obscure and distort diagnostically important information. An investigation into the sources of measurement error is used as a basis for improving the quality of the 3-D reconstruction. Reduction of measurement errors by image registration is feasible during the reconstruction stage. A novel reconstruction algorithm which performs registration of image slices is described. Several experiments are then performed and the resulting reconstructions are much clearer and of greatly enhanced diagnostic utility. The registration is achieved by applying visual tracking techniques outside their traditional area of application. Since the algorithm is automatic and incremental, it can be easily incorporated into existing 3-D ultrasound systems. Future research will attempt to improve the registration method and apply it to a variety of clinical cases.

(ftp:) (http:)
PDF (automatically generated from original PostScript document - may be badly aliased on screen):
  (ftp:) rohling_firstyear.pdf | (http:) rohling_firstyear.pdf

If you have difficulty viewing files that end '.gz', which are gzip compressed, then you may be able to find tools to uncompress them at the gzip web site.

If you have difficulty viewing files that are in PostScript, (ending '.ps' or '.ps.gz'), then you may be able to find tools to view them at the gsview web site.

We have attempted to provide automatically generated PDF copies of documents for which only PostScript versions have previously been available. These are clearly marked in the database - due to the nature of the automatic conversion process, they are likely to be badly aliased when viewed at default resolution on screen by acroread.

© 2005 Cambridge University Engineering Dept
Information provided by milab-maintainer