Affiliations: Medical Physics Department, Royal Sussex County
Hospital, Brighton BN2 5BE, UK
Note: [] Corresponding author: Dr. Julian Liu, Medical Physics
Department, Royal Sussex County Hospital, Brighton BN2 5BE, UK. Tel.: +44 1273
664598; Fax: +44 1273 664507; E-mail: [email protected];
[email protected]
Abstract: This study introduces a method to reduce the artefact caused by
metal implant, and improve the image quality. The factors affecting the image
quality of the existing methods are analysed from a different point of view.
The observed projection is decomposed into several components including the
correspondence of biological tissues, the correspondence of metal implant,
noises, and inconsistencies caused by beam hardening. The correspondence of
metal implant is identified by initial reconstruction and forward modelling,
and the noises are detected and isolated from the projection in wavelet domain.
The inconsistencies are approximated and compensated. A patient with medial
epicondyle of right femur replaced using femoral component made by Biomet Inc
was scanned using a GE Lightspeed 16 X-ray CT scanner and the observed
projection is processed by this method. The output image shows that all of the
streaking caused by metal implant is eliminated, and the darkness areas caused
by beam hardening are retrieved. Comparing with the default output of the CT
scanner, the image quality has been significantly improved.
