Incident angle-dependent gain correction for reflection images on ultrasound computed tomography

摘要

We are performing clinical studies on breast cancer examinations at Hokkaido University Hospital with an ultrasoundcomputed tomography (USCT) system. Our studies have revealed that some reflection images exhibit intensityinhomogeneity because ultrasound waves, shot by a 1-D ring array transducer, go non-vertically into the object surface.This trend significantly increases the burden of interpretation. Therefore, we developed a calibration method to removethis heterogeneity based on the distribution of the incident angle of waves that are estimated from the slope of the subjectsurface morphologically extracted from multi-slice reflection images. Results showed that applying this correctionmethod to clinical images enabled the image contrast and uniformity to be successfully recovered.