A Symmetry Similarity Measure via the Log-Gabor Transform for B-Mode Ultrasound Images and Magnetic Resonance Volumes

This paper presents a similarity measure that enables the comparison between B-mode ultrasound images and magnetic resonance volumes. Based on the different MR slices a 3D volume was reconstructed, aiming to obtain virtual 2D slices and to improve the comparison with B-mode images. Symmetry Similarity Measure (SSM) values range from − 1 to 1, where 1 is the maximum similarity measure, which is based on frequency approach to symmetry with Log-Gabor filters. SSM was tested in anatomic ex-vivo organ pieces of 20 − 30 cm3 of volume. Virtual MR slices, corresponding to different degrees of inclination were computed, aiming to find the most similar MR slices with the fixed B-mode image. This will serve for the evaluation of ultrasound image quality. For the analyzed images, a maximum SSM of 0.94 was found for virtual slices coincident with the B-mode images acquisition, as expected.