ABSTRACT
The exact boundary extraction of liver using abdominal computed tomography (CT) images continues to be the greatest challenge in the computer-assisted diagnosis of liver tumour, as the organ boundary is very weak. In this paper, an efficient algorithm is proposed to enhance the edge information of the CT images prior to segmentation, by means of multislice image fusion and anisotropic diffusion filtering in non-subsampled contourlet (NSCT) domain. The two adjacent slices of CT images are decomposed using NSCT, and the fusion of low- and high-frequency coefficients is obtained by means of phase congruency and sum-modified Laplacian operators, respectively. The major highlight of this work is that, prior to high-frequency fusion; the high-frequency coefficients of both images are processed using anisotropic diffusion to strengthen the edge information. Finally, the edge-enhanced image is obtained by NSCT reconstruction. The performance metrics show that the information pertaining to the edges is found to be precise in the fused image. The proposed logic, when applied to the real-time contrast-enhanced triple-phase CT image, has proven to be highly effective. All the image samples used in this work for test purpose were obtained from Jawaharlal Institute of Postgraduate Medical Education Research (JIPMER), a Medical Research Institute and Hospital at Puducherry, India.
ACKNOWLEDGEMENTS
The authors would like to thank Dr K. S. Santhosh Anand, Senior Resident, Department of Surgical Gastroenterology, JIPMER, Puducherry for extending his support towards obtaining the CT images used in this study.
ORCID
B. Lakshmi Priya http://orcid.org/0000-0002-4460-6915
Additional information
Funding
Notes on contributors
B. Lakshmi Priya
B Lakshmi priya received her BTech degree in electronics and communication engineering from Pondicherry University and MTech subsequently from St. Peter’s University, Chennai, India. Currently, she is persuing PhD programme in Pondicherry Engineering College, Puducherry, India. Her areas of interest include bio - signal and image processing.
K. Jayanthi
K Jayanthi completed her under graduation from Madras University in 1997 and obtained her master’s & doctorate degrees from Pondicherry Central University in 1999 and 2007, respectively. She is currently a Professor in the Department of Electronics and Communication Engineering Pondicherry Engineering College. Her research interests include biomedical signal and image processing. Email: [email protected]
Biju Pottakkat
Biju Pottakkat obtained his under graduation in Medicine from Medical College, Calicut, Kerala in 1996, MS from Medical College, Kottayam, Kerala in 2001, MCh from SGPGIMS, Lucknow in 2005. Currently, he is a Professor and Head, Department of Surgical Gastroenterology, JIPMER, Puducherry. Email: [email protected]
G. Ramkumar
G Ramkumar completed his graduation in Medicine from Tirunelveli Medical College, Tamilnadu in 2003, DMRD from Stanley Medical College, Chennai in 2006 and DNB (RD) from Amrita Institute of Medical Sciences, Kochi in 2009. He is currently an Assistant Professor in the Department of Radiodiagnosis, JIPMER, Puducherry. Email: [email protected]