“…1. The majority of the studies (Kwok et al, 2004;Ferrari et al, 2004;Karssemeijer, 1998;Aylward et al, 1998;Chen and Zwiggelaar, 2010;Chakraborty et al, 2012;Rampun et al, 2017b;Taghanaki et al, 2017;Bora et al, 2016;Vikhe and Thool, 2017;Chen et al, 2015;Yoon et al, 2016) tried to manually model the curve structure of the pectoral muscle either using straight-line techniques, curve-based techniques or a combination of these two. In other words, the majority of the existing methods are hand-crafted models that require specific knowledge and were insufficient in dealing with the large variation of pectoral muscle boundaries.…”