Paraspinal muscle segmentation in CT images using a single atlas

Paraspinal muscles support spine and are the source of movement force. The cross section area (CSA) size, shape, density and volume are affected by many factors, such as surgery, age, health condition, exercise, and low back pain. Minimally invasive spine surgery (MISS) was introduced to provide less muscle tissue injury, less postoperative pain and earlier mobilization than traditional open back surgery. Manual measurements of paraspinal muscle CSA and volume in CT images is inaccurate and time consuming. In this work, an atlas-based image registration is used to segment the muscle region in CT images. In order to address the challenge of large variations of muscle shape and region direction, a local contour optimization is performed after global registration. Experimental results show that the proposed method can successfully segment paraspinal muscle regions in target images. The results can be used to evaluate paraspinal muscle volume hence tissue injury and postoperative back muscle atrophy of MISS patients.