Table 1.

The number of CL and the background pixels before and after an ROI procedure for three slices. The number of the CL pixels did not change before ROI ($R_b$) and after ROI ($R_a$), but the number of background pixels is reduced significantly after the ROI procedure

Slice	CL Size			Background Pixel#
ID	Pixel#	Ratio($R_b$)	Ratio($R_a$)	Before ROI	After ROI
1	198	0.3%	1.6%	65338	12090
2	209	0.3%	1.7%	65327	12079
3	187	0.28%	1.5%	65349	12101