Table 4.

Bone-destruction characteristics

Destruction property	Clinical feature (X-ray image)	Image feature (X-ray image after pre-processing)
Geographic pattern (Fig. 7a)	1. Abnormal bone contour shape	∙ Multiple (≥ 3) connected components in left or right contour line
	2. Small zone of transition	∙ Low-valued concavity change rate on left or right contour line
		∙ Few long surface lines
		∙ Small length of spread
Moth-eaten pattern (Fig. 7b)	1. Area of destruction with ragged border	∙ Multiple (≥ 3) connected components with in-between gap in left or right contour line
	2. Multiple scattered holes	∙ High concavity change rate value for left and right contour line
	2. Longer transition zone	∙ Multiple small surface lines
		∙ Wide length of spread
Permeative pattern (Fig. 7c)	1. Poorly demarcated border	∙ Single or multiple (≥ 2) connected components with very small in-between gap in left or right contour line
	2. Numerous elongated holes	∙ High concavity change rate value for left and right contour line
	3. Long transition zone spread parallel to long-bone axis	∙ Few small surface lines
		∙ Wide length of spread parallel to bone axis
Presence of calcification (Fig. 7d)	1. Flecks of calcification appear	∙ Single connected component in left and right contour line
	2. Small transition zone	∙ High concavity change rate value for left or right contour line
		∙ Few long surface lines
		∙ Small length of spread
Presence of giant cyst (Fig. 7e)	1. Irregular or fragmented bone contour	∙ Multiple (≥ 3) connected component in left and right contour line
	2. Large affected area appears as transparent to X-ray	∙ High concavity change rate value for left and right contour line
		∙ Very few (≤ 5) small surface lines
		∙ Wide length of spread