Comparison of Otsu and an adapted Chan–Vese method to determine thyroid active volume using Monte Carlo generated SPECT images

EJNMMI Physics

Table 4 Otsu threshold values for each case

Volume	Background AC (%)	Hotspot 0	Hotspot +50	Hotspot +100	Hotspot +150
20	5	80	80	87	92
	10	82	97	97	97
	15	91	91	91	91
	20	107	107	107	107
35	5	103	103	103	103
	10	98	110	110	110
	15	97	97	97	97
	20	89	107	89	107
50	5	80	80	80	80
	10	77	71	77	77
	15	73	73	73	73
	20	80	70	70	70

Volume	Background AC (%)	Hotspot 0	Hotspot +50	Hotspot +100	Hotspot +150
20	5	80	80	87	92
	10	82	97	97	97
	15	91	91	91	91
	20	107	107	107	107
35	5	103	103	103	103
	10	98	110	110	110
	15	97	97	97	97
	20	89	107	89	107
50	5	80	80	80	80
	10	77	71	77	77
	15	73	73	73	73
	20	80	70	70	70

Volume	Background AC (%)	Hotspot 0	Hotspot +50	Hotspot +100	Hotspot +150
20	5	80	80	87	92
	10	82	97	97	97
	15	91	91	91	91
	20	107	107	107	107
35	5	103	103	103	103
	10	98	110	110	110
	15	97	97	97	97
	20	89	107	89	107
50	5	80	80	80	80
	10	77	71	77	77
	15	73	73	73	73
	20	80	70	70	70

Volume	Background AC (%)	Hotspot 0	Hotspot +50	Hotspot +100	Hotspot +150
20	5	80	80	87	92
	10	82	97	97	97
	15	91	91	91	91
	20	107	107	107	107
35	5	103	103	103	103
	10	98	110	110	110
	15	97	97	97	97
	20	89	107	89	107
50	5	80	80	80	80
	10	77	71	77	77
	15	73	73	73	73
	20	80	70	70	70