Table 2.

Results of single factor K-M analysis of ultrasound characteristics and their relation to recurrence of MTC

group	character	recurrence group (cases)	Non- recurrence group (cases)	Chi-square	P
Number	single focus	10	42	0.847	0.357
	multiple focus	7	15
Composition	solid	16	51	0.605	0.437
	cystic solid	1	6
	cystic	0	0
Echo	very low echo	3	17	1.119	0.773
	low echo	12	36
	equal echo	2	3
	high echo	0	1
Boundary	clear	10	41	1.370	0.242
	unclear	7	16
Morphology	regular	4	26	2.609	0.106
	irregular	13	31
Aspect ratio (Front and back diameter/ Left and right diameter)	≥1	2	5	0.023	0.881
	<1	15	52
Calcification	yes	12	36	0.525	0.469
	no	5	21
Blood flow*	yes	12	38	0.337	0.562
	no	2	11

*Notes: Only 63 patients had ultrasonic data on blood flow