Table 6.

Comparison of performance of MRI by duration classification.

Degree of injury	Ligament	Acute					Chronic
		Sn	Sp	PPV	NPV	Acc	Sn	Sp	PPV	NPV	Acc
Normal	ATFL	0	95	0	100	95	0	78	0	97	76
	CFL	82	55	41	89	63	88	58	56	88	69
Partial tear	ATFL	70	94	94	70	80	9	80	33	44	43
	CFL	45	89	83	57	65	33	85	56	70	67
Complete tear	ATFL	88	74	71	89	80	68	87	81	77	79
	CFL	71	97	83	94	93	55	94	75	85	83

Acc = accuracy; ATFL = anterior talofibular ligament; CFL = calcaneofibular ligament; MRI = magnetic resonance imaging; NPV = negative predictive value; PPV = positive predictive value; Sn = sensitivity; Sp = specificity.