Table 3.

Receiver operating characteristic (ROC) analysis of peak parameters and Washout in diagnosing early-phase spinal tuberculosis

Variables		AUC	95%CI	Sensitivity (%)	Specificity (%)	Cut-off value	Y-index	P
PH	4 weeks	0.78	(0.62, 0.94)	80.00	80.00	≥ 865.00	0.60	0.010
	6 weeks	0.74	(0.58, 0.91)	64.00	90.00	≥ 1402.00	0.54	0.026
	8 weeks	0.75	(0.57, 0.93)	76.00	70.00	≥ 1476.50	0.46	0.024
TTP	4 weeks	0.58	(0.35, 0.81)	88.00	40.00	≤ 32.50	0.28	0.454
	6 weeks	0.60	(0.35, 0.85)	84.00	50.00	≤ 36.00	0.34	0.342
	8 weeks	0.59	(0.35, 0.84)	100.00	40.00	≤ 44.50	0.40	0.391
MSI	4 weeks	0.78	(0.58, 0.98)	96.00	70.00	≥ 0.90	0.66	0.010
	6 weeks	0.77	(0.58, 0.95)	92.00	60.00	≥ 1.21	0.52	0.014
	8 weeks	0.77	(0.60, 0.95)	76.00	80.00	≥ 1.72	0.56	0.013
Emax	4 weeks	0.75	(0.56, 0.94)	68.00	80.00	≥ 1.07	0.48	0.021
	6 weeks	0.78	(0.62, 0.94)	56.00	100.00	≥ 1.66	0.56	0.012
	8 weeks	0.83	(0.68, 0.97)	84.00	80.00	≥ 2.28	0.64	0.003
SER	4 weeks	0.78	(0.60, 0.97)	60.00	90.00	≥ 1.01	0.50	0.010
	6 weeks	0.78	(0.62, 0.94)	84.00	70.00	≥ 1.22	0.54	0.011
	8 weeks	0.88	(0.76, 0.99)	76.00	100.00	≥ 1.78	0.76	0.001
Washout	4 weeks	0.46	(0.20, 0.71)	76.00	50.00	≥ 11.49	0.26	0.701
	6 weeks	0.42	(0.20, 0.64)	100.00	10.00	≥ 12.84	0.10	0.465
	8 weeks	0.54	(0.29, 0.79)	88.00	50.00	≥ 25.25	0.38	0.715

AUC area under ROC curve, 95%CI 95% Confidence interval, PH peak height, TTP time to peak, MSI maximum slope of increase, Emax Maximum signal enhancement rate, SER Signal enhancement ratio