Table 4. Accuracy of optimal thresholds for ischemic core (major reperfusion group).

Threshold (within delay time ≥ 3 s)	Youden’s Index	Sensitivity	Specificity	Mean magnitude (ml)	r	P value
rCBF ≤ 30%	0.40	0.64	0.76	10.8	0.881	< 0.001
CBF ≤ 6 ml/100 g/min	0.36	0.55	0.81	19.4	0.716	< 0.001
rCBV ≤ 50%	0.27	0.49	0.78	24.7	0.530	< 0.001
CBV ≤ 1 ml/100 g	0.26	0.40	0.86	22.5	0.566	< 0.001
Delay time ≥ 7 s	0.28	0.57	0.71	17.6	0.752	< 0.001
rMTT ≥ 200%	0.20	0.53	0.66	18.4	0.743	< 0.001
MTT ≥ 13 s	0.20	0.41	0.79	27.0	0.348	0.017

More data in supplemental material.

CBF, cerebral blood flow; CBV, cerebral blood volume; MTT, mean transient time.