Table 1.

Summary of studies comparing CTP-based infarct prediction to a DWI reference.

Study	N	CT-MRI interval Inclusion criteria median [IQR]	DWI outline method	Reference region for ROC analysis	CTP parameters tested	Optimal CTP threshold for core prediction	Volume difference DWI-CTP, ml Mean (95% CI)
Current Study	103	≤3 h 36 min [25–77]	Manual	Hypo-perfused region (Tmax>4 s)	rCBF	<38%	0.3 (−3.6 to 4.2)
Wintermark 8	25	≤12 h 25 min [–]	Manual	Whole brain	CBV rCBV MTT/rMTT TTP/rTTP CBF/rCBF	<2.0 ml/100 g <60%	–
Bivard 3	57 a	– 28 min [20–40]	Semi-automatic	Ipsilesional hemisphere	rCBF CBV/rCBV Tmax MTT	<45%	–
Bivard 2	67 a	≤12 h 162 min [185–240]	Manual	Ipsilesional hemisphere	rCBF CBF MTT TTP/rTTP CBV/rCBV	<40%	–
Kamalian7	48	≤1 h 34 min [28–43]	Semi-automatic	Not specified	rCBF CBF CBV/rCBV MTT/rMTT	<16–32% depending on software used	–
Campbell4,6	54 a	≤1 h 27 min [25–35]	Manual	Hypo-perfused region (rTTP>2 s)	rCBF CBF CBV/rCBV MTT Tmax TTP	<31%	11.0 (–)
Bivard1	67 a	≤1 h – [–]	Semi-automatic	Ipsilesional hemisphere	rCBF CBF CBV/rCBV Tmax/DT	<40%	0.5 (−0.1 to 0.9)
Bivard5	33 a	≤1 h – [–]	manual	Ipsilesional hemisphere	rCBF CBF CBV/rCBV MTT TTP	<50%	4.2 (3.4 to 7.2)
Schaefer9	55	≤3 h 51 min [41–65]	Semi-automatic	Ipsilesional hemisphere	rCBF CBV	<15%	−2.6 (–)b

^–= not provided; IQR = interquartile range; ROC = Receiver operating characteristic; CTP = computer tomography perfusion; DWI = diffusion weighted imaging; CI = confidence interval; R²= correlation coefficient; h = hours; CBV = cerebral blood volume; rCBV = relative cerebral blood volume; MTT = ; rMTT = relative mean transit time; TTP = time to peak; rTTP = relative time to peak; CBF = cerebral blood flow, rCBF = relative cerebral blood flow; T_max = time-to-maximum of the residue function; DT = delay time.

^aSubset of these patients is included in the current study.

^b95% CI not reported; prediction interval reported as ± 56.7.