Table 5. Threshold values and test characteristics of CT perfusion parameters for the prediction and diagnosis of DCI.
| Quality | CTP parameter | Study | CTP threshold | AUC % (95% CI) | Sensitivity % (95% CI) | Specificity % (95% CI) | PPV % (95% CI) | NPV % (95% CI) | OR |
|---|---|---|---|---|---|---|---|---|---|
| Predicting DCI | CBF | Van der Schaaf8 | Least perfused flow territorya | 53 | |||||
| Van der Schaaf8 | Largest asymmetryb | 80 | |||||||
| Van der Schaaf8 | Ratio <0.72b | 75 (51–90) | 93 (79–98) | ||||||
| CBV | Van der Schaaf8 | Least perfused flow territorya | 56 | ||||||
| Van der Schaaf8 | Largest asymmetryb | 75 | |||||||
| Van der Schaaf8 | Ratio <0.78b | 75 (51–90) | 70 (52–83) | ||||||
| MTT | Lagares7 | Mean ⩾5.9 secondsa,c | 74 | 47 | 100 | 100 | 62 | ||
| Lagares7 | Any ROI with ⩾5.9 secondsa,c | 76 | 85 | 76 | 75 | 80 | 12 (2.5–57) | ||
| Van der Schaaf8 | Least perfused flow territorya | 57 | |||||||
| Van der Schaaf8 | Largest asymmetryb | 79 | |||||||
| Van der Schaaf8 | Difference >0.87 secondsb | 75 (51–90) | 70 (52–83) | ||||||
| TTP | Van der Schaaf8 | Least perfused flow territorya | 59 | ||||||
| Van der Schaaf8 | Largest asymmetryb | 81 | |||||||
| Van der Schaaf8 | Difference >1.0 secondsb | 75 (51–90) | 90 (74–97) | ||||||
| Diagnosing DCI | CBF | Dankbaar6 | <36.3 mL/100 g per minutea | 71 (60–82) | 74 (66–78) | 63 (54–69) | |||
| Dankbaar6 | Ratio <0.77b | 72 (61–83) | 76 (68–80) | 63 (54–69) | |||||
| Sanelli11 | a | 81 (77–85) | |||||||
| Sanelli11 | <30.5 mL/100 g per minutea | 78 | 70 | ||||||
| Sviri17 | minimal <25 mL/100 g per minutea | 73 | 76 | 73 | 78 | ||||
| CBV | Dankbaar6 | <2.78 mL/100 ga | 57 (45–70) | 52 (45–58) | 63 (54–69) | ||||
| Dankbaar6 | Ratio <0.80b | 64 (52–76) | 64 (57–69) | 63 (54–69) | |||||
| Sanelli11 | a | 61 (55–67) | |||||||
| MTT | Dankbaar6 | >5.85 secondsa | 76 (66–86) | 70 (62–74) | 77 (67–81) | ||||
| Dankbaar6 | Difference >1.08 secondsb | 78 (68–87) | 80 (72–83) | 63 (54–69) | |||||
| Sanelli11 | a | 78 (73–83) | |||||||
| Sanelli11 | >5.0 secondsa | 72 | 70 | ||||||
| Sviri17 | Maximal >6.5 secondsa | 71 | 81 | 78.5 | 74 | ||||
| TTP | Dankbaar6 | >25.2 secondsa | 60 (48–72) | 54 (47–60) | 63 (54–69) | ||||
| Dankbaar6 | Difference >0.99 secondsb | 75 (65–86) | 70 (62–74) | 66 (57–72) | |||||
| Qualitative | Hickmann14 | CTP defects on CBF mapd | 25 | 80.9 | |||||
| Hickmann14 | CTP defects on CBV mapd | 25 | 80.9 | ||||||
| Hickmann14 | CTP defects on TTP mapd | 25 | 84.6 | ||||||
| Killeen16 | CTP defectsd | 80 (68–92) | 67 (40–93) | 90 (82–96) | 47 (27–62) | 8.0 (1.96–32.6) | |||
| Sanelli11 | CTP defectsd | 81 (68–90) | 83 (70–91) | 83 (70–91) | 82 (69–90) |
AUC, area under the curve; CBF, cerebral blood flow; CBV, cerebral blood volume; CTP, CT perfusion; DCI, delayed cerebral ischemia; min, minutes; MTT, mean transit time; NPV, negative predictive value; OR, odds ratio; PPV, positive predictive value; sec, seconds; TTP, time-to-peak.
a
Quantitatively (absolute) measured.
b
Semi-quantitatively (relative) measured.
c
The MTT threshold of 5.9 seconds was a validation of the threshold by Dankbaar et al.6
d
Qualitatively (visual) measured.