Article Figures & Data
Figures
- FIG 1.
Noncontrast CT, conventional CTA, and dynamic CTA for 2 exemplary patients with acute ischemic stroke. Patient A (left column) underwent imaging within 293 minutes from symptom onset, and patient B (right column), within 284 minutes from symptom onset. Both patients had an ASPECTS of 10 on noncontrast CT (subfigures A1 and B1). Conventional CTA reveals an acute occlusion of the M1 segment of the left MCA (indicated by the arrows on subfigures A2 and B2) for both patients. On dynamic CTA, patient A had good collateral supply, and arterial contrast-enhancement was almost synchronous, compared with the unaffected right hemisphere (early arterial phase [A3]; parenchymal phase [A4]; late venous phase [A5]). In contrast, patient B exhibited poor collateral supply on dynamic CTA with delayed and reduced arterial enhancement (reduced and delayed contrast-enhancement by 2 phases compared with the contralateral hemisphere [B3–B5]).
- FIG 2.
Tmax maps (A1 and B1) and CBF maps (A2 and B2) for 2 patients with either good (patient A, left column) or poor collateral supply (patient B, right column). Tmax lesion sizes, HIR, and CBF lesion sizes are all considerably smaller for patient A with good collateral supply compared with patient B with poor collateral supply. See Fig 1 for the corresponding noncontrast CT, CTA, and dynamic CTA for the same patients.
- FIG 3.
Receiver operating characteristics for rCBF < 38% (solid line), Tmax > 8 seconds (dashed line), the CBV-index (dot-dashed line), and HIR (dotted line) for the identification of good collateral status. The AUC was highest for rCBF < 38% with an AUC of 0.83.
Tables
Perfusion Parameter All Patients Patients with Poor Collaterals (Score, 0–3) Patients with Good Collaterals (Score, 4–5) P Value Tmax > 6 sec (mL) 111 (102–119) 135 (124–145) 88 (77–99) <.001 Tmax > 8 sec (mL) 74 (67– 82) 97 (88–107) 53 (44–63) <.001 Tmax > 10 sec (mL) 48 (43–54) 66 (58–74) 32 (25–39) <.001 rCBF < 30%, mL 24 (19–28) 41 (33–49) 8 (5–11) <.001 rCBF < 34%, mL 30 (25–35) 50 (41–58) 11 (8–14) <.001 rCBF < 38%, mL 36 (31–42) 59 (50–68) 15 (12–19) <.001 CBV-index 0.68 (0.65–0.70) 0.60 (0.56–0.63) 0.76 (0.72–0.78) <.001 HIR 0.37 (0.34–0.40) 0.46 (0.42–0.50) 0.29 (0.24–0.33) <.001 ↵a Data are given as mean values and 95% confidence intervals.
- Table 2:
Results from the Spearman rank correlation analysis for collateral score as a function of perfusion parameters (ρ [95% CI] and P value) and from ROC analysis for the identification of good collateral statusa
Perfusion Parameter ρ (95% CI) P Value AUC (95% CI) Cutoff Value Sensitivity Specificity Accuracy Tmax >6 sec (mL) −0.50 (−0.61 to −0.39) <.001 0.75 (0.68–0.81)b 124 mL 56% 82% 69% Tmax >8 sec (mL) −0.54 (−0.64 to −0.43) <.001 0.77 (0.71–0.83)b 74 mL 68% 76% 72% Tmax >10 sec (mL) −0.50 (−0.60 to−0.39) <.001 0.77 (0.71–0.83)b 53 mL 64% 80% 72% rCBF < 30% (mL) −0.61 (−0.71 to −0.52) <.001 0.81 (0.75–0.87) 14 mL 72% 82% 77% rCBF < 34% (mL) −0.64 (−0.73 to −0–55) <.001 0.83 (0.77–0.88) 25 mL 67% 87% 77% rCBF < 38% (mL) −0.66 (−0.74 to −0.57) <.001 0.83 (0.78–0.89) 27 mL 75% 80% 77% CBV-index +0.51 (0.40–0.63) <.001 0.76 (0.69–0.81)b 0.8 60% 78% 69% HIR −0.49 (−0.60−0.37) <.001 0.73 (0.66–0.79)b 0.4 75% 62% 65% Volume with rCBF <38%:
Collateral Status<27 mL ≥27 mL Total Good collateral status (score 4−5) 89 22 111 Poor collateral status (score 0–3) 26 77 103 Total 115 99 214 ↵a Good collateral status was significantly associated with a smaller rCBF < 38% lesion size (Fisher exact test was significant with P < .001).
