Article Figures & Data
Figures
- FIG 1.
Patient selection flow chart.
- FIG 2.
Plaque enhancement index (PEI; the mean signal intensity of plaque normalized by CSF) change of culprit and nonculprit plaques over time. The boxes were drawn with the median (line in the box) as well as the 25th and 75th percentiles. The bars above and below the box are the maximum and minimum values of the PEI, respectively. The PEI values of all intracranial plaques and culprit plaques increase over the 4 phases (P = .033, P = .034, respectively). The PEI values of the nonculprit plaques show no significant differences among the 4 postcontrast phases (P = .450). *, P < .05; ns, not significant.
- FIG 3.
Cases of the culprit and nonculprit plaque signal intensity change during the 4 postcontrast phases.
- FIG 4.
The ROC of the plaque enhancement index in the 4 contrast-enhanced phases for differentiating between culprit and nonculprit plaques.
Tables
- Table 1:
Demographic and intracranial plaque characteristics of 30 patients with acute stroke
Patient Demographics Mean ± SD or Median (IQR) or n (%) Age (years) 59.0 ± 9.7 Body mass index (kg/cm2) 24.6 ± 2.9 Sex (male) 18 (60.0%) Hypertension 21 (70.0%) Diabetes 11 (36.7%) Dyslipidemia 6 (20.0%) Current smoking 5 (16.7%) Plaque location Internal carotid artery (C4–7) 25 (22.1%) Middle cerebral artery 34 (30.1%) Anterior cerebral artery 6 (5.3%) Basilar artery 17 (15.0%) Vertebral artery 21 (18.6%) Posterior cerebral artery 10 (8.9%) Plaque stenosis (%) 30% ≤ stenosis < 50% (grade I) 74 (65.5%) 50% ≤ stenosis < 70% (grade II) 15 (13.3%) Stenosis ≥ 70% (grade III) 24 (21.2%) Plaque numbers (n) 3.0 (2.0–6.0) Phase PEI All Plaques (n = 113)a Nonculprit Plaque (n = 83)a Culprit Plaque (n = 30)b 1st 0.66 ± 0.51 0.54 ± 0.44 1.02 ± 0.53 2nd 0.72 ± 0.52 0.55 ± 0.42 1.17 ± 0.50 3rd 0.73 ± 0.47 0.58 ± 0.39 1.16 ± 0.41 4th 0.76 ± 0.53 0.60 ± 0.44 1.20 ± 0.49 Pc .033 .450 .034 P 1st versus 2nd .014 .578 .007 P 1st versus 3rd .049 .446 .057 P 1st versus 4th .029 .401 .035 P 2nd versus 3rd .879 .640 .869 P 2nd versus 4th .502 .572 .680 P 3rd versus 4th .458 .771 .477 ↵a A mixed-effects model repeated measures ANOVA for continuous variables was used to analyze the differences between all 4 postcontrast phases in all plaque groups and the nonculprit plaque group.
↵b A 1-way repeated-measures ANOVA for continuous variables was used to analyze the differences between the 4 postcontrast phases in the culprit plaque group. This was followed by a pair-wise comparison post hoc analysis using Bonferroni correction to compare the differences between the PEI values of each 2 contrast phases.
↵c P values of the comparisons of the 4 postcontrast phases.
- Table 3:
Plaque enhancement index in different contrast-enhanced phases to differentiate between culprit and nonculprit plaques
Variables AUC (95% CI) Sensitivity/Specificity Cutoff P Value PEI 1st 0.768 (0.680–0.843) 59.0%/86.7% 0.48 <.001 PEI 2nd 0.829 (0.746–0.893) 80.7%/70.0% 0.83 <.001 PEI 3rd 0.840 (0.759–0.902) 83.1%/70.0% 0.95 <.001 PEI 4th 0.812 (0.727–0.879) 84.3%/70.0% 0.98 <.001 - Table 4:
Comparison of ROC curves of PEI to differentiate between culprit and nonculprit plaques between 4 postcontrast phases
Variables Difference between AUC area 95% CI z statistic P Value PEI 1st versus PEI 2nd 0.060 ± 0.026 0.009–0.112 2.293 .022 PEI 1st versus PEI 3rd 0.071 ± 0.039 −0.005–0.148 1.824 .068 PEI 1st versus PEI 4th 0.043 ± 0.038 −0.032–0.118 1.131 .258 PEI 2nd versus PEI 3rd 0.011 ± 0.025 −0.038–0.060 0.444 .657 PEI 2nd versus PEI 4th 0.017 ± 0.027 −0.036–0.070 0.628 .530 PEI 3rd versus PEI 4th 0.028 ± 0.024 −0.020–0.076 1.151 .249
