Article Figures & Data
Figures
- Fig 1.
Bland Altman plot of intrascan (A), intrasession (B), and intersession (C) WB-CBF differences plotted against mean WB-CBF. WB intrascan, intrasession, and intersession CBF differences are randomly distributed and are not dependent on mean WB-CBF. Dotted lines indicate that the mean WB-CBF difference ± 1.96 SD. 95% of the differences between repeated measurements are within 1.96 SD of the mean difference.
- Fig 2.
Absolute WB-CBF difference, as a function of the number of averages. Steady CBF values are reached after 20 averages.
- Fig 3.
Intrasession and intersession ICC as a function of the number of averages.
- Fig 4.
CASL sections obtained at 3T with 10, 20, 30, 40, and 50 averages, respectively (left to right); no clear differences are visible between perfusion images on the basis of 20 and 50 averages.
Tables
Means ± SD (ml/100 g/min) WB RACA LACA RMCA LMCA RPCA LPCA All sessions 56.1 ± 11.1 60.2 ± 12.5 61.9 ± 13.5 63.8 ± 14.1 61.8 ± 13.8 54.8 ± 13.0 53.0 ± 14.2 Male 54.2 ± 9.2 Female 58.1 ± 12.6 Mean Session I 56.0 ± 12.1 60.4 ± 14.0 61.5 ± 14.5 63.0 ± 16.0 62.0 ± 14.0 54.2 ± 13.5 52.9 ± 13.4 Mean Session II 55.6 ± 9.5 59.8 ± 10.4 61.0 ± 11.6 63.2 ± 11.1 61.0 ± 13.2 55.2 ± 12.1 53.0 ± 14.2 Mean Session III 56.8 ± 12.0 60.3 ± 13.5 63.0 ± 14.7 65.4 ± 15.5 62.3 ± 14.7 55.2 ± 13.8 53.0 ± 15.5 Note:—CBF indicates cerebral blood flow; LACA, left anterior cerebral artery; LMCA, left middle cerebral artery; LPCA, left posterior cerebral artery; RACA, right anterior cerebral artery; RMCA, right middle cerebral artery; RPCA, right posterior cerebral artery; WB, whole brain.
- Table 2:
Intrascan reproducibility on the basis of the measurement differences between the first 25 and the last 25 averages
Reproducibility WB RACA LACA RMCA LMCA RPCA LPCA Intrascan RI (mL/100 g/min) 10.2 12.4 13.1 12.2 13.5 12.8 11.6 ICC (95% CI) 0.88 (0.81–0.93) 0.86 (0.78–0.92) 0.87 (0.79–0.92) 0.89 (0.83–0.93) 0.86 (0.78–0.92) 0.87 (0.79–0.92) 0.91 (0.85–0.95)* Note:—CI indicates confidence interval; ICC, intraclass correlation coefficient; RI, repeatability index.
* Log10 transformed data used in the calculation of the ICC.
Reproducibility 20 averages WB RACA LACA RMCA LMCA RPCA LPCA Intrasession RI (ml/100 g/min) 10.7 13.3 13.7 13.4 12.6 14.1 14.7 ICC (95% CI) 0.85 (0.72–0.93) 0.82 (0.65–0.91) 0.85 (0.70–0.92) 0.86 (0.73–0.93) 0.87 (0.75–0.94) 0.82 (0.66–0.91) 0.79 (0.60–0.89)* Intersession RI (mL/100 g/min) 16.8 18.0 20.7 21.7 19.4 17.5 16.0 ICC (95% CI) 0.61 (0.24–0.87) 0.63 (0.27–0.88) 0.62 (0.25–0.87) 0.60 (0.22–0.87) 0.68 (0.33–0.90) 0.70 (0.37–0.91) 0.78 (0.50–0.93)* * Log10 transformed data used in the calculation of the ICC.
Reproducibility 50 averages WB RACA LACA RMCA LMCA RPCA LPCA Intrasession RI (mL/100 g/min) 10.7 13.7 14.1 13.2 12.2 14.1 11.1 ICC (95% CI) 0.88 (0.76–0.94) 0.85 (0.70–0.92) 0.86 (0.73–0.93) 0.89 (0.78–0.95) 0.90 (0.80–0.95) 0.85 (0.71–0.93) 0.90 (0.80–0.95)* Intersession RI (ml/100 g/min) 14.2 14.0 16.6 19.5 17.0 13.8 12.4 ICC (95% CI) 0.78 (0.49–0.93) 0.83 (0.59–0.95) 0.79 (0.52–0.94) 0.74 (0.43–0.92) 0.80 (0.53–0.94) 0.84 (0.62–0.95) 0.89 (0,72–0,97)* * Log10 transformed data used in the calculation of the ICC.
