1. The Performance of MRI-Based Cerebral Blood Flow Measurements in Acute and Subacute Stroke Compared With 15O-Water Positron Emission Tomography
by Olivier Zaro-Weber, Walter Moeller-Hartmann, Wolf-Dieter Heiss, and Jan Sobesky
Stroke
Volume 40(7):
July 1, 2009
Copyright © American Heart Association, Inc. All rights reserved.

2. Figure 1. Volumetric comparison of CBFPET and CBFMRI volumes.
Figure 1. Volumetric comparison of CBFPET and CBFMRI volumes. Within an individual brain atlas of the affected hemisphere (A), the volume of CBF <20 mL/100 g/min on PET (red) and the volumes of predefined CBF thresholds on MRI (blue) were generated (B). Then, PET and MRI volumes were compared (C). The degree of congruence was expressed as the ratio C (Cx=volume CBFMRI <x/volume CBFPET <20; x refers to the thresholds <40, <30, <20, <10 mL/100 g/min).
Olivier Zaro-Weber et al. Stroke. 2009;40:
Copyright © American Heart Association, Inc. All rights reserved.

3. Figure 2. Comparison of perfusion measurement with MRI and PET in 3 patients with different hypoperfusion volumes.
Figure 2. Comparison of perfusion measurement with MRI and PET in 3 patients with different hypoperfusion volumes. The resulting volumes defined by a threshold of <20 mL/100 g/min in each modality are displayed on the right side (red: PET, blue: MRI).
Olivier Zaro-Weber et al. Stroke. 2009;40:
Copyright © American Heart Association, Inc. All rights reserved.

4. Figure 3. Mean of the volumetric ratio (C-ratio).
Figure 3. Mean of the volumetric ratio (C-ratio). This ratio compares the volume delineated by different CBFMRI thresholds to the volume of hypoperfusion <20 mL/100 g/min on CBFPET. Values are given as the median (line), 25th/75th percentile (box plot), 10th/90th percentile (bars), and range (black circles). Dotted line: complete volumetric congruence.
Olivier Zaro-Weber et al. Stroke. 2009;40:
Copyright © American Heart Association, Inc. All rights reserved.

5. Figure 4. Scatter plots comparing the hypoperfusion volumes obtained by CBFPET (<20 mL/100 g/min) with the volumes obtained by different CBFMRI thresholds (<40, <30, <20, <10 mL/100 g/min).
Figure 4. Scatter plots comparing the hypoperfusion volumes obtained by CBFPET (<20 mL/100 g/min) with the volumes obtained by different CBFMRI thresholds (<40, <30, <20, <10 mL/100 g/min). Solid lines represent the linear regression and the 95% CI. Dashed lines represent the line of identity. The values for the linear regression are shown in the plots.
Olivier Zaro-Weber et al. Stroke. 2009;40:
Copyright © American Heart Association, Inc. All rights reserved.

6. Figure 5. The standard Bland-Altman plot compares the hypoperfusion volumes obtained by MRI (threshold of CBFMRI <20 mL/100 g/min) and PET (threshold of CBFPET <20 mL/100 g/min).
Figure 5. The standard Bland-Altman plot compares the hypoperfusion volumes obtained by MRI (threshold of CBFMRI <20 mL/100 g/min) and PET (threshold of CBFPET <20 mL/100 g/min). The volumetric difference between 2 values (y-axis) is plotted against the average (x-axis).
Olivier Zaro-Weber et al. Stroke. 2009;40:
Copyright © American Heart Association, Inc. All rights reserved.