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Comparison of cerebral blood flow acquired by simultaneous [15O]water positron emission tomography and arterial spin labeling magnetic resonance imaging.

Zhang K, Herzog H, Mauler J, Filss C, Okell TW, Kops ER, Tellmann L, Fischer T, Brocke B, Sturm W, Coenen HH, Shah NJ - J. Cereb. Blood Flow Metab. (2014)

Bottom Line: This study presents results of CBF measurements recorded simultaneously with [(15)O]water and ASL.A statistically significant (P<0.05) correlation was observed between the two modalities; the whole-brain CBF values determined with PET and pCASL were 43.3±6.1 mL and 51.9±7.1 mL per 100 g per minute, respectively.Regional and individual differences were found despite the overall similarity between ASL and PET, requiring further detailed investigations.

View Article: PubMed Central - PubMed

Affiliation: Institute of Neuroscience and Medicine-4: Medical Imaging Physics, Forschungszentrum Jülich, Jülich, Germany.

ABSTRACT
Until recently, no direct comparison between [(15)O]water positron emission tomography (PET) and arterial spin labeling (ASL) for measuring cerebral blood flow (CBF) was possible. With the introduction of integrated, hybrid magnetic resonance (MR)-PET scanners, such a comparison becomes feasible. This study presents results of CBF measurements recorded simultaneously with [(15)O]water and ASL. A 3T MR-BrainPET scanner was used for the simultaneous acquisition of pseudo-continuous ASL (pCASL) magnetic resonance imaging (MRI) and [(15)O]water PET. Quantitative CBF values were compared in 10 young healthy male volunteers at baseline conditions. A statistically significant (P<0.05) correlation was observed between the two modalities; the whole-brain CBF values determined with PET and pCASL were 43.3±6.1 mL and 51.9±7.1 mL per 100 g per minute, respectively. The gray/white matter (GM/WM) ratio of CBF was 3.0 for PET and 3.4 for pCASL. A paired t-test revealed differences in regional CBF between ASL and PET with higher ASL-CBF than PET-CBF values in cortical areas. Using an integrated, hybrid MR-PET a direct simultaneous comparison between ASL and [(15)O]water PET became possible for the first time so that temporal, physiologic, and functional variations were avoided. Regional and individual differences were found despite the overall similarity between ASL and PET, requiring further detailed investigations.

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Averaged PET and ASL-CBF images (n=10) after normalization into the MNI space. The CBF values from both methods show an agreement in the value range of 0 to 120 mL per 100 g per minute. The averaged whole-brain CBF from PET is 43.3±6.1 mL and 51.9±7.1 mL per 100 g per minute from ASL. ASL, arterial spin labeling; CBF, cerebral blood flow; MNI, Montreal Neurological Institute; PET, positron emission tomography.
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fig2: Averaged PET and ASL-CBF images (n=10) after normalization into the MNI space. The CBF values from both methods show an agreement in the value range of 0 to 120 mL per 100 g per minute. The averaged whole-brain CBF from PET is 43.3±6.1 mL and 51.9±7.1 mL per 100 g per minute from ASL. ASL, arterial spin labeling; CBF, cerebral blood flow; MNI, Montreal Neurological Institute; PET, positron emission tomography.

Mentions: A visual comparison of the averaged (n=10) PET-CBF and ASL-CBF maps in MNI space reveals a good overall agreement (Figure 2). Both the PET and ASL data fit well within the color scale ranging from 0 to 120 mL per 100 g per minute without lower and upper cutoffs. Averaged whole-brain CBF of the 10 subjects measured at baseline condition after sleep was 43.3±6.1 mL per 100 g per minute for PET and 51.9±7.1 mL per 100 g per minute for ASL. Compared with PET, the averaged CBF in GM measured by ASL is higher (67.3±8.2 versus 51.8±7.7 mL per 100 g per minute) and the averaged CBF in WM is similar (19.5±5.8 versus 17.4±3.1 mL per 100 g per minute), which results in a GM/WM ratio of 3.4 and 3.0 for ASL and PET, respectively. A closer look at the WM results revealed a variation within the WM VOIs for ASL-CBF, which was twice the variation for PET-CBF. The mean (n=10) coefficient of variation in the WM VOIs was 56% for ASL-CBF and 29% for PET-CBF. In comparison, the corresponding results for GM were 23% and 32%.


Comparison of cerebral blood flow acquired by simultaneous [15O]water positron emission tomography and arterial spin labeling magnetic resonance imaging.

Zhang K, Herzog H, Mauler J, Filss C, Okell TW, Kops ER, Tellmann L, Fischer T, Brocke B, Sturm W, Coenen HH, Shah NJ - J. Cereb. Blood Flow Metab. (2014)

Averaged PET and ASL-CBF images (n=10) after normalization into the MNI space. The CBF values from both methods show an agreement in the value range of 0 to 120 mL per 100 g per minute. The averaged whole-brain CBF from PET is 43.3±6.1 mL and 51.9±7.1 mL per 100 g per minute from ASL. ASL, arterial spin labeling; CBF, cerebral blood flow; MNI, Montreal Neurological Institute; PET, positron emission tomography.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126098&req=5

fig2: Averaged PET and ASL-CBF images (n=10) after normalization into the MNI space. The CBF values from both methods show an agreement in the value range of 0 to 120 mL per 100 g per minute. The averaged whole-brain CBF from PET is 43.3±6.1 mL and 51.9±7.1 mL per 100 g per minute from ASL. ASL, arterial spin labeling; CBF, cerebral blood flow; MNI, Montreal Neurological Institute; PET, positron emission tomography.
Mentions: A visual comparison of the averaged (n=10) PET-CBF and ASL-CBF maps in MNI space reveals a good overall agreement (Figure 2). Both the PET and ASL data fit well within the color scale ranging from 0 to 120 mL per 100 g per minute without lower and upper cutoffs. Averaged whole-brain CBF of the 10 subjects measured at baseline condition after sleep was 43.3±6.1 mL per 100 g per minute for PET and 51.9±7.1 mL per 100 g per minute for ASL. Compared with PET, the averaged CBF in GM measured by ASL is higher (67.3±8.2 versus 51.8±7.7 mL per 100 g per minute) and the averaged CBF in WM is similar (19.5±5.8 versus 17.4±3.1 mL per 100 g per minute), which results in a GM/WM ratio of 3.4 and 3.0 for ASL and PET, respectively. A closer look at the WM results revealed a variation within the WM VOIs for ASL-CBF, which was twice the variation for PET-CBF. The mean (n=10) coefficient of variation in the WM VOIs was 56% for ASL-CBF and 29% for PET-CBF. In comparison, the corresponding results for GM were 23% and 32%.

Bottom Line: This study presents results of CBF measurements recorded simultaneously with [(15)O]water and ASL.A statistically significant (P<0.05) correlation was observed between the two modalities; the whole-brain CBF values determined with PET and pCASL were 43.3±6.1 mL and 51.9±7.1 mL per 100 g per minute, respectively.Regional and individual differences were found despite the overall similarity between ASL and PET, requiring further detailed investigations.

View Article: PubMed Central - PubMed

Affiliation: Institute of Neuroscience and Medicine-4: Medical Imaging Physics, Forschungszentrum Jülich, Jülich, Germany.

ABSTRACT
Until recently, no direct comparison between [(15)O]water positron emission tomography (PET) and arterial spin labeling (ASL) for measuring cerebral blood flow (CBF) was possible. With the introduction of integrated, hybrid magnetic resonance (MR)-PET scanners, such a comparison becomes feasible. This study presents results of CBF measurements recorded simultaneously with [(15)O]water and ASL. A 3T MR-BrainPET scanner was used for the simultaneous acquisition of pseudo-continuous ASL (pCASL) magnetic resonance imaging (MRI) and [(15)O]water PET. Quantitative CBF values were compared in 10 young healthy male volunteers at baseline conditions. A statistically significant (P<0.05) correlation was observed between the two modalities; the whole-brain CBF values determined with PET and pCASL were 43.3±6.1 mL and 51.9±7.1 mL per 100 g per minute, respectively. The gray/white matter (GM/WM) ratio of CBF was 3.0 for PET and 3.4 for pCASL. A paired t-test revealed differences in regional CBF between ASL and PET with higher ASL-CBF than PET-CBF values in cortical areas. Using an integrated, hybrid MR-PET a direct simultaneous comparison between ASL and [(15)O]water PET became possible for the first time so that temporal, physiologic, and functional variations were avoided. Regional and individual differences were found despite the overall similarity between ASL and PET, requiring further detailed investigations.

Show MeSH
Related in: MedlinePlus