Tracy Ssali1,2, Udunna C Anazodo3,2, Jonathan D Thiessen3,2, Frank S Prato3,2, Keith St Lawrence3,2. 1. Lawson Health Research Institute, London, Ontario, Canada; and tssali@uwo.ca. 2. Department of Medical Biophysics, Western University, London, Ontario, Canada. 3. Lawson Health Research Institute, London, Ontario, Canada; and.
Abstract
Although PET with 15O-water is the gold standard for imaging cerebral blood flow (CBF), quantification requires measuring the arterial input function (AIF), which is an invasive and noisy procedure. To circumvent this problem, we propose a noninvasive PET/MRI approach that eliminates the need to measure AIF by using global CBF determined by phase-contrast (PC) MRI as a reference region. This approach not only is noninvasive but also involves no additional imaging time, because PC MRI and 15O-water PET are acquired simultaneously. The purpose of this study was to test the accuracy of this hybrid method in an animal model in which AIF was measured directly and CBF was varied by changing the arterial CO2 tension. Methods: PET and MRI data were simultaneously acquired in juvenile pigs at hypocapnia (n = 5), normocapnia (n = 5), and hypercapnia (n = 4). CBF was measured by the MRI reference method and by PET alone using an MRI-compatible blood sampling system to measure AIF. Results: Global CBF estimates from PC MRI and 15O-water PET agreed well, with a correlation coefficient of 0.9 and a slope of 0.88. Strong positive correlations (R2 > 0.96) were also found between regional CBF generated by the PET-only and the MRI-reference methods. Conclusion: These findings demonstrate the accuracy of this hybrid PET/MRI approach, which might prove useful in patients for whom obtaining accurate CBF measurements is challenging.
Although PET with 15O-water is the gold standard for imaging cerebral blood flow (CBF), quantification requires measuring the arterial input function (AIF), which is an invasive and noisy procedure. To circumvent this problem, we propose a noninvasive PET/MRI approach that eliminates the need to measure AIF by using global CBF determined by phase-contrast (PC) MRI as a reference region. This approach not only is noninvasive but also involves no additional imaging time, because PC MRI and 15O-water PET are acquired simultaneously. The purpose of this study was to test the accuracy of this hybrid method in an animal model in which AIF was measured directly and CBF was varied by changing the arterial CO2 tension. Methods: PET and MRI data were simultaneously acquired in juvenile pigs at hypocapnia (n = 5), normocapnia (n = 5), and hypercapnia (n = 4). CBF was measured by the MRI reference method and by PET alone using an MRI-compatible blood sampling system to measure AIF. Results: Global CBF estimates from PC MRI and 15O-water PET agreed well, with a correlation coefficient of 0.9 and a slope of 0.88. Strong positive correlations (R2 > 0.96) were also found between regional CBF generated by the PET-only and the MRI-reference methods. Conclusion: These findings demonstrate the accuracy of this hybrid PET/MRI approach, which might prove useful in patients for whom obtaining accurate CBF measurements is challenging.
Authors: Yosuke Ishii; Thoralf Thamm; Jia Guo; Mohammad Mehdi Khalighi; Mirwais Wardak; Dawn Holley; Harsh Gandhi; Jun Hyung Park; Bin Shen; Gary K Steinberg; Frederick T Chin; Greg Zaharchuk; Audrey Peiwen Fan Journal: J Magn Reson Imaging Date: 2019-05-01 Impact factor: 4.813
Authors: Mark B Vestergaard; Hashmat Ghanizada; Ulrich Lindberg; Nanna Arngrim; Olaf B Paulson; Albert Gjedde; Messoud Ashina; Henrik B W Larsson Journal: Cereb Cortex Date: 2022-03-04 Impact factor: 5.357
Authors: Lucas Narciso; Tracy Ssali; Linshan Liu; Heather Biernaski; John Butler; Laura Morrison; Jennifer Hadway; Jeffrey Corsaut; Justin W Hicks; Michael C Langham; Felix W Wehrli; Hidehiro Iida; Keith St Lawrence Journal: J Nucl Med Date: 2021-03-19 Impact factor: 11.082
Authors: Linshan Liu; Kobra Alizadeh; Sarah C Donnelly; Praveen Dassanayake; Tian Tian Hou; Rebecca McGirr; R Terry Thompson; Frank S Prato; Neil Gelman; Lisa Hoffman; Donna E Goldhawk Journal: PLoS One Date: 2019-06-06 Impact factor: 3.240
Authors: Ephraim E Parent; Ila Sethi; Jonathon Nye; Chad Holder; Jeffrey J Olson; Jeffrey Switchenko; Funmilayo Tade; Oladunni O Akin-Akintayo; Olayinka A Abiodun-Ojo; Akinyemi Akintayo; David M Schuster Journal: Q J Nucl Med Mol Imaging Date: 2019-12-09 Impact factor: 2.346