RT Journal Article SR Electronic T1 Measurement of cerebral blood flow using 15O-water PET-MRI with a noninvasive method. JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 365 OP 365 VO 58 IS supplement 1 A1 Hidehiko Okazawa A1 Yoshifumi Higashino A1 Tetsuya Tsujikawa A1 Tetsuya Mori A1 Hidetaka Arishima A1 Yasushi Kiyono A1 Ken-Ichiro Kikuta YR 2017 UL http://jnm.snmjournals.org/content/58/supplement_1/365.abstract AB 365Objectives: Measurement of cerebral blood flow (CBF) using positron emission tomography (PET) and H215O is useful and reliable approach for evaluation of brain circulation and hemodynamic changes. Recently a new modality of PET-MRI system, a hybrid scanner of PET and MRI, has become available for precise fusion of high grade anatomical images and PET molecular images, which should be very beneficial in clinical use. However, it is very difficult to sample arterial blood from the patient during PET-MRI scans. In this study, a noninvasive method was developed to estimate input function directly from brain H215O-PET scans for measurement of CBF.Methods: Eleven healthy volunteers (9 males and 2 female, 43.9 ± 10.9y) underwent H215O PET and MRI scans using a whole body PET-MRI scanner (GE Signa PET/MR). A 3-min list-mode PET scan was started with 555 MBq tracer administration. MRI data were acquired simultaneously during the H215O-PET for images of 3D-T1WI and arterial spin labeling (ASL) perfusion MRI with 2.0 sec post-labeling delay (PLD). PET images were reconstructed as dynamic data in frames of 12 x 5 sec, 6 x 10 sec, 3 x 20 sec using two types of resolution and time-of-flight algorithm. The image derived input function (IDIF) method extracted the time-activity curves of the internal carotid artery from several image slices at the skull base in the dynamic PET data. CBF images were calculated using a single compartment model (CM) and a one tissue CM (1-TCM).Results: The global means of CBF obtained by the single CM, 1-TCM, and ASL-MRI were 44.8 ± 4.3, 47.9 ± 5.9 and 57.9 ± 8.6 (mL/100g/min), respectively. CBF from ASL-MRI was significantly greater compared with CBF from H215O-PET (P < 0.001). However, these CBF values were significantly correlated each other in the scatter plots (P < 0.05).Conclusion: Noninvasive measurement of CBF using H215O PET-MRI and IDIF provided reasonable quantitative values, which is useful for clinical application. The ASL-MRI perfusion image from the simultaneous acquisition tended to overestimate CBF values in healthy volunteers. Research Support: This study was partly funded by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (15K15453).