TY - JOUR T1 - Comparison of quantitative cerebral blood flow measured by simultaneous arterial spin labeling MRI and oxygen-15 labeled gases PET scans using integrated PET/MRI scanner. JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 382 LP - 382 VL - 60 IS - supplement 1 AU - Hitoshi Kubo AU - Hiroshi Ito AU - Kazuhiro Takahashi AU - Shiro Ishii Y1 - 2019/05/01 UR - http://jnm.snmjournals.org/content/60/supplement_1/382.abstract N2 - 382Objectives: The aim of this study was to compare quantitative cerebral blood flow measured by simultaneous arterial spin labeling (ASL) MRI and oxygen-15 labeled gases PET scans using integrated PET/MRI scanner. Methods: PET/MRI measurements with the steady-state method of oxygen-15 labeled gases were performed on six healthy men using mMR (Siemens Healthcare). Static 4 minutes PET scanning was started 3 min after 1 min of continuous inhalation of oxygen-15 labeled carbon monoxide gas (C15O). Static 10 minutes PET scannings were performed during inhalation of oxygen-15 labeled oxygen gas (15O2), and oxygen-15 labeled carbon dioxide gas (C15O2), respectively. During each PET scanning, arterial blood samplings were performed to measure the radioactivity concentration in blood. During the waiting time for radioactivity decay between the PET scans, MR images of T1, T2, DWI, etc. were performed. ASL scan was performed just after finishing PET scanning for C15O2 gas. Q2TIPS was adopted as the ASL sequence and relCBF-map that generated automatically was used as CBF map by MRI. (1, 2) The parameters of ASL sequence were as below; TR = 2500ms., TE = 13ms., TI = 1800ms., Number of slices = 7, Slice thickness = 8mm. CBF maps by PET were calculated using the PET images of C15O2 gas and blood sampling data. (3, 4) Three attenuation corrections for PET were performed using MRI with Dixon sequence (PET_DIXON), ultra-short TE sequence (PET_UTE), and Dixon sequence with model-based bone segmentation (PET_DIXONbone). CBF values were measured using OSIRIX by setting the region of interests on frontal white matter (WM), parietal grey matter (GM), putamen, thalamus, and corpus callosum. Results: Mean and SD values of CBF in frontal WM measured by MRI, PET_DIXON, PET_UTE, and PET_DIXONbone were 7.7±3.0, 14.8±1.0, 13.7±0.9, and 15.8±1.1 mL/100mL/min, respectively. Values in thalamus were 38.8±9.3, 38.5±7.9, 35.1±4.6, and 42.3±9.3, respectively. Good correlation was found between MRI and each PET data in the range of over 15mL/100mL/min. Spearman's rank correlation coefficients between MRI and PET_DIXON, PET_UTE, and PET_DIXONbone were 0.868, 0.879, and 0.817, respectively. Measurements were unstable in the range of under 15mL/100mL/min. Conclusions: Good correlation on CBF values was found between MRI and PET in the range of over 15mL/100mL/min. Both methods will be able to use equally to measure CBF quantitatively in the clinical setting. ER -