RT Journal Article SR Electronic T1 [17F]Fluoromethane PET imaging of regional cerebral blood flow in rhesus during amphetamine challenge JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1753 OP 1753 VO 54 IS supplement 2 A1 Alexander Converse A1 Jeff Moirano A1 Leo Flores A1 Kacey Kronenfeld A1 Todd Barnhart A1 Terrence Oakes A1 Andrew Roberts A1 James Holden A1 Robert Nickles A1 Richard Davidson YR 2013 UL http://jnm.snmjournals.org/content/54/supplement_2/1753.abstract AB 1753 Objectives To obtain absolute measures of regional cerebral blood flow (rCBF) using the inert diffusible tracer fluoromethane (CH3F) labeled with 17F (t1/2 = 65 s) and to better understand the effects of amphetamine in the brain, we imaged nonhuman primates by PET. Methods Five adult male rhesus macaques were imaged under isoflurane anesthesia with continuous arterial sampling. [17F]CH3F was injected i.v. in 4 boluses separated by 15 minutes followed by a bolus injection of d-amphetamine (0.4 mg/kg) and another 4 boluses of [17F]CH3F. Images were reconstructed in 60 s frames without decay correction. Time-activity curves were determined for whole brain and various regions of interest. The entire time course was modeled with a single tissue compartment model including a term for radioactive decay. The volume of distribution and extraction fraction were set to 1. Response to amphetamine was assumed to follow a step function. Free parameters for each region were the pre-amphetamine blood flow, K1pre, the fractional change in K1 due to amphetamine, and the time between tracer arrival at tissue and at the blood detector. Results Whole brain blood flow K1pre = 0.49 ± 0.13 mL/min/mL (mean ± SD, n=5, CV = 26%). Mean rCBF ranged from 0.42 to 0.73 mL/min/mL across regions with CVs of 20% to 43% across subjects. Rank order of rCBF was CgG > Cb > CdPu > Fr Ctx > WB = Occ Ctx > Par Ctx > Temp Ctx, and of alteration due to amphetamine was CdPu > CgG > Cb > Fr Ctx > Temp Ctx > WB > 0% > Par Ctx > Occ Ctx. Conclusions The whole brain and regional measures of absolute blood flow agree with the literature. As expected, amphetamine increased rCBF in frontostriatal regions. Akin to the established tracer [18F]CH3F, the novel tracer [17F]CH3F is suitable for quantitative measurement of rCBF. The 65 s half-life of 17F permits frequent sampling of blood flow in acute challenge protocols. Research Support Funded by NIH R21EB00482 to AKC.