Biograph truepoint 6 pet ct

[¹⁸F]FMT PET tracer was used to measure dopamine synthesis capacity. Similar to 6-[¹⁸F]fluorodopa, [¹⁸F]FMT is a substrate for aromatic amino acid decarboxylase, an enzyme in the dopamine synthesis cascade. Although not the rate-limiting step in synthesis, its activity provides an estimate of dopamine synthesis capacity when provided with enough substrate (Dejesus, 2003 ). [¹⁸F]FMT was synthesized at Lawrence Berkeley National Laboratory using methods previously described (VanBrocklin et al., 2004 (link)). Participants ingested 2.5 mg/kg of carbdopa approximately 1 hr before scanning to minimize the peripheral metabolism of [¹⁸F]FMT. Data were acquired using a Siemens Biograph Truepoint 6 PET/CT (Siemens Medical Systems). After a short CT scan, participants were injected with approximately 2.5 mCi of [¹⁸F]FMT as a bolus in an antecubital vein. Dynamic acquisition frames were obtained over 90 min in 3-D mode (25 frames total: 5 × 1 min, 3×2 min, 3×3 min, 14 × 5 min). Data were re-constructed using an ordered subset expectation maximization algorithm with weighted attenuation, corrected for scatter, and smoothed with a 4-mm FWHM kernel.