CT attenuation correction for myocardial perfusion quantification using a PET/CT hybrid scanner

In routine PET, a 10- to 20-min transmission scan with a rotating 68Ge source is commonly obtained for attenuation correction (AC). AC is time-consuming using this procedure and could considerably be shortened by instead using a rapid CT scan. Our aim was to evaluate the feasibility of CT AC in quantitative myocardial perfusion PET using a hybrid PET/CT scanner. Methods: 13N-labeled NH3 and PET were used to measure myocardial blood flow (MBF) (mL/min/g) at rest and during standard adenosine stress. In group 1 (n 7), CT scans (0.5 s) of the heart area with different tube currents (10, 40, 80, and 120 mA) were compared with a standard 68Ge transmission (20 min) and with no AC. In group 2 (n 3), the repeatability of 8 consecutive CT scans at a tube current of 10 mA was assessed. In group 3 (n 4), emission was preceded and followed by 3 CT scans (10 mA) and 1 68Ge scan for each patient. For reconstruc