Biograph 40 mct pet ct scanner

A mean activity of ⁶⁸Ga-PSMA-11 of 120 ± 19 MBq was administered intravenously, followed by a 500 mL infusion of NaCl 0.9%. No diuretics were applied. The mean time between injection and PET acquisition was approximately 60 min according to standard procedures for prostate cancer imaging [22 (link)]. PET/CT datasets were acquired on a Biograph 40 mCT PET/CT scanner (Siemens Medical Solutions, Knoxville, TN, USA) (acquisition time: 3 min/bed position; extended FOV: 21.4 cm (TrueV), slice thickness: 3.0 mm) with EANM Research Ltd. accreditation. A standard LD spiral CT was acquired for attenuation correction and anatomical localization using an X-ray tube voltage of 120 keV and a modulation of the tube current applying CARE Dose4D with a reference tube current of 50 mAs. CT images were reconstructed as a 512 × 512 matrix with an increment of 3 mm and a slice thickness of 5.0 mm. The PET images were iteratively reconstructed using the three-dimensional OSEM (ordered-subset expectation maximization) algorithm with 3 iterations, 24 subsets, and with Gaussian filtering to a transaxial resolution of 5 mm at full-width at half-maximum (FWHM). Attenuation correction was performed using the low-dose non-enhanced CT data.

For PET imaging, a mean activity of 127 ± 18 MBq [⁶⁸Ga]Ga-PSMA-11 was applied, followed by a 500 mL infusion of NaCl 0.9%. In accordance with standard procedures for prostate cancer imaging [31 (link)], the time between injection and PET acquisition was 64 ± 9 min. All PET/CT scans were performed using a Biograph mCT 40 PET/CT scanner (Siemens Medical Solutions, Knoxville, TN, USA) ¹⁸F-accredited by European Association of Nuclear Medicine (EANM) Research Ltd. With respect to ⁶⁸Ga, inhouse phantom measurements were also routinely performed to allow valid PET quantification. The PET acquisition was conducted from vertex to proximal femur with a 3 min acquisition time per bed position (extended field of view: 21.4 cm). CT data was acquired in low-dose technique using an X-ray tube voltage of 120 keV and a modulation of the tube current by applying ‘CARE Dose4D’ with a maximal tube current time product of 30 mAs. The PET data sets were reconstructed using an iterative 3D OSEM (ordered subset expectation maximization) algorithm (3 iterations, 24 subsets) with Gaussian filtering and slice thickness of 5 mm. Random correction, decay correction, scatter attenuation and attenuation correction were applied.