Ge discovery mi pet ct scanner

Pigs were CT scanned using a GE Discovery MI PET/CT scanner (GE Healthcare, Waukesha, USA). They were scanned in the rostral caudal direction with initial alignment of the pig performed by a localizer. Subsequent CT during freezing was performed every 30 s using a 120 kVp (peak kilovoltage) and 300 mA (milliampere) current in a helical trajectory covering the animal’s skull. To avoid metal artefacts from the probe and other metal objects in the field of view, a metal artefact reconstruction (MAR) with a slice thickness of 0.625 mm was made. Final images were in-plane reconstructed in 512 × 512 matrices in a 50 cm field of view.

Anonymised data from sixteen subjects enrolled in a clinical study were included in the present work. Eight subjects were healthy controls (mean age 38.6), and eight subjects were diagnosed with multiple sclerosis (MS) (mean age 43.1). MS patients' data were included due to their scans being available from a clinical parent study involving the investigation of the effect of acetazolamide on CBF in MS patients. ¹⁵O–water PET data with accompanying blood measures are rare and so all data from this other study were included to maximise the amount of data available. All subjects gave their informed consent before inclusion, and the study was approved by the medical ethics review board in Uppsala (2014/453).
Each subject underwent two dynamic PET scans both starting simultaneously with a controlled bolus injection of 5 MBq/kg of ¹⁵O–water (10 ml at 1 ml/s followed by a 30-ml saline flush at 2 ml/s) on a GE Discovery MI PET/CT scanner (GE Healthcare, Waukesha) [29 (link)]. Approximately 10 min before the second scan, the subjects were administered acetazolamide (9 mg/kg up to 1 g). The pharmacological manipulation was not of interest to the current study—all scans were included. The time between scan starts was approximately 20 min to allow for radioactive decay.