Perelman School of Medicine at the University of Pennsylvania

Physics and Instrumentation Group

PET Center

The Department of Radiology PET Center operates four whole-body PET/CT scanners; Philips Gemini TF Ingenuity, Philips Gemini TF BB, Siemens Biograph mCT, and Siemens Biograph Vision. All scanners are located in the Perelman Center for Advanced Medicine. Separate rooms are available for patient preparation and injection of radiopharmaceuticals. In addition, there is a nearby hot lab for preparing and extracting doses and a blood lab for sampling and counting. The Philips Gemini TF BB is located in Radiation Oncology and used primarily for treatment planning, whereas the other scanners are located in Radiology and used for diagnostic clinical imaging. The Philips Gemini TF Ingenuity is shared 50/50 between research and clinical examinations. The radiotracers are provided by the Cyclotron Facility. (PET Center Website).

Daily quality control is performed by the Nuclear Medicine technologists, while system calibration and maintenance is provided by the Physics and Instrumentation Group in the Nuclear Medicine section of Radiology. Our group also provides imaging protocol development and algorithm optimization to improve imaging performance and ensure accurate image quantitation. In addition, new instrument implementation and testing is performed by the clinical physicists within the group. Our PET Center received the first time-of-flight (TOF) PET/CT scanner, the Philips Gemini TF in 2005 and performed the initial characterization of this system [Surti et al JNM 2007]. The underlying technology of this new TOF scanner was developed collaboratively with our group, and the resulting characterization of the clinical benefits of TOF [Karp et al JNM 2008] helped to establish TOF PET/CT as the standard diagnostic tool. The most recent PET/CT system in the PET Center is the Siemens Biograph Vision, which was installed in October 2018. This system is based on the newest solid-state photosensor technology and offers improved time-of-flight (TOF) resolution of 210 ps. It also has the largest axial field-of-view of 26 cm and the highest sensitivity of 15.6 kcps/MBq. Having the first installation of this new PET/CT system in the USA our group reported on the performance of this system in [Reddin et al, MIC 2018].   

An example of a clinical FDG study with the Siemens Biograph Vision is shown below. The excellent image quality of this large patient with high BMI is due to a combination of the high sensitivity and excellent TOF resolution.

41 y.o. female, breast Ca with bony metastases, BMI: 43.6
Injection: 15.0 mCi.; Uptake: 54 min
Table speed: 1.4 mm/s, Scan duration: 11 min
Recon: PSF+TOF, 4 iter, 5 subsets, 5 mm Gaus. Voxels: 1.65 x 1.65 x 4mm3