PET characteristics of a dedicated breast PET/CT scanner prototype.
A dedicated breast PET/CT system has been constructed at our institution, with the goal of having increased spatial resolution and sensitivity compared to whole-body systems. The purpose of this work is to describe the design and the performance characteristics of the PET component of this device. Average spatial resolution of a line source in warm background using maximum a posteriori (MAP) reconstruction was 2.5 mm, while the average spatial resolution of a phantom containing point sources using filtered back projection (FBP) was 3.27 mm. A sensitivity profile was computed with a point source translated across the axial field of view (FOV) and a peak sensitivity of 1.64% was measured at the center of the FOV. The average energy resolution determined on a per-crystal basis was 25%. The characteristic dead time for the front-end electronics and data acquisition (DAQ) was determined to be 145 ns and 3.6 micros, respectively. With no activity outside the FOV, a peak noise-equivalent count rate of 18.6 kcps was achieved at 318 microCi (11.766 MBq) in a cylindrical phantom of diameter 75 mm. After the effects of exposing PET detectors to x-ray flux were evaluated and ameliorated, a combined PET/CT scan was performed. The percentage standard deviations of uniformity along axial and transaxial directions were 3.7% and 2.8%, respectively. The impact of the increased reconstructed spatial resolution compared to typical whole-body PET scanners is currently being assessed in a clinical trial.
Wu
Yibao
Y
Department of Biomedical Engineering, University of California, Davis, Genome and Biomedical Sciences, CA, USA. ybwu@ucdavis.edu
Bowen
Spencer L
SL
Yang
Kai
K
Packard
Nathan
N
Fu
Lin
L
Burkett
George
G
Qi
Jinyi
J
Boone
John M
JM
Cherry
Simon R
SR
Badawi
Ramsey D
RD
D001943:Breast Neoplasms / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D019047:Phantoms, Imaging; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*