Abstract
We estimated the detectability of spheres of different sizes but equal activity contrast, embedded in a clinically realistic phantom in order to compare two-dimensional (2D) and three-dimensional (3D) whole-body (WB) PET imaging for a relevant diagnostic task. Five plastic spheres with inside diameters of 0.8 to 3.4 cm, containing 74 kBq/ml of Ge-68, were placed in an anthropomorphic torso phantom. The background organs contained F-18 activity concentrations in appropriate physiologic proportions, as did a head phantom positioned outside the field of view (FOV) of our ECAT-HR+ system. The phantom was scanned for 9 hours at one bed position as the F-18 decayed from 97 to 3.2 kBq/ml. We obtained ten, 1-minute scans for each activity contrast level, alternating among three acquisitions: 2D mode with standard maximum ring difference (MRD=7), standard 3D mode (MRD=22), and 3D mode with MRD=13 (3D*). Images from 2D and 3D acquisitions were reconstructed by filtered backprojection and 3D reprojection (3DRP); 3D data were also reconstructed by FBP after Fourier rebinning (FORE+FBP). Sphere detectability was estimated using non-prewhitening (NPW) matched filtering to compute the detection signal-to-noise ratio, NPW SNR. In almost all cases, NPW-SNR was greater for 3D or 3D* than for 2D, although 2D outperformed 3D with 3DRP reconstruction at the earliest time points for two spheres located near opposite ends of the axial FOV; FORE+FBP reconstruction significantly improved the detectability of these spheres, compared to 3DRP, and demonstrated the expected near equivalence of 3D and 3D* data from spheres near the ends of the FOV. Our results were not predictable from global NEC considerations alone.
Original language | English (US) |
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Title of host publication | IEEE Nuclear Science Symposium and Medical Imaging Conference |
Editors | D. Merelli, J. Surget, M. Ulma |
Volume | 3 |
State | Published - 2000 |
Externally published | Yes |
Event | 2000 IEEE Nuclear Science Symposium Conference Record - Lyon, France Duration: Oct 15 2000 → Oct 20 2000 |
Other
Other | 2000 IEEE Nuclear Science Symposium Conference Record |
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Country | France |
City | Lyon |
Period | 10/15/00 → 10/20/00 |
ASJC Scopus subject areas
- Computer Vision and Pattern Recognition
- Industrial and Manufacturing Engineering