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Title: Preliminary results from the new large-area PETRRA positron camera

Journal Article · · IEEE Transactions on Nuclear Science
DOI:https://doi.org/10.1109/23.790825· OSTI ID:687368
; ; ; ;  [1]; ; ;  [2]
  1. Inst. of Cancer Research/Royal Marsden Hospital, Sutton (United Kingdom). Physics Dept.
  2. Rutherford-Appleton Lab., Chilton (United Kingdom)

The PETRRA positron camera is based on the use of BaF{sub 2} scintillators interfaced to large area multiwire proportional chambers filled with a photo-sensitive vapor (TMAE). The camera consists of two 60cm x 40cm annihilation photon detectors mounted on a rotating gantry. Initial measurements with the camera show that the spatial resolution is {approximately}6.5{+-}1mm FWHM all through the field-of-view, and the timing resolution is between 7ns and 10ns FWHM. Detection efficiency for annihilation photons is {approximately}30% per detector. The count rates obtained, by using a 20cm diameter by 11cm long water filled phantom containing {sup 18}F, were {approximately}1.35 {times} 10{sup 6} singles and {approximately}1.2 {times} 10{sup 5} cps raw coincidences at which point data-rates are limited by the dead-time in the readout system. The randoms rate varies between 5 and 50% with activity in the field of view of 10--100MBq (0.27--2.7mCi) with a timing gate of 20ns. Initial results show that the randoms corrected sensitivity is >3--4kcps/kBq/ml (120--150kcps/{micro}Ci/ml) for activities up to 30MBq (0.81mCi) in a 20cm diameter water-filled phantom. However, these values include a high (60%) scatter fraction due to detector support structures. The camera has not yet been fully optimized and it is expected that the performance will substantially improve by further tuning and a reduction in the scattering structures. With a 40cm axial FoV the camera is ideally suited to whole-body imaging in oncology.

OSTI ID:
687368
Report Number(s):
CONF-981110-; ISSN 0018-9499; TRN: 99:010344
Journal Information:
IEEE Transactions on Nuclear Science, Vol. 46, Issue 4Pt2; Conference: 1998 IEEE nuclear science symposium and medical imaging conference, Toronto (Canada), 10-12 Nov 1998; Other Information: PBD: Aug 1999
Country of Publication:
United States
Language:
English