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Title: HEADTOME III: A high quantitation and high resolution brain positron emission tomograph

Conference · · J. Nucl. Med.; (United States)
OSTI ID:7087721

HEADTOME III, a high quantitation and high resolution positron emission tomograph (PET) has been developed. HEADTOME III was basically designed as a brain PET of 3 rings 5 planes. Each ring (75 cm diam) consists of 160 BGOs (13.4 x 25 x 40 mm). Shadow masks and septa can be used independently, corresponding to low (LR) and high resolution mode (HR), and low (LQ) and high quantitation mode (HQ) respectively. Planar resolutions at the center of the field of view (FOV) were 8.2 and 6.5 mm FWHM in LR an HR, respectively. Deterioration of resolution at 8 cm radius were 0.6 and 0.8 in FWHM. Slice thicknesses were 12.8 and 9.1 mm FWHM at the center of FOV with LQ and HQ, respectively, its deviation being 1.1 and 0.8 mm over FOV with each, and 0.1 mm difference between direct and cross planes in LQ mode. Sensitivities, true events for Ga-68 20 cm diam cylinder, were 32(68), 17(33), 18 and 9 kcps/ (..mu..Ci/ml) with the direct (cross) planes of LRLQ, direct (cross) planes of HRLQ, direct planes of LRHQ and HRHQ, respectively. Count rates were declined 10% at 30 kcps true events per plane but recovered up to 100 kcps within 5% error by software correction using random coincidence events. Scattered fraction after corrected by subtracting a mean of outside the FOV in sinogram was 10 and 3% in the reconstructed images in LQ and HQ, respectively. Long term stability evaluated cross calibration factor checked weekly in the last half year was 1.9% COV as an average of 5 planes and 2.2% at maximum plane. These data imply that HEADTOME III permits an accurate analysis of tracer kinetics.

Research Organization:
Research Institute of Brain and Blood Vessels-AKITA, Akita
OSTI ID:
7087721
Report Number(s):
CONF-840619-
Journal Information:
J. Nucl. Med.; (United States), Vol. 25:5; Conference: 31. annual meeting of the Society of Nuclear Medicine, Los Angeles, CA, USA, 5 Jun 1984
Country of Publication:
United States
Language:
English