High-energy (511-keV) imaging with the scintillation camera.
A dual-head scintillation camera has been adapted for high-energy (511-keV) imaging by extending the useful energy range and linearity maps to 560 keV, implementing high-energy sensitivity maps, and developing high-energy collimators. High-energy parallel-hole collimators have inferior spatial resolution and sensitivity relative to the low-energy, high-resolution collimators commonly in use. With high-energy parallel-hole collimators, phantom studies show that the limit for detectability of "hot" lesions is 1.5 cm and 1.3 cm in diameter or larger for 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) uptake ratios of 5:1 and 10:1, respectively, if one assumes adequate counting statistics. Dual-isotope, single-acquisition techniques for using technetium-99m methoxy isobutyl isonitrile and FDG have been developed and proved useful in identification of ischemic but viable myocardium. High-energy fan-beam collimators have superior spatial resolution but inferior sensitivity relative to low-energy, high-resolution collimators. Metabolic images of the brain obtained with FDG demonstrate spatial resolution comparable with that of positron emission tomography, but such studies are often limited by inadequate counting statistics.
Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232-2675, USA.
J A
JA
Patton
M P
MP
Sandler
I
I
Ohana
Z
Z
Weinfeld
D001921:Brain / Q000000981:diagnostic imaging; D003847:Deoxyglucose / Q000031:analogs & derivatives; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D015902:Gamma Cameras; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D009369:Neoplasms / Q000000981:diagnostic imaging; D019047:Phantoms, Imaging; D017256:Technetium Tc 99m Sestamibi; D013679:Technology, Radiologic; D014055:Tomography, Emission-Computed / Q000295:instrumentation* / Q000379:methods; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation* / Q000379:methods
D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D017256:Technetium Tc 99m Sestamibi; D003847:Deoxyglucose