Effects of scintillator on the detective quantum efficiency (DQE) of a digital imaging system.
OBJECTIVE
To compare the effects of scintillator on the detective quantum efficiency (DQE) of a charge-coupled device (CCD) digital intraoral radiographic system.


METHODS
Three screens composed of 3 different scintillator materials, namely europium-doped lutetium oxide (Lu2(O3):Eu3+), transparent optical ceramic (TOC), thallium-doped cesium iodide (CsI:Tl; CsI), and terbium-doped gadolinium oxysulfide (Gd2(O2)S:Tb; GOS) were compared, in turn, in combination with a CCD detector having square pixels with height and width dimensions of 19.5 microm. DQE was investigated using the slanted-slit-derived MTF and surrogate signal-to-noise ratio (SNR) measurements derived from calculations of the mean and standard deviations from the mean pixel values of multiple random patches from various uniform exposures. An Irix x-ray generator operated at 70 kVp and 8 mA, with a nominal focal spot size of 0.7 mm and 2.5 mm Al equivalent filtration, was used in making all exposures.


RESULTS
Using TOC, the peak DQE was 62% at 5 cycles/mm. For CsI, the peak DQE was 22% at 2 cycles/mm. With GOS, the peak DQE was 10% at 1 cycle/mm.


CONCLUSIONS
Under identical experimental settings, TOC consistently resulted in higher DQE than CsI and commercially available GOS scintillators combined with the same high-resolution solid-state detector.
Farman
Taeko T
TT
Division of Radiology and Imaging Science, Department of Surgical and Hospital Dentistry, The University of Louisville, KY, USA.
Vandre
Robert H
RH
Pajak
John C
JC
Miller
Stuart R
SR
Lempicki
Alex
A
Farman
Allan G
AG
D000465:Algorithms; D016477:Artifacts; D002516:Ceramics; D002586:Cesium; D005374:Filtration / Q000295:instrumentation; D005682:Gadolinium; D007454:Iodides; D019252:Radiography, Dental, Digital / Q000295:instrumentation*; D012666:Semiconductors; D012815:Signal Processing, Computer-Assisted; D014963:X-Ray Intensifying Screens; D014965:X-Rays
D007454:Iodides; C021197:gadolinium sulfoxylate; D002586:Cesium; D005682:Gadolinium; C040050:cesium iodide