On the response of a europium doped phosphor-coated CMOS digital imaging detector

Seferis, I.; Michail, C.; Valais, I.; Fountos, G.; Kalyvas, N.; Stromatia, F.; Oikonomou, Georgia; Kandarakis, I.; Panayiotakis, George

doi:10.1016/j.nima.2013.06.107

Cited by 36 publications

(27 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This value is higher than what has been reported in literature that is 10% MTF at 6 cycles/mm for a CMOS/Gd 2 O 2 S:Eu (65.1 mg/cm 2 ) combination [3]. However other CMOS/scintillator combinations such as CMOS/Gd 2 O 2 S:Eu (33.3 mg/cm 2 ) and CMOS/Lu 2 O 3 :Eu (65.1 mg/cm 2 ) demonstrates 10% MTF above 11 cycles/mm [4].The exposure conditions in these cases were not exactly the same since the 70kVp X-ray spectrum was hardened by the addition of 21 mm Al [3,4] Other dental detectors, by means of viewing the image of a bar pattern, have reported a resolution limit above 10 cycles/mm [8]. In figure 3 the NNPS curves at 60 kVp, 104.8 µGy and 70 kVp, 100.8 µGy are demonstrated.…”

Section: Resultscontrasting

confidence: 64%

“…PVR characterizes the linearity of the detector response with respect to X-ray exposure. In addition spatial frequency image quality metrics are available like MTF, demonstrating the ability of the detector to resolve objects of different dimensions, as well as, NNPS which demonstrates the relative noise components in spatial frequency domain [3,4]. In current work a digital detector SCHICK CDR CMOS was examined.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Examining the Spatial Frequency Components of a Digital Dental Detector

Αναστασίου

Michail

Koukou

et al. 2017

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Abstract. Digital X-ray detectors are widely used in dental radiography. The scope of this work is the examination of the spatial frequency component of a dedicated dental CMOS detector. A commercially available SCHICK CDR CMOS detector was irradiated at a Del Medical Eureka X-ray system at 60kVp and 70kVp. The irradiation setup included images of an edge, for Modulation Transfer Function (MTF) calculation. The air-KERMA was measured with an RTI PIRANHA X-ray multimeter. The images were evaluated in 'for presentation' format with the use of ImageJ software. The linear range of the detector was found in the range 13µGy-183µGy at 60 kVp and 18µGy-180µGy at 70 kVp. By inspecting the MTF curves it was found that MTF(6lp/mm)60kVp=0.29 and MTF(6lp/mm)70kVp=0.25. The inspection of the Normalized Noise Power Spetrum (NNPS) showed similar low noise components. Our results indicate that this detector presents comparable performance at both kVp, although its Xray response (pixel value vs air KERMA) was not equal to previously published results, for the same detector type.

show abstract

Section: Resultscontrasting

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Examining the Spatial Frequency Components of a Digital Dental Detector

Αναστασίου

Michail

Koukou

et al. 2017

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…For all the ROIs taken from each image, 2D fast Fourier transform (FFT) of each ROI was calculated and added to the NPS ensemble. NNPS was obtained by dividing NPS by the square of the corresponding mean pixel value, and afterward, the ensemble average was obtained [21,22].…”

Section: Normalized Noise Power Spectra (Nnps)mentioning

confidence: 99%

On the response of semitransparent nanoparticulated films of LuPO4:Eu in poly-energetic X-ray imaging applications

et al. 2016

View full text Add to dashboard Cite

In the present work, we demonstrate the fabrication technique of highly translucent layers of nanoparticulated (*50 nm) LuPO 4 :Eu phosphor, present their basic luminescent properties and give results of their performance in a planar imaging system coupled to a CMOS photodetector. For comparison, the imaging performance of an opaque Gd 2 O 2 S:Eu phosphor screen prepared by sedimentation is also shown. The X-ray detection parameters as well as the luminescence efficiency of the investigated films were discussed. Results show that the in-line transmittance at *600-700 nm, in the range of the phosphor luminescence, varies with respect to the thickness of the films from 40 to 50 % for a film of 67 lm thick to 4-12 % when the thickness increases to 460 lm. Yet, X-ray detection parameters get enhanced as the thickness of the films increases. Those results affect the luminescence efficiency curves of the films under poly-energetic X-ray radiation of various tube energies. The normalized noise power spectrum values were found similar for LuPO 4 :Eu films and a phosphor screen made using commercial Gd 2 O 2 S:Eu powder. The detective quantum efficiency of our films is clearly lower compared to the Gd 2 O 2 S:Eu screen from 2 to 10 cycles mm -1 frequency range while the modulation transfer function is lower from 0 to 5.5 cycles mm -1 frequency range. The acquired data allow to predict that high-temperature sintering of our films under pressure may help to improve their imaging quality, since such a processing should increase the luminescence efficiency without significant growth of the grains and thus without sacrificing their translucent character.

show abstract

“…This scintillator was selected due to its efficiency and imaging properties, which are superior in comparison to other detectors [17]. The density of Gd 2 O 2 S:Tb is 7.34 g/cm 3 .…”

Section: Methodsmentioning

confidence: 99%

Optimization of breast cancer detection in Dual Energy X-ray Mammography using a CMOS imaging detector

Koukou

Fountos

Martini

et al. 2015

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

View the article online for updates and enhancements. Abstract. Dual energy mammography has the ability to improve the detection of microcalcifications leading to early diagnosis of breast cancer. In this simulation study, a prototype dual energy mammography system, using a CMOS based imaging detector with different X-ray spectra, was modeled. The device consists of a 33.91 mg/cm 2 Gd 2 O 2 S:Tb scintillator screen, placed in direct contact with the sensor, with a pixel size of 22.5 m  .Various filter materials and tube voltages of a Tungsten (W) anode for both the low and high energy were examined. The selection of the filters applied to W spectra was based on their Kedges (K-edge filtering). Hydroxyapatite (HAp) was used to simulate microcalcifications. Calcification signal-to-noise ratio (SNR tc ) was calculated for entrance surface dose within the acceptable levels of conventional mammography. Optimization was based on the maximization of SNR tc while minimizing the entrance dose. The best compromise between SNR tc value and dose was provided by a 35kVp X-ray spectrum with added beam filtration of 100μm Pd and a 70kVp Yb filtered spectrum of 800 m  for the low and high energy, respectively. Computer simulation results show that a SNR tc value of 3.6 can be achieved for a calcification size of 200 m  . Compared with previous studies, this method can improve detectability of microcalcifications.

show abstract

On the response of a europium doped phosphor-coated CMOS digital imaging detector

Cited by 36 publications

References 50 publications

Examining the Spatial Frequency Components of a Digital Dental Detector

Examining the Spatial Frequency Components of a Digital Dental Detector

On the response of semitransparent nanoparticulated films of LuPO4:Eu in poly-energetic X-ray imaging applications

Optimization of breast cancer detection in Dual Energy X-ray Mammography using a CMOS imaging detector

Contact Info

Product

Resources

About