Objective performance characteristics of a new asymmetric screen‐film system

Metter, Richard Van; Dickerson, Robert E.

doi:10.1118/1.597407

Cited by 23 publications

(12 citation statements)

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“…Figure 10 compares the DQE of the present detector with those of other commercially available radiographic detection systems whose DQE curves have been previously reported. 2,18,19 The spectra used for the different measurements are nominally similar, although it is difficult to ensure this because the measurements were made independently in different laboratories. Nevertheless, it is safe to say that, below its Nyquist frequency, the present detector has a DQE that is much greater than that of screen/film and computed radiography photostimulable phosphor plates, the two technologies in common use today.…”

Section: Discussionmentioning

confidence: 99%

“…This spectrum was used first because it is similar to spectra used by many other authors for measuring DQE of detectors designed for similar purposes. 14,18,19 Second, the way the spectrum is generated provides some correction for differences in the inherent filtration of different x-ray tubes and for variation in calibration among generators. This is because the spectrum is adjusted to provide a HVL of 7 mm of Al, independent of the tube or generator.…”

Section: Methodsmentioning

confidence: 99%

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Performance of a 41×41‐cm amorphous silicon flat panel x‐ray detector for radiographic imaging applications

2000

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We report the performance of a 41 X 41-cm2 amorphous silicon-based flat panel detector designed for radiographic imaging applications. The detector consists of an array of photodiodes and thin film transistor switches on a 0.2-mm pitch with an overlying thallium-doped cesium iodide scintillator. The performance of the detector was evaluated through measurement of the frequency-dependent detective quantum efficiency [DQE(f)]. Measurements of the characteristic curve and modulation transfer function (MTF) are also reported. All measurements were made in a radiographic imaging mode with a readout time of 125 ms. We evaluated a total of 15 detectors. One detector was characterized at a range of exposures and at three different electronic gain settings. Measurements of DQE(f) and MTF were also performed as a function of position on one detector. The measured DQE at an exposure of about 1 mR was 0.66 at zero spatial frequency and fell smoothly with frequency to a value of 0.24 at the Nyquist frequency, 2.5 cycles/mm. The DQE is independent of exposure for exposures in the upper 80% of each gain range, but is reduced somewhat at lower exposures because of the influence of additive system noise. The reduction can be controlled by adjusting the electronic gain. For a gain that allows a maximum exposure of 5 mR, the DQE at 0.056 mR was 0.64 at zero frequency and 0.19 at 2.5 cycles/mm. The standard deviation in DQE among measurements on different detectors was less than 0.02 at any frequency. The presampling MTF was 0.26 at 2.5 cycles/mm. The standard deviation in MTF among measurements on different detectors was less than 0.01 at any frequency. Both MTF and DQE were substantially independent of position on the detector.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Performance of a 41×41‐cm amorphous silicon flat panel x‐ray detector for radiographic imaging applications

2000

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“…Figure 9 shows typical presampling MTFs for different technologies used in general radiography. The MTFs for screen-film systems and storage phosphor systems exhibit similar values over the spatial frequency range [24,25]. Indirect converting flat detectors, based on CsI, show an improved MTF, particularly at higher spatial frequencies [12,26].…”

Section: Modulation Transfer Functionmentioning

confidence: 84%

“…Figure 10 shows DQEs for the most frequently used technologies in general radiography. Screen-film [24] and storage phosphor systems [25,30] reach values between 20 and 30% at spatial frequencies below 1 lp/mm. Compared to screen-film, however, storage phosphor systems show a much more rapid fall-off at higher spatial frequencies.…”

Section: Modulation Transfer Functionmentioning

confidence: 98%

Flat detectors and their clinical applications

Spahn

2005

Eur Radiol

111

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Diagnostic and interventional flat detector X-ray systems are penetrating the market in all application segments. First introduced in radiography and mammography, they have conquered cardiac and general angiography and are getting increasing attention in fluoroscopy. Two flat detector technologies prevail. The dominating method is based on an indirect X-ray conversion process, using cesium iodide scintillators. It offers considerable advantages in radiography, angiography and fluoroscopy. The other method employs a direct converter such as selenium which is particularly suitable for mammography. Both flat detector technologies are based on amorphous silicon active pixel matrices. Flat detectors facilitate the clinical workflow in radiographic rooms, foster improved image quality and provide the potential to reduce dose. This added value is based on their large dynamic range, their high sensitivity to X-rays and the instant availability of the image. Advanced image processing is instrumental in these improvements and expand the range of conventional diagnostic methods. In angiography and fluoroscopy the transition from image intensifiers to flat detectors is facilitated by ample advantages they offer, such as distortion-free images, excellent coarse contrast, large dynamic range and high X-ray sensitivity. These characteristics and their compatibility with strong magnetic fields are the basis for improved diagnostic methods and innovative interventional applications.

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“…Soft tissue (axillary fat planes) (8) not applicable* (0) fat planes not visualized (0) fat planes poorly visualized (2) fat planes adequately visualized (6) fat planes optimally visualized (8) 6. Pulmonary vessels (21) not applicable* (0) not visualized (0) visualized to first third (7) visualized to mid third (16) visualized beyond mid third (21) 7. Aorta (15) not applicable* (0) not visualized (0) aortic knob visualized (9) descending aorta visualized (15) *Evaluation of anatomic landmark precluded by disease, positioning, or unusual but not abnormal anatomy.…”

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confidence: 99%

<title>Comparative evaluation of conventional and zero-crossover rare-earth screen-film systems in pediatric chest radiography</title>

et al. 1997

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ABSTRACFThis study compares the image quality of conventional and zero-crossover symmetric and asymmetric rareearth screen film systems for the specific imaging task ofchest radiography in pediatric patients by means of evaluation of the visualization of anatomic landmarks.Advances in anticrossover technology in double emulsion film have made it possible to design each emulsion layer in a double-emulsion film as ifit were a distinct system.Chest radiographs of 120 pediatric patients performed with one of six screen-film systems (two conventional rare-earth, two zero crossover symmetric and two zero crossover asymmetric screen-film systems) were evaluated for image quality by three radiologist observers. The evaluation was based on the visualization of anatomic landmarks and the subjective evaluation of the physical properties of each film.InSight VHC Thoracic Imaging system with IPC film and Pediatric InSight screens with InSight Pediatric film were ranked highest by the radiologist observers both with respect to the visualization of anatomic landmarks and the subjective evaluation ofthe physical properties ofthe systems. The difference between these two systems was not statistically significant (p'zO.05), however, the ranking ofthese systems is statistically different (p

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Objective performance characteristics of a new asymmetric screen‐film system

Cited by 23 publications

References 0 publications

Performance of a 41×41‐cm amorphous silicon flat panel x‐ray detector for radiographic imaging applications

Performance of a 41×41‐cm amorphous silicon flat panel x‐ray detector for radiographic imaging applications

Flat detectors and their clinical applications

<title>Comparative evaluation of conventional and zero-crossover rare-earth screen-film systems in pediatric chest radiography</title>

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