A simple method for determining the modulation transfer function in digital radiography

Fujita, Hiroshi; Tsai, Du-Yih; Itoh, T.; Doi, Kunio; Morishita, Junji; Ueda, Katsuhiko; Ohtsuka, Akiyoshi

doi:10.1109/42.126908

Cited by 612 publications

(404 citation statements)

References 13 publications

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“…Then the averaged ESF was differentiated to obtain the line spread function (LSF). The 1D presampling MTF in either x (horizontal MTF(u)) or y direction (vertical MTF(v)) was calculated from the fast Fourier transform (FFT) of the oversampled LSF (Fujita et al 1992, Konstantinidis et al 2013, Zhao et al 2015b. The horizontal presampling MTF at θ i is given by…”

Section: Methodsmentioning

confidence: 99%

Three-dimensional cascaded system analysis of a 50µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

et al. 2017

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Abstract. High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 μm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30°. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g. ±30°) improves the low spatial frequency (below 5 mm -1 ) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used.Theoretical analysis suggests that a pixelated scintillator in combination with the 50 μm pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film A c c e p t e d M a n u s c r i p t transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared.Keywords: CMOS active pixel sensor, x-ray detector, digital breast tomosynthesis, three-dimensional, cascaded system analysis, pixelated scintillator, detective quantum efficiency IntroductionHigh performance x-ray detectors based on the complementary metal-oxide-semiconductor ( Up to now, most studies focus on CMOS APS detector evaluation by measuring the one-dimensional (1D) or 2D modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) using a single x-ray projection at the zero-degree incident angle (perpendicular to the detector). Nevertheless, since DBT is a quasi-three-dimensional (3D) imaging technology, the DBT image quality is influenced by the system geometry and reconstruction algorithms (Sechopoulos 2013a(Sechopoulos , 2013b. Therefore, the 3D imaging performance should be evaluated for the CMOS APS detectors. However, it is difficult to empirically investigate the 3D image quality. To deal with this issue, the 3D cascaded system analysis for CMOS APS detectors was developed and is presented in this study.Cascaded system analysis can accurately model the signal and noise propagation and blurring within ...

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Section: Methodsmentioning

confidence: 99%

Three-dimensional cascaded system analysis of a 50µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

et al. 2017

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“…The cylindrical case was placed at the isocenter, and the phantom rotation was adjusted so that the long axis of the bar-pattern phantom was tilted slightly (roughly 2.5°) relative to the y-axis. This tilting was needed to provide a sufficiently small effective sampling pitch for the Fourier analysis described below [19]. To make the contrast (DHU) between the bar pattern and the background 50 HU, the case was filled with diluted iodine contrast medium (2.7 mgI/ml).…”

Section: Bar-pattern Methodsmentioning

confidence: 99%

Spatial resolution measurement for iterative reconstruction by use of image-averaging techniques in computed tomography

Urikura

Ichikawa

Hara

et al. 2014

Radiol Phys Technol

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The purpose of our study was to investigate the validity of a spatial resolution measuring method that uses a combination of a bar-pattern phantom and an imageaveraging technique, and to evaluate the spatial resolution property of iterative reconstruction (IR) images with middle-contrast (50 HU) objects. We used computed tomography (CT) images of the bar-pattern phantom reconstructed by the IR technology Adaptive Iterative Dose Reduction 3D (AIDR 3D), which was installed in the multidetector CT system Aquilion ONE (Toshiba Medical Systems, Otawara, Japan). The contrast of the bar-pattern image was set to 50 HU, which is considered to be a middle contrast that requires higher spatial resolution clinically. We employed an image-averaging technique to eliminate the influence of image noise, and we obtained averaged images of the bar-pattern phantom with sufficiently low noise. Modulation transfer functions (MTFs) were measured from the images. The conventional wire method was also used for comparison; in this method, AIDR 3D showed MTF values equivalent to those of filtered back projection. For the middle-contrast condition, the results showed that the MTF of AIDR 3D decreased with the strength of IR processing. Further, the MTF of AIDR 3D decreased with dose reduction. The imageaveraging technique used was effective for correct evaluation of the spatial resolution for middle-contrast objects in IR images. The results obtained by our method clarified that the resolution preservation of AIDR 3D was not sufficient for middle-contrast objects.

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“…Numero di dettagli visibili in un Numero di dettagli con rapporto AAPM TG10 [9] oggetto tion (MTF) using one of the methods suggested in the literature [12,13]. The software can determine the MTF from the images of a slit camera, of a line pair pattern and of a sharp edge according to the methods specified in the literature.…”

Section: Grandezzamentioning

confidence: 99%

Automated quality control in Computed Radiography

et al. 2006

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Purpose. The purpose of this paper is to describe the automation of quality control procedures on photostimulable imaging plates by means of an image-processing tool providing automatic reading of the images and automatic calculation of the quality parameters monitored. Materials and methods. Quality-control procedures were performed according to the main available guidelines. The quality assurance programme was applied to several Kodak and Philips devices in four radiological departments. The automatic imageprocessing tool was developed using public domain software (Java-based ImageJ software) and contains both reading and computation procedures.Results. The quality checks and algorithms described were successfully applied, proving useful for identification of defective plates and for implementation of the quality assurance programme. The use of automation allowed significant savings in the time required for quality checks. Conclusions. Completely automated image reading allows substantial economic and human resources savings, as it eliminates much of the transfer, reproduction, processing and filing procedures. Key words

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A simple method for determining the modulation transfer function in digital radiography

Cited by 612 publications

References 13 publications

Three-dimensional cascaded system analysis of a 50µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

Three-dimensional cascaded system analysis of a 50µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

Spatial resolution measurement for iterative reconstruction by use of image-averaging techniques in computed tomography

Automated quality control in Computed Radiography

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