Evaluating radiographic parameters for mobile chest computed radiography: Phantoms, image quality and effective dose

Background: Concern has been raised regarding the mounting collective radiation doses from computed tomography (CT), increasing the risk of radiation-induced cancers in exposed populations. Purpose: To compare radiation dose and image quality in a chest phantom and in patients for the diagnosis of pulmonary embolism (PE) at 100 and 120 peak kilovoltage (kVp) using 16-multichannel detector computed tomography (MDCT). Material and Methods: A 20-ml syringe containing 12 mg I/ml was scanned in a chest phantom at 100/120 kVp and 25 milliampere seconds (mAs). Consecutive patients underwent 100 kVp ( n = 50) and 120 kVp ( n = 50) 16-MDCT using a “quality reference” effective mAs of 100, 300 mg I/kg, and a 12-s injection duration. Attenuation (CT number), image noise (1 standard deviation), and contrast-to-noise ratio (CNR; fresh clot = 70 HU) of the contrast medium syringe and pulmonary arteries were evaluated on 3-mm-thick slices. Subjective image quality was assessed. Computed tomography dose index (CTDIvol) and dose–length product (DLP) were presented by the CT software, and effective dose was estimated. Results: Mean values in the chest phantom and patients changed as follows when X-ray tube potential decreased from 120 to 100 kVp: attenuation +23% and +40%, noise +38% and +48%, CNR −6% and 0%, and CTDIvol −38% and −40%, respectively. Mean DLP and effective dose in the patients decreased by 42% and 45%, respectively. Subjective image quality was excellent or adequate in 49/48 patients at 100/120 kVp. No patient with a negative CT had any thromboembolism diagnosed during 3-month follow-up. Conclusion: By reducing X-ray tube potential from 120 to 100 kVp, while keeping all other scanning parameters unchanged, the radiation dose to the patient may be almost halved without deterioration of diagnostic quality, which may be of particular benefit in young individuals.

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Image Quality and Dose Reduction by Dual Source Computed Tomography Coronary Angiography: Protocol Comparison

Dose-Response ◽

10.1177/1559325818805838 ◽

2018 ◽

Vol 16 (4) ◽

pp. 155932581880583 ◽

Cited By ~ 1

Author(s):

Ernesto Forte ◽

Serena Monti ◽

Chiara Anna Parente ◽

Lukas Beyer ◽

Roberto De Rosa ◽

...

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Coronary Angiography ◽

Effective Dose ◽

Computed Tomography Coronary Angiography ◽

Correct Selection ◽

Dual Source ◽

Group A ◽

Noise Ratio ◽

Dual Source Computed Tomography

Purpose: To compare image quality and radiation dose among different protocols in patients who underwent a 128-slice dual source computed tomography coronary angiography (DSCT-CTCA). Methods: Ninety patients were retrospectively grouped according to heart rate (HR): 26 patients (group A) with stable HR ≤60 bpm were acquired using high pitch spiral mode (FLASH); 48 patients (group B) with irregular HR ≤60 bpm or stable HR between 60 and 70 bpm using step and shoot mode; and 16 patients (group C) with irregular HR >60 bpm or stable HR ≥70 bpm by retrospective electrocardiogram pulsing acquisition. Signal to noise ratio (SNR) and contrast to noise ratio (CNR) were measured for the main vascular structures. Moreover, the dose-length product and the effective dose were assessed. Results: Both SNR and CNR were higher in group A compared to group C (18.27 ± 0.32 vs 11.22 ± 0.50 and 16.75 ± 0.32 vs 10.17 ± 0.50; P = .001). The effective dose was lower in groups A and B (2.09 ± 1.27 mSv and 4.60 ± 2.78 mSv, respectively) compared to group C (9.61 ± 5.95 mSv) P < .0001. Conclusion: The correct selection of a low-dose, HR-matched CTCA scan protocol with a DSCT scanner provides substantial reduction of radiation exposure and better SNR and CNR.

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Image Quality Assessment of Four Different Computed Radiography Systems for NDT Applications

Volume 5: High-Pressure Technology; ASME NDE Division; Rudy Scavuzzo Student Paper Symposium ◽

10.1115/pvp2013-97704 ◽

2013 ◽

Author(s):

Angela Peterzol ◽

Bruno Bader ◽

Julien Banchet ◽

Claire Caperaa ◽

Vivian Didier

Keyword(s):

Image Quality ◽

Image Quality Assessment ◽

Computed Radiography ◽

Conventional Radiography ◽

Performance Comparison ◽

Source Image ◽

Imaging Plate ◽

Performance Limits ◽

Joint Project ◽

Comparison Results

Computed radiography (CR) is a digital radiographic technique, which uses very similar equipment to conventional radiography except that in place of a film to create the latent image, an imaging plate (IP) made of a photostimulable phosphor is used [1]. CR systems are commonly used in medical applications since they have proven reliability over more than two decades. Conversely, the NDT community has discussed the efficacy of film replacement by CR for more than 15 years. Though some standards were introduced in 2005 (ASTM E 2033, CEN EN 14784-2) and others are on the way (PR ISO 17636-2), CR is actually not included within the French RCCM, while the technique is commonly used in US for nuclear applications according to ASME (Section V, article 2). Since 2006, AREVA has been evaluating the performance of CR in comparison to conventional RT in the framework of EN 14784 for the digital part and the RCCM for the conventional part. The objective was to build a technical justification report to eventually support introduction of CR into the RCCM. In 2009 the subject gave rise to collaboration between AREVA NP – NETEC and EDF-CEIDRE, for a joint project to establish performance limits of CR towards EN 14784 specifications and RCCM image quality indicator (IQI) requirements [2]. In this paper, we present performance comparison results of four different CR systems. The measurements were conducted in 2012 and they demonstrate the current state of achievable image quality in CR. The performance has been evaluated for steel with a thickness range of 20÷60 mm using an Iridium 192 gamma source. Image quality has been assessed in terms of EN 462 and ASTM (E 747, E 1742) IQI. The results have been scored considering the PR ISO 17636-2, RCCM 2007, and ASME V-2010. This also permitted comparison among the different standard requirements.

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Comparison study of image quality and effective dose in dual energy chest digital tomosynthesis

Radiation Physics and Chemistry ◽

10.1016/j.radphyschem.2018.02.025 ◽

2018 ◽

Vol 148 ◽

pp. 112-120

Author(s):

Donghoon Lee ◽

Sunghoon Choi ◽

Haenghwa Lee ◽

Dohyeon Kim ◽

Seungyeon Choi ◽

...

Keyword(s):

Image Quality ◽

Effective Dose ◽

Dual Energy ◽

Digital Tomosynthesis ◽

Comparison Study

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Implementation of exposure index for optimize image quality and patient dose estimation with computed radiography (a clinical study of adult posteroanterior chest and anteroposterior abdomen radiography)

Journal of Physics Conference Series ◽

10.1088/1742-6596/1153/1/012032 ◽

2019 ◽

Vol 1153 ◽

pp. 012032

Author(s):

Dwi Rochmayanti ◽

Gatot Murti Wibowo ◽

Fatimah ◽

Agung Nugroho Setiawan

Keyword(s):

Clinical Study ◽

Image Quality ◽

Computed Radiography ◽

Patient Dose ◽

Exposure Index ◽

Dose Estimation

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RADIOGRAPHIC IMAGE ENHANCEMENT USING HYBRID ALGORITHM

Jurnal Teknologi ◽

10.11113/jt.v78.9089 ◽

2016 ◽

Vol 78 (6-7) ◽

Author(s):

Varin Chouvatut ◽

Ekkarat Boonchieng

Keyword(s):

Image Quality ◽

Spatial Resolution ◽

Computed Radiography ◽

Median Filter ◽

Correct Diagnosis ◽

Image Contrast ◽

Radiographic Image ◽

Radiographic Image Enhancement ◽

Radiographic Images ◽

Low Contrast

Radiographic image quality is important in the medical field since it can increase the visibility of anatomical structures and even improve the medical diagnosis. Because the image quality depends on contrast, noise, and spatial resolution, images with low contrast, a lot of noises, or low resolution will decrease image quality, leading to an incorrect diagnosis. Therefore, radiographic images should be enhanced to facilitate medical expertise in making correct diagnosis. In this paper, radiographic images are enhanced by hybrid algorithms based on the idea of combining three image processing techniques: Contrast Limited Adaptive Histogram Equalization for enhancing image contrast, Median Filter for removing noises, and Unsharp Masking for increasing spatial resolution. Two series of medical images consisting of 20 x-ray images and 20 computed radiography images are enhanced with this method. Peak Signal to Noise Ratio (PSNR) and image contrast are computed in order to measure image quality. The results indicate that the enhanced images have better PSNR.

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