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Samueli B, Aizenberg N, Shaco-Levy R, Katzav A, Kezerle Y, Krausz J, Mazareb S, Niv-Drori H, Peled HB, Sabo E, Tobar A, Asa SL. Complete digital pathology transition: A large multi-center experience. Pathol Res Pract 2024; 253:155028. [PMID: 38142526 DOI: 10.1016/j.prp.2023.155028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/08/2023] [Indexed: 12/26/2023]
Abstract
INTRODUCTION Transitioning from glass slide pathology to digital pathology for primary diagnostics requires an appropriate laboratory information system, an image management system, and slide scanners; it also reinforces the need for sophisticated pathology informatics including synoptic reporting. Previous reports have discussed the transition itself and relevant considerations for it, but not the selection criteria and considerations for the infrastructure. OBJECTIVE To describe the process used to evaluate slide scanners, image management systems, and synoptic reporting systems for a large multisite institution. METHODS Six network hospitals evaluated six slide scanners, three image management systems, and three synoptic reporting systems. Scanners were evaluated based on the quality of image, speed, ease of operation, and special capabilities (including z-stacking, fluorescence and others). Image management and synoptic reporting systems were evaluated for their ease of use and capacity. RESULTS Among the scanners evaluated, the Leica GT450 produced the highest quality images, while the 3DHistech Pannoramic provided fluorescence and superior z-stacking. The newest generation of scanners, released relatively recently, performed better than slightly older scanners from major manufacturers Although the Olympus VS200 was not fully vetted due to not meeting all inclusion criteria, it is discussed herein due to its exceptional versatility. For Image Management Software, the authors believe that Sectra is, at the time of writing the best developed option, but this could change in the very near future as other systems improve their capabilities. All synoptic reporting systems performed impressively. CONCLUSIONS Specifics regarding quality and abilities of different components will change rapidly with time, but large pathology practices considering such a transition should be aware of the issues discussed and evaluate the most current generation to arrive at appropriate conclusions.
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Affiliation(s)
- Benzion Samueli
- Department of Pathology, Soroka University Medical Center, P.O. Box 151, Be'er Sheva 8410101, Israel; Faculty of Health Sciences, Ben Gurion University of the Negev, P.O. Box 653, Be'er Sheva 8410501, Israel.
| | - Natalie Aizenberg
- Department of Pathology, Soroka University Medical Center, P.O. Box 151, Be'er Sheva 8410101, Israel; Faculty of Health Sciences, Ben Gurion University of the Negev, P.O. Box 653, Be'er Sheva 8410501, Israel
| | - Ruthy Shaco-Levy
- Department of Pathology, Soroka University Medical Center, P.O. Box 151, Be'er Sheva 8410101, Israel; Faculty of Health Sciences, Ben Gurion University of the Negev, P.O. Box 653, Be'er Sheva 8410501, Israel; Department of Pathology, Barzilai Medical Center, 2 Ha-Histadrut St, Ashkelon 7830604, Israel
| | - Aviva Katzav
- Pathology Institute, Meir Medical Center, Kfar Saba 4428164, Israel
| | - Yarden Kezerle
- Department of Pathology, Soroka University Medical Center, P.O. Box 151, Be'er Sheva 8410101, Israel; Faculty of Health Sciences, Ben Gurion University of the Negev, P.O. Box 653, Be'er Sheva 8410501, Israel
| | - Judit Krausz
- Department of Pathology, HaEmek Medical Center, 21 Yitzhak Rabin Ave, Afula 183411, Israel
| | - Salam Mazareb
- Department of Pathology, Carmel Medical Center, 7 Michal Street, Haifa 3436212, Israel
| | - Hagit Niv-Drori
- Department of Pathology, Rabin Medical Center, 39 Jabotinsky St, Petah Tikva 4941492, Israel; Faculty of Medicine, Tel Aviv University, P.O. Box 39040, Tel Aviv 6139001, Israel
| | - Hila Belhanes Peled
- Department of Pathology, HaEmek Medical Center, 21 Yitzhak Rabin Ave, Afula 183411, Israel
| | - Edmond Sabo
- Department of Pathology, Carmel Medical Center, 7 Michal Street, Haifa 3436212, Israel; Rappaport Faculty of Medicine, Technion Israel Institute of Technology, Haifa 3525433, Israel
| | - Ana Tobar
- Department of Pathology, Rabin Medical Center, 39 Jabotinsky St, Petah Tikva 4941492, Israel; Faculty of Medicine, Tel Aviv University, P.O. Box 39040, Tel Aviv 6139001, Israel
| | - Sylvia L Asa
- Institute of Pathology, University Hospitals Cleveland Medical Center, Case Western Reserve University, 11100 Euclid Avenue, Room 204, Cleveland, OH 44106, USA
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Marshall NW, Vandenbroucke D, Cockmartin L, Wanninger F, Smet M, Feng Y, Ni Y, Bosmans H. Seven general radiography x-ray detectors with pixel sizes ranging from 175 to 76 μm: technical evaluation with the focus on orthopaedic imaging. Phys Med Biol 2023; 68:195007. [PMID: 37659394 DOI: 10.1088/1361-6560/acf642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 09/01/2023] [Indexed: 09/04/2023]
Abstract
Aim. Flat panel detectors with small pixel sizes general can potentially improve imaging performance in radiography applications requiring fine detail resolution. This study evaluated the imaging performance of seven detectors, covering a wide range of pixel sizes, in the frame of orthopaedic applications.Material and methods. Pixel sizes ranged from 175 (detector A175) to 76μm (detector G76). Modulation transfer function (MTF) and detective quantum efficiency (DQE) were measured using International Electrotechnical Commission (IEC) RQA3 beam quality. Threshold contrast (CT) and a detectability index (d') were measured at three air kerma/image levels. Rabbit shoulder images acquired at 60 kV, over five air kerma levels, were evaluated in a visual grading study for anatomical sharpness, image noise and overall diagnostic image quality by four radiologists. The detectors were compared to detector E124.Results. The 10% point of the MTF ranged from 3.21 to 4.80 mm-1, in going from detector A175to detector G76. DQE(0.5 mm-1) measured at 2.38μGy/image was 0.50 ± 0.05 for six detectors, but was higher for F100at 0.62. High frequency DQE was superior for the smaller pixel detectors, howeverCTfor 0.25 mm discs correlated best with DQE(0.5 mm-1). Correlation betweenCTand the detectability model was good (R2= 0.964).CTfor 0.25 mm diameter discs was significantly higher for D150and F100compared to E124. The visual grading data revealed higher image quality ratings for detectors D125and F100compared to E124. An increase in air kerma was associated with improved perceived sharpness and overall quality score, independent of detector. Detectors B150, D125, F100and G76, performed well in specific tests, however only F100consistently outperformed the reference detector.Conclusion. Pixel size alone was not a reliable predictor of small detail detectability or even perceived sharpness in a visual grading analysis study.
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Affiliation(s)
- N W Marshall
- UZ Gasthuisberg, Department of Radiology, Herestraat 49, B-3000 Leuven, Belgium
- Medical Imaging Research Center, Medical Physics and Quality Assessment, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
- Agfa N.V., Septestraat 27, B-2640 Mortsel, Belgium
| | | | - L Cockmartin
- UZ Gasthuisberg, Department of Radiology, Herestraat 49, B-3000 Leuven, Belgium
| | - F Wanninger
- Agfa-Gevaert HealthCare GmbH, München, Germany
| | - M Smet
- UZ Gasthuisberg, Department of Radiology, Herestraat 49, B-3000 Leuven, Belgium
| | - Y Feng
- Theragnostic Laboratory, Biomedical Group, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
| | - Y Ni
- Theragnostic Laboratory, Biomedical Group, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
| | - H Bosmans
- UZ Gasthuisberg, Department of Radiology, Herestraat 49, B-3000 Leuven, Belgium
- Medical Imaging Research Center, Medical Physics and Quality Assessment, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
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Jørgensen PB, Krag-Nielsen N, Lindgren L, Mørup RMS, Kaptein B, Stilling M. Radiostereometric analysis: comparison of radiation dose and precision in digital and computed radiography. Arch Orthop Trauma Surg 2023; 143:5919-5926. [PMID: 36422666 DOI: 10.1007/s00402-022-04674-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/23/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Radiostereometric Analysis (RSA) is used to measure fixation of joint prosthesis. This study compared radiation dose and image quality of a digital radiography (DR) RSA system and a computed radiography (CR) RSA system in a clinical setting. METHODS RSA recordings of 24 hips and shoulders were analyzed. We compared two systems: (1) Arcoma T0 with ST-VI image plates and Profect CR-IR 363 reader to (2) AdoraRSA with CXDI-70C wireless DR detectors in a clinical uniplanar RSA set-up with a ± 20 degrees tube angulation and 35 cm × 43 cm detectors. Effective dose was calculated using dedicated software. Image quality was evaluated using calibration errors as calculated by the RSA software. RESULTS The mean dose for hips was 0.14 (SD 0.04) mSv in the CR system and 0.05 (SD 0.02) mSv in the DR system. The mean dose for shoulders was 0.16 (SD 0.07) mSv in the CR system and 0.09 (SD 0.03) mSv in the DR system. Radiation dose was 64% (p < 0.001) and 43% (p = 0.03) lower in the DR system compared with the CR system for hip and shoulder RSA, respectively. Image quality was better for the DR system with 60-80% less calibration errors compared to the CR system. CONCLUSION Owing to highly efficient detectors and added filtration at the x-ray tubes, the DR system considerably reduced radiation dose compared with the CR system without compromising image quality. Based on the findings in this study, we recommend replacing CR RSA systems with DR RSA systems. REGISTRATION Patients were selected from clinical studies performed on the two systems and approved by the local ethics committee [20060165, M-20100112, M-20070082, M-20110224, and 20070258] and registered with ClinicalTrials.gov [NCT00408096, NCT01289834, NCT00913679, NCT02311179, and NCT00679120].
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Affiliation(s)
- Peter Bo Jørgensen
- AutoRSA Research Group, Orthopaedic Research Unit, Aarhus University Hospital, Palle Juul-Jensens, Boulevard 99, 8200, Aarhus N, Denmark.
| | | | - Lars Lindgren
- Department of Radiology, Aarhus University Hospital, Aarhus, Denmark
| | - Rikke Margrethe Staghøj Mørup
- AutoRSA Research Group, Orthopaedic Research Unit, Aarhus University Hospital, Palle Juul-Jensens, Boulevard 99, 8200, Aarhus N, Denmark
| | - Bart Kaptein
- Biomechanics and Imaging Group (BIG), Leiden University Medical Center, Leiden, The Netherlands
| | - Maiken Stilling
- AutoRSA Research Group, Orthopaedic Research Unit, Aarhus University Hospital, Palle Juul-Jensens, Boulevard 99, 8200, Aarhus N, Denmark
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Steiner N, Ludewig E, Tebrün W, Pees M. Radiation Dose Reduction in Different Digital Radiography Systems: Impact on Assessment of Defined Bony Structures in Bearded Dragons ( Pogona vitticeps). Animals (Basel) 2023; 13:ani13101613. [PMID: 37238043 DOI: 10.3390/ani13101613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Three different digital detector systems were used to study the effect of a defined radiation dose reduction on the image quality of digital radiographs in bearded dragons (Pogona vitticeps). A series of radiographs of seven bearded-dragon cadavers with a body mass ranging from 132 g to 499 g were taken in dorsoventral projection. The digital systems employed included two computed radiography systems (CR) (one system with a needle-based and one with a powdered-based scintillator) and one direct radiography system (DR). Three levels of the detector dose were selected: A standard dose (defined based on the recommended exposure value of the CRP, D/100%), a half dose (D/50%), and a quarter dose (D/25%). Four image criteria and one overall assessment were defined for each of four anatomic skeletal regions (femur, rib, vertebra, and phalanx) and evaluated blinded by four veterinarians using a predefined scoring system. The results were assessed for differences between reviewers (interobserver variability), radiography systems, and dosage settings (intersystem variability). The comparison of the ratings was based on visual grading characteristic (VGC) analysis. Dose reduction led to significantly lower scores in all criteria by every reviewer, indicating a linear impairment of image quality in different skeletal structures in bearded dragons. Scores did not differ significantly between the different systems used, indicating no advantage in using a computed or direct radiography system to evaluate skeletal structures in bearded dragons. The correlation was significant (p ≤ 0.05) for interobserver variability in 100% of the cases, with correlation coefficients between 0.50 and 0.59. While demonstrating the efficacy of the use of digital radiography in bearded dragons and the similar quality in using different computed or direct radiography systems, this study also highlights the importance of the appropriate level of detector dose and demonstrates the limits of post-processing algorithm to compensate for insufficient radiation doses in bearded dragons.
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Affiliation(s)
- Natalie Steiner
- Department of Small Mammal, Reptile and Avian Diseases, University of Veterinary Medicine, 30559 Hanover, Germany
| | - Eberhard Ludewig
- Division of Diagnostic Imaging, Department of Small Animals and Horses, University of Veterinary Medicine, 1210 Vienna, Austria
| | - Wiebke Tebrün
- Wimex Agrarprodukte Import and Export GmbH, 93128 Regenstauf, Germany
| | - Michael Pees
- Department of Small Mammal, Reptile and Avian Diseases, University of Veterinary Medicine, 30559 Hanover, Germany
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Al-Naser YA. The impact of artificial intelligence on radiography as a profession: A narrative review. J Med Imaging Radiat Sci 2023; 54:162-166. [PMID: 36376210 DOI: 10.1016/j.jmir.2022.10.196] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/27/2022] [Accepted: 10/14/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND AND PURPOSE Artificial intelligence (AI) algorithms, particularly deep learning, have made significant strides in image recognition and classification, providing remarkable diagnostic accuracy to various diseases. This domain of AI has been the focus of many research papers as it directly relates to the roles and responsibilities of a radiologist. However, discussions on the impact of such technology on the radiography profession are often overlooked. To address this gap in the literature, this paper aims to address the application of AI in radiography and how AI's rapid emergence into healthcare is impacting not only standard radiographic protocols but the role of the radiographic technologist as well. METHODS A review of the literature on AI and radiography was performed, using databases within PubMed, Google Scholar, and ScienceDirect. Video presentations from YouTube were also utilized to weigh the varying opinions of world leaders at the fore of artificial intelligence. RESULTS AI can augment routine standard radiographic protocols. It can automatically ensure optimal patient positioning within the gantry as well as automate image processing. As AI technologies continue to emerge in diagnostic imaging, practicing radiologic technologists are urged to achieve threshold computational and technical literacy to operate AI-driven imaging technology. CONCLUSION There are many applications of AI in radiography including acquisition and image processing. In the near future, it will be important to supply the demand for radiographers skilled in AI-driven technologies.
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Ball S, McKerrow M, Murphy A. Do radiographers collimate? A retrospective analysis of radiographic collimation of common musculoskeletal examinations at an adult trauma centre. J Med Radiat Sci 2023; 70:21-29. [PMID: 36319191 PMCID: PMC9977647 DOI: 10.1002/jmrs.630] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 10/14/2022] [Indexed: 11/07/2022] Open
Abstract
INTRODUCTION Collimation of the primary beam is an important factor in radiography to reduce dose and improve image quality. The introduction of larger detector plates in direct digital radiography (DR) allows the exposed area to be calculated by removing cropping applied to the image. The aim of this study was to assess whether the exposed area was larger than a reference standard across five different projections on different body types, with the reference size being the corresponding cassette size used in traditional film/screen or computed radiography (CR). METHOD A retrospective clinical audit of five common musculoskeletal radiographic projections (AP knee, AP shoulder, horizontal beam lateral hip, lateral cervical spine and lateral facial bones), of 359 patients was undertaken. The electronic cropping was removed from projections, and the superior-inferior, antero-posterior and medio-lateral collimation size was measured, depending on the projection. The two measurements were multiplied to give an exposed field of view area. The three measurements were compared with a reference standard, being the size of the corresponding cassette size used in the department on film/screen or computed radiography. RESULTS From the five projections, 1071 measurements were analysed. 416 (38.8%) of these measurements were less than or equal to the agreed reference standard. 655 (61.2%) were greater than the agreed reference standard. CONCLUSION The study demonstrates that the majority (61.2%) of the measurements taken were above the reference standard. This results in an increase in radiation dose to patients and detrimental impacts on image quality.
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Affiliation(s)
- Sally Ball
- Department of Medical ImagingPrincess Alexandra HospitalBrisbaneAustralia
| | - Megan McKerrow
- Department of Medical ImagingPrincess Alexandra HospitalBrisbaneAustralia
| | - Andrew Murphy
- Department of Medical ImagingPrincess Alexandra HospitalBrisbaneAustralia,School of Clinical Sciences, Faculty of HealthQueensland University of Technology (QUT)BrisbaneQueenslandAustralia
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Long Z, Walz-Flannigan AI, Littrell LA, Schueler BA. Technical note: Four-year experience with utilization of DICOM metadata analytics in clinical digital radiography practice. Med Phys 2023; 50:831-836. [PMID: 36542418 DOI: 10.1002/mp.16170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/13/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Digital radiography (DR) still presents many challenges and could have complex imaging acquisition and processing patterns in a clinical practice hindering quality standardization. PURPOSE This technical note aims to report the 4-year experience with utilizing a custom DICOM metadata analytics program in clinical DR at a large institution. METHODS Thirty-eight DR systems of three vendors at multiple locations were configured to automatically send clinical DICOM images to a DICOM receiver. A suite of custom MATLAB programs was established to extract and store public and private header data weekly. Specific use cases are provided for systematic image acquisition investigation, image processing harmonization, exposure index (EI) longitudinal monitoring and EI target optimization. RESULTS For systematic acquisition investigation, an example of adult lumbar spine exam analysis was provided with statistics on manual acquisition versus the use of automatic exposure control (AEC, including AEC dose level, active cell, and backup timer), grid usage, and collimation for various projections. For processing harmonization, up to 12.6% of protocols were revealed to have processing parameter differences in an example of a mobile radiography fleet. In addition, inconsistent use of a post-acquisition image size function was also demonstrated, which resulted in anatomy size display variations. Bimonthly monitoring of median EI values showed expected trends, including changes after an AEC dose level adjustment for adult posterior-anterior chest imaging on a scanner system. An example of adult axillary shoulder EI target refinement was shared using the median value, eμ , based on the lognormal EI data distribution after parsing down to acquisitions with appropriate techniques. CONCLUSIONS This analytics program enables systematic analysis of image acquisition and processing details. The information provides invaluable insights into real practice patterns, which can support data-driven quality standardization and optimization.
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Affiliation(s)
- Zaiyang Long
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | - Beth A Schueler
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
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Wilson PW, Dunn IC, Mccormack HA. Development of an in vivo radiographic method with potential for use in improving bone quality and the welfare of laying hens through genetic selection. Br Poult Sci 2023; 64:1-10. [PMID: 36196860 DOI: 10.1080/00071668.2022.2119835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
1. Genetic selection for bone quality can improve this, as it is heritable. A method was established using digital X-ray which took around 40 s in total and gave an image that allowed quantification of bone density from many appendicular bones.2. The tibiotarsus measurement of bone density on the live hen across the different experiments had correlations with post-mortem whole bone radiographic density from 0.62 to 0.7, similar to that between density and material properties for example. Differences between groups of hens, where calcium and phosphorus in the diet were manipulated, were detected within 3 weeks of treatment using live hen measurement (P < 0.001, n = 24).3. In a gage analysis, 'hen' explained more than 86% of the variance, demonstrating the ability to observe clear differences between hens. The effect of different operators' analysis on the contribution to variance was very low as was the repeated measurement of the same hen.4. The measurement of bone density on the live hen described in this paper represented major progress to a usable method for genetic selection to improve bone strength in laying hens. The method has the potential to reduce the number of animals needed to test nutritional and management interventions to improve bone health.
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Affiliation(s)
- P W Wilson
- The Roslin Institute, University of Edinburgh, Scotland, UK
| | - I C Dunn
- The Roslin Institute, University of Edinburgh, Scotland, UK
| | - H A Mccormack
- The Roslin Institute, University of Edinburgh, Scotland, UK
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Han B, Park M, Kim K, Lee Y. Characterization of Flexible Amorphous Silicon Thin-Film Transistor-Based Detectors with Positive-Intrinsic-Negative Diode in Radiography. Diagnostics (Basel) 2022; 12:diagnostics12092103. [PMID: 36140503 PMCID: PMC9497934 DOI: 10.3390/diagnostics12092103] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
Low-dose exposure and work convenience are required for mobile X-ray systems during the COVID-19 pandemic. We investigated a novel X-ray detector (FXRD-4343FAW, VIEWORKS, Anyang, Korea) composed of a thin-film transistor based on amorphous silicon with a flexible plastic substrate. This detector is composed of a thallium-doped cesium iodide scintillator with a pixel size of 99 μm, pixel matrix of 4316 × 4316, and weight of 2.95 kg. The proposed detector has the advantages of high-noise characteristics and low weight, which provide patients and workers with an advantage in terms of the dose and work efficiency, respectively. We performed a quantitative evaluation and an experiment to demonstrate its viability. The modulation transfer function, noise power spectrum, and detective quantum efficiency were identified using the proposed and comparative detectors, according to the International Electrotechnical Commission protocol. Additionally, the contrast-to-noise ratio and coefficient of variation were investigated using a human-like phantom. Our results indicate that the proposed detector efficiently increases the image performance in terms of noise characteristics. The detailed performance evaluation demonstrated that the outcomes of the use of the proposed detector confirmed the viability of mobile X-ray devices that require low doses. Consequently, the novel FXRD-4343FAW X-ray detector is expected to improve the image quality and work convenience in extended radiography.
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Affiliation(s)
- Bongju Han
- Quality Assurance Team, Business Division, Vieworks, 41-3, Burim-ro 170beon-gil, Dongan-gu, Anyang-si 14055, Korea
| | - Minji Park
- Department of Radiological Science, College of Health Science, Gachon University, 191, Hambakmoe-ro, Yeonsu-gu, Incheon 21936, Korea
- Department of Health Science, General Graduate School of Gachon University, 191, Hambakmoe-ro, Yeonsu-gu, Incheon 21936, Korea
| | - Kyuseok Kim
- Department of Integrative Medicine, Major in Digital Healthcare, Yonsei University College of Medicine, Unju-ro, Gangman-gu, Seoul 06229, Korea
- Correspondence: (K.K.); (Y.L.); Tel.: +82-02-2019-5447 (K.K.); +82-32-820-4362 (Y.L.)
| | - Youngjin Lee
- Department of Radiological Science, College of Health Science, Gachon University, 191, Hambakmoe-ro, Yeonsu-gu, Incheon 21936, Korea
- Correspondence: (K.K.); (Y.L.); Tel.: +82-02-2019-5447 (K.K.); +82-32-820-4362 (Y.L.)
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10
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Utilization of upper and lower limits of exposure index in clinical digital radiography. Radiol Phys Technol 2022; 15:349-357. [PMID: 36036873 DOI: 10.1007/s12194-022-00674-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 08/13/2022] [Accepted: 08/16/2022] [Indexed: 10/15/2022]
Abstract
In many digital X-ray imaging systems, although air kerma on a surface of each detector is used, a standardized dose index called an exposure index (EI) has been proposed by the IEC, which is expected to be utilized for dose management. In clinical practices, EI is effectively utilized using a deviation index (DI), which is a deviation between a target EI (EIT) set for each imaging region and an EIT of the acquired image. However, an important issue in clinical uses of EI is a suppression of excessive doses. It is difficult to achieve a reliable reduction in exposure doses by indicating DI. In this study, physical image characteristics of detectors, visual detectability by charts, and observer experiments using a chest phantom were examined to determine upper (DImax) and lower (DImin) limits of the EIT and DI to achieve a reliable dose reduction in chest examinations. As the result, the tolerance ranges indicated by DImax and DImin, which were set based on the results of physical and visual evaluations, proved to be almost consistent with the distribution of EI values in 735 clinical images taken with a photo-timer control in real clinical practices.
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Wang M, Meng Y, Zhu Y, Song J, Yang J, Liu C, Zhu H, Yan D, Xu C, Liu Y. Afterglow-Suppressed Lu 2O 3:Eu 3+ Nanoscintillators for High-Resolution and Dynamic Digital Radiographic Imaging. Inorg Chem 2022; 61:11293-11305. [PMID: 35820030 DOI: 10.1021/acs.inorgchem.2c01417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lu2(1-x)Eu2xO3 nanoscintillators (x = 0.005, 0.01, 0.03, 0.05, 0.07, and 0.10) with red emission were synthesized by a coprecipitation method. It is found that their photo- and radioluminescence intensities increase with increasing Eu3+ concentration until x = 0.05. According to their concentration-dependent luminescence intensity ratios (I610(C2)/I582(S6)), the existing energy transfer from Eu3+(S6) (occupying S6 sites) to Eu3+(C2) (occupying C2 sites) can be confirmed. Based on the spectral data and density functional theory (DFT) calculations, the origin of Lu2O3:Eu3+ persistent luminescence at low concentration might be related to the tunneling processes between Eu3+ (occupying C2 and S6 sites) and oxygen interstitials (Oi×). After dispersing afterglow-suppressed Lu2O3:Eu3+ nanoscintillators into polymethyl methacrylate (PMMA) polymer-acetone solution, flexible PMMA-Lu2O3:Eu3+ composite films with high thermal stability and radiation resistance were fabricated by a doctor blade method. As the flexible composite film was used as an imaging plate, static X-ray images with high spatial resolution (5.5 lp/mm) under an extremely low dose of ∼1.1 μGyair can be acquired. When a watch with a moving second hand was used as an object, the dynamic X-ray imaging can be realized under a dose rate of 55 μGyair·s-1. Our results demonstrate that Lu2O3:Eu3+ nanoscintillators can be regarded as candidate materials for dynamic digital radiographic imaging.
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Affiliation(s)
- Mingwei Wang
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Yangqi Meng
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Yaqi Zhu
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Jia Song
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Jian Yang
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Chunguang Liu
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Hancheng Zhu
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Duanting Yan
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Changshan Xu
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Yuxue Liu
- School of Physics, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
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12
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Li F, Zhou L, Wang Y, Chen C, Yang S, Shan F, Liu L. Modeling long-range dependencies for weakly supervised disease classification and localization on chest X-ray. Quant Imaging Med Surg 2022; 12:3364-3378. [PMID: 35655823 PMCID: PMC9131331 DOI: 10.21037/qims-21-1117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/14/2022] [Indexed: 12/31/2023]
Abstract
BACKGROUND Computer-aided diagnosis based on chest X-ray (CXR) is an exponentially growing field of research owing to the development of deep learning, especially convolutional neural networks (CNNs). However, due to the intrinsic locality of convolution operations, CNNs cannot model long-range dependencies. Although vision transformers (ViTs) have recently been proposed to alleviate this limitation, those trained on patches cannot learn any dependencies for inter-patch pixels and thus, are insufficient for medical image detection. To address this problem, in this paper, we propose a CXR detection method which integrates CNN with a ViT for modeling patch-wise and inter-patch dependencies. METHODS We experimented on the ChestX-ray14 dataset and followed the official training-test set split. Because the training data only had global annotations, the detection network was weakly supervised. A DenseNet with a feature pyramid structure was designed and integrated with an adaptive ViT to model inter-patch and patch-wise long-range dependencies and obtain fine-grained feature maps. We compared the performance using our method with that of other disease detection methods. RESULTS For disease classification, our method achieved the best result among all the disease detection methods, with a mean area under the curve (AUC) of 0.829. For lesion localization, our method achieved significantly higher intersection of the union (IoU) scores on the test images with bounding box annotations than did the other detection methods. The visualized results showed that our predictions were more accurate and detailed. Furthermore, evaluation of our method in an external validation dataset demonstrated its generalization ability. CONCLUSIONS Our proposed method achieves the new state of the art for thoracic disease classification and weakly supervised localization. It has potential to assist in clinical decision-making.
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Affiliation(s)
- Fangyun Li
- Institute of Biomedical Sciences, Fudan University, Shanghai, China
| | - Lingxiao Zhou
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, China
| | - Yunpeng Wang
- Institute of Biomedical Sciences, Fudan University, Shanghai, China
| | - Chuan Chen
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Shuyi Yang
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
- Shanghai Institute of Medical Imaging, Shanghai, China
| | - Fei Shan
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Lei Liu
- Institute of Biomedical Sciences, Fudan University, Shanghai, China
- School of Basic Medical Sciences, Fudan University, Shanghai, China
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13
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Lawson M, Qian L, Lau KK, Lau T, Massey D, Badawy M. Efficacy of the scatter correction algorithm in portable chest radiography. Emerg Radiol 2022; 29:809-817. [PMID: 35612644 PMCID: PMC9130995 DOI: 10.1007/s10140-022-02063-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/17/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE Portable chest radiographs (CXRs) continue to be a vital diagnostic tool for emergency and critical care medicine. The scatter correction algorithm (SCA) is a post-processing algorithm aiming to reduce scatter within portable images. This study aimed to assess whether the SCA improved image quality (IQ) in portable CXRs. METHODS Objective and subjective IQ assessments were undertaken on both phantom and clinical images, respectively. For objective analysis, attenuators were placed on the anterior surface of the patient's thorax to simulate pathologies present within uniform regions of the phantom's lung and heart. Phantom CXRs were acquired with three different tube-current-times (mAs). Phantom images were processed with different SCA strengths. Contrast to noise ratios (CNR) within the attenuator were determined for each algorithm strength and compared to non-SCA images. For subjective analysis, two independent radiologists graded 30 clinical images with and without the SCA activated. The images were graded for IQ in different anatomical structures and overall diagnostic confidence. RESULTS Objectively, most strengths of the SCA improved the CNR in both regions. However, a detrimental effect was recorded for some algorithm strengths in regions of high contrast. Subjectively, both observers recorded the SCA significantly improved IQ in clinical CXRs in all anatomical regions. Observers indicated the greatest improvement in the lung and hilar regions, and least improvement in the chest wall and bone. All images with and without the SCA were deemed diagnostic. CONCLUSION This study shows the potential radiation dose neutral IQ improvement when using an SCA in clinical patient CXRs.
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Affiliation(s)
- Michael Lawson
- Monash Imaging, Monash Health, Clayton, VIC 3168 Australia
- Centre for Medical and Radiation Physics, School of Physics, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW 2500 Australia
| | - Lijun Qian
- Monash Imaging, Monash Health, Clayton, VIC 3168 Australia
| | - Kenneth K. Lau
- Monash Imaging, Monash Health, Clayton, VIC 3168 Australia
- Department of Medicine, Monash University, Clayton, VIC 3168 Australia
| | - Theo Lau
- QScan Radiology Clinics, Aspley, QLD Australia
| | - David Massey
- Monash Imaging, Monash Health, Clayton, VIC 3168 Australia
| | - Mohamed Badawy
- Monash Imaging, Monash Health, Clayton, VIC 3168 Australia
- Department of Medical Imaging and Radiation Sciences, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC 3800 Australia
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14
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Sun J, Wu Z, Yu Z, Chen H, Du C, Xu L, Zhong J, Feng J, Coatrieux G, Coatrieux JL, Chen Y. Automatic video analysis framework for exposure region recognition in X-ray imaging automation. IEEE J Biomed Health Inform 2022; 26:4359-4370. [PMID: 35503854 DOI: 10.1109/jbhi.2022.3172369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The deep learning-based automatic recognition of the scanning or exposing region in medical imaging automation is a promising new technique, which can decrease the heavy workload of the radiographers, optimize imaging workflow and improve image quality. However, there is little related research and practice in X-ray imaging. In this paper, we focus on two key problems in X-ray imaging automation: automatic recognition of the exposure moment and the exposure region. Consequently, we propose an automatic video analysis framework based on the hybrid model, approaching real-time performance. The framework consists of three interdependent components: Body Structure Detection, Motion State Tracing, and Body Modeling. Body Structure Detection disassembles the patient to obtain the corresponding body keypoints and body Bboxes. Combining and analyzing the two different types of body structure representations is to obtain rich spatial location information about the patient body structure. Motion State Tracing focuses on the motion state analysis of the exposure region to recognize the appropriate exposure moment. The exposure region is calculated by Body Modeling when the exposure moment appears. A large-scale dataset for X-ray examination scene is built to validate the performance of the proposed method. Extensive experiments demonstrate the superiority of the proposed method in automatically recognizing the exposure moment and exposure region. This paradigm provides the first method that can enable automatically and accurately recognize the exposure region in X-ray imaging without the help of the radiographer.
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15
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Advances in multiscale image processing and its effects on image quality in skeletal radiography. Sci Rep 2022; 12:4726. [PMID: 35304544 PMCID: PMC8933435 DOI: 10.1038/s41598-022-08699-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/09/2022] [Indexed: 11/08/2022] Open
Abstract
Multi-frequency processing (MFP) leads to enhanced image quality (IQ) of radiographs. This study is to determine the effect of third generation MFP (M3) on IQ in comparison to standard second-generation MFP (M2). 20 cadavers were examined and post-processing of radiographs was performed with both M2 and M3. Three readers blinded to the MFP used for each image independently compared corresponding image pairs according to overall IQ and depiction of bony structures and soft tissue (+ 2: notably better > 0: equal > - 2: notably worse). A significant deviation of the median grade from grade 0 (equal) (p < 0.01) for each evaluator A, B and C speaks against an equal image quality of M2- and M3-images. M3-images were categorized with better grades (+ 1, + 2) in 87.7% for overall image quality, in 90.4% for soft tissue and 81.8% for bony structures. M3 images showed significant higher averaged SNR and CNR for all investigated lower extremities than that of M2 images (0.031 < p < 0.049). The newest generation of MFP leads to significantly better depiction of anatomical structures and overall image quality than in images processed with the preceding generation of MFP. This provides increased diagnostic accuracy and further decreased radiation exposure.
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16
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Kamburoğlu K, Samunahmetoğlu E, Eratam N, Sönmez G, Karahan S. Clinical comparison of intraoral CMOS and PSP detectors in terms of time efficiency, patient comfort, and subjective image quality. Imaging Sci Dent 2022; 52:93-101. [PMID: 35387105 PMCID: PMC8967495 DOI: 10.5624/isd.20210241] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/13/2021] [Accepted: 12/29/2021] [Indexed: 11/18/2022] Open
Affiliation(s)
- Kıvanç Kamburoğlu
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey
| | - Erçin Samunahmetoğlu
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey
| | - Nejlan Eratam
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey
| | - Gül Sönmez
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Adakent University, Mersin, Turkey
| | - Sevilay Karahan
- Department of Biostatistics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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17
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Chung L, Kumar S, Oldfield J, Phillips M, Stratfold M. The Use of Anatomical Side Markers in General Radiology: A Systematic Review of the Current Literature. J Patient Saf 2022; 18:e115-e123. [PMID: 32398536 DOI: 10.1097/pts.0000000000000716] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The use of an anatomical side marker (ASM) on x-rays, be it digital or radiopaque, is an important quality and safety concept within general radiology. Using radiopaque ASMs is best practice, and lack of any ASMs may have dire consequences in terms of patient safety. To date, there have been no systematic reviews investigating the use of ASMs in clinical practice. METHODS A systematic search of electronic databases (CINAHL, the Cochrane Library, Medline, EMBASE, ERIC, and JBI) from inception to March 1, 2018, was undertaken. Gray literature searching (through Google) and pearling was conducted. Methodological quality was assessed using a modified version of the McMaster Critical Appraisal tool for quantitative studies. A customized data extraction tool was developed, which included characteristics of the studies. RESULTS Of 624 studies, 7 studies met the eligibility criteria. Despite diverse study designs, collectively, the studies demonstrated that only a small number of x-rays did not include an ASM. On x-rays that did use a radiopaque ASM, most of them were positioned in the primary radiation field. A noticeable shift in practice from the use of radiopaque ASMs to digital ASM was also identified. Multifaceted barriers were reported for the use of ASM in routine clinical practice. CONCLUSIONS Although missing ASMs on x-rays were a small feature, findings from this review highlight opportunities for improvement and a need to ameliorate barriers for ASM use.
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Affiliation(s)
- Lilian Chung
- From the UniSA Allied Health and Human Performance, University of South Australia
| | - Saravana Kumar
- From the UniSA Allied Health and Human Performance, University of South Australia
| | - Joanne Oldfield
- From the UniSA Allied Health and Human Performance, University of South Australia
| | - Maureen Phillips
- From the UniSA Allied Health and Human Performance, University of South Australia
| | - Megan Stratfold
- SA Medical Imaging, Women's and Children's Hospital, Adelaide, Australia
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18
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Ou X, Chen X, Xu X, Xie L, Chen X, Hong Z, Bai H, Liu X, Chen Q, Li L, Yang H. Recent Development in X-Ray Imaging Technology: Future and Challenges. RESEARCH (WASHINGTON, D.C.) 2021; 2021:9892152. [PMID: 35028585 PMCID: PMC8724686 DOI: 10.34133/2021/9892152] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 11/23/2021] [Indexed: 11/18/2022]
Abstract
X-ray imaging is a low-cost, powerful technology that has been extensively used in medical diagnosis and industrial nondestructive inspection. The ability of X-rays to penetrate through the body presents great advances for noninvasive imaging of its internal structure. In particular, the technological importance of X-ray imaging has led to the rapid development of high-performance X-ray detectors and the associated imaging applications. Here, we present an overview of the recent development of X-ray imaging-related technologies since the discovery of X-rays in the 1890s and discuss the fundamental mechanism of diverse X-ray imaging instruments, as well as their advantages and disadvantages on X-ray imaging performance. We also highlight various applications of advanced X-ray imaging in a diversity of fields. We further discuss future research directions and challenges in developing advanced next-generation materials that are crucial to the fabrication of flexible, low-dose, high-resolution X-ray imaging detectors.
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Affiliation(s)
- Xiangyu Ou
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Xue Chen
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Xianning Xu
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Lili Xie
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Xiaofeng Chen
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Zhongzhu Hong
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Hua Bai
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Xiaowang Liu
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Qiushui Chen
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
| | - Lin Li
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Huanghao Yang
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
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19
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Satharasinghe D, Jeyasugiththan J, Jeyasuthan M, Amalaraj T, Abeyweera AL, Wanninayake WMNMB, Pallewatte AS. IMPACT OF COLLIMATION ON RADIATION EXPOSURE IN ADULT AND PAEDIATRIC DIGITAL X-RAY IMAGING. RADIATION PROTECTION DOSIMETRY 2021; 197:19-27. [PMID: 34718821 DOI: 10.1093/rpd/ncab155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/01/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
This study aimed to evaluate the collimation practices and quantify the overexposure due to extensive X-ray field area. The study was carried out in four digital X-ray units (including one paediatric X-ray unit). A total of 749 X-ray projections (555 adult and 194 paediatric) were evaluated. In adult X-ray units, the radiation field size was two times larger than the electronically collimated field. In the paediatric unit, the radiation field was 3.7 times larger than the electronic collimated field. The average additional entrance surface dose due to the excess radiation field used in a paediatric X-ray unit varied between 9.3 (2.5%) and 201.4 $\mu $Gy (10.9%). Therefore, proper pre-patient collimation should be applied whenever feasible, which reduces the patient radiation dose considerably.
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Affiliation(s)
- Duminda Satharasinghe
- Department of Nuclear Science, Faculty of Science, University of Colombo, Colombo, Sri Lanka
- Horizon Campus, Malabe, Sri Lanka
| | - J Jeyasugiththan
- Department of Nuclear Science, Faculty of Science, University of Colombo, Colombo, Sri Lanka
| | - M Jeyasuthan
- Department of Radiology, Tellippalai Base Hospital, Jaffna, Sri Lanka
| | - T Amalaraj
- Department of Nuclear Science, Faculty of Science, University of Colombo, Colombo, Sri Lanka
| | | | | | - A S Pallewatte
- Department of Radiology, National Hospital of Sri Lanka, Colombo, Sri Lanka
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20
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Vo LNQ, Codlin A, Ngo TD, Dao TP, Dong TTT, Mo HTL, Forse R, Nguyen TT, Cung CV, Nguyen HB, Nguyen NV, Nguyen VV, Tran NT, Nguyen GH, Qin ZZ, Creswell J. Early Evaluation of an Ultra-Portable X-ray System for Tuberculosis Active Case Finding. Trop Med Infect Dis 2021; 6:163. [PMID: 34564547 PMCID: PMC8482270 DOI: 10.3390/tropicalmed6030163] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 12/20/2022] Open
Abstract
X-ray screening is an important tool in tuberculosis (TB) prevention and care, but access has historically been restricted by its immobile nature. As recent advancements have improved the portability of modern X-ray systems, this study represents an early evaluation of the safety, image quality and yield of using an ultra-portable X-ray system for active case finding (ACF). We reported operational and radiological performance characteristics and compared image quality between the ultra-portable and two reference systems. Image quality was rated by three human readers and by an artificial intelligence (AI) software. We deployed the ultra-portable X-ray alongside the reference system for community-based ACF and described TB care cascades for each system. The ultra-portable system operated within advertised specifications and radiologic tolerances, except on X-ray capture capacity, which was 58% lower than the reported maximum of 100 exposures per charge. The mean image quality rating from radiologists for the ultra-portable system was significantly lower than the reference (3.71 vs. 3.99, p < 0.001). However, we detected no significant differences in TB abnormality scores using the AI software (p = 0.571), nor in any of the steps along the TB care cascade during our ACF campaign. Despite some shortcomings, ultra-portable X-ray systems have significant potential to improve case detection and equitable access to high-quality TB care.
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Affiliation(s)
- Luan Nguyen Quang Vo
- Friends for International TB Relief, Ha Noi 100000, Vietnam; (A.C.); (T.T.T.D.); (R.F.)
| | - Andrew Codlin
- Friends for International TB Relief, Ha Noi 100000, Vietnam; (A.C.); (T.T.T.D.); (R.F.)
| | - Thuc Doan Ngo
- IRD VN, Ho Chi Minh City 700000, Vietnam; (T.D.N.); (T.P.D.); (H.T.L.M.); (N.T.T.); (G.H.N.)
| | - Thang Phuoc Dao
- IRD VN, Ho Chi Minh City 700000, Vietnam; (T.D.N.); (T.P.D.); (H.T.L.M.); (N.T.T.); (G.H.N.)
| | - Thuy Thi Thu Dong
- Friends for International TB Relief, Ha Noi 100000, Vietnam; (A.C.); (T.T.T.D.); (R.F.)
| | - Huong Thi Lan Mo
- IRD VN, Ho Chi Minh City 700000, Vietnam; (T.D.N.); (T.P.D.); (H.T.L.M.); (N.T.T.); (G.H.N.)
| | - Rachel Forse
- Friends for International TB Relief, Ha Noi 100000, Vietnam; (A.C.); (T.T.T.D.); (R.F.)
| | | | - Cong Van Cung
- National Lung Hospital, Ha Noi 100000, Vietnam; (C.V.C.); (H.B.N.); (N.V.N.)
| | - Hoa Binh Nguyen
- National Lung Hospital, Ha Noi 100000, Vietnam; (C.V.C.); (H.B.N.); (N.V.N.)
| | - Nhung Viet Nguyen
- National Lung Hospital, Ha Noi 100000, Vietnam; (C.V.C.); (H.B.N.); (N.V.N.)
| | | | - Ngan Thi Tran
- IRD VN, Ho Chi Minh City 700000, Vietnam; (T.D.N.); (T.P.D.); (H.T.L.M.); (N.T.T.); (G.H.N.)
| | - Giang Hoai Nguyen
- IRD VN, Ho Chi Minh City 700000, Vietnam; (T.D.N.); (T.P.D.); (H.T.L.M.); (N.T.T.); (G.H.N.)
| | - Zhi Zhen Qin
- Stop TB Partnership, 1218 Geneva, Switzerland; (Z.Z.Q.); (J.C.)
| | - Jacob Creswell
- Stop TB Partnership, 1218 Geneva, Switzerland; (Z.Z.Q.); (J.C.)
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21
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Brusan A, Durmaz FA, Yaman A, Öztürk C. iBEX: Modular Open-Source Software for Digital Radiography. J Digit Imaging 2021; 33:708-721. [PMID: 31845123 DOI: 10.1007/s10278-019-00304-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
A device-independent software package, named iBEX, is developed to accelerate the research and development efforts for X-ray imaging setups such as chest radiography, linear and multidirectional tomography, and dental and skeletal radiography. Its extension mechanism makes the software adaptable for a wide range of digital X-ray imaging hardware combinations and provides capabilities for researchers to develop image processing plug-ins. Independent of the X-ray sensor technology, iBEX could integrate with heterogeneous communication channels of digital detectors. iBEX is a freeware option for preclinical and early clinical testing of radiography devices. It provides tools to calibrate the device, integrate to health information infrastructure, acquire image, store studies on local storage, and send them to Picture Archiving and Communication System (PACS). iBEX is a unique open-source project bringing X-ray imaging devices' software into the scope of the open-source community to reduce the X-ray scanners' research effort, potentially increase the image quality, and cut down the production and testing costs of radiography devices.
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Affiliation(s)
- Altay Brusan
- Institute of Biomedical Engineering, Bogazici University, Kandilli Campus, Feza Gursey Bld., 34684, Cengelkoy-Istanbul, Turkey.
| | - F Aytaç Durmaz
- Institute of Biomedical Engineering, Bogazici University, Kandilli Campus, Feza Gursey Bld., 34684, Cengelkoy-Istanbul, Turkey
| | - Alper Yaman
- Fraunhofer Institute for Manufacturing Engineering and Automation IPA Department of Biomechatronic Systems, Stuttgart, Germany
| | - Cengizhan Öztürk
- Institute of Biomedical Engineering, Bogazici University, Kandilli Campus, Feza Gursey Bld., 34684, Cengelkoy-Istanbul, Turkey
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22
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Junda M, Muller H, Friedrich-Nel H. Local diagnostic reference levels for routine chest X-ray examinations at a public sector hospital in central South Africa. Health SA 2021; 26:1622. [PMID: 34522394 PMCID: PMC8424719 DOI: 10.4102/hsag.v26i0.1622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/23/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Dose optimisation is a radiation protection guideline recommended by the International Commission on Radiological Protection (ICRP) for adherence to the 'as low as reasonably achievable' (ALARA) principle. Diagnostic reference levels (DRLs) are used to optimise patients' radiation protection for diagnostic and interventional procedures and are particularly useful for frequently performed examinations such as chest X-rays. AIM To establish the local diagnostic reference levels (LDRLs) for routine chest X-rays. SETTING Public sector hospital, Northern Cape province, South Africa. METHODS Sixty patients referred for chest X-rays fulfilling the inclusion criteria participated in this study. Patients were ≥ 18 years of age and weighed between 60 kg and 80 kg. Consent for participation was obtained. The entrance skin air kerma (ESAK) was measured by using the indirect method recommended by the International Atomic Energy Agency (IAEA). Statistical software (SAS version 9.2) was used to determine the LDRLs for chest X-rays in three different rooms. In two rooms, computed radiography (CR) was used and the other one was a digital radiography (DR) unit. The LDRL values at the research site were compared with various published international values. RESULTS LDRLs for chest X-rays were established. The CR LDRL value for the posteroanterior (PA) chest projection was higher than the DR (flat panel detector [FPD]) LDRL value. The LDRLs of the PA chest projections were 0.3 mGy for CR and 0.2 mGy for DR. The lateral (LAT) chest projection LDRL value was 0.8 mGy for both CR and DR (FPD) projections. The resultant LDRL between rooms at the research site was 0.3 mGy for PA 0.3 mGy and 0.8 mGy for LAT chest projections. CONCLUSION The LDRLs for chest X-rays established at this research site were lower than internationally reported DRLs. We recommend that LDRLs for routine chest X-rays should be repeated every 3 years, according to the ICRP. CONTRIBUTION Currently, no established or published DRL values prescribed by the Directorate of Radiation Control (DRC) are available in South Africa. The LDRLs established for routine chest X-ray examinations at this research site can serve as a guideline for the establishment of DRL values for other anatomical regions at the research site and other radiology departments in the country.
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Affiliation(s)
- Maurice Junda
- Department of Clinical Sciences, Faculty of Health and Environmental Sciences, Central University of Technology, Bloemfontein, South Africa
| | - Henra Muller
- Department of Clinical Sciences, Faculty of Health and Environmental Sciences, Central University of Technology, Bloemfontein, South Africa
| | - Hesta Friedrich-Nel
- Department of Clinical Sciences, Faculty of Health and Environmental Sciences, Central University of Technology, Bloemfontein, South Africa
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23
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Pereira L, Ferreira MT, Lima AGF, Salata C, Ferreira-Machado SC, Lima I, Morandi V, Magalhães LAG. Biological effects induced by doses of mammographic screening. Phys Med 2021; 87:90-98. [PMID: 34130221 DOI: 10.1016/j.ejmp.2021.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 05/31/2021] [Accepted: 06/04/2021] [Indexed: 10/21/2022] Open
Abstract
PURPOSE Mammography is the diagnostic imaging practice used in screening to detect early lesions suspected of malignancy. It uses a low energy X-ray beam in which a low dose in the order of 2-3 mGy is delivered to patient breast cells. However, it has been speculated that it could lead to significant cell damage, when compared to conventional X-ray. We investigated the biological effects of low doses, with mean glandular doses (MGDs) of 2.5 mGy and 2.5 + 2.5 mGy, on mammary cells in vitro. METHODS We used the non-tumorigenic cell line (MCF-10A) and two tumor cells lines (MCF-7 and MDA-MB-231). Colony formation, apoptosis, and double-strand DNA breaks (DSBs) were quantified. RESULTS The selected MGD regimens did not alter the formation of colonies by any of the cell lines. MCF-7 cells exhibited a markedly increase in apoptosis, 24 h after the single-dose protocol; MCF-10A cells underwent apoptosis only after 72 h, with both irradiation regimens, while MDA-MB-231 cells (highly invasive and metastatic) were not susceptible to apoptosis. The detection of γH2AX histone in the nuclei of irradiated cells showed that the double-dose resulted in increase of DSBs, especially in tumor cell lines. CONCLUSIONS Although the health benefits of early breast screening remain indisputable, our future perspective is to better understand the biological basis for the effects of low dose radiation on breast cells and to investigate if and under what conditions there would be a risky situation in repeated mammography screening, in both asymptomatic and symptomatic women.
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Affiliation(s)
- Leslie Pereira
- Department of Medical Physics, Institute of Radiation Protection and Dosimetry (IRD), Av. Salvador Allende, 3773, Barra da Tijuca, Rio de Janeiro, RJ CEP 22783-127, Brazil; Nuclear Engineering Department (DNC), Federal University of Rio de Janeiro (UFRJ), sala 206, Centro de Tecnologia, Av. Horácio Macedo, 2030, Bloco G, Fundão, Rio de Janeiro, RJ CEP 21941-941, Brazil.
| | - Marcella T Ferreira
- Department of Cell Biology, University of the State of Rio de Janeiro (UERJ), Pavilhão Haroldo Lisboa da Cunha, LabAngio, Rua São Francisco Xavier, 524, Maracanã, Rio de Janeiro, RJ CEP 20550-900, Brazil
| | - Antonio Gilcler F Lima
- Department of Cell Biology, University of the State of Rio de Janeiro (UERJ), Pavilhão Haroldo Lisboa da Cunha, LabAngio, Rua São Francisco Xavier, 524, Maracanã, Rio de Janeiro, RJ CEP 20550-900, Brazil
| | - Camila Salata
- CGMI/DRS, Brazilian National Nuclear Energy Comission (CNEN), Rua General Severiano, 90, Botafogo, Rio de Janeiro, RJ CEP 22290-901, Brazil.
| | - Samara C Ferreira-Machado
- Department of Radiological Sciences (LCR), State University of Rio de Janeiro (UERJ), Pavilhão Haroldo Lisboa da Cunha, Rua São Francisco Xavier, 524, Maracanã, Rio de Janeiro, RJ CEP 20550-900, Brazil; Department of General Biology, Federal Fluminense University, Niterói, RJ CEP 21045-900, Brazil
| | - I Lima
- Nuclear Engineering Department (DNC), Federal University of Rio de Janeiro (UFRJ), sala 206, Centro de Tecnologia, Av. Horácio Macedo, 2030, Bloco G, Fundão, Rio de Janeiro, RJ CEP 21941-941, Brazil.
| | - Verônica Morandi
- Department of Cell Biology, University of the State of Rio de Janeiro (UERJ), Pavilhão Haroldo Lisboa da Cunha, LabAngio, Rua São Francisco Xavier, 524, Maracanã, Rio de Janeiro, RJ CEP 20550-900, Brazil.
| | - Luís A G Magalhães
- Department of Radiological Sciences (LCR), State University of Rio de Janeiro (UERJ), Pavilhão Haroldo Lisboa da Cunha, Rua São Francisco Xavier, 524, Maracanã, Rio de Janeiro, RJ CEP 20550-900, Brazil
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Proper Management of the Clinical Exposure Index Based on Body Thickness Using Dose Optimization Tools in Digital Chest Radiography: A Phantom Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18105203. [PMID: 34068390 PMCID: PMC8153559 DOI: 10.3390/ijerph18105203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/10/2021] [Accepted: 05/12/2021] [Indexed: 11/17/2022]
Abstract
In radiography, the exposure index (EI), as per the International Electrotechnical Commission standard, depends on the incident beam quality and exposure dose to the digital radiography system. Today automatic exposure control (AEC) systems are commonly employed to obtain the optimal image quality. An AEC system can maintain a constant incident exposure dose on the image receptor regardless of the patient thickness. In this study, we investigated the relationship between body thickness, entrance surface dose (ESD), EI, and the exposure indicator (S value) with the aim of using EI as the dose optimization tool in digital chest radiography (posterior-anterior and lateral projection). The exposure condition from the Korean national survey for determining diagnostic reference levels and two digital radiography systems (photostimulable phosphor plate and indirect flat panel detector) were used. As a result, ESD increased as the phantom became thicker with constant exposure indicator, which indicates similar settings to an AEC system, but the EI indicated comparatively constant values without following the tendency of ESD. Therefore, body thickness should be considered under the AEC system for introducing EI as the dose optimization tool in digital chest radiography.
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Notohamiprodjo S, Roeper KM, Treitl KM, Hoberg B, Wanninger F, Verstreepen L, Mueck FG, Maxien D, Fischer F, Peschel O, Wirth S. Image quality is resilient against tube voltage variations in post-mortem skeletal radiography with a digital flat-panel detector. Sci Rep 2021; 11:7701. [PMID: 33833315 PMCID: PMC8032833 DOI: 10.1038/s41598-021-87294-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 03/24/2021] [Indexed: 11/09/2022] Open
Abstract
In recent phantom studies low-contrast detectability was shown to be independent from variations in tube voltage in digital radiography (DR) systems. To investigate the transferability to a clinical setting, the lower extremities of human cadavers were exposed at constant detector doses with different tube voltages in a certain range, as proposed in the phantom studies. Three radiologists independently graded different aspects of image quality (IQ) in a comparative analysis. The grades show no correlation between IQ and kV, which means that the readers were not able to recognize a significant IQ difference at different kV. Signal-to-noise and contrast-to-noise ratios showed no significant differences in IQ despite the kV-setting variations. These findings were observed from a limited kV range setting. Higher kV-settings resulted in lowest patient exposure at constant IQ. These results confirm the potential of DR-systems to contribute to standardization of examination protocols comparable to computed tomography. This may prevent the trend to overexpose. Further investigations in other body regions and other DR-systems are encouraged to determine transferability.
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Affiliation(s)
- S Notohamiprodjo
- Department of Nuclear Medicine, Klinikum Rechts Der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
| | - K M Roeper
- Department of Ophtalmology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
| | - K M Treitl
- Department of Radiology, University Hospital of Munich, LMU Munich, Munich, Germany
| | - B Hoberg
- Agfa HealthCare Germany GmbH, Bonn, Germany
| | - F Wanninger
- Agfa-Gevaert HealthCare GmbH, Munich, Germany
| | | | - F G Mueck
- Department of Radiology, HELIOS Klinikum München West, Munich, Germany
| | - D Maxien
- Radiologie Zentrum München, Munich, Germany
| | - F Fischer
- Institute of Forensic Medicine, LMU Munich, Munich, Germany
| | - O Peschel
- Institute of Forensic Medicine, LMU Munich, Munich, Germany
| | - S Wirth
- Institute of Radiology, Schwarzwald-Baar Klinikum, Villingen-Schwenningen, Germany
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Kimoto N, Hayashi H, Asakawa T, Lee C, Asahara T, Maeda T, Goto S, Kanazawa Y, Katsumata A, Yamamoto S, Okada M. Effective atomic number image determination with an energy-resolving photon-counting detector using polychromatic X-ray attenuation by correcting for the beam hardening effect and detector response. Appl Radiat Isot 2021; 170:109617. [DOI: 10.1016/j.apradiso.2021.109617] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 11/30/2022]
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Lee JJ, Venna AM, McCarthy I, Cilento BG, Demers MG, MacDougall RD, Beaulieu D, Nosrati R, Nelson CP, Kurtz MP. Flat Panel Detector c-Arms Are Associated with Dramatically Reduced Radiation Exposure During Ureteroscopy and Produce Superior Images. J Endourol 2021; 35:789-794. [PMID: 33528298 DOI: 10.1089/end.2020.0974] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: We wished to determine whether newly available flat panel detector (FPD) c-arms were (1) associated with lower radiation dose during ureteroscopy (URS) than conventional image intensifier (CII) c-arms and (2) to compare fluoroscopic image quality between the units. Materials and Methods: We retrospectively reviewed 44 consecutive patients undergoing URS at a pediatric hospital, with c-arms assigned by availability in the operating room. We performed dosimetry experiments using the same c-arms on standard phantoms. Results: Patient and case characteristics did not differ significantly between the two groups of patients. The median dose in the FPD group was less than a quarter of the dose in the CII group, 0.48 [0.42, 0.97] mGy vs 2.2 [1.1, 3.8] mGy, p < 0.0001. The FPD dose remained at less than one-third of the CII dose accounting for any difference in fluoroscopy time, and remained significant in a multivariate model including fluoroscopy time and patient weight (β = 2.4, p = 0.007). Phantom studies showed higher image quality for FPDs at all simulated patient sizes, even at lower radiation doses. Conclusions: This is the first report comparing radiation dose from c-arms of image intensifiers and FPDs in adults or children. Use of an FPD during URS was associated with a substantially decreased absorbed dose for patients while simultaneously improving image quality.
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Affiliation(s)
- Jason J Lee
- Department of Urology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Alyssia M Venna
- Department of Urology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Ian McCarthy
- Department of Urology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Bartley G Cilento
- Department of Urology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Michael G Demers
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Robert D MacDougall
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Danielle Beaulieu
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Reyhaneh Nosrati
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Caleb P Nelson
- Department of Urology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Michael P Kurtz
- Department of Urology, Boston Children's Hospital, Boston, Massachusetts, USA
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Tsalafoutas IA, Tsapaki V, Triantopoulou I. Evaluation of image quality and patient exposure in fluoroscopy using a phantom: Is there any clinical relevance? Eur J Radiol 2021; 138:109607. [PMID: 33667936 DOI: 10.1016/j.ejrad.2021.109607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 02/02/2021] [Accepted: 02/15/2021] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To investigate the impact of X-ray preset acquisition protocol settings on fluoroscopy image quality (IQ) and radiation exposure. MATERIALS & METHODS A quality control (QC) phantom was imaged with a modern digital C-arm system, using various preset fluoroscopy protocols. IQ was assessed using human observers and in-house software for automated evaluation, based on contrast-to-noise ratios of details and their background. Patient radiation exposure was evaluated using the displayed Incident Air-Kerma and Kerma-Area Product values. RESULTS Protocol selection affects radiation exposure by a factor of about 3. IQ evaluation showed that acquisition protocols produce images with quite different characteristics. The visual IQ evaluation method was time consuming and cumbersome. The automated method, utilized the visual IQ evaluation results for calibration of detection thresholds. However, it failed to reproduce these results for all images and details types. In some images, digital image processing created artifacts which affected the pixel value distributions around details in a way that could be handled only by the human vision. CONCLUSION Manufacturers provide many preset protocols designated for specific clinical uses, which have large impact on IQ characteristics and radiation exposure. However, protocol settings' selection rationale is essentially a "black box" for the end user. Though QC phantoms are currently used for IQ evaluation, they are not appropriate for drawing firm conclusions concerning the expected performance of each protocol in clinical practice. Currently, there is no consensus on the optimum technical characteristics of preset protocols for specific procedures. More work is needed in this area.
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Affiliation(s)
- I A Tsalafoutas
- OHS Department, Radiation Safety Section, Hamad Medical Corporation, Doha, Qatar
| | - V Tsapaki
- Medical Physics Unit, Konstantopoulio Hospital, Nea Ionia, Athens, 142 33, Greece.
| | - I Triantopoulou
- Medical Physics Unit, Konstantopoulio Hospital, Nea Ionia, Athens, 142 33, Greece
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Tækker M, Kristjánsdóttir B, Graumann O, Laursen CB, Pietersen PI. Diagnostic accuracy of low-dose and ultra-low-dose CT in detection of chest pathology: a systematic review. Clin Imaging 2021; 74:139-148. [PMID: 33517021 DOI: 10.1016/j.clinimag.2020.12.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/12/2020] [Accepted: 12/31/2020] [Indexed: 02/02/2023]
Abstract
PURPOSE Studies have evaluated imaging modalities with a lower radiation dose than standard-dose CT (SD-CT) for chest examination. This systematic review aimed to summarize evidence on diagnostic accuracy of these modalities - low-dose and ultra-low-dose CT (LD- and ULD-CT) - for chest pathology. METHOD Ovid-MEDLINE, Ovid-EMBASE and the Cochrane Library were systematically searched April 29th-30th, 2019 and screened by two reviewers. Studies on diagnostic accuracy were included if they defined their index tests as 'LD-CT', 'Reduced-dose CT' or 'ULD-CT' and had SD-CT as reference standard. Risk of bias was evaluated on study level using the Quality Assessment of Diagnostic Accuracy Studies-2. A narrative synthesis was conducted to compare the diagnostic accuracy measurements. RESULTS Of the 4257 studies identified, 18 were eligible for inclusion. SD-CT (3.17 ± 1.47 mSv) was used as reference standard in all studies to evaluate diagnostic accuracy of LD- (1.22 ± 0.34 mSv) and ULD-CT (0.22 ± 0.05 mSv), respectively. LD-CT had high sensitivities for detection of bronchiectasis (82-96%), honeycomb (75-100%), and varying sensitivities for nodules (63-99%) and ground glass opacities (GGO) (77-91%). ULD-CT had high sensitivities for GGO (93-100%), pneumothorax (100%), consolidations (90-100%), and varying sensitivities for nodules (60-100%) and emphysema (65-90%). CONCLUSION The included studies found LD-CT to have high diagnostic accuracy in detection of honeycombing and bronchiectasis and ULD-CT to have high diagnostic accuracy for pneumothorax, consolidations and GGO. Summarizing evidence on diagnostic accuracy of LD- and ULD-CT for other chest pathology was not possible due to varying outcome measures, lack of precision estimates and heterogeneous study design and methodology.
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Affiliation(s)
- Maria Tækker
- Research and Innovation Unit of Radiology, University of Southern Denmark, Kloevervaenget 10, entrance 112, 2nd floor, 5000 Odense C, Denmark; Department of Radiology, Odense University Hospital, Kloevervaenget 47, 5000 Odense C, Denmark.
| | - Björg Kristjánsdóttir
- Research and Innovation Unit of Radiology, University of Southern Denmark, Kloevervaenget 10, entrance 112, 2nd floor, 5000 Odense C, Denmark; Department of Radiology, Odense University Hospital, Kloevervaenget 47, 5000 Odense C, Denmark.
| | - Ole Graumann
- Research and Innovation Unit of Radiology, University of Southern Denmark, Kloevervaenget 10, entrance 112, 2nd floor, 5000 Odense C, Denmark; Department of Radiology, Odense University Hospital, Kloevervaenget 47, 5000 Odense C, Denmark.
| | - Christian B Laursen
- Department of Respiratory Medicine, Odense University Hospital, Kloevervaenget 2, entrance 87-88, 5000 Odense C, Denmark; Department of Clinical Research, Faculty of Health Science, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark.
| | - Pia I Pietersen
- Department of Respiratory Medicine, Odense University Hospital, Kloevervaenget 2, entrance 87-88, 5000 Odense C, Denmark; Regional Center for Technical Simulation, Odense University Hospital, Region of Southern Denmark, J. B. Winsløws Vej 4, 5000 Odense C, Denmark.
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Hata A, Yamada Y, Tanaka R, Nishino M, Hida T, Hino T, Ueyama M, Yanagawa M, Kamitani T, Kurosaki A, Sanada S, Jinzaki M, Ishigami K, Tomiyama N, Honda H, Kudoh S, Hatabu H. Dynamic Chest X-Ray Using a Flat-Panel Detector System: Technique and Applications. Korean J Radiol 2020; 22:634-651. [PMID: 33289365 PMCID: PMC8005348 DOI: 10.3348/kjr.2020.1136] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/21/2020] [Accepted: 10/26/2020] [Indexed: 12/13/2022] Open
Abstract
Dynamic X-ray (DXR) is a functional imaging technique that uses sequential images obtained by a flat-panel detector (FPD). This article aims to describe the mechanism of DXR and the analysis methods used as well as review the clinical evidence for its use. DXR analyzes dynamic changes on the basis of X-ray translucency and can be used for analysis of diaphragmatic kinetics, ventilation, and lung perfusion. It offers many advantages such as a high temporal resolution and flexibility in body positioning. Many clinical studies have reported the feasibility of DXR and its characteristic findings in pulmonary diseases. DXR may serve as an alternative to pulmonary function tests in patients requiring contact inhibition, including patients with suspected or confirmed coronavirus disease 2019 or other infectious diseases. Thus, DXR has a great potential to play an important role in the clinical setting. Further investigations are needed to utilize DXR more effectively and to establish it as a valuable diagnostic tool.
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Affiliation(s)
- Akinori Hata
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Yoshitake Yamada
- Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan
| | - Rie Tanaka
- Department of Radiological Technology, School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Ishikawa, Japan
| | - Mizuki Nishino
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Tomoyuki Hida
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takuya Hino
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Masako Ueyama
- Department of Health Care, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Masahiro Yanagawa
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Takeshi Kamitani
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Atsuko Kurosaki
- Department of Diagnostic Radiology, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Shigeru Sanada
- Clinical Engineering, Komatsu University, Ishikawa, Japan
| | - Masahiro Jinzaki
- Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan
| | - Kousei Ishigami
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Noriyuki Tomiyama
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hiroshi Honda
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Shoji Kudoh
- Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Hiroto Hatabu
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Datta A, Zhong Z, Motakef S. A new generation of direct X-ray detectors for medical and synchrotron imaging applications. Sci Rep 2020; 10:20097. [PMID: 33208782 PMCID: PMC7676260 DOI: 10.1038/s41598-020-76647-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 10/30/2020] [Indexed: 11/24/2022] Open
Abstract
Large-area X-ray imaging is one of the most widely used imaging modalities that spans several scientific and technological fields. Currently, the direct X-ray conversion materials that are being commercially used for large-area (> 8 cm × 4 cm without tiling) flat panel applications, such as amorphous selenium (a-Se), have usable sensitivities of up to only 30 keV. Although there have been many promising candidates (such as polycrystalline HgI2 and CdTe), none of the semiconductors were able to assuage the requirement for high energy (> 40 keV) large-area X-ray imaging applications due to inadequate cost, manufacturability, and long-term performance metrics. In this study, we successfully demonstrate the potential of the hybrid Methylammonium lead iodide (MAPbI3) perovskite-based semiconductor detectors in satisfying all the requirements for its successful commercialization in synchrotron and medical imaging. This new generation of hybrid detectors demonstrates low dark current under electric fields needed for high sensitivity X-ray imaging applications. The detectors have a linear response to X-ray energy and applied bias, no polarization effects at a moderate bias, and signal stability over long usage durations. Also, these detectors have demonstrated a stable detection response under BNL's National Synchrotron Light Source II (NSLS-II) 70 keV monochromatic synchrotron beamline.
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Affiliation(s)
- A Datta
- CapeSym, Inc., Natick, MA, 01760, USA.
| | - Z Zhong
- National Synchrotron Light Source I & II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - S Motakef
- CapeSym, Inc., Natick, MA, 01760, USA
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Tsapaki V. Radiation dose optimization in diagnostic and interventional radiology: Current issues and future perspectives. Phys Med 2020; 79:16-21. [PMID: 33035737 DOI: 10.1016/j.ejmp.2020.09.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 09/04/2020] [Accepted: 09/19/2020] [Indexed: 12/16/2022] Open
Affiliation(s)
- Virginia Tsapaki
- Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Austria.
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Psichis K, Kalyvas N, Kandarakis I, Panayiotakis G. MTF of columnar phosphors with a homogenous part: an analytical approach. Med Biol Eng Comput 2020; 58:2551-2565. [PMID: 32815028 DOI: 10.1007/s11517-020-02243-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 07/30/2020] [Indexed: 11/26/2022]
Abstract
A method for the theoretical estimation of the MTF of columnar phosphors with a homogeneous part at the end used in X-ray imaging has been developed. This method considers the light transport inside the scintillator through an analytical modelling, the optical photon beams distribution on the scintillator-optical sensor interface, and uses the definition of the PSF and a Gauss fitted LSF to estimate the MTF of an indirect detector. This method was applied to a columnar CsI:Tl scintillator and validated against experimental results found in literature, and a good agreement was observed. It was found that, by increasing the pixel size of the optical detector and the thickness of the scintillator, the MTF decreased as expected. This method may be used in evaluating the performance of the columnar phosphors used in medical imaging, given their physical and geometrical characteristics.Graphical abstract (a) Side view of a part of the scintillator where five crystal columns with homogeneous ends attached to an optical sensor is shown. (b) Propagation of two random optical photon beams emitted from point K with different angles of emission is shown. All the symbols are explained analytically in the text.
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Affiliation(s)
- Konstantinos Psichis
- Department of Medical Physics, School of Medicine, University of Patras, 26500, Patras, Greece
| | - Nektarios Kalyvas
- Department of Biomedical Engineering, University of West Attica, 12210, Athens, Greece
| | - Ioannis Kandarakis
- Department of Biomedical Engineering, University of West Attica, 12210, Athens, Greece
| | - George Panayiotakis
- Department of Medical Physics, School of Medicine, University of Patras, 26500, Patras, Greece.
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Bellizzi A, Zarb F. Optimisation of the lateral lumbar spine projection using an air-gap technique. Radiography (Lond) 2020; 26:227-233. [PMID: 32052755 DOI: 10.1016/j.radi.2019.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/22/2019] [Accepted: 12/10/2019] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Lumbar spine radiography is considered as having a high radiation dose compared to other planar radiography examinations. The aim of this study was to investigate the feasibility of replacing an antiscatter grid with an air gap technique to achieve dose reduction for lateral lumbar spine radiography while maintaining image quality on a direct digital radiography (DDR) system. METHODS In phase 1, an experimental study using an anthropomorphic phantom identified the optimal airgap technique. In phase 2, lateral projections of the lumbar spine were performed on 50 patients randomly assigned equally into a control group (using the antiscatter grid) and an experimental group (using the airgap technique). The dose area product (DAP) was recorded, keeping other variables constant. Image quality evaluation was performed by 5 radiologists performing Absolute Visual Grading Analysis (VGA) using an image quality score tool, with resultant scores analysed using Visual Grading Characteristics (VGC). RESULTS A 10 cm airgap in conjunction with a source to image distance (SID) of 121 cm was found as the optimal airgap technique. The clinical application of this technique resulted in a statistically significant (p < 0.05) reduction in DAP of 72%. Image quality scores were higher for the antiscatter grid but variation between the two techniques was not significant (p > 0.05). CONCLUSION Replacing the antiscatter grid with an airgap technique in lateral lumbar spine digital radiography, provides a significant dose reduction whilst still maintaining diagnostic image quality. IMPLICATIONS FOR PRACTICE The airgap technique is a simple and easy technique to implement and radiographers should find no difficulties in applying it, as It involves no additional cost and no additional equipment.
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Affiliation(s)
- A Bellizzi
- Department of Radiography, Faculty of Health Sciences, University of Malta, Msida, Malta.
| | - F Zarb
- Department of Radiography, Faculty of Health Sciences, University of Malta, Msida, Malta.
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Shi L, Lu M, Bennett NR, Shapiro E, Zhang J, Colbeth R, Star-Lack J, Wang AS. Characterization and potential applications of a dual-layer flat-panel detector. Med Phys 2020; 47:3332-3343. [PMID: 32347561 PMCID: PMC7429359 DOI: 10.1002/mp.14211] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/02/2020] [Accepted: 04/21/2020] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Dual-energy (DE) x-ray imaging has many clinical applications in radiography, fluoroscopy, and CT. This work characterizes a prototype dual-layer (DL) flat-panel detector (FPD) and investigates its DE imaging capabilities for applications in two-dimensional (2D) radiography/fluoroscopy and quantitative three-dimensional (3D) cone-beam CT. Unlike other DE methods like kV switching, a DL FPD obtains DE images from a single exposure, making it robust against patient and system motion. METHODS The DL FPD consists of a top layer with a 200 µm-thick CsI scintillator coupled to an amorphous silicon (aSi) FPD of 150 µm pixel size and a bottom layer with a 550 µm thick CsI scintillator coupled to an identical aSi FPD. The two layers are separated by a 1-mm Cu filter to increase spectral separation. Images (43 × 43 cm2 active area) can be readout in 2 × 2 binning mode (300 µm pixels) at up to 15 frames per second. Detector performance was first characterized by measuring the MTF, NPS, and DQE for the top and bottom layers. For 2D applications, a qualitative study was conducted using an anthropomorphic thorax phantom containing a porcine heart with barium-filled coronary arteries (similar to iodine). Additionally, fluoroscopic lung tumor tracking was investigated by superimposing a moving tumor phantom on the thorax phantom. Tracking accuracies of single-energy (SE) and DE fluoroscopy were compared against the ground truth motion of the tumor. For 3D quantitative imaging, a phantom containing water, iodine, and calcium inserts was used to evaluate overall DE material decomposition capabilities. Virtual monoenergetic (VM) images ranging from 40 to 100 keV were generated, and the optimal VM image energy which achieved the highest image uniformity and maximum contrast-to-noise ratio (CNR) was determined. RESULTS The spatial resolution of the top layer was substantially higher than that of the bottom layer (top layer 50% MTF = 2.2 mm-1 , bottom layer = 1.2 mm-1 ). A substantial increase in NNPS and reduction in DQE were observed for the bottom layer mainly due to photon loss within the top layer and Cu filter. For 2D radiographic and fluoroscopic applications, the DL FPD was capable of generating high-quality material-specific images separating soft tissue from bone and barium. For lung tumor tracking, DE fluoroscopy yielded more accurate results than SE fluoroscopy, with an average reduction in the root mean square error (RMSE) of over 10×. For the DE-CBCT studies, accurate basis material decompositions were obtained. The estimated material densities were 294.68 ± 17.41 and 92.14 ± 15.61 mg/ml for the 300 and 100 mg/ml calcium inserts, respectively, and 8.93 ± 1.45, 4.72 ± 1.44, and 2.11 ± 1.32 mg/ml for the 10, 5, and 2 mg/ml iodine inserts, respectively, with an average error of less than 5%. The optimal VM image energy was found to be 60 keV. CONCLUSIONS We characterized a prototype DL FPD and demonstrated its ability to perform accurate single-exposure DE radiography/fluoroscopy and DE-CBCT. The merits of the DL detector approach include superior spatial and temporal registration between its constituent images, and less complicated acquisition sequences.
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Affiliation(s)
- Linxi Shi
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - Minghui Lu
- Varex Imaging Corporation, San Jose, CA 95134, USA
| | - N. Robert Bennett
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | | | - Jin Zhang
- Varex Imaging Corporation, San Jose, CA 95134, USA
| | | | | | - Adam S. Wang
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
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McGuigan MB, Theodorakou C, Duncan HF, Davies J, Sengupta A, Horner K. An investigation into dose optimisation for imaging root canal anatomy using cone beam CT. Dentomaxillofac Radiol 2020; 49:20200072. [PMID: 32464075 DOI: 10.1259/dmfr.20200072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To identify a dose as low as diagnostically acceptable and a threshold level of image quality for cone beam CT (CBCT) imaging root canals, using maxillary first molar (M1M) second mesiobuccal (MB2) canals of varying complexity for two CBCT scanners. METHODS Dose-area product (DAP) and contrast-to-noise ratio (CNR) were measured for two scanners at a range of exposure parameters. Subjective-image-quality assessment at the same exposures was performed for three M1Ms of varying MB2 complexity, positioned in an anthropomorphic phantom. Nine raters (three endodontists, three dental radiologists and three junior staff) assessed canal visibility, using a 5-point confidence scale rating. RESULTS Identification of simple-moderate MB2 canal complexity was achieved at a range of protocols, with DAP values of ≥209.3 and ≥203.2 mGy cm² and CNRs of 3 and 7.6 for Promax®3D and Accuitomo-F170® respectively. For complex canal anatomy, target subjective image quality was not achieved, even at the highest DAP values for both scanners. Junior staff classified significantly more images as undiagnostic compared with senior staff (p = 0.043). CONCLUSIONS In this first study to address optimisation of CBCT imaging of root canal anatomy, a similar threshold dose for both scanners was identified for M1Ms with simple-moderate MB2 canal complexity. Increasing dose to enhance visualisation of more complex canal anatomy was ineffective. Selection of standard protocols (while avoiding lower kV/mA protocols) instead of high-resolution scans was a practical means of reducing patient dose. CNR is not a transferable measure of image quality.
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Affiliation(s)
| | - Christie Theodorakou
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
| | - Henry F Duncan
- Dublin Dental University Hospital, Trinity College Dublin, Dublin, Ireland
| | - Jonathan Davies
- Guy's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Anita Sengupta
- Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester, UK
| | - Keith Horner
- Dublin Dental University Hospital, Trinity College Dublin, Dublin, Ireland.,Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester, UK
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Nshimirimana R, Abraham A, Nothnagel G, Engelbrecht A. X-Ray and Neutron Radiography System Optimization by Means of a Multiobjective Approach and a Simplified Ray-Tracing Method. NUCL TECHNOL 2020. [DOI: 10.1080/00295450.2020.1740562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Robert Nshimirimana
- University of Pretoria, Department of Computer Science, Pretoria, South Africa
- South African Nuclear Energy Corporation SOC Ltd., Radiation Science Department, Brits Magisterial District, South Africa
| | - Ajith Abraham
- Machine Intelligence Research Labs (MIR Labs), Scientific Network for Innovation and Research Excellence, Auburn, Washington
| | - Gawie Nothnagel
- South African Nuclear Energy Corporation SOC Ltd., Radiation Science Department, Brits Magisterial District, South Africa
| | - Andries Engelbrecht
- University of Stellenbosch, Department of Industrial Engineering, Stellenbosch, South Africa
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Abiola GO, Sheth NM, Zbijewski W, Jacobson MW, Bailey C, Filtes J, Kleinszig G, Vogt SK, Soellradl S, Bialkowski J, Anderson WS, Siewerdsen JH, Weiss CR. Evaluation of image quality and task performance for a mobile C-arm with a complementary metal-oxide semiconductor detector. J Med Imaging (Bellingham) 2020; 7:015501. [PMID: 32016135 DOI: 10.1117/1.jmi.7.1.015501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/26/2019] [Indexed: 11/14/2022] Open
Abstract
We assessed interventional radiologists' task-based image quality preferences for two- and three-dimensional images obtained with a complementary metal-oxide semiconductor (CMOS) flat-panel detector versus a hydrogenated amorphous silicon (a-Si:H) flat-panel detector. CMOS and a-Si:H detectors were implemented on identical mobile C-arms to acquire radiographic, fluoroscopic, and cone-beam computed tomography (CBCT) images of cadavers undergoing simulated interventional procedures using low- and high-dose settings. Images from both systems were displayed side by side on calibrated, diagnostic-quality displays, and three interventional radiologists evaluated task performance relevant to each image and ranked their preferences based on visibility of pertinent anatomy and interventional devices. Overall, CMOS images were preferred in fluoroscopy ( p = 0.002 ) and CBCT ( p = 0.004 ), at low-dose settings ( p = 0.001 ), and for tasks associated with high levels of spatial resolution [e.g., fine anatomical details ( p = 0.006 ) and assessment of interventional devices ( p = 0.015 )]. No significant difference was found for fluoroscopic imaging tasks emphasizing temporal resolution ( p = 0.072 ), for radiography tasks ( p = 0.825 ), when using high-dose settings ( p = 0.360 ), or tasks involving general anatomy ( p = 0.174 ). The image quality preferences are consistent with reported technical advantages of CMOS regarding finer pixel size and reduced electronic noise.
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Affiliation(s)
- Godwin O Abiola
- Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
| | - Niral M Sheth
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
| | - Wojciech Zbijewski
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
| | - Matthew W Jacobson
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
| | - Christopher Bailey
- The Johns Hopkins University School of Medicine, Department of Radiology and Radiologic Science, Baltimore, Maryland, United States
| | - John Filtes
- Columbia University Medical Center, New York, New York, United States
| | | | | | | | | | - William S Anderson
- The Johns Hopkins University School of Medicine, Department of Neurosurgery, Baltimore, Maryland, United States
| | - Jeffrey H Siewerdsen
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States.,The Johns Hopkins University School of Medicine, Department of Radiology and Radiologic Science, Baltimore, Maryland, United States.,The Johns Hopkins University School of Medicine, Department of Neurosurgery, Baltimore, Maryland, United States
| | - Clifford R Weiss
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States.,The Johns Hopkins University School of Medicine, Department of Radiology and Radiologic Science, Baltimore, Maryland, United States
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Kang H, Lee ES, Park HJ, Park BK, Park JY, Suh SW. Abdominal Digital Radiography with a Novel Post-Processing Technique: Phantom and Patient Studies. JOURNAL OF THE KOREAN SOCIETY OF RADIOLOGY 2020; 81:920-932. [PMID: 36238179 PMCID: PMC9432201 DOI: 10.3348/jksr.2020.81.4.920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 10/09/2019] [Accepted: 10/18/2019] [Indexed: 11/15/2022]
Abstract
Purpose Materials and Methods Results Conclusion
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Affiliation(s)
- Hyein Kang
- Department of Radiology, Chung-Ang University Hospital, Seoul, Korea
| | - Eun Sun Lee
- Department of Radiology, Chung-Ang University Hospital, Seoul, Korea
- College of Medicine, Chung-Ang University, Seoul, Korea
| | - Hyun Jeong Park
- Department of Radiology, Chung-Ang University Hospital, Seoul, Korea
- College of Medicine, Chung-Ang University, Seoul, Korea
| | - Byung Kwan Park
- College of Medicine, Chung-Ang University, Seoul, Korea
- Department of Surgery, Chung-Ang University Hospital, Seoul, Korea
| | - Jae Yong Park
- College of Medicine, Chung-Ang University, Seoul, Korea
- Department of Internal Medicine, Chung-Ang University Hospital, Seoul, Korea
| | - Suk-Won Suh
- College of Medicine, Chung-Ang University, Seoul, Korea
- Department of Surgery, Chung-Ang University Hospital, Seoul, Korea
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Alsleem H, Davidson R, Al‐Dhafiri B, Alsleem R, Ameer H. Evaluation of radiographers' knowledge and attitudes of image quality optimisation in paediatric digital radiography in Saudi Arabia and Australia: a survey-based study. J Med Radiat Sci 2019; 66:229-237. [PMID: 31697039 PMCID: PMC6920681 DOI: 10.1002/jmrs.366] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 09/23/2019] [Accepted: 10/02/2019] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION Digital radiography (DR) systems enable radiographers to reduce the radiation dose to patients while maintaining optimised image quality. However, concerns still exist about paediatric patients who may be exposed to an increased level of radiation dose which is not needed for clinical practice. The purpose of this study was to evaluate the knowledge, awareness and attitudes, in terms of image quality optimisation of radiographers undertaking paediatric DR in Australia and Saudi Arabia. METHODS A survey-based study was devised and distributed to radiographers from Australia and Saudi Arabia. Questions focused on Australian and Saudi Arabian radiographers' knowledge and attitude of paediatric DR examinations. RESULTS There were 376 participants who responded to the survey from both countries. A major finding showed that most participants lack knowledge in the area of paediatric DR examinations. Most participants from Australia had received no formal training in paediatric digital radiography (79%), whereas nearly half of the participants from Saudi Arabia received no training (45%). Approximately three out of four radiographers from both countries believed that when using DR they did not need to change the way they collimate the beam as DR images can be cropped using post-processing methods. CONCLUSION The finding of this study demonstrates that radiographers from both countries should improve their understanding and clinical use of DR in paediatric imaging. More education and training for both students and clinicians is needed to enhance radiographer performance in digital radiography and improve their clinical practices.
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Affiliation(s)
- Haney Alsleem
- Imam Abdulrahman Bin Faisal UniversityDammamSaudi Arabia
- University of CanberraCanberraAustralia
| | | | | | | | - Hussain Ameer
- Imam Abdulrahman Bin Faisal UniversityDammamSaudi Arabia
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Steffensen C, Trypis G, Mander GTW, Munn Z. Effectiveness of adjusting radiographic technique parameters on image quality in direct digital radiography: a systematic review protocol. JBI DATABASE OF SYSTEMATIC REVIEWS AND IMPLEMENTATION REPORTS 2019; 17:2165-2173. [PMID: 31305289 DOI: 10.11124/jbisrir-2017-003888] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE The purpose of this review is to investigate the effectiveness of adjusting radiographic technique parameters on image quality of projectional radiographs acquired on a direct digital radiography system. INTRODUCTION Projectional radiography performed with direct digital detectors is now commonplace in many medical imaging departments across the world. While the acquisition technology has advanced, it appears that many sites have not optimized their radiographic technique factors for this new technology. The aim of this review is to uncover evidence to support the continued use of these traditional technique parameters or to suggest changes in clinical practice that would produce optimized results. INCLUSION CRITERIA The review will consider studies that include projectional radiographs acquired on a direct digital radiography system of the axial and appendicular skeleton. Only studies that investigate a human subject (living or post-mortem), or an anthropomorphic phantom will be included. Studies that directly investigate the effect of changing a technique parameter on the resultant image quality and the effect on patient dose will be included. METHODS A comprehensive search of both published and unpublished literature will be performed to uncover studies meeting the inclusion criteria. Studies will be screened for inclusion by two reviewers and disagreements resolved through discussion or with a third reviewer. Studies included in final analysis will be critically appraised for methodological quality. Data will be extracted by a single reviewer and checked by the author team for accuracy. Statistical meta-analysis and subgroup analyses will be performed as appropriate, and a Summary of Findings created. SYSTEMATIC REVIEW REGISTRATION NUMBER PROSPERO CRD42019137806.
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Affiliation(s)
- Caitlin Steffensen
- Philips Australia and New Zealand, Murrarie, Australia
- Joanna Briggs Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
| | - Gregory Trypis
- Department of Medical Imaging, Sunshine Coast University Hospital, Birtinya, Australia
| | - Gordon T W Mander
- Joanna Briggs Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
- Department of Medical Imaging, Toowoomba Hospital, Toowoomba, Australia
| | - Zachary Munn
- Joanna Briggs Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
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Kawashima H, Ichikawa K, Hanaoka S, Matsubara K. Optimizing image quality using automatic exposure control based on the signal-difference-to-noise ratio: a phantom study. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2019; 42:803-810. [PMID: 31396856 DOI: 10.1007/s13246-019-00784-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 10/26/2022]
Abstract
This study proposes to adjust the sensitivity of automatic exposure control (AEC) for achieving consistent image quality over a range of subject thicknesses in abdominal radiography simulations. The relation between image quality and subject thickness was investigated using a digital radiography system with 10-, 15-, 20-, and 25-cm-thick acrylic phantom. Simple pixel signal-to-noise ratio (SNR) was measured to check the default AEC accuracy for each thickness, and image quality was evaluated using the signal-difference-to-noise ratio (SDNR) with an additional acrylic plate and bone-equivalent material. Based on the figure of merit theory, dose ratios to obtain constant image quality regardless of the subject thickness were calculated from SDNR results. The AEC setup was manually modified using this dose ratio, and visibility was examined using a CDRAD 2.0 contrast-detail analysis phantom. Moreover, the entrance surface dose (ESD) was estimated as an index of exposure dose using exposure parameters. The default AEC setup provided a constant simple pixel SNR for each subject thickness with a high accuracy. SDNRs decreased with an increase in the subject thickness. The calculated dose ratios relative to the results for 20 cm thickness were 0.424, 0.647, and 1.43 for 10, 15 and 25 cm, respectively, and a > 25% decrease in ESD was observed for smaller patients. CDRAD analysis using the modified AEC setup showed almost identical visibility for each thickness. Adjusting the sensitivity of AEC according to subject thickness can contribute toward the optimization of the exposure condition.
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Affiliation(s)
- Hiroki Kawashima
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 920-0942, Japan.
| | - Katsuhiro Ichikawa
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 920-0942, Japan
| | - Shinsuke Hanaoka
- Radiology Division, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, 920-8641, Japan
| | - Kosuke Matsubara
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 920-0942, Japan
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The impact of image processing algorithms on digital radiography of patients with metalic hip implants. Phys Med 2019; 64:238-244. [DOI: 10.1016/j.ejmp.2019.07.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 05/25/2019] [Accepted: 07/17/2019] [Indexed: 11/17/2022] Open
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Needle-based storage-phosphor detector radiography is superior to a conventional powder-based storage phosphor detector and a high-resolution screen-film system in small patients (budgerigars and mice). Sci Rep 2019; 9:10057. [PMID: 31296929 PMCID: PMC6624299 DOI: 10.1038/s41598-019-46546-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 07/01/2019] [Indexed: 11/09/2022] Open
Abstract
This method comparison study used radiographs of 20 mice and 20 budgerigars to investigate comparability between computed radiography (CR) and high-resolution screen-film systems and study the effects of reduced radiation doses on image quality of digital radiographs of small patients. Exposure settings used with the mammography screen-film system (SF) were taken as baseline settings. A powder-based storage-phosphor system (CRP) and a needle-based storage-phosphor system (CRN) were used with the same settings (D/100%) and half the detector dose (D/50%). Using a scoring system four reviewers assessed five criteria per species covering soft tissue and bone structures. Results were evaluated for differences between reviewers (interobserver variability), systems and settings (intersystem variability, using visual grading characteristic analysis). Correlations were significant (p ≤ 0.05) for interobserver variability in 86.7% of the cases. Correlation coefficients ranged from 0.206 to 0.772. For mice and budgerigars, the CRN system was rated as superior to the SF and CRP system for most criteria, being significant in two cases each. Comparing the SF and CRP system, the conventional method scored higher for all criteria, in one case significantly. For both species and both digital systems, dose reduction to 50% resulted in significantly worse scores for most criteria. In summary, the needle-based storage-phosphor technique proved to be superior compared to the conventional storage-phosphor and mammography screen-film system. Needle-based detector systems are suitable substitutes for high-resolution screen–film systems when performing diagnostic imaging of small patients. Dose reduction to 50% of the corresponding dose needed in high-resolution film-screen systems cannot be recommended.
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Campbell S, Morton D, Grobler A. Transitioning from analogue to digital imaging: Challenges of South African analogue-trained radiographers. Radiography (Lond) 2019; 25:e39-e44. [DOI: 10.1016/j.radi.2018.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 08/07/2018] [Accepted: 10/04/2018] [Indexed: 11/17/2022]
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Optimal beam quality for chest flat panel detector system: realistic phantom study. Eur Radiol 2019; 29:4538-4543. [PMID: 30737566 DOI: 10.1007/s00330-019-5998-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 12/09/2018] [Accepted: 01/04/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVE To investigate optimal beam quality for chest flat panel detector (FPD) system by semi-quantitatively assessment using a realistic lung phantom. MATERIALS AND METHODS Chest FPD radiographs were obtained on a realistic lung phantom with simulated lung opacities using various X-ray tube voltage levels (90-140 kV) with/without copper filter. Entrance skin dose was set to maintain identical for all images (0.1 mGy). Three chest radiologists unaware of the exposure settings independently evaluated the image quality of each simulated opacity and normal structure using a 5-point scale (+ 2: clearly superior to the standard; + 1: slightly superior to the standard; 0: equal to the standard; - 1: slightly inferior to the standard; - 2: clearly inferior to the standard). The traditional FPD image obtained at a tube voltage of 120 kV was used as the standard. The scores of image quality were statistically compared using the Wilcoxon rank test with Bonferroni correction. RESULTS FPD images using 90-kV shot with copper filter were superior to the traditional 120-kV shot without filter with respect to the visibility of vertebra, pulmonary vessels, and nodules overlapping diaphragm and heart (p < 0.05). There was no significant difference with respect to the visibility of all other simulated lung opacities (lung nodules except for overlying diaphragm/heart and honeycomb opacity) between each tube voltage level with/without copper filter and the traditional 120-kV shot without filter. CONCLUSION Image quality of FPD images using 90 kV with copper filtration is superior to that using standard tube voltage when dose is identical. KEY POINTS • FPD image quality using 90 kV with filter is superior to that using traditional beam. • Ninety-kilovolt shot with copper filter may be suitable for chest FPD image. • Clinical study dealing with chest FPD beam optimization would be warranted.
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Na ER, Aljawad H, Lee KM, Hwang HS. A comparative study of the reproducibility of landmark identification on posteroanterior and anteroposterior cephalograms generated from cone-beam computed tomography scans. Korean J Orthod 2018; 49:41-48. [PMID: 30603624 PMCID: PMC6306316 DOI: 10.4041/kjod.2019.49.1.41] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/22/2018] [Accepted: 07/18/2018] [Indexed: 11/10/2022] Open
Abstract
Objective This in-vivo study aimed to compare landmark identification errors in anteroposterior (AP) and posteroanterior (PA) cephalograms generated from cone-beam computed tomography (CBCT) scan data in order to examine the feasibility of using AP cephalograms in clinical settings. Methods AP and PA cephalograms were generated from CBCT scans obtained from 25 adults. Four experienced and four inexperienced examiners were selected depending on their experience levels in analyzing frontal cephalograms. They identified six cephalometric landmarks on AP and PA cephalograms. The errors incurred in positioning the cephalometric landmarks on the AP and PA cephalograms were calculated by using the straight-line distance and the horizontal and vertical components as parameters. Results Comparison of the landmark identification errors in CBCT-generated frontal cephalograms revealed that landmark-dependent differences were greater than experience- or projection-dependent differences. Comparisons of landmark identification errors in the horizontal and vertical directions revealed larger errors in identification of the crista galli and anterior nasal spine in the vertical direction and the menton in the horizontal direction, in comparison with the other landmarks. Comparison of landmark identification errors between the AP and PA projections in CBCT-generated images revealed a slightly higher error rate in the AP projections, with no inter-examiner differences. Statistical testing of the differences in landmark identification errors between AP and PA cephalograms showed no statistically significant differences for all landmarks. Conclusions The reproducibility of CBCT-generated AP cephalograms is comparable to that of PA cephalograms; therefore, AP cephalograms can be generated reliably from CBCT scan data in clinical settings.
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Affiliation(s)
- Eui-Ri Na
- Department of Periodontology, School of Dentistry, Chonnam National University, Gwangju, Korea
| | - Hussein Aljawad
- Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea
| | - Kyung-Min Lee
- Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea
| | - Hyeon-Shik Hwang
- Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea
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Direct Thermal Growth of Large Scale Cl-doped CdTe Film for Low Voltage High Resolution X-ray Image Sensor. Sci Rep 2018; 8:14810. [PMID: 30287874 PMCID: PMC6172199 DOI: 10.1038/s41598-018-33240-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 09/20/2018] [Indexed: 11/28/2022] Open
Abstract
Polycrystalline cadmium telluride (CdTe) X-ray photodetector with advanced performance was fabricated in a Schottky diode form by direct thermal deposition (evaporation) on pixelized complementary metal oxide semiconductor (CMOS) readout panel. Our CdTe X-ray detector shows such a variety of benefits as relatively low process temperature, low cost, low operation voltage less than 40 V, and higher sensitivity and spatial resolution than those of commercial a-Se detectors. CdTe has cubic Zinc Blende structure and maintains p-type conduction after growth in general. For low voltage operation, we succeeded in Cl doping at all stage of CdTe film deposition, and as a result, hole concentration of p-type CdTe was reduced to ~1012 cm−3 from ~1015 cm−3, and such concentration reduction could enable our Schottky diode with Ti electrode to operate at a reverse bias of less than 40 V. Our CdTe Schottky diode/CMOS pixel array as a direct conversion type imager demonstrates much higher resolution X-ray imaging in 7 × 9 cm2 large scale than that of CsI/CMOS array, an indirect conversion imager. To our limited knowledge, our results on polycrystalline CdTe Schottky diode/CMOS array would be very novel as a first demonstration of active pixel sensor system equipped with directly deposited large scale X-ray detector.
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Missrie I, Hochhegger B, Zanon M, Capobianco J, César de Macedo Neto A, Maciel RP, Antunes VB, de Figueiredo CM, Szarf G, Meirelles G. Small low-risk pulmonary nodules on chest digital radiography: can we predict whether the nodule is benign? Clin Radiol 2018; 73:902-906. [PMID: 29980325 DOI: 10.1016/j.crad.2018.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 06/04/2018] [Indexed: 12/11/2022]
Abstract
AIM To evaluate digital chest radiography (CR) performance compared to computed tomography (CT) for characterising small low-risk pulmonary nodules detected incidentally in non-oncological patients. A second aim was to assess the prevalence of calcification and possible false-positive findings mimicking nodules. MATERIALS AND METHODS Two hundred and seven patients who presented with a pulmonary nodule on CR and underwent CT were included prospectively. Nine radiologists blinded to the CT images reviewed the CRs assessing for the presence of nodules. Afterwards, the same radiologists evaluated the corresponding CT for the presence of nodules, dimensions, and calcification. If the nodule was not present on CT, it was considered a false-positive finding, and possible confounding factors on CR were investigated. RESULTS Among all 213 nodules seen on CR, 32.4% were revealed to be false-positive findings on CT, mostly due to images formed by vessels (53.6%), osseous aetiologies (30.4%), and skin lesions (13%). Most nodules <6 mm detected on radiographies had benign calcification on CT (n=90; 67.7%). Comparatively, only 41.2% of nodules ≥6 mm on the CR had benign calcification. Among all nodules <6 mm detected on CR, 95.5% were calcified or not present at CT against 81.2% for those ≥6 mm (p<0.001). CONCLUSION The present study demonstrated that 95.5% of pulmonary nodules smaller than 6 mm on CRs are either calcified (benign) or represent a false-positive finding on CT. These results suggest that nodule measures on CR smaller than 6 mm most likely represent a benign finding.
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Affiliation(s)
- I Missrie
- Fleury Group, R. Cincinato Braga, 282, Sao Paulo 01333910, Brazil
| | - B Hochhegger
- Medical Imaging Research Lab, LABIMED, Department of Radiology, Pavilhão Pereira Filho Hospital, Irmandade Santa Casa de Misericórdia de Porto Alegre, Av. Independência, 75, Porto Alegre 90020160, Brazil; Department of Diagnostic Methods, Federal University of Health Sciences of Porto Alegre, R. Sarmento Leite, 245, Porto Alegre 90050-170, Brazil; Department of Radiology, Pontificia Universidade Católica do Rio Grande do Sul, Av. Ipiranga, 6681, Porto Alegre 90619900, Brazil
| | - M Zanon
- Medical Imaging Research Lab, LABIMED, Department of Radiology, Pavilhão Pereira Filho Hospital, Irmandade Santa Casa de Misericórdia de Porto Alegre, Av. Independência, 75, Porto Alegre 90020160, Brazil; Department of Diagnostic Methods, Federal University of Health Sciences of Porto Alegre, R. Sarmento Leite, 245, Porto Alegre 90050-170, Brazil.
| | - J Capobianco
- Fleury Group, R. Cincinato Braga, 282, Sao Paulo 01333910, Brazil
| | | | - R Pereira Maciel
- Fleury Group, R. Cincinato Braga, 282, Sao Paulo 01333910, Brazil
| | | | | | - G Szarf
- Fleury Group, R. Cincinato Braga, 282, Sao Paulo 01333910, Brazil
| | - G Meirelles
- Fleury Group, R. Cincinato Braga, 282, Sao Paulo 01333910, Brazil
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