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Van Acker JWG, Yvergneaux C, Jacquet W, Dierens M, Hommez G, Van Acker J, Boone M, Rajasekharan S, Martens LC. Vertical root fracture detection with cone-beam computed tomography in Biodentine™ filled teeth. BMC Oral Health 2024; 24:1178. [PMID: 39367348 DOI: 10.1186/s12903-024-04947-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Accepted: 09/23/2024] [Indexed: 10/06/2024] Open
Abstract
PURPOSE This study aimed to evaluate the accuracy of detecting vertical root fractures in Biodentine™-filled teeth using the Promax 3Dmax cone-beam computed tomography (CBCT) unit compared to periapical radiographs. It tested hypotheses regarding CBCT's diagnostic superiority in non-root-filled and Biodentine™-root-filled maxillary central incisors and assessed the impact of smaller field of view and lower intensity settings on detection accuracy. MATERIALS AND METHODS Extracted maxillary incisors were divided into groups based on fracture status and root filling material, then placed in a Thiel-embalmed skull to simulate clinical conditions. The teeth were imaged using periapical radiographs and the CBCT unit under different settings. Fracture thickness was measured with microcomputed tomography for accuracy benchmarking. Multiple observers assessed the images, and statistical analyses were conducted to evaluate diagnostic performance. RESULTS Intra-rater reliabilities of consensus scores ranged from good to very good. Specificities were generally higher than sensitivities across all imaging modalities, but sensitivities remained constantly low. None of the Area Under the Curve scores exceeded 0.6, indicating poor overall accuracy for all imaging modalities. Paired comparisons of the area differences under Receiver Operator Characteristic curves revealed no significant differences between the CBCT and periapical radiograph techniques for detecting vertical root fractures in either Biodentine™-filled or non-root-filled teeth. CONCLUSIONS There was no significant accuracy improvement of the current CBCT device (Promax 3Dmax, Planmeca, Finland) over periapical radiographs in detecting small vertical root fractures in both non-root-filled and Biodentine™-root-filled maxillary central incisors. A smaller field of view with lower intensity did not enhance detection accuracy. These results highlight the challenges in accurately detecting small VRFs, emphasizing the need for further research and technological advancements in this domain.
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Affiliation(s)
- Jakob W G Van Acker
- ELOHA (Equal Lifelong Oral Health for All) research group, Paediatric Dentistry, Oral Health Sciences, Ghent University, Ghent, Belgium.
| | - Charlotte Yvergneaux
- ELOHA (Equal Lifelong Oral Health for All) research group, Paediatric Dentistry, Oral Health Sciences, Ghent University, Ghent, Belgium
| | - Wolfgang Jacquet
- Localities Ontologies Commons Integrated (LOCI), Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Oral Health Research Group (ORHE), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Melissa Dierens
- Department of Periodontology and Oral Implantology, Ghent University, Ghent, Belgium
| | - Geert Hommez
- Oral Health Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, 9000, Belgium
| | - Joris Van Acker
- UGent-Woodlab - Laboratory of Wood Technology, Department of Environment, Ghent University, Coupure links 653, Ghent, 9000, Belgium
- Centre for X-ray Tomography, Physics and Astronomy, Ghent University, Ghent, Belgium
| | - Matthieu Boone
- Centre for X-ray Tomography, Physics and Astronomy, Ghent University, Ghent, Belgium
| | - Sivaprakash Rajasekharan
- ELOHA (Equal Lifelong Oral Health for All) research group, Paediatric Dentistry, Oral Health Sciences, Ghent University, Ghent, Belgium
| | - Luc C Martens
- ELOHA (Equal Lifelong Oral Health for All) research group, Paediatric Dentistry, Oral Health Sciences, Ghent University, Ghent, Belgium
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Maruyama S, Watanabe H, Shimosegawa M. An image quality assessment index based on image features and keypoints for X-ray CT images. PLoS One 2024; 19:e0304860. [PMID: 38990930 PMCID: PMC11238976 DOI: 10.1371/journal.pone.0304860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 05/21/2024] [Indexed: 07/13/2024] Open
Abstract
Optimization tasks in diagnostic radiological imaging require objective quantitative metrics that correlate with the subjective perception of observers. However, although one such metric, the structural similarity index (SSIM), is popular, it has limitations across various aspects in its application to medical images. In this study, we introduce a novel image quality evaluation approach based on keypoints and their associated unique image feature values, focusing on developing a framework to address the need for robustness and interpretability that are lacking in conventional methodologies. The proposed index quantifies and visualizes the distance between feature vectors associated with keypoints, which varies depending on changes in the image quality. This metric was validated on images with varying noise levels and resolution characteristics, and its applicability and effectiveness were examined by evaluating images subjected to various affine transformations. In the verification of X-ray computed tomography imaging using a head phantom, the distances between feature descriptors for each keypoint increased as the image quality degraded, exhibiting a strong correlation with the changes in the SSIM. Notably, the proposed index outperformed conventional full-reference metrics in terms of robustness to various transformations which are without changes in the image quality. Overall, the results suggested that image analysis performed using the proposed framework could effectively visualize the corresponding feature points, potentially harnessing lost feature information owing to changes in the image quality. These findings demonstrate the feasibility of applying the novel index to analyze changes in the image quality. This method may overcome limitations inherent in conventional evaluation methodologies and contribute to medical image analysis in the broader domain.
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Affiliation(s)
- Sho Maruyama
- Department of Radiological Technology, Gunma Prefectural College of Health Sciences, Maebashi, Gunma, Japan
| | - Haruyuki Watanabe
- Department of Radiological Technology, Gunma Prefectural College of Health Sciences, Maebashi, Gunma, Japan
| | - Masayuki Shimosegawa
- Department of Radiological Technology, Gunma Prefectural College of Health Sciences, Maebashi, Gunma, Japan
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Kuramoto T, Takarabe S, Kanzaki Y, Shibayama Y, Yamasaki Y, Kitamura Y. Correlation Between Contrast-Detail Analysis and Clinical Image Quality Assessment of Intrapulmonary Lesions in Dual-Energy Subtraction Chest Radiography Using the Two-Shot Method: A Phantom Study. Acad Radiol 2024; 31:2118-2127. [PMID: 38008645 DOI: 10.1016/j.acra.2023.10.016] [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: 06/18/2023] [Revised: 10/05/2023] [Accepted: 10/05/2023] [Indexed: 11/28/2023]
Abstract
RATIONALE AND OBJECTIVES Dual-energy subtraction (DES) imaging constitutes a technique that has demonstrated efficacy in enhancing the detectability of pulmonary nodules on chest radiographs. However, a simple and quantitative methodology for evaluating the clinical image quality of DES images is currently lacking. The objective of this study was to investigate the applicability of contrast-detail (C-D) phantom analysis to the visual clinical image quality evaluation of chest DES images. MATERIALS AND METHODS We employed a custom-made phantom incorporating the C-D phantom and a multipurpose anthropomorphic adult chest phantom. Two phantom sizes were utilized to simulate standard- and large-bodied adult patients for each phantom. The custom-made phantom images were scored automatically using dedicated software, yielding an inverse image quality figure (IQFinv) value. The multipurpose anthropomorphic adult chest phantom was employed in a visual grading analysis (VGA) study that was conducted by two experienced radiologists and five radiological technologists. Each nodule placed in the chest phantom image was rated on a 4-point Likert scale. RESULTS A statistically significant correlation was observed between the VGA scores of the seven observers and the obtained IQFinv values. CONCLUSION The findings of this study suggest that DES image analysis of the C-D phantom possesses the potential to be utilized for the evaluation of clinical DES image quality based on chest lesion detectability.
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Affiliation(s)
- Taku Kuramoto
- Department of Radiological Technology, Faculty of Health Sciences, Kobe Tokiwa University, 2-6-2 Otanicho, Nagata-ku, Kobe 653-0838, Japan (T.K.).
| | - Shinya Takarabe
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan (S.T., Y.K., Y.S.)
| | - Yui Kanzaki
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan (S.T., Y.K., Y.S.)
| | - Yusuke Shibayama
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan (S.T., Y.K., Y.S.)
| | - Yuzo Yamasaki
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan (Y.Y., Y.K.)
| | - Yoshiyuki Kitamura
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan (Y.Y., Y.K.)
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Tsalafoutas IA, AlKhazzam S, Tsapaki V, Kharita MH. Automatic image quality evaluation in digital radiography using for-processing and for-presentation images. J Appl Clin Med Phys 2024; 25:e14285. [PMID: 38317593 PMCID: PMC11005988 DOI: 10.1002/acm2.14285] [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: 11/20/2023] [Revised: 12/27/2023] [Accepted: 01/03/2024] [Indexed: 02/07/2024] Open
Abstract
PURPOSE To investigate the impact of digital image post-processing algorithms on various image quality (IQ) metrics of radiographic images under different exposure conditions. METHODS A custom-made phantom constructed according to the instructions given in the IAEA Human Health Series No.39 publication was used, along with the respective software that automatically calculates various IQ metrics. Images with various exposure parameters were acquired with a digital radiography unit, which for each acquisition produces two images: one for-processing (raw) and one for-presentation (clinical). Various examination protocols were used, which incorporate diverse post-processing algorithms. The IQ metrics' values (IQ-scores) obtained were analyzed to investigate the effects of increasing incident air kerma (IAK) on the image receptor, tube potential (kVp), additional filtration, and examination protocol on image quality, and the differences between image type (raw or clinical). RESULTS The IQ-scores were consistent for repeated identical exposures for both raw and clinical images. The effect that changes in exposure parameters and examination protocol had on IQ-scores were different depending on the IQ metric and image type. The expected positive effect that increasing IAK and decreasing tube potential should have on IQ was clearly exhibited in two IQ metrics only, the signal difference-to-noise-ratio (SDNR) and the detectability index (d'), for both image types. No effect of additional filtration on any of the IQ metrics was detected on images of either type. An interesting finding of the study was that for all different image acquisition selections the d' scores were larger in raw images, whereas the other IQ metrics were larger in clinical images for most of the cases. CONCLUSIONS Since IQ-scores of raw and their respective clinical images may be largely different, the same type of image should be consistently used for monitoring IQ constancy and when results from different X-ray systems are compared.
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Affiliation(s)
| | - Shady AlKhazzam
- Medical Physics SectionOHS DepartmentHamad Medical CorporationDohaQatar
| | - Virginia Tsapaki
- NAHU ‐ Dosimetry and Medical Radiation Physics SectionIAEAViennaAustria
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Al‐Murshedi S, Alzyoud K, Benhalim M, Alresheedi N, Papathanasiou S, England A. Effects of body part thickness on low-contrast detail detection and radiation dose during adult chest radiography. J Med Radiat Sci 2024; 71:85-90. [PMID: 38050453 PMCID: PMC10920928 DOI: 10.1002/jmrs.741] [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: 01/06/2023] [Accepted: 11/10/2023] [Indexed: 12/06/2023] Open
Abstract
INTRODUCTION Differences in patient size often provide challenges for radiographers, particularly when choosing the optimum acquisition parameters to obtain radiographs with acceptable image quality (IQ) for diagnosis. This study aimed to assess the effect of body part thickness on IQ in terms of low-contrast detail (LCD) detection and radiation dose when undertaking adult chest radiography (CXR). METHODS This investigation made use of a contrast detail (CD) phantom. Polymethyl methacrylate (PMMA) was utilised to approximate varied body part thicknesses (9, 11, 15 and 17 cm) simulating underweight, standard, overweight and obese patients, respectively. Different tube potentials were tested against a fixed 180 cm source to image distance (SID) and automatic exposure control (AEC). IQ was analysed using bespoke software thus providing an image quality figure inverse (IQFinv ) value which represents LCD detectability. Dose area product (DAP) was utilised to represent the radiation dose. RESULTS IQFinv values decreased statistically (P = 0.0001) with increasing phantom size across all tube potentials studied. The highest IQFinv values were obtained at 80 kVp for all phantom thicknesses (2.29, 2.02, 1.8 and 1.65, respectively). Radiation dose increased statistically (P = 0.0001) again with increasing phantom thicknesses. CONCLUSION Our findings demonstrate that lower tube potentials provide the highest IQFinv scores for various body part thicknesses. This is not consistent with professional practice because radiographers frequently raise the tube potential with increased part thickness. Higher tube potentials did result in radiation dose reductions. Establishing a balance between dose and IQ, which must be acceptable for diagnosis, can prevent the patient from receiving unnecessary additional radiation dose.
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Affiliation(s)
- Sadeq Al‐Murshedi
- College of Health and Medical TechnologyAL‐Zahraa University for WomenKarbalaIraq
- Physics Department, College of Education for Pure ScienceUniversity of BabylonBabilIraq
| | - Kholoud Alzyoud
- Department of Medical Imaging, Faculty of Applied Health scienceThe Hashemite UniversityZarqaJordan
| | | | - Nadi Alresheedi
- Department of General studies, Royal Commission for Jubail and YanbuYanbu Industrial CollegeYanbuKingdom of Saudi Arabia
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Liang Z, Tang J, Xu P, Zeng W, Zhang J, Zhang Y, Zeng L, Wang H, Xia C, Li Z. Image feature index: A novel metric for quantifying chest radiographic image quality. Med Phys 2023; 50:2805-2815. [PMID: 36606328 DOI: 10.1002/mp.16206] [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: 03/31/2022] [Revised: 12/23/2022] [Accepted: 12/23/2022] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Radiographic X-ray imaging is a common clinical examination. Current objective methods for quantifying image quality for radiographs struggle to capture the combined impact of factors throughout the imaging chain on the perceived image quality. Therefore, there is a need to further develop metrics that correlate with image quality as perceived by the observer. OBJECTIVES We proposed the image feature index (IFI) to comprehensively quantify radiographic X-ray image quality. We also aimed to study the correlation between IFI and observer-perceived image quality for chest radiographs. MATERIALS AND METHODS The IFI algorithm was developed, which measured the amount of information, textural features, and noise in the image. A total of 70 chest phantom radiographs were generated under 60-120 kV and 0.2-80 mAs. A vendor-proprietary exposure index (EI) and dose area product (DAP) were extracted from the DICOM header in addition to calculating IFI for each image to investigate the relationships between IFI, EI and DAP. The quality of the images was rated by three observers, and the correlation between IFI and subjective score of image quality was tested. Next, a retrospective study using a random sample of 50 clinical chest radiographs was performed, and the correlation between IFI and subjective score was tested. The correlation was determined by the Spearman test. RESULTS The curves of IFI versus DAP and IFI versus EI both demonstrated a similar three-stage form where IFI is above zero: in the first stage, IFI increases rapidly with increased DAP or EI, whereas in the second stage, the slope of the curves decreased towards an asymptote, that is, minimal gain in IFI with increased DAP or EI-until they hit the inflection point and then descended sharply in the third stage. For both phantom and clinical chest images, IFI demonstrated good correlation with subjective score (r = 0.9084 for phantom images, r = 0.8153 for clinical images). CONCLUSIONS IFI is a feasible and efficient descriptor for image quality for chest radiographs. Future studies with larger sample sizes and sample types are needed to confirm the feasibility of IFI for other exam types and anatomical views, thus fulfilling and extending the potential applications of IFI in quality control and radiation dose reduction.
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Affiliation(s)
- Zejun Liang
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jing Tang
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Peng Xu
- Radiology Department, Shenzhen Mindray Bio-Medical Electronics Co., Ltd, Shenzhen, China
| | - Wen Zeng
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jiye Zhang
- Radiology Department, Shenzhen Mindray Bio-Medical Electronics Co., Ltd, Shenzhen, China
| | - Yu Zhang
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Lingming Zeng
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Hairong Wang
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Chunchao Xia
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Zhenlin Li
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
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Kanzaki Y, Kuramoto T, Takarabe S, Shibayama Y, Yoshikawa H, Kato T. Effect of high- and low-energy entrance surface dose allocation ratio for two-shot dual-energy subtraction imaging on low-contrast resolution. Radiography (Lond) 2023; 29:240-246. [PMID: 36608378 DOI: 10.1016/j.radi.2022.11.007] [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: 08/26/2022] [Revised: 11/08/2022] [Accepted: 11/20/2022] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Dual-energy subtraction (DES) imaging can obtain chest radiographs with high contrast between nodules and healthy lung tissue, and evaluating of chest radiography and evaluating exposure conditions is crucial to obtain a high-quality diagnostic image. This study aimed to investigate the effect of the dose allocation ratio of entrance surface dose (ESD) between high- and low-energy projection in low-contrast resolution of soft-tissue images for two-shot DES imaging in digital radiography using a contrast-detail phantom (CD phantom). METHODS A custom-made phantom mimicking a human chest that combined a CD phantom, polymethylmethacrylate square plate, and an aluminum plate (1-3 mm) was used. The tube voltage was 120 kVp (high-energy) and 60 kVp (low-energy). The ESD was changed from 0.1 to 0.5 mGy in 0.1 mGy increments. Dose allocation ratio of ESD between 120 kVp and 60 kVp projection was set at 1:1, 1:2, 1:3, and 2:1. Inverse image quality figure (IQFinv) was calculated from the custom-made phantom images. RESULTS When the total ESD and aluminum thickness were constant, no significant difference in IQFinv was observed under most conditions of varied dose allocation ratio. Similarly, when the total ESD and the dose allocation ratio were constant, there was no significant difference in IQFinv based on the aluminum plate thickness. CONCLUSION Using IQFinv to evaluate the quality of the two-shot DES image suggested that dose allocation ratio did not have a significant effect on low-contrast resolution of soft-tissue images. IMPLICATIONS FOR PRACTICE The present results provide useful information for determining exposure conditions for two-shot DES imaging.
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Affiliation(s)
- Y Kanzaki
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - T Kuramoto
- Department of Radiological Technology, Faculty of Health Sciences, Kobe Tokiwa University, 2-6-2 Otanicho, Nagata-ku, Kobe 653-0838, Japan.
| | - S Takarabe
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Y Shibayama
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - H Yoshikawa
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - T Kato
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Sayed M, Knapp KM, Fulford J, Heales C, Alqahtani SJ. The principles and effectiveness of X-ray scatter correction software for diagnostic X-ray imaging: A scoping review. Eur J Radiol 2023; 158:110600. [PMID: 36444818 DOI: 10.1016/j.ejrad.2022.110600] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 10/17/2022] [Accepted: 11/06/2022] [Indexed: 11/18/2022]
Abstract
PURPOSE An anti-scatter grid is often used in X-ray radiography to reduce the scattered X-rays generated from the patient. However, the presence of a grid means the patient dose subsequently increases. Recently,severalmanufacturers have developedsoftwarethat is capable of correctingfor scattered X-rays withouttheuse ofa conventional grid. This scoping review aims to systematically map the research assessing scattering correction software and to identify any existing knowledge gaps. METHODS This scoping review involved conducting a systematic search in PubMed, Scopus, and Web of science to reveal studies that were relevant to the research question. Articles published between 01.01.2000 and 31.12.2021 examining X-ray scatter correction software for X-ray imaging were included. A part of the PRISMA model and PICO framework were utilised to establish eligibility criteria. A structured summary table was utilised to extract data from the selected articles. RESULTS In this scoping review, 20 years of literature in X-ray conventional radiography. 11 articles were included in the data synthesis. The study populations of the included studies were varied: patients, image quality phantoms and anatomical phantoms. The clinical applications of X-ray scatter correction software were found to be limited to specific body parts (cervical spine, chest, shoulder, lumbar spine, hip and pelvis). The scatter correction software appears to be effective in terms of image quality and in reducing the radiation dose. However, the conventional grid still provides a higher image quality. CONCLUSIONS X-ray scatter correction software can be effective and provides potentialbenefits for some circumstances or clinical scenarios.
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Affiliation(s)
- Mohammad Sayed
- Diagnostic Radiology Department, College of Applied Medical Sciences, Najran University, Najran 61441, Saudi Arabia; Department of Medical Imaging, College of Medicine and Health, University of Exeter, St Luke's Campus, Heavitree Road, Exeter EX1 2LU, UK.
| | - Karen M Knapp
- Department of Medical Imaging, College of Medicine and Health, University of Exeter, St Luke's Campus, Heavitree Road, Exeter EX1 2LU, UK.
| | - Jon Fulford
- Medical School, University of Exeter, Medical School Building, St Luke's Campus, Magdalen Road, Exeter EX1 2LU, UK.
| | - Christine Heales
- Department of Medical Imaging, College of Medicine and Health, University of Exeter, St Luke's Campus, Heavitree Road, Exeter EX1 2LU, UK.
| | - Saeed J Alqahtani
- Diagnostic Radiology Department, College of Applied Medical Sciences, Najran University, Najran 61441, Saudi Arabia.
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Chang CT, Chou MC. Comparison of Non-Uniform Image Quality Caused by Anode Heel Effect between Two Digital Radiographic Systems Using a Circular Step-Wedge Phantom and Mutual Information. ENTROPY (BASEL, SWITZERLAND) 2022; 24:1781. [PMID: 36554186 PMCID: PMC9778271 DOI: 10.3390/e24121781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/29/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
The purpose of this study was to compare non-uniform image quality caused by the anode heel effect between two radiographic systems using a circular step-wedge (CSW) phantom and the normalized mutual information (nMI) metric. Ten repeated radiographic images of the CSW and contrast-detail resolution (CDR) phantoms were acquired from two digital radiographic systems with 16- and 12-degree anode angles, respectively, using various kVp and mAs. To compare non-uniform image quality, the CDR phantom was physically rotated at different orientations, and the directional nMI metrics were calculated from the CSW images. The directional visible ratio (VR) metrics were calculated from the CDR images. Analysis of variance (ANOVA) was performed to understand whether the nMI metric significantly changed with kVp, mAs, and orientations with Bonferroni correction. Mann-Whitney's U test was performed to compare the metrics between the two systems. Contrary to the VR metrics, the nMI metrics significantly changed with orientations in both radiographic systems. In addition, the system with the 12-degree anode angle exhibited less uniform image quality compared to the system with the 16-degree anode angle. A CSW phantom using the directional nMI metric can be significantly helpful to compare non-uniform image quality between two digital radiographic systems.
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Affiliation(s)
- Ching-Ting Chang
- Department of Medical Imaging, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan
- Department of Radiology, Kaohsiung Medical University Gangshan Hospital, Kaohsiung 82060, Taiwan
- Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Ming-Chung Chou
- Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Center for Big Data Research, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan
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Relationship between the visual evaluation of pathology visibility and the physical measure of low contrast detail detectability in neonatal chest radiography. Radiography (Lond) 2022; 28:1116-1121. [PMID: 36099681 DOI: 10.1016/j.radi.2022.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/11/2022] [Accepted: 08/16/2022] [Indexed: 11/22/2022]
Abstract
INTRODUCTION The detectability of low contrast detail (LCD) is a method used to assess image quality (IQ) in neonatal radiography; however, there is a lack of data on the relationship between LCD detectability and visual IQ. The study aims at investigating the relationship between the LCD detectability and visual IQ and pathology visibility (PV). METHODS Several acquisition parameters were employed to obtain a group of images from a neonatal Gammex chest phantom. Three observers applied relative visual grading analysis (VGA) for assessing the IQ and PV. A simulated pneumothorax visibility (PNV) and simulated hyaline membrane disease visibility (HMV) represented PV. Next, a CDRAD 2.0 phantom was radiographed utilising the same acquisition protocols, and several paired images were obtained. With the use of CDRAD analyser software, the detectability of LCD was assessed and expressed by an image quality figure inverse (IQFiinv) metric. The correlation between the IQFinv and each of IQ, PNV and HMV was examined. RESULTS The physical measure (IQFinv) and the visual assessment of IQ were shown to be strongly correlated (r = 0.95; p < 0.001). Using Pearson's correlation, the IQFinv, PNV, and HMV were found to be strongly correlated (r = 0.94; p < 0.001) and (r = 0.92; p < 0.001), correspondingly. CONCLUSION Results of the study show that physical measures of LCD detectability utilising the CDRAD 2.0 phantom is strongly corelated with visual IQ and PV (PNV and HMV) and can be used to evaluate IQ when undertaking neonatal chest radiography (CXR). IMPLICATIONS FOR PRACTICE This study establishes the feasibility of utilising the physical measure (IQFinv) and the CDRAD 2.0 phantom in routine quality assurance and neonatal CXR optimisation studies.
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Stouthandel MEJ, Pullens P, Bogaert S, Schoepen M, Vangestel C, Achten E, Veldeman L, Van Hoof T. Application of frozen Thiel-embalmed specimens for radiotherapy delineation guideline development: a method to create accurate MRI-enhanced CT datasets. Strahlenther Onkol 2022; 198:582-592. [DOI: 10.1007/s00066-022-01928-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 03/10/2022] [Indexed: 11/30/2022]
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Abstract
OBJECTIVES We evaluated the different Virtual Grid software ratios (Fujifilm, Tokyo, Japan) on gridless clinical chest radiographs with visual grading analysis (VGA). In addition, we investigated the 2 image quality assessment algorithms (IQAAs). MATERIALS AND METHODS Gridless chest radiographs of 50 different intensive care unit patients were collected and afterward processed with Virtual Grid software. Different software (SW) grid ratios-6:1, 10:1, 13:1, 17:1, and 20:1-were applied to investigate the image quality (IQ) improvement. Image quality improvement was assessed by 4 radiologists in a relative VGA study where the reference image was processed with SW grid ratio of 10:1. One of the IQAAs used to analyze the radiographs was implemented in our department but was originally developed by the research group of the Duke University Medical Center. A general IQ score (IQS) was calculated based on contrast, detail, and noise. Another IQAA-NIQE (naturalness image quality evaluator)-available in Matlab (MATLAB Research R2019b; the MathWorks, Inc) was evaluated. Both methods were compared with VGA. RESULTS Visual grading analysis scores of gridless radiographs are significantly lower (P < 0.001). Image quality increases with increasing SW grid ratios, up to grid ratio of 17:1. However, some anatomical structures-spine and ribs-are negatively affected by the higher grid ratios. A correlation coefficient of 0.99 between the VGA and the IQS was observed. The correlation coefficient between VGA and NIQE was 1.00. CONCLUSIONS Virtual Grid with SW grid ratio of 6:1 improves the IQ of gridless chest bedside radiographs. The grid ratios 17:1 and 20:1 should be considered carefully as the SW negatively affects parts of the ribs and spine. Therefore, grid ratios up to 13:1 can be advised. The IQAAs are promising and could be used to detect differences in IQ when different scatter correction SW settings are used.
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Characterizing Scatter Correction Software of 5 Mobile Radiography Units: An Anthropomorphic Phantom Study. Invest Radiol 2022; 57:444-452. [PMID: 35085123 DOI: 10.1097/rli.0000000000000856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Bedside radiographs are usually obtained gridless, without a physical scatter correction grid because of several limitations. Therefore, multiple manufacturers of mobile radiography systems provide the possibility to apply scatter correction software (SC SW) on those images. The purpose of this study was to characterize different series of radiographs-gridless, SC SW, and physical grid-with an image quality assessment algorithm (IQAA). Furthermore, we investigated the potential dose reduction and the correlation between the output of the IQAA and the human observers. MATERIALS AND METHODS We obtained different series of radiographs with an anthropomorphic phantom (multipurpose chest phantom N1 "Lungman," Kyoto Kagaku, Kyoto, Japan). All radiographs were obtained with flat-panel detectors of 5 different manufacturers in a wall bucky system. An IQAA to analyze the radiographs was implemented in our department but was originally developed by the research group of the Duke University Medical Center. Seven physical quantities were calculated by the IQAA: rib-lung contrast (RLcontrast), subdiaphragm-lung contrast (SLcontrast), lung detail (Ldetail), mediastinum detail (Mdetail), lung noise (Lnoise), mediastinum noise (Mnoise), and rib-lung sharpness (RLsharpness). In a proof of concept, the results of the IQAA were validated by 3 experienced radiologists. RESULTS Regression coefficients (b) of the linear regression model indicate that the human observer results correlate well with the IQAA (b ≥ 0.89, R2 ≥ 0.83). All manufacturers have SC SW that increases the 7 physical quantities of the gridless images. However, several manufacturers have SC SW that increases the physical metrics to the same level as the physical grid images. The SC SW radiographs obtained with a reduced tube load have an increased level of contrast, detail, sharpness, and noise compared with the gridless images obtained with the higher tube load. CONCLUSIONS We have proven in a proof of concept that the originally developed IQAA can be used to characterize different series of images of different manufacturers. Based on the physical quantities, SC SW increases the contrast, detail, sharpness, and noise. The experimental results in this study assume a patient dose reduction could be possible when SC SW is applied.
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Natale G, Stouthandel MEJ, Van Hoof T, Bocci G. The Lymphatic System in Breast Cancer: Anatomical and Molecular Approaches. MEDICINA (KAUNAS, LITHUANIA) 2021; 57:1272. [PMID: 34833492 PMCID: PMC8624129 DOI: 10.3390/medicina57111272] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 12/30/2022]
Abstract
Breast cancer is one of the most important causes of premature mortality among women and it is one of the most frequently diagnosed tumours worldwide. For this reason, routine screening for prevention and early diagnosis is important for the quality of life of patients. Breast cancer cells can enter blood and lymphatic capillaries, then metastasizing to the regional lymph nodes in the axilla and to both visceral and non-visceral sites. Rather than at the primary site, they seem to enter the systemic circulation mainly through the sentinel lymph node and the biopsy of this indicator can influence the axillary dissection during the surgical approach to the pathology. Furthermore, secondary lymphoedema is another important issue for women following breast cancer surgical treatment or radiotherapy. Considering these fundamental aspects, the present article aims to describe new methodological approaches to assess the anatomy of the lymphatic network in the axillary region, as well as the molecular and physiological control of lymphatic vessel function, in order to understand how the lymphatic system contributes to breast cancer disease. Due to their clinical implications, the understanding of the molecular mechanisms governing lymph node metastasis in breast cancer are also examined. Beyond the investigation of breast lymphatic networks and lymphatic molecular mechanisms, the discovery of new effective anti-lymphangiogenic drugs for future clinical settings appears essential to support any future development in the treatment of breast cancer.
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Affiliation(s)
- Gianfranco Natale
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
- Museum of Human Anatomy “Filippo Civinini”, University of Pisa, 56126 Pisa, Italy
| | - Michael E. J. Stouthandel
- Department of Human Structure and Repair, Ghent University, 9000 Ghent, Belgium; (M.E.J.S.); (T.V.H.)
| | - Tom Van Hoof
- Department of Human Structure and Repair, Ghent University, 9000 Ghent, Belgium; (M.E.J.S.); (T.V.H.)
| | - Guido Bocci
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy;
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Visual Evaluation of Image Quality of a Low Dose 2D/3D Slot Scanner Imaging System Compared to Two Conventional Digital Radiography X-ray Imaging Systems. Diagnostics (Basel) 2021; 11:diagnostics11101932. [PMID: 34679630 PMCID: PMC8534907 DOI: 10.3390/diagnostics11101932] [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: 09/10/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 11/23/2022] Open
Abstract
The purpose of this study was to assess the image quality of the low dose 2D/3D slot scanner (LDSS) imaging system compared to conventional digital radiography (DR) imaging systems. Visual image quality was assessed using the visual grading analysis (VGA) method. This method is a subjective approach that uses a human observer to evaluate and optimise radiographic images for different imaging technologies. Methods and materials: ten posterior-anterior (PA) and ten lateral (LAT) images of a chest anthropomorphic phantoms and a knee phantom were acquired by an LDSS imaging system and two conventional DR imaging systems. The images were shown in random order to three (chest) radiologists and three experienced (knee) radiographers, who scored the images against a number of criteria. Inter- and intraobserver agreement was assessed using Fleiss’ kappa and weighted kappa. Results: the statistical comparison of the agreement between the observers showed good interobserver agreement, with Fleiss’ kappa coefficients of 0.27–0.63 and 0.23–0.45 for the chest and knee protocols, respectively. Comparison of intraobserver agreement also showed good agreement with weighted kappa coefficients of 0.27–0.63 and 0.23–0.45 for the chest and knee protocols, respectively. The LDSS imaging system achieved significantly higher VGA image quality compared to the DR imaging systems in the AP and LAT chest protocols (p < 0.001). However, the LDSS imaging system achieved lower image quality than one DR system (p ≤ 0.016) and equivalent image quality to the other DR systems (p ≤ 0.27) in the knee protocol. The LDSS imaging system achieved effective dose savings of 33–52% for the chest protocol and 30–35% for the knee protocol compared with DR systems. Conclusions: this work has shown that the LDSS imaging system has the potential to acquire chest and knee images at diagnostic quality and at a lower effective dose than DR systems.
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Cruz-Bastida JP, Marshall EL, Reiser N, George J, Pearson EA, Feinstein KA, Al-Hallaq HA, Burton CS, Beaulieu D, MacDougall RD, Reiser I. Development of a neonate X-ray phantom for 2D imaging applications using single-tone inkjet printing. Med Phys 2021; 48:4944-4954. [PMID: 34255871 DOI: 10.1002/mp.15086] [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: 09/12/2020] [Revised: 04/16/2021] [Accepted: 06/17/2021] [Indexed: 11/11/2022] Open
Abstract
PURPOSE Inkjet printers can be used to fabricate anthropomorphic phantoms by the use of iodine-doped ink. However, challenges persist in implementing this technique. The calibration from grayscale to ink density is complex and time-consuming. The purpose of this work is to develop a printing methodology that requires a simpler calibration and is less dependent on printer characteristics to produce the desired range of x-ray attenuation values. METHODS Conventional grayscale printing was substituted by single-tone printing; that is, the superposition of pure black layers of iodinated ink. Printing was performed with a consumer-grade inkjet printer using ink made of potassium-iodide (KI) dissolved in water at 1 g/ml. A calibration for the attenuation of ink was measured using a commercial x-ray system at 70 kVp. A neonate radiograph obtained at 70 kVp served as an anatomical model. The attenuation map of the neonate radiograph was processed into a series of single-tone images. Single-tone images were printed, stacked, and imaged at 70 kVp. The phantom was evaluated by comparing attenuation values between the printed phantom and the original radiograph; attenuation maps were compared using the structural similarity index measure (SSIM), while attenuation histograms were compared using the Kullback-Leibler (KL) divergence. A region of interest (ROI)-based analysis was also performed, where the attenuation distribution within given ROIs was compared between phantom and patient. The phantom sharpness was evaluated in terms of modulation transfer function (MTF) estimates and signal spread profiles of high spatial resolution features in the image. RESULTS The printed phantom required 36 pages. The printing queue was automated and it took about 2 h to print the phantom. The radiograph of the printed phantom demonstrated a close resemblance to the original neonate radiograph. The SSIM of the phantom with respect to that of the patient was 0.53. Both patient and phantom attenuation histograms followed similar distributions, and the KL divergence between such histograms was 0.20. The ROI-based analysis showed that the largest deviations from patient attenuation values were observed at the higher and lower ends of the attenuation range. The limiting resolution of the proposed methodology was about 1 mm. CONCLUSION A methodology to generate a neonate phantom for 2D imaging applications, using single-tone printing, was developed. This method only requires a single-value calibration and required less than 2 h to print a complete phantom.
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Affiliation(s)
| | - Emily L Marshall
- Department of Radiology, University of Chicago, Chicago, IL, 60637, USA
| | - Nikolaj Reiser
- Department of Radiology, University of Chicago, Chicago, IL, 60637, USA
| | - Jonathan George
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, 60637, USA
| | - Erik A Pearson
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, 60637, USA
| | - Kate A Feinstein
- Department of Radiology, University of Chicago, Chicago, IL, 60637, USA
| | - Hania A Al-Hallaq
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, 60637, USA
| | - Christiane S Burton
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Danielle Beaulieu
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Robert D MacDougall
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Ingrid Reiser
- Department of Radiology, University of Chicago, Chicago, IL, 60637, USA
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Evaluation of Non-Uniform Image Quality Caused by Anode Heel Effect in Digital Radiography Using Mutual Information. ENTROPY 2021; 23:e23050525. [PMID: 33922996 PMCID: PMC8145656 DOI: 10.3390/e23050525] [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: 03/30/2021] [Revised: 04/24/2021] [Accepted: 04/24/2021] [Indexed: 11/17/2022]
Abstract
Anode heel effects are known to cause non-uniform image quality, but no method has been proposed to evaluate the non-uniform image quality caused by the heel effect. Therefore, the purpose of this study was to evaluate non-uniform image quality in digital radiographs using a novel circular step-wedge (CSW) phantom and normalized mutual information (nMI). All X-ray images were acquired from a digital radiography system equipped with a CsI flat panel detector. A new acrylic CSW phantom was imaged ten times at various kVp and mAs to evaluate overall and non-uniform image quality with nMI metrics. For comparisons, a conventional contrast-detail resolution phantom was imaged ten times at identical exposure parameters to evaluate overall image quality with visible ratio (VR) metrics, and the phantom was placed in different orientations to assess non-uniform image quality. In addition, heel effect correction (HEC) was executed to elucidate the impact of its effect on image quality. The results showed that both nMI and VR metrics significantly changed with kVp and mAs, and had a significant positive correlation. The positive correlation is suggestive that the nMI metrics have a similar performance to the VR metrics in assessing the overall image quality of digital radiographs. The nMI metrics significantly changed with orientations and also significantly increased after HEC in the anode direction. However, the VR metrics did not change significantly with orientations or with HEC. The results indicate that the nMI metrics were more sensitive than the VR metrics with regards to non-uniform image quality caused by the anode heel effect. In conclusion, the proposed nMI metrics with a CSW phantom outperformed the conventional VR metrics in detecting non-uniform image quality caused by the heel effect, and thus are suitable for quantitatively evaluating non-uniform image quality in digital radiographs with and without HEC.
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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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Hong GS, Do KH, Son AY, Jo KW, Kim KP, Yun J, Lee CW. Value of bone suppression software in chest radiographs for improving image quality and reducing radiation dose. Eur Radiol 2021; 31:5160-5171. [PMID: 33439320 DOI: 10.1007/s00330-020-07596-w] [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: 06/14/2020] [Revised: 11/07/2020] [Accepted: 12/03/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVES To compare image quality and radiation dose between dual-energy subtraction (DES)-based bone suppression images (D-BSIs) and software-based bone suppression images (S-BSIs). METHODS Chest radiographs (CXRs) of forty adult patients were obtained with the two X-ray devices, one with DES and one with bone suppression software. Three image quality metrics (relative mean absolute error (RMAE), peak signal-to-noise ratio (PSNR), and structural similarity index (SSIM)) between original CXR and BSI for each of D-BSI and S-SBI groups were calculated for each bone and soft tissue areas. Two readers rated the visual image quality for original CXR and BSI for each of D-BSI and S-SBI groups. The dose area product (DAP) values were recorded. Paired t test was used to compare the image quality and DAP values between D-BSI and S-BSI groups. RESULTS In bone areas, S-BSIs had better SSIM values than D-BSI (94.57 vs. 87.77) but worse RMAE and PSNR values (0.50 vs. 0.20; 20.93 vs. 34.37) (all p < 0.001). In soft tissue areas, S-BSIs had better SSIM values than D-BSI (97.56 vs. 91.42) but similar RMAE and PSNR values (0.29 vs. 0.27; 31.35 vs. 29.87) (all p < 0.001). Both readers gave S-BSIs significantly higher image quality scores than D-BSI (p < 0.001). The mean DAP in software-related images (0.98 dGy·cm2) was significantly lower than that in the DES-related images (1.48 dGy·cm2) (p < 0.001). CONCLUSION Bone suppression software significantly improved the image quality of bone suppression images with a relatively lower radiation dose, compared with dual-energy subtraction technique. KEY POINTS • Bone suppression software preserves structure similarity of soft tissues better than dual-energy subtraction technique in bone suppression images. • Bone suppression software achieves superior image quality for lung lesions than dual-energy subtraction technique in bone suppression images. • Bone suppression software can decrease the radiation dose over the hardware-based image processing technique.
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Affiliation(s)
- Gil-Sun Hong
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Kyung-Hyun Do
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea.
| | - A-Yeon Son
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Kyung-Wook Jo
- Division of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Kwang Pyo Kim
- Department of Nuclear Engineering, Kyung Hee University, Seoul, South Korea
| | - Jihye Yun
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Choong Wook Lee
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea
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Enevoldsen S, Kusk MW. Image quality of bedside chest radiographs in intensive care beds with integrated detector tray: A phantom study. Radiography (Lond) 2020; 27:453-458. [PMID: 33158751 DOI: 10.1016/j.radi.2020.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/18/2020] [Accepted: 10/19/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Vendors offer intensive care beds with integrated detector trays for bedside radiography, promoting better ergonomics and patient comfort. However, no documentation of the effects on diagnostic image quality has been located. This study examines measured and subjective image quality of supine bedside chest radiographs with and without use of such a detector tray. METHODS A contrast-detail phantom (CDRAD 2.0) was exposed using standard supine chest exposure parameters. Plexiglass plates of 16 and 21 cm were placed in front to simulate patient attenuation for standard and adipose patients. Exposures were repeated with the detector placed in tray and directly in bed. Images were analysed using dedicated software giving a figure-of-merit IQFinv. Results were compared using ANOVA. Then an anthropomorphic chest phantom (Lungman) was exposed using the same parameters, and the same placements of the detector. Exposures were done with and without extra conformal tissue to simulate varying patient sizes, and with and without added typical intensive care equipment. Images were analysed by two radiologists using a three-point scale, on five image quality criteria. Radiologist also stated whether the images were sufficient for diagnosis. Results were compared using Visual Grading Characteristics, using dedicated software, resulting in Areas Under the Curve (AUC-VGC) for each combination and criteria. Inter- and intra-rater reliability were assessed with kappa statistics. Composite Visual Grading Analysis (VGAS) scores were calculated for each image. Both IQFinv and were normalized and compared. RESULTS For all criteria both IQFinv and AUC-VGC was significantly better when exposing the detector directly in bed, than with the detector placed in the tray across all exposures. When stratified into thin and adipose patients, IQFinv decreased significantly for thin patients, while VGAS-scores did not. For adipose patients, both figures were significantly lower with the detector in the tray. CONCLUSION Use of detector tray for bedside chest imaging decreases image quality. IMPLICATIONS FOR PRACTICE Radiographers should critically evaluate image quality and experimentally determine optimal exposure factors, when taking equipment with integrated trays into use.
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Affiliation(s)
- S Enevoldsen
- University Hospital Southwest Denmark, Department of Radiology and Nuclear Medicine, Finsensgade 35, 6700 Esbjerg, Denmark.
| | - M W Kusk
- University Hospital Southwest Denmark, Department of Radiology and Nuclear Medicine, Finsensgade 35, 6700 Esbjerg, Denmark.
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Survey of chest radiography systems: Any link between contrast detail measurements and visual grading analysis? Phys Med 2020; 76:62-71. [DOI: 10.1016/j.ejmp.2020.06.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 06/10/2020] [Accepted: 06/13/2020] [Indexed: 12/14/2022] Open
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Yalcin A, Olgar T, Sancak T, Atac GK, Akyar S. Correlation between physical measurements and observer evaluations of image quality in digital chest radiography. Med Phys 2020; 47:3935-3944. [DOI: 10.1002/mp.14244] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/27/2020] [Accepted: 05/01/2020] [Indexed: 11/06/2022] Open
Affiliation(s)
- Asena Yalcin
- Institute of Nuclear Sciences Ankara University Ankara 06100 Turkey
| | - Turan Olgar
- Institute of Nuclear Sciences Ankara University Ankara 06100 Turkey
- Faculty of Engineering Department of Engineering Physics Ankara University Ankara 06100 Turkey
| | - Tanzer Sancak
- Department of Radiology TOBB University of Economics and Technology Hospital Ankara Turkey
| | - Gokce Kaan Atac
- Faculty of Medicine Department of Radiology Ufuk University Ankara Turkey
| | - Serdar Akyar
- Department of Radiology Ankara University School of Medicine Ankara Turkey
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Coloma L, Cabello R, González C, Quicios C, Bueno G, García JV, Arribas AB, Clascá F. Cadaveric Models for Renal Transplant Surgery Education: a Comprehensive Review. Curr Urol Rep 2020; 21:10. [PMID: 32166557 DOI: 10.1007/s11934-020-0961-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE OF REVIEW To evaluate the utility of cadaveric models for kidney transplant (KT) surgery training. RECENT FINDINGS Medline® and PubMed® databases were searched for English and Spanish language articles published describing different learning models used in KT formation. We evaluated the use of cadavers preserved by Thiel's embalming method (TEM) as KT simulation models. Students were divided in groups of 4 people: four trainees mentored by an expert in KT surgery. Among the trainees were surgical residents and low-experience surgeons. A total of 39 TEM preserved bodies were used, of which 75 viable renal grafts were obtained. In each cadaver, two complete transplantation processes were performed, each consisting of en bloc nephrectomy with the trunk of aorta and inferior vena cava, bench surgery and perfusion with saline of the organ, and KT surgery. As with any surgical procedure, learning KT surgery is a stepwise process that requires years of dedication. The models available for the surgical simulation of KT surgery allow to practice and achieve dexterity in performing the procedure in a safe and reproducible way. Training on TEM-preserved corpses offers a highly realistic model for the surgical simulation of KT surgery.
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Affiliation(s)
- Lidia Coloma
- Urology Department, Hospital Universitario Fundación Jiménez Díaz/Universidad Autónoma de Madrid, Madrid, Spain
| | - Ramiro Cabello
- Urology Department, Hospital Universitario Fundación Jiménez Díaz/Universidad Autónoma de Madrid, Madrid, Spain.
| | - Carmen González
- Urology Department, Hospital Universitario Fundación Jiménez Díaz/Universidad Autónoma de Madrid, Madrid, Spain
| | - Cristina Quicios
- Urology Department, Hospital Universitario Fundación Jiménez Díaz/Universidad Autónoma de Madrid, Madrid, Spain
| | - Gonzalo Bueno
- Urology Department, Hospital Universitario Fundación Jiménez Díaz/Universidad Autónoma de Madrid, Madrid, Spain
| | - Juan Vicente García
- Urology Department, Hospital Universitario Fundación Jiménez Díaz/Universidad Autónoma de Madrid, Madrid, Spain
| | - Ana Begoña Arribas
- Vascular Surgery Department, Hospital Universitario Fundación Jiménez Díaz/Universidad Autónoma de Madrid, Madrid, Spain
| | - Francisco Clascá
- Anatomy, Histology and Neuroscience Department, School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
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Impact of Software Parameter Settings on Image Quality of Virtual Grid Processed Radiography Images: A Contrast-Detail Phantom Study. Invest Radiol 2020; 55:374-380. [PMID: 31985603 DOI: 10.1097/rli.0000000000000646] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Mobile radiography systems are commonly used in the intensive care unit. The use of a physical antiscatter grid with these systems is uncommon because of drawbacks. In 2015, Virtual Grid (Fujifilm, Tokyo, Japan) became available for chest and abdomen examinations. In this study, we compared image quality (IQ) with a contrast-detail phantom (CDRAD 2.0; Artinis Medical Systems, Zetten, the Netherlands) of digital radiographs acquired without any grid (gridless) with those corrected for scatter by either software (SW)-based scatter correction (Virtual Grid) or a physical grid (grid). Furthermore, we determined the optimal Virtual Grid settings that lead to the best contrast-detail IQ score (inverse IQ figure). MATERIALS AND METHODS Images were obtained with a cassette spot film device with an inserted portable flat-panel detector (Fujifilm, Tokyo, Japan). The CDRAD phantom was sandwiched between polymethylmethacrylate (PMMA) with total thicknesses of 12, 16, 21, and 26 cm to simulate patient attenuation and scatter. Tube voltages of 81, 90, 109, and 125 kVp were used to make the radiographs. In total, 12 different Virtual Grid settings (grid ratio, line pairs (lp)/cm, and type of interstitial material) were applied for every phantom thickness and tube voltage. RESULTS An average increase of 32% in IQ was obtained when Virtual Grid images with a SW grid ratio 10:1 were compared with gridless images (P < 0.001). Increasing the SW grid ratio to 20:1 resulted in a further increased IQ. With a phantom thickness of 12 cm PMMA, Virtual Grid outperformed the removable physical grid presented in the cassette spot film device. The linear mixed-effects model showed that IQ is mainly affected by PMMA, tube voltage, and the SW grid ratio. CONCLUSIONS Virtual Grid improves images obtained without physical grid for a wide range of experimental conditions. Despite the different possible settings of the Virtual Grid SW, the most important parameter affecting IQ is the SW grid ratio.
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Moorman L, Precht H, Jensen J, Svalastoga E, Nielsen DH, Proschowsky HF, McEvoy FJ. Assessment of Image Quality in Digital Radiographs Submitted for Hip Dysplasia Screening. Front Vet Sci 2019; 6:428. [PMID: 31850383 PMCID: PMC6901622 DOI: 10.3389/fvets.2019.00428] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/13/2019] [Indexed: 11/25/2022] Open
Abstract
Digital radiography is widely seen to be forgiving of poor exposure technique and to provide consistent high quality diagnostic images. Optimal quality images are however not universal; sub-optimal images are encountered. Evaluators on hip dysplasia schemes encounter images from multiple practices produced on equipment from multiple manufacturers. For images submitted to the Danish Kennel Club for hip dysplasia screening, a range of quality is seen and the evaluators are of the impression that variations in image quality area associated with particular equipment. This study was undertaken to test the hypothesis that there is an association between image quality in digital radiography and the manufacturer of the detector equipment, and to demonstrate the applicability of visual grading analysis (VGA) for image quality evaluation in veterinary practice. Data from 16,360 digital images submitted to the Danish Kennel Club were used to generate the hypothesis that there is an association between detector manufacturer and image quality and to create groups for VGA. Image quality in a subset of 90 images randomly chosen from 6 manufacturers to represent high and low quality images, was characterized using VGA and the results used to test for an association between image quality and system manufacturer. The range of possible scores in the VGA was −2 to +2 (higher scores are better). The range of the VGA scores for the images in the low image quality group (n = 45) was −1.73 to +0.67, (median −1.2). Images in the high image quality group (n = 44) ranged from −1.52 to +0.53, (median −0.53). This difference was statistically significant (p < 0.001). The study shows an association between VGA scores of image quality and detector manufacturer. Possible causes may be that imaging hardware and/or software are not equal in terms of quality, that the level of support sought and given differs between systems, or a combination of the two. Clinicians purchasing equipment should be mindful that image quality can differ across systems. VGA is practical for veterinarians to compare image quality between systems or within a system over time.
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Affiliation(s)
- Lilah Moorman
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Helle Precht
- Health Sciences Research Centre: Diagnosis and Treatment CONRAD, University College Lillebælt, Odense, Denmark
| | - Janni Jensen
- Research and Innovation Unit of Radiology, University of Southern Denmark, Odense, Denmark.,Department of Radiology, Odense University Hospital, Odense, Denmark
| | - Eiliv Svalastoga
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dorte H Nielsen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Fintan J McEvoy
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Audenaert EA, Khanduja V, Bauwens C, Van Hoof T, Pattyn C, Steenackers G. A discrete element model to predict anatomy of the psoas muscle and path of the tendon: Design implications for total hip arthroplasty. Clin Biomech (Bristol, Avon) 2019; 70:186-191. [PMID: 31526958 DOI: 10.1016/j.clinbiomech.2019.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/05/2019] [Accepted: 09/08/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND The accurate estimation of a muscle's line of action is a fundamental requirement in computational modelling. We present a novel anatomical muscle wrapping technique and demonstrate its clinical use on the evaluation of the Psoas muscle mechanics in hip arthroplasty. METHODS A volume preserving, spring model to parameterize muscle anatomy changes during motion is presented. Validation was performed by a CT scan of a cadaver model in multiple positions. The predicted psoas musculotendinous path was compared with the actual imaging findings. In a second stage, psoas kinetics were compared between a conventional versus a resurfacing hip arthroplasty during gait. FINDINGS Anatomy prediction error was found to be 2.12 mm on average (SD 1.34 mm). When applied to psoas mechanics during walking, the muscle was found to wrap predominantly around the femoral head providing a biomechanically efficient and nearly constant moment arm for flexion during the entire gait cycle. However, this advantage was found to be lost in small diameter hip arthroplasty designs resulting in an important mechanical disadvantage. The moment arm for flexion, was on average 36% (SD 0.03%) lower in the small diameter conventional hip arthroplasty as compared to the large diameter head of the hip resurfacing and this difference was highly significant. (p < 0.001). INTERPRETATION Despite the shortcomings of an "in silico" and cadaveric study, our findings are in accordance with previous clinical and gait studies. Furthermore, the findings are strongly in favour of large diameter implant designs, warranting their further development and optimisation.
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Affiliation(s)
- E A Audenaert
- Department of Orthopedic Surgery and Traumatology, Ghent University Hospital, Corneel Heymanslaan 10, 9000 Ghent, Belgium; Department of Trauma and Orthopedics, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge CB2 0QQ, UK; Department of Electromechanics, Op3Mech research group, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; Department of Human Structure and Repair, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium.
| | - V Khanduja
- Department of Trauma and Orthopedics, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge CB2 0QQ, UK
| | - C Bauwens
- Department of Human Structure and Repair, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium
| | - T Van Hoof
- Department of Human Structure and Repair, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium
| | - C Pattyn
- Department of Human Structure and Repair, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium
| | - G Steenackers
- Department of Electromechanics, Op3Mech research group, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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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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Pelegrino Bastos Maués NH, Fattori Alves AF, Menegatti Pavan AL, Marrone Ribeiro S, Yamashita S, Petean Trindade A, Mascarenhas YM, Nicolucci P, Rodrigues de Pina D. ABDOMEN-PELVIS COMPUTED TOMOGRAPHY PROTOCOL OPTIMIZATION: AN IMAGE QUALITY AND DOSE ASSESSMENT. RADIATION PROTECTION DOSIMETRY 2019; 184:66-72. [PMID: 30371858 DOI: 10.1093/rpd/ncy181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 09/20/2018] [Accepted: 10/19/2018] [Indexed: 06/08/2023]
Abstract
Computed tomography (CT) has a high level of sensitivity and specificity for the diagnosis and follow-up of pathologies of the abdomen-pelvis region. Some features, such as automatic tube current modulation (ATCM), permits the acquisition of quality images with low radiation doses. This study evaluated the image quality and radiation dose of abdomen-pelvis CT protocols with ATCM technique. Were performed five CT protocols using 16-slice and 64-slice scanners, an anthropomorphic phantom for dosimetric measurements, an analytical phantom and retrospective examinations for image quality analysis. Were found significant reduction in effective dose. The highest absorbed doses were found in the stomach and spleen (56.1 and 47.2 mGy, respectively). Objective parameters as noise, low contrast and spatial resolution did not significantly differ between the protocols (p > 0.05). All protocols received the range of 'Optimum/Acceptable' in patient's image quality analysis. This methodology can be reproduced in any clinical routine to optimize CT protocols.
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Affiliation(s)
| | - Allan Felipe Fattori Alves
- São Paulo State University (UNESP), Instituto de Biociências de Botucatu, Departamento de Física e Biofísica, Botucatu, São Paulo, Brazil
| | - Ana Luiza Menegatti Pavan
- São Paulo State University (UNESP), Instituto de Biociências de Botucatu, Departamento de Física e Biofísica, Botucatu, São Paulo, Brazil
| | - Sergio Marrone Ribeiro
- São Paulo State University (UNESP), Faculdade de Medicina de Botucatu, Departamento de Doenças Tropicais e Diagnóstico por Imagem, Botucatu, São Paulo, Brazil
| | - Seizo Yamashita
- São Paulo State University (UNESP), Faculdade de Medicina de Botucatu, Departamento de Doenças Tropicais e Diagnóstico por Imagem, Botucatu, São Paulo, Brazil
| | - André Petean Trindade
- São Paulo State University (UNESP), Faculdade de Medicina de Botucatu, Departamento de Doenças Tropicais e Diagnóstico por Imagem, Botucatu, São Paulo, Brazil
| | | | - Patrícia Nicolucci
- Universidade de São Paulo (USP), Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Centro de Instrumentação, Dosimetria e Radioproteção (CIDRA), Av. Bandeirantes, 3900 Bairro Monte Alegre, Ribeirão Preto, São Paulo, Brazil
| | - Diana Rodrigues de Pina
- São Paulo State University (UNESP), Faculdade de Medicina de Botucatu, Departamento de Doenças Tropicais e Diagnóstico por Imagem, Botucatu, São Paulo, Brazil
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Comparative analysis of radiation dose and low contrast detail detectability using routine paediatric chest radiography protocols. Eur J Radiol 2019; 113:198-203. [DOI: 10.1016/j.ejrad.2019.02.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/11/2018] [Accepted: 02/13/2019] [Indexed: 11/24/2022]
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Rowan C, Puggioni A, Hoey SE, O'Leary JM, Kearney C, Connolly SE, Skelly C. Assessing the Effect of Packing the Sulcus on Image Quality in Equine Digital Radiography. Vet Rec 2019; 184:221. [PMID: 30711918 DOI: 10.1136/vr.104737] [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: 10/07/2017] [Revised: 10/07/2018] [Accepted: 12/22/2018] [Indexed: 11/04/2022]
Abstract
The requirement to pack the sulcus of the equine foot as an aid to diagnostic interpretation before acquisition of dorsoproximal-palmarodistal oblique projections is debatable. The purpose of this study was to investigate the benefit of packing the sulcus in the assessment of normal anatomy. 23 cadaver limbs were radiographed in a podoblock (https://www.podoblock.com/products-page/podoblock/podoblock/) A non-packed image (NP) and a packed image (P) of the same foot were acquired. The image quality of P was graded against the reference NP by five observers, where -1=P was superior, 0=no difference between P and NP, and +1=NP was superior. Four anatomical criteria were used: the distal solar margin of the distal phalanx (DP), the vascular channels of DP, the palmar aspect of the distal interphalangeal joint and the articulation of the navicular bone with DP. A total Visual Grading Analysis Score of 0.28 indicates a preference for NP images. Packing was of benefit in only 10.8 per cent of cases. While judicious high-quality packing may be of benefit in a minority of cases, the routine packing of the sulcus in equine radiography was not found to be of benefit in the assessment of anatomical features in this study.
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Affiliation(s)
- Conor Rowan
- Equine Clinical Studies, Diagnostic Imaging and Anaesthesia, School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Antonella Puggioni
- Equine Clinical Studies, Diagnostic Imaging and Anaesthesia, School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Séamus E Hoey
- Equine Clinical Studies, Diagnostic Imaging and Anaesthesia, School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - John Mark O'Leary
- Equine Clinical Studies, Diagnostic Imaging and Anaesthesia, School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Clodagh Kearney
- Equine Clinical Studies, Diagnostic Imaging and Anaesthesia, School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | | | - Cliona Skelly
- Equine Clinical Studies, Diagnostic Imaging and Anaesthesia, School of Veterinary Medicine, University College Dublin, Dublin, Ireland
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Al-Murshedi S, Hogg P, Lanca L, England A. A novel method for comparing radiation dose and image quality, between and within different x-ray units in a series of hospitals. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2018; 38:1344-1358. [PMID: 30251707 DOI: 10.1088/1361-6498/aae3fa] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVES To develop a novel method for comparing radiation dose and image quality (IQ) to evaluate adult chest x-ray (CXR) imaging among several hospitals. METHODS CDRAD 2.0 phantom was used to acquire images in eight hospitals (17 digital x-ray units) using local adult CXR protocols. IQ was represented by image quality figure inverse (IQFinv), measured using CDRAD analyser software. Signal to noise ratio, contrast to noise ratio and conspicuity index were calculated as additional measures of IQ. Incident air kerma (IAK) was measured using a solid-state dosimeter for each acquisition. Figure of merit (FOM) was calculated to provide a single estimation of IQ and radiation dose. RESULTS IQ, radiation dose and FOM varied considerably between hospitals and x-ray units. For IQFinv, the mean (range) between and within the hospitals were 1.42 (0.83-2.18) and 1.87 (1.52-2.18), respectively. For IAK, the mean (range) between and within the hospitals were 93.56 (17.26-239.15) μGy and 180.85 (122.58-239.15) μGy, respectively. For FOM, the mean (range) between and within hospitals were 0.05 (0.01-0.14) and 0.03 (0.02-0.05), respectively. CONCLUSIONS The suggested method for comparing IQ and dose using FOM concept along with the new proposed FOM, is a valid, reliable and effective approach for monitoring and comparing IQ and dose between and within hospitals. It is also can be beneficial for the optimisation of x-ray units in clinical practice. Further optimisation for the hospitals/x-ray units with low FOM are required to minimise radiation dose without degrading IQ.
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Affiliation(s)
- Sadeq Al-Murshedi
- School of Health Sciences, University of Salford, Salford M6 6PU, United Kingdom
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Boute B, Veldeman L, Speleers B, Van Greveling A, Van Hoof T, Van de Velde J, Vercauteren T, De Neve W, Detand J. The relation between patient discomfort and uncompensated forces of a patient support device for breast and regional lymph node radiotherapy. APPLIED ERGONOMICS 2018; 72:48-57. [PMID: 29885727 DOI: 10.1016/j.apergo.2018.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 04/12/2018] [Accepted: 05/04/2018] [Indexed: 06/08/2023]
Abstract
Although many authors stated that a user-centred design approach in medical device development has added values, the most common research approach within healthcare is evidence-based medicine, which tend to focus on functional data rather than patient wellbeing and comfort. End user comfort is well addressed in literature for commercial products such as seats and hand tools but no data was found for medical devices. A commercial patient support device for breast radiotherapy was analysed and a relation was found between discomfort and uncompensated internal body forces. Derived from CT-images, simplified patient free-body diagrams were analysed and pain and comfort evaluated. Subsequently, a new patient position was established and prototypes were developed. Patient comfort- and prototype optimization was done through iterative prototyping. With this approach, we were able to compensate all internal body forces and establish a force neutral patient free-body diagram. This resulted in comfortable patient positioning and favourable medical results.
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Affiliation(s)
- Bert Boute
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Belgium; Industrial Design Centre, Faculty of Engineering and Architecture, Ghent University, Belgium.
| | - Liv Veldeman
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Belgium; Department of Radiation Oncology, University Hospital Ghent, Belgium
| | - Bruno Speleers
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Belgium
| | | | - Tom Van Hoof
- Department of Anatomy, Faculty of Medicine and Health Sciences, Ghent University, Belgium
| | - Joris Van de Velde
- Department of Anatomy, Faculty of Medicine and Health Sciences, Ghent University, Belgium
| | - Tom Vercauteren
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Belgium; Department of Radiation Oncology, University Hospital Ghent, Belgium
| | - Wilfried De Neve
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Belgium; Department of Radiation Oncology, University Hospital Ghent, Belgium
| | - Jan Detand
- Industrial Design Centre, Faculty of Engineering and Architecture, Ghent University, Belgium
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Al-Murshedi S, Hogg P, England A. An investigation into the validity of utilising the CDRAD 2.0 phantom for optimisation studies in digital radiography. Br J Radiol 2018; 91:20180317. [PMID: 29906239 DOI: 10.1259/bjr.20180317] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVES To determine if a relationship exists between low contrast detail (LCD) detectability using the CDRAD 2.0 phantom, visual measures of image quality (IQ) and simulated lesion visibility (LV) when performing digital chest radiography (CXR). METHODS Using a range of acquisition parameters, a CDRAD 2.0 phantom was used to acquire a set of images with different levels of image quality. LCD detectability using the CDRAD 2.0 phantom, represented by an image quality figure inverse (IQFinv) metric, was determined using the phantom analyser software. A Lungman chest phantom was loaded with two simulated lesions, of different sizes/placed in different locations, and was imaged using the same acquisition factors as the CDRAD 2.0 phantom. A relative visual grading analysis (VGA) was used by seven observers for IQ and LV evaluation of the Lungman images. Correlations between IQFinv, IQ and LV were investigated. RESULTS Pearson's correlation demonstrated a strong positive correlation (r = 0.91; p < 0.001) between the IQ and the IQFinv. Spearman's correlation showed a good positive correlation (r = 0.79; p < 0.001) and (r = 0.68; p < 0.001) between the IQFinv and the LV for the first lesion (left upper lobe) and the second lesion (right middle lobe), respectively. CONCLUSIONS From results presented in this study, the automated evaluation of LCD detectability using CDRAD 2.0 phantom is likely to be a suitable option for IQ and LV evaluation in digital CXR optimisation studies. Advances in knowledge: This research establishes the potential of the CDRAD 2.0 phantom in digital CXR optimisation studies.
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Affiliation(s)
- Sadeq Al-Murshedi
- 1 School of Health Sciences, University of Salford , Salford , United Kingdom
| | - Peter Hogg
- 1 School of Health Sciences, University of Salford , Salford , United Kingdom
| | - Andrew England
- 1 School of Health Sciences, University of Salford , Salford , United Kingdom
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Evaluation of automatic image quality assessment in chest CT - A human cadaver study. Phys Med 2017; 36:32-37. [PMID: 28410683 DOI: 10.1016/j.ejmp.2017.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 11/20/2022] Open
Abstract
PURPOSE The evaluation of clinical image quality (IQ) is important to optimize CT protocols and to keep patient doses as low as reasonably achievable. Considering the significant amount of effort needed for human observer studies, automatic IQ tools are a promising alternative. The purpose of this study was to evaluate automatic IQ assessment in chest CT using Thiel embalmed cadavers. METHODS Chest CT's of Thiel embalmed cadavers were acquired at different exposures. Clinical IQ was determined by performing a visual grading analysis. Physical-technical IQ (noise, contrast-to-noise and contrast-detail) was assessed in a Catphan phantom. Soft and sharp reconstructions were made with filtered back projection and two strengths of iterative reconstruction. In addition to the classical IQ metrics, an automatic algorithm was used to calculate image quality scores (IQs). To be able to compare datasets reconstructed with different kernels, the IQs values were normalized. RESULTS Good correlations were found between IQs and the measured physical-technical image quality: noise (ρ=-1.00), contrast-to-noise (ρ=1.00) and contrast-detail (ρ=0.96). The correlation coefficients between IQs and the observed clinical image quality of soft and sharp reconstructions were 0.88 and 0.93, respectively. CONCLUSIONS The automatic scoring algorithm is a promising tool for the evaluation of thoracic CT scans in daily clinical practice. It allows monitoring of the image quality of a chest protocol over time, without human intervention. Different reconstruction kernels can be compared after normalization of the IQs.
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Influence of Contrast Agent Dilution on Ballon Deflation Time and Visibility During Tracheal Balloon Dilation: A 3D Printed Phantom Study. Cardiovasc Intervent Radiol 2016; 40:285-290. [PMID: 27826787 DOI: 10.1007/s00270-016-1497-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 10/26/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE To determine the effect of contrast medium dilution during tracheal balloon dilation on balloon deflation time and visibility using a 3-dimensional (3D) printed airway phantom. MATERIALS AND METHODS A comparison study to investigate balloon deflation times and image quality was performed using two contrast agents with different viscosities, i.e., iohexol and ioxithalamate, and six contrast dilutions with a 3D printed airway phantom. RESULTS Compared to 1:0 concentration, 3:1, 2:1, 1:1, 1:2, and 1:3, contrast/saline ratios resulted in a 46% (56.2 s), 59.8% (73.1 s), 74.9% (91.6 s), 81.7% (99.8 s), and 83.5% (102 s) reduction for iohexol, respectively, and a 51.8% (54.7 s), 63.8% (67.6 s), 74.7% (79.2 s), 80.5% (85.3 s), and 82.4% (87.4 s) reduction for ioxithalamate, respectively, in the mean balloon deflation time, although at the expense of decreased balloon opacity (3.5, 6.9, 11.1, 12.4, and 13.9%, for iohexol, respectively, and 3.2, 6, 9.6, 10.8, and 12.4%, for ioxithalamate, respectively). CONCLUSIONS Use of a lower viscosity contrast agent and higher contrast dilution is considered to be able to reduce balloon deflation times and then simultaneously decrease visualization of balloons. The rapid balloon deflation time is likely to improve the safe performance of interventional procedures.
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Davidson R, Alsleem H, Floor M, van der Burght R. A new image quality measure in CT: Feasibility of a contrast-detail measurement method. Radiography (Lond) 2016. [DOI: 10.1016/j.radi.2016.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Tesselaar E, Dahlström N, Sandborg M. CLINICAL AUDIT OF IMAGE QUALITY IN RADIOLOGY USING VISUAL GRADING CHARACTERISTICS ANALYSIS. RADIATION PROTECTION DOSIMETRY 2016; 169:340-346. [PMID: 26410763 DOI: 10.1093/rpd/ncv411] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The aim of this work was to assess whether an audit of clinical image quality could be efficiently implemented within a limited time frame using visual grading characteristics (VGC) analysis. Lumbar spine radiography, bedside chest radiography and abdominal CT were selected. For each examination, images were acquired or reconstructed in two ways. Twenty images per examination were assessed by 40 radiology residents using visual grading of image criteria. The results were analysed using VGC. Inter-observer reliability was assessed. The results of the visual grading analysis were consistent with expected outcomes. The inter-observer reliability was moderate to good and correlated with perceived image quality (r(2) = 0.47). The median observation time per image or image series was within 2 min. These results suggest that the use of visual grading of image criteria to assess the quality of radiographs provides a rapid method for performing an image quality audit in a clinical environment.
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Affiliation(s)
- Erik Tesselaar
- Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Nils Dahlström
- Radiology, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Michael Sandborg
- Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
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Geso M, Shanahan M, Alghamdi SS, Davidson R, Alghamdi S. Low-Contrast Detail Phantom: Proof of Concept. J Med Imaging Radiat Sci 2016; 47:60-65. [DOI: 10.1016/j.jmir.2015.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 10/07/2015] [Accepted: 11/04/2015] [Indexed: 10/22/2022]
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Van de Velde J, Wouters J, Vercauteren T, De Gersem W, Achten E, De Neve W, Van Hoof T. Optimal number of atlases and label fusion for automatic multi-atlas-based brachial plexus contouring in radiotherapy treatment planning. Radiat Oncol 2016; 11:1. [PMID: 26743131 PMCID: PMC4705618 DOI: 10.1186/s13014-015-0579-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 12/30/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The present study aimed to define the optimal number of atlases for automatic multi-atlas-based brachial plexus (BP) segmentation and to compare Simultaneous Truth and Performance Level Estimation (STAPLE) label fusion with Patch label fusion using the ADMIRE® software. The accuracy of the autosegmentations was measured by comparing all of the generated autosegmentations with the anatomically validated gold standard segmentations that were developed using cadavers. MATERIALS AND METHODS Twelve cadaver computed tomography (CT) atlases were used for automatic multi-atlas-based segmentation. To determine the optimal number of atlases, one atlas was selected as a patient and the 11 remaining atlases were registered onto this patient using a deformable image registration algorithm. Next, label fusion was performed by using every possible combination of 2 to 11 atlases, once using STAPLE and once using Patch. This procedure was repeated for every atlas as a patient. The similarity of the generated automatic BP segmentations and the gold standard segmentation was measured by calculating the average Dice similarity (DSC), Jaccard (JI) and True positive rate (TPR) for each number of atlases. These similarity indices were compared for the different number of atlases using an equivalence trial and for the two label fusion groups using an independent sample-t test. RESULTS DSC's and JI's were highest when using nine atlases with both STAPLE (average DSC = 0,532; JI = 0,369) and Patch (average DSC = 0,530; JI = 0,370). When comparing both label fusion algorithms using 9 atlases for both, DSC and JI values were not significantly different. However, significantly higher TPR values were achieved in favour of STAPLE (p < 0,001). When fewer than four atlases were used, STAPLE produced significantly lower DSC, JI and TPR values than did Patch (p = 0,0048). CONCLUSIONS Using 9 atlases with STAPLE label fusion resulted in the most accurate BP autosegmentations (average DSC = 0,532; JI = 0,369 and TPR = 0,760). Only when using fewer than four atlases did the Patch label fusion results in a significantly more accurate autosegmentation than STAPLE.
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Affiliation(s)
- Joris Van de Velde
- Department of Anatomy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
- Department of Radiotherapy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Johan Wouters
- Department of Anatomy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Tom Vercauteren
- Department of Radiotherapy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Werner De Gersem
- Department of Radiotherapy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Eric Achten
- Department of Radiology, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Wilfried De Neve
- Department of Radiotherapy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Tom Van Hoof
- Department of Anatomy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
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Van de Velde J, Wouters J, Vercauteren T, De Gersem W, Achten E, De Neve W, Van Hoof T. The effect of morphometric atlas selection on multi-atlas-based automatic brachial plexus segmentation. Radiat Oncol 2015; 10:260. [PMID: 26696278 PMCID: PMC4688981 DOI: 10.1186/s13014-015-0570-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/14/2015] [Indexed: 11/29/2022] Open
Abstract
Purpose The present study aimed to measure the effect of a morphometric atlas selection strategy on the accuracy of multi-atlas-based BP autosegmentation using the commercially available software package ADMIRE® and to determine the optimal number of selected atlases to use. Autosegmentation accuracy was measured by comparing all generated automatic BP segmentations with anatomically validated gold standard segmentations that were developed using cadavers. Materials and methods Twelve cadaver computed tomography (CT) atlases were included in the study. One atlas was selected as a patient in ADMIRE®, and multi-atlas-based BP autosegmentation was first performed with a group of morphometrically preselected atlases. In this group, the atlases were selected on the basis of similarity in the shoulder protraction position with the patient. The number of selected atlases used started at two and increased up to eight. Subsequently, a group of randomly chosen, non-selected atlases were taken. In this second group, every possible combination of 2 to 8 random atlases was used for multi-atlas-based BP autosegmentation. For both groups, the average Dice similarity coefficient (DSC), Jaccard index (JI) and Inclusion index (INI) were calculated, measuring the similarity of the generated automatic BP segmentations and the gold standard segmentation. Similarity indices of both groups were compared using an independent sample t-test, and the optimal number of selected atlases was investigated using an equivalence trial. Results For each number of atlases, average similarity indices of the morphometrically selected atlas group were significantly higher than the random group (p < 0,05). In this study, the highest similarity indices were achieved using multi-atlas autosegmentation with 6 selected atlases (average DSC = 0,598; average JI = 0,434; average INI = 0,733). Conclusions Morphometric atlas selection on the basis of the protraction position of the patient significantly improves multi-atlas-based BP autosegmentation accuracy. In this study, the optimal number of selected atlases used was six, but for definitive conclusions about the optimal number of atlases and to improve the autosegmentation accuracy for clinical use, more atlases need to be included.
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Affiliation(s)
- Joris Van de Velde
- Department of Anatomy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium. .,Department of Radiotherapy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Johan Wouters
- Department of Anatomy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Tom Vercauteren
- Department of Radiotherapy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Werner De Gersem
- Department of Radiotherapy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Eric Achten
- Department of Radiology, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Wilfried De Neve
- Department of Radiotherapy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Tom Van Hoof
- Department of Anatomy, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
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Perks TD, Dendere R, Irving B, Hartley T, Scholtz P, Lawson A, Trauernicht C, Steiner S, Douglas TS. Filtration to reduce paediatric dose for a linear slot-scanning digital X-ray machine. RADIATION PROTECTION DOSIMETRY 2015; 167:552-561. [PMID: 25433049 DOI: 10.1093/rpd/ncu339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 10/29/2014] [Indexed: 06/04/2023]
Abstract
This paper describes modelling, application and validation of a filtration technique for a linear slot-scanning digital X-ray system to reduce radiation dose to paediatric patients while preserving diagnostic image quality. A dose prediction model was implemented, which calculates patient entrance doses using variable input parameters. Effective dose is calculated using a Monte Carlo simulation. An added filter of 1.8-mm aluminium was predicted to lower the radiation dose significantly. An objective image quality study was conducted using detective quantum efficiency (DQE). The PTW Normi 4FLU test phantom was used for quantitative assessment, showing that image contrast and spatial resolution were maintained with the proposed filter. A paediatric cadaver full-body imaging trial assessed the diagnostic quality of the images and measured the dose reduction using a 1.8-mm aluminium filter. Assessment by radiologists indicated that diagnostic quality was maintained with the added filtration, despite a reduction in DQE. A new filtration technique for full-body paediatric scanning on the Lodox Statscan has been validated, reducing entrance dose for paediatric patients by 36 % on average and effective dose by 27 % on average, while maintaining image quality.
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Affiliation(s)
- T D Perks
- MRC/UCT Medical Imaging Research Unit and Biomedical Engineering Programme, University of Cape Town, Cape Town, South Africa
| | - R Dendere
- MRC/UCT Medical Imaging Research Unit and Biomedical Engineering Programme, University of Cape Town, Cape Town, South Africa
| | - B Irving
- MRC/UCT Medical Imaging Research Unit and Biomedical Engineering Programme, University of Cape Town, Cape Town, South Africa University of Oxford, Oxford, UK
| | - T Hartley
- Groote Schuur Hospital, Observatory, Cape Town, South Africa
| | - P Scholtz
- Groote Schuur Hospital, Observatory, Cape Town, South Africa
| | - A Lawson
- Red Cross War Memorial Children's Hospital, Mowbray, Cape Town, South Africa
| | - C Trauernicht
- Department of Medical Physics, University of Cape Town, Cape Town, South Africa
| | - S Steiner
- MRC/UCT Medical Imaging Research Unit and Biomedical Engineering Programme, University of Cape Town, Cape Town, South Africa Lodox Systems, Johannesburg, South Africa
| | - T S Douglas
- MRC/UCT Medical Imaging Research Unit and Biomedical Engineering Programme, University of Cape Town, Cape Town, South Africa
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Hayashi S, Naito M, Kawata S, Qu N, Hatayama N, Hirai S, Itoh M. History and future of human cadaver preservation for surgical training: from formalin to saturated salt solution method. Anat Sci Int 2015; 91:1-7. [PMID: 26670696 DOI: 10.1007/s12565-015-0299-5] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 08/18/2015] [Indexed: 01/07/2023]
Abstract
Traditionally, surgical training meant on-the-job training with live patients in an operating room. However, due to advancing surgical techniques, such as minimally invasive surgery, and increasing safety demands during procedures, human cadavers have been used for surgical training. When considering the use of human cadavers for surgical training, one of the most important factors is their preservation. In this review, we summarize four preservation methods: fresh-frozen cadaver, formalin, Thiel's, and saturated salt solution methods. Fresh-frozen cadaver is currently the model that is closest to reality, but it also presents myriad problems, including the requirement of freezers for storage, limited work time because of rapid putrefaction, and risk of infection. Formalin is still used ubiquitously due to its low cost and wide availability, but it is not ideal because formaldehyde has an adverse health effect and formalin-embalmed cadavers do not exhibit many of the qualities of living organs. Thiel's method results in soft and flexible cadavers with almost natural colors, and Thiel-embalmed cadavers have been appraised widely in various medical disciplines. However, Thiel's method is relatively expensive and technically complicated. In addition, Thiel-embalmed cadavers have a limited dissection time. The saturated salt solution method is simple, carries a low risk of infection, and is relatively low cost. Although more research is needed, this method seems to be sufficiently useful for surgical training and has noteworthy features that expand the capability of clinical training. The saturated salt solution method will contribute to a wider use of cadavers for surgical training.
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Affiliation(s)
- Shogo Hayashi
- Department of Anatomy, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-Ku, Tokyo, 160-8402, Japan.
| | - Munekazu Naito
- Department of Anatomy, School of Medicine, Aichi Medical University, Aichi, Japan
| | - Shinichi Kawata
- Department of Anatomy, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-Ku, Tokyo, 160-8402, Japan
| | - Ning Qu
- Department of Anatomy, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-Ku, Tokyo, 160-8402, Japan
| | - Naoyuki Hatayama
- Department of Anatomy, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-Ku, Tokyo, 160-8402, Japan
| | - Shuichi Hirai
- Department of Anatomy, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-Ku, Tokyo, 160-8402, Japan
| | - Masahiro Itoh
- Department of Anatomy, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-Ku, Tokyo, 160-8402, Japan
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Van de Velde J, Bogaert S, Vandemaele P, Huysse W, Achten E, Leijnse J, De Neve W, Van Hoof T. Brachial plexus 3D reconstruction from MRI with dissection validation: a baseline study for clinical applications. Surg Radiol Anat 2015; 38:229-36. [DOI: 10.1007/s00276-015-1549-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 08/17/2015] [Indexed: 02/01/2023]
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De Crop A, Smeets P, Van Hoof T, Vergauwen M, Dewaele T, Van Borsel M, Achten E, Verstraete K, D'Herde K, Thierens H, Bacher K. Correlation of clinical and physical-technical image quality in chest CT: a human cadaver study applied on iterative reconstruction. BMC Med Imaging 2015; 15:32. [PMID: 26286596 PMCID: PMC4541737 DOI: 10.1186/s12880-015-0075-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 08/10/2015] [Indexed: 12/14/2022] Open
Abstract
Background The first aim of this study was to evaluate the correlation between clinical and physical-technical image quality applied to different strengths of iterative reconstruction in chest CT images using Thiel cadaver acquisitions and Catphan images. The second aim was to determine the potential dose reduction of iterative reconstruction compared to conventional filtered back projection based on different clinical and physical-technical image quality parameters. Methods Clinical image quality was assessed using three Thiel embalmed human cadavers. A Catphan phantom was used to assess physical-technical image quality parameters such as noise, contrast-detail and contrast-to-noise ratio (CNR). Both Catphan and chest Thiel CT images were acquired on a multislice CT scanner at 120 kVp and 0.9 pitch. Six different refmAs settings were applied (12, 30, 60, 90, 120 and 150refmAs) and each scan was reconstructed using filtered back projection (FBP) and iterative reconstruction (SAFIRE) algorithms (1,3 and 5 strengths) using a sharp kernel, resulting in 24 image series. Four radiologists assessed the clinical image quality, using a visual grading analysis (VGA) technique based on the European Quality Criteria for Chest CT. Results Correlation coefficients between clinical and physical-technical image quality varied from 0.88 to 0.92, depending on the selected physical-technical parameter. Depending on the strength of SAFIRE, the potential dose reduction based on noise, CNR and the inverse image quality figure (IQFinv) varied from 14.0 to 67.8 %, 16.0 to 71.5 % and 22.7 to 50.6 % respectively. Potential dose reduction based on clinical image quality varied from 27 to 37.4 %, depending on the strength of SAFIRE. Conclusion Our results demonstrate that noise assessments in a uniform phantom overestimate the potential dose reduction for the SAFIRE IR algorithm. Since the IQFinv based dose reduction is quite consistent with the clinical based dose reduction, an optimised contrast-detail phantom could improve the use of contrast-detail analysis for image quality assessment in chest CT imaging. In conclusion, one should be cautious to evaluate the performance of CT equipment taking into account only physical-technical parameters as noise and CNR, as this might give an incomplete representation of the actual clinical image quality performance.
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Affiliation(s)
- An De Crop
- Department of Basic Medical Sciences, Ghent University, Proeftuinstraat 86, B-9000, Ghent, Belgium.
| | - Peter Smeets
- Department of Radiology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
| | - Tom Van Hoof
- Department of Basic Medical Sciences, Ghent University, Proeftuinstraat 86, B-9000, Ghent, Belgium.
| | - Merel Vergauwen
- Department of Radiology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
| | - Tom Dewaele
- Department of Radiology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
| | - Mathias Van Borsel
- Department of Radiology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
| | - Eric Achten
- Department of Radiology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
| | - Koenraad Verstraete
- Department of Radiology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
| | - Katharina D'Herde
- Department of Basic Medical Sciences, Ghent University, Proeftuinstraat 86, B-9000, Ghent, Belgium.
| | - Hubert Thierens
- Department of Basic Medical Sciences, Ghent University, Proeftuinstraat 86, B-9000, Ghent, Belgium.
| | - Klaus Bacher
- Department of Basic Medical Sciences, Ghent University, Proeftuinstraat 86, B-9000, Ghent, Belgium.
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Van de Velde J, Wouters J, Vercauteren T, De Gersem W, Duprez F, De Neve W, Van Hoof T. Morphometric Atlas Selection for Automatic Brachial Plexus Segmentation. Int J Radiat Oncol Biol Phys 2015; 92:691-8. [PMID: 25956831 DOI: 10.1016/j.ijrobp.2015.02.045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 02/17/2015] [Accepted: 02/23/2015] [Indexed: 12/25/2022]
Abstract
PURPOSE The purpose of this study was to determine the effects of atlas selection based on different morphometric parameters, on the accuracy of automatic brachial plexus (BP) segmentation for radiation therapy planning. The segmentation accuracy was measured by comparing all of the generated automatic segmentations with anatomically validated gold standard atlases developed using cadavers. METHODS AND MATERIALS Twelve cadaver computed tomography (CT) atlases (3 males, 9 females; mean age: 73 years) were included in the study. One atlas was selected to serve as a patient, and the other 11 atlases were registered separately onto this "patient" using deformable image registration. This procedure was repeated for every atlas as a patient. Next, the Dice and Jaccard similarity indices and inclusion index were calculated for every registered BP with the original gold standard BP. In parallel, differences in several morphometric parameters that may influence the BP segmentation accuracy were measured for the different atlases. Specific brachial plexus-related CT-visible bony points were used to define the morphometric parameters. Subsequently, correlations between the similarity indices and morphometric parameters were calculated. RESULTS A clear negative correlation between difference in protraction-retraction distance and the similarity indices was observed (mean Pearson correlation coefficient = -0.546). All of the other investigated Pearson correlation coefficients were weak. CONCLUSIONS Differences in the shoulder protraction-retraction position between the atlas and the patient during planning CT influence the BP autosegmentation accuracy. A greater difference in the protraction-retraction distance between the atlas and the patient reduces the accuracy of the BP automatic segmentation result.
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Affiliation(s)
- Joris Van de Velde
- Department of Anatomy, Ghent University, Ghent, Belgium; Department of Radiotherapy, Ghent University, Ghent, Belgium.
| | - Johan Wouters
- Department of Anatomy, Ghent University, Ghent, Belgium
| | - Tom Vercauteren
- Department of Radiotherapy, Ghent University, Ghent, Belgium
| | | | - Fréderic Duprez
- Department of Radiotherapy, Ghent University, Ghent, Belgium
| | | | - Tom Van Hoof
- Department of Anatomy, Ghent University, Ghent, Belgium
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Eloot L, Thierens H, Taeymans Y, Drieghe B, De Pooter J, Van Peteghem S, Buytaert D, Gijs T, Lapere R, Bacher K. Novel X-ray imaging technology enables significant patient dose reduction in interventional cardiology while maintaining diagnostic image quality. Catheter Cardiovasc Interv 2015; 86:E205-12. [PMID: 25754018 PMCID: PMC6680340 DOI: 10.1002/ccd.25913] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 02/26/2015] [Indexed: 12/31/2022]
Abstract
Objectives The purpose of this study was to quantify the reduction in patient radiation dose during coronary angiography (CA) by a new X‐ray technology, and to assess its impact on diagnostic image quality. Background Recently, a novel X‐ray imaging technology has become available for interventional cardiology, using advanced image processing and an optimized acquisition chain for radiation dose reduction. Methods 70 adult patients were randomly assigned to a reference X‐ray system or the novel X‐ray system. Patient demographics were registered and exposure parameters were recorded for each radiation event. Clinical image quality was assessed for both patient groups. Results With the same angiographic technique and a comparable patient population, the new imaging technology was associated with a 75% reduction in total kerma‐area product (KAP) value (decrease from 47 Gycm2 to 12 Gycm2, P < 0.001). Clinical image quality showed an equivalent detail and contrast for both imaging systems. On the other hand, the subjective appreciation of noise was more apparent in images of the new image processing system, acquired at lower doses, compared to the reference system. However, the higher noise content did not affect the overall image quality score, which was adequate for diagnosis in both systems. Conclusions For the first time, we present a new X‐ray imaging technology, combining advanced noise reduction algorithms and an optimized acquisition chain, which reduces patient radiation dose in CA drastically (75%), while maintaining diagnostic image quality. Use of this technology may further improve the radiation safety of cardiac angiography and interventions. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Liesbeth Eloot
- Department of Basic Medical Sciences, Ghent University, Ghent, Belgium
| | - Hubert Thierens
- Department of Basic Medical Sciences, Ghent University, Ghent, Belgium
| | - Yves Taeymans
- Heart Centre, Ghent University Hospital, Ghent, Belgium
| | - Benny Drieghe
- Heart Centre, Ghent University Hospital, Ghent, Belgium
| | - Jan De Pooter
- Heart Centre, Ghent University Hospital, Ghent, Belgium
| | | | - Dimitri Buytaert
- Department of Basic Medical Sciences, Ghent University, Ghent, Belgium
| | - Thomas Gijs
- Department of Basic Medical Sciences, Ghent University, Ghent, Belgium
| | - Régine Lapere
- Department of Basic Medical Sciences, Ghent University, Ghent, Belgium
| | - Klaus Bacher
- Department of Basic Medical Sciences, Ghent University, Ghent, Belgium
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Healy SE, Rai BP, Biyani CS, Eisma R, Soames RW, Nabi G. Thiel Embalming Method for Cadaver Preservation: A Review of New Training Model for Urologic Skills Training. Urology 2015; 85:499-504. [DOI: 10.1016/j.urology.2014.11.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 11/06/2014] [Accepted: 11/13/2014] [Indexed: 12/01/2022]
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Hayashi S, Homma H, Naito M, Oda J, Nishiyama T, Kawamoto A, Kawata S, Sato N, Fukuhara T, Taguchi H, Mashiko K, Azuhata T, Ito M, Kawai K, Suzuki T, Nishizawa Y, Araki J, Matsuno N, Shirai T, Qu N, Hatayama N, Hirai S, Fukui H, Ohseto K, Yukioka T, Itoh M. Saturated salt solution method: a useful cadaver embalming for surgical skills training. Medicine (Baltimore) 2014; 93:e196. [PMID: 25501070 PMCID: PMC4602773 DOI: 10.1097/md.0000000000000196] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
This article evaluates the suitability of cadavers embalmed by the saturated salt solution (SSS) method for surgical skills training (SST). SST courses using cadavers have been performed to advance a surgeon's techniques without any risk to patients. One important factor for improving SST is the suitability of specimens, which depends on the embalming method. In addition, the infectious risk and cost involved in using cadavers are problems that need to be solved. Six cadavers were embalmed by 3 methods: formalin solution, Thiel solution (TS), and SSS methods. Bacterial and fungal culture tests and measurement of ranges of motion were conducted for each cadaver. Fourteen surgeons evaluated the 3 embalming methods and 9 SST instructors (7 trauma surgeons and 2 orthopedists) operated the cadavers by 21 procedures. In addition, ultrasonography, central venous catheterization, and incision with cauterization followed by autosuture stapling were performed in some cadavers. The SSS method had a sufficient antibiotic effect and produced cadavers with flexible joints and a high tissue quality suitable for SST. The surgeons evaluated the cadavers embalmed by the SSS method to be highly equal to those embalmed by the TS method. Ultrasound images were clear in the cadavers embalmed by both the methods. Central venous catheterization could be performed in a cadaver embalmed by the SSS method and then be affirmed by x-ray. Lungs and intestines could be incised with cauterization and autosuture stapling in the cadavers embalmed by TS and SSS methods. Cadavers embalmed by the SSS method are sufficiently useful for SST. This method is simple, carries a low infectious risk, and is relatively of low cost, enabling a wider use of cadavers for SST.
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Affiliation(s)
- Shogo Hayashi
- From the Department of Anatomy (SH, SK, TS, NQ, NH, SH, MI); Department of Emergency and Critical Care Medicine (HH, JO, KK, TS, TY); Department of Anesthesiology (TN, HF, KO), Tokyo Medical University, Tokyo, Japan; Department of Anatomy (MN), Aichi Medical University School of Medicine, Aichi, Japan; Department of Diagnostic Radiology/Division of Ultrasound (AK), Tokyo Medical University Hospital, Tokyo, Japan; Department of Primary Care and Emergency Medicine (NS), Graduate School of Medicine and University School of Medicine, Kyoto University, Kyoto, Japan; Advanced Disaster Medical and Emergency Critical Care Center (TF), Niigata University Medical and Dental Hospital, Niigata, Japan; Department of Emergency and Critical Care Medicine (HT), Kinki University School of Medicine, Osaka, Japan; Shock and Trauma Center (KM), Chiba Hokusoh Hospital, Nippon Medical School, Chiba, Japan; Department of Emergency and Critical Care Medicine (TA), Nihon University School of Medicine Itabashi Hospital, Tokyo, Japan; Department of Orthopaedic Surgery (MI), Niigata City General Hospital, Niigata, Japan; Department of Colorectal Surgery (YN), National Cancer Center Hospital East, Chiba, Japan; Department of Plastic Surgery (JA), University of Tokyo Graduate School of Medicine, Tokyo, Japan; and Division of Gastroenterological and General Surgery (NM), Asahikawa Medical University School of Medicine, Hokkaido, Japan
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Abstract
In this essay Roos Eisma and Tracey Wilkinson describe how the Thiel technique has expanded the range of applications in which embalmed human cadavers can be used. For decades, embalmed cadavers have played an important role in teaching anatomy to the scientists and doctors of the future. Most anatomy departments use a traditional formaldehyde-based embalming method, but formalin embalming makes the bodies very rigid, which limits their usefulness for procedures other than dissection. A more recent embalming method developed by W. Thiel has allowed these “silent teachers” to take on a further role in applied anatomy research and teaching: to act as models for surgical training and medical research.
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Affiliation(s)
- Roos Eisma
- Centre for Anatomy and Human Identification, University of Dundee, Dundee, Scotland, United Kingdom
- * E-mail:
| | - Tracey Wilkinson
- Centre for Anatomy and Human Identification, University of Dundee, Dundee, Scotland, United Kingdom
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50
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Van de Velde J, Vercauteren T, De Gersem W, Wouters J, Vandecasteele K, Vuye P, Vanpachtenbeke F, D’Herde K, Kerckaert I, De Neve W, Van Hoof T. Reliability and accuracy assessment of radiation therapy oncology group-endorsed guidelines for brachial plexus contouring. Strahlenther Onkol 2014; 190:628-32, 634-5. [DOI: 10.1007/s00066-014-0657-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/11/2014] [Indexed: 12/25/2022]
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