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Decoster R, Toomey R, Smits D, Haygood TM, Ryan ML. Understanding reasons for image rejection by radiologists and radiographers. J Med Radiat Sci 2022. [PMID: 36565472 DOI: 10.1002/jmrs.641] [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: 03/29/2022] [Accepted: 11/28/2022] [Indexed: 12/25/2022] Open
Abstract
INTRODUCTION A core element of a radiographer's role is the decision on whether a radiograph is sufficient for diagnosis, or a repeat examination is needed. Studies illustrate the disagreement on the diagnostic value of radiographs between radiographers and radiologists, which may influence repeat examinations. This study investigates if parameters contributing to image quality are possible determinants to explain the difference between professions. METHODS A total of 74 radiographers and radiologists from three different countries assessed three data sets (chest PA, hip HBL, c-spine lateral), each containing 25 radiographs. All observers scored image quality in terms of anatomical visualisation, positioning, collimation, detector exposure and judged the diagnostic value using the ACR RadLex classification. All assessments were performed on a clinically relevant display. Visual grading characteristics were used to compare image quality evaluations between groups. RESULTS Radiographers scored the visualisation of anatomical structures lower than radiologists though the difference was not statistically significant. A difference in classification using the RadLex categories - with radiographers rejecting more radiographs - was demonstrated. Only the subjective evaluation of the detector exposure correlated statistically with RadLex ratings. There was no difference between radiographers and radiologists when reviewing patient positioning and collimation. CONCLUSION Radiographers and radiologists agree on the visualisation of anatomical structures, but radiographers are more critical towards the diagnostic value. Within the criteria studied, the evaluation of anatomical structures does not explain the difference. Radiographs have a higher change of being rejected if the observer (subjectively) assessed the detector exposure as inappropriate. This correlation is stronger for radiographers.
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Affiliation(s)
- Robin Decoster
- School of Medicine, University College Dublin, Dublin, Ireland
| | - Rachel Toomey
- School of Medicine, University College Dublin, Dublin, Ireland
| | - Dirk Smits
- Health Care Science, Odisee University College, Brussel, Belgium
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Holstensson M, Smedby Ö, Poludniowski G, Sanchez-Crespo A, Savitcheva I, Öberg M, Grybäck P, Gabrielson S, Sandqvist P, Bartholdson E, Axelsson R. Comparison of acquisition protocols for ventilation/perfusion SPECT-a Monte Carlo study. Phys Med Biol 2019; 64:235018. [PMID: 31362272 DOI: 10.1088/1361-6560/ab36ee] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
One of the most commonly used imaging techniques for diagnosing pulmonary embolism (PE) is ventilation/perfusion (V/P) scintigraphy. The aim of this study was to evaluate the performance of the currently used imaging protocols for V/P single photon emission computed tomography (V/P SPECT) at two nuclear medicine department sites and to investigate the effect of altering important protocol parameters. The Monte Carlo technique was used to simulate 4D digital phantoms with perfusion defects. Six imaging protocols were included in the study and a total of 72 digital patients were simulated. Six dually trained radiologists/nuclear medicine physicians reviewed the images and reported all perfusion mismatch findings. The radiologists also visually graded the image quality. No statistically significant differences in diagnostic performance were found between the studied protocols, but visual grading analysis pointed out one protocol as significantly superior to four of the other protocols. Considering the study results, we have decided to harmonize our clinical protocols for imaging patients with suspected PE. The administered Technegas and macro aggregated albumin activities have been altered, a low energy all purpose collimator is used instead of a low energy high resolution collimator and the acquisition times have been lowered.
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Affiliation(s)
- Maria Holstensson
- Medical Radiation Physics and Nuclear Medicine, Imaging and Physiology, Karolinska University Hospital, Stockholm, Sweden. Department of Clinical Science, Intervention and Technology (CLINTEC), Division of Functional Imaging and Technology, Karolinska Institutet, Stockholm, Sweden. Author to whom any corrrespondence should be addressed
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Jang JS, Yang HJ, Koo HJ, Kim SH, Park CR, Yoon SH, Shin SY, Do KH. Image quality assessment with dose reduction using high kVp and additional filtration for abdominal digital radiography. Phys Med 2018; 50:46-51. [PMID: 29891093 DOI: 10.1016/j.ejmp.2018.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 05/04/2018] [Accepted: 05/06/2018] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Dose reduction using additional filters with high kilovoltage peak (kVp) for abdominal digital radiography has received much attention recently. We evaluated image quality with dose reduction in abdominal digital radiography by using high kVp and additional copper filters at a tertiary hospital. METHODS Between June 2016 and July 2016, 82 patients underwent abdominal digital radiography using 80 kVp in X-ray room 1 and 82 were imaged using 92 kVp with 0.1-mm copper filtration in X-ray room 2. The effective dose was calculated using a PC-based Monte Carlo program. Image quality of the abdominal radiography acquired in the two rooms was evaluated using a five-point ordinal scale, as well as the signal-to-noise and contrast-to-noise ratios. RESULTS The mean effective dose decreased by 25.8% and 25.7% for the supine and standing positions, respectively, when abdominal digital radiography using 92 kVp with 0.1-mm copper filtration was performed. In the 20 patients who performed abdominal digital radiography twice in each room, visual grading scores for visualisation of psoas outlines and kidney outlines are higher in room 1. However, there was no statistical significant difference of visual grading scores among the 124 patients who underwent only one abdominal radiography in the room 1 or 2 (P > 0.05). CONCLUSIONS Dose reduction for abdominal digital radiography can be achieved with comparable image quality by performing abdominal digital radiography using 92 kVp with 0.1-mm copper filtration, despite the higher AEC dose.
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Affiliation(s)
- Ji Sung Jang
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, South Korea; Department of Medical Physics, Korea University, South Korea
| | - Hyung Jin Yang
- Department of Medical Physics, Korea University, South Korea
| | - Hyun Jung Koo
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, South Korea
| | - Sung Ho Kim
- Department of Medical Physics, Korea University, South Korea
| | - Chan Rok Park
- Department of Medical Physics, Korea University, South Korea
| | - Suk Hwan Yoon
- Department of Medical Physics, Korea University, South Korea
| | - So Youn Shin
- Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, South Korea
| | - Kyung-Hyun Do
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, South Korea.
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Kataria B, Althén JN, Smedby Ö, Persson A, Sökjer H, Sandborg M. Assessment of image quality in abdominal CT: potential dose reduction with model-based iterative reconstruction. Eur Radiol 2018; 28:2464-2473. [PMID: 29368163 PMCID: PMC5938296 DOI: 10.1007/s00330-017-5113-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/23/2017] [Accepted: 09/29/2017] [Indexed: 01/20/2023]
Abstract
PURPOSE To estimate potential dose reduction in abdominal CT by visually comparing images reconstructed with filtered back projection (FBP) and strengths of 3 and 5 of a specific MBIR. MATERIAL AND METHODS A dual-source scanner was used to obtain three data sets each for 50 recruited patients with 30, 70 and 100% tube loads (mean CTDIvol 1.9, 3.4 and 6.2 mGy). Six image criteria were assessed independently by five radiologists. Potential dose reduction was estimated with Visual Grading Regression (VGR). RESULTS Comparing 30 and 70% tube load, improved image quality was observed as a significant strong effect of log tube load and reconstruction method with potential dose reduction relative to FBP of 22-47% for MBIR strength 3 (p < 0.001). For MBIR strength 5 no dose reduction was possible for image criteria 1 (liver parenchyma), but dose reduction between 34 and 74% was achieved for other criteria. Interobserver reliability showed agreement of 71-76% (κw 0.201-0.286) and intra-observer reliability of 82-96% (κw 0.525-0.783). CONCLUSION MBIR showed improved image quality compared to FBP with positive correlation between MBIR strength and increasing potential dose reduction for all but one image criterion. KEY POINTS • MBIR's main advantage is its de-noising properties, which facilitates dose reduction. • MBIR allows for potential dose reduction in relation to FBP. • Visual Grading Regression (VGR) produces direct numerical estimates of potential dose reduction. • MBIR strengths 3 and 5 dose reductions were 22-34 and 34-74%. • MBIR strength 5 demonstrates inferior performance for liver parenchyma.
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Affiliation(s)
- Bharti Kataria
- Department of Radiology, Department of Medical and Health Sciences, Center for Medical Image Science and Visualization (CMIV), Linköping University, S-581 85, Linköping, Sweden.
| | - Jonas Nilsson Althén
- Department of Medical Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Örjan Smedby
- School of Technology and Health (STH), KTH Royal Institute, Stockholm, Sweden
| | - Anders Persson
- Department of Radiology, Department of Medical and Health Sciences, Center for Medical Image Science and Visualization (CMIV), Linköping University, S-581 85, Linköping, Sweden
| | - Hannibal Sökjer
- Department of Medical and Health Sciences, Linköping University, S-581 83, Linköping, Sweden
| | - Michael Sandborg
- Department of Medical Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
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Jensen K, Andersen HK, Smedby Ö, Østerås BH, Aarsnes A, Tingberg A, Fosse E, Martinsen AC. Quantitative Measurements Versus Receiver Operating Characteristics and Visual Grading Regression in CT Images Reconstructed with Iterative Reconstruction: A Phantom Study. Acad Radiol 2018; 25:509-518. [PMID: 29198945 DOI: 10.1016/j.acra.2017.10.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/16/2017] [Accepted: 10/26/2017] [Indexed: 01/11/2023]
Abstract
RATIONALE AND OBJECTIVES This study aimed to evaluate the correlation of quantitative measurements with visual grading regression (VGR) and receiver operating characteristics (ROC) analysis in computed tomography (CT) images reconstructed with iterative reconstruction. MATERIALS AND METHODS CT scans on a liver phantom were performed on CT scanners from GE, Philips, and Toshiba at three dose levels. Images were reconstructed with filtered back projection (FBP) and hybrid iterative techniques (ASiR, iDose, and AIDR 3D of different strengths). Images were visually assessed by five readers using a four- and five-grade ordinal scale for liver low contrast lesions and for 10 image quality criteria. The results were analyzed with ROC and VGR. Standard deviation, signal-to-noise ratios, and contrast-to-noise ratios were measured in the images. RESULTS All data were compared to FBP. The results of the quantitative measurements were improved for all algorithms. ROC analysis showed improved lesion detection with ASiR and AIDR and decreased lesion detection with iDose. VGR found improved noise properties for all algorithms, increased sharpness with iDose and AIDR, and decreased artifacts from the spine with AIDR, whereas iDose increased the artifacts from the spine. The contrast in the spine decreased with ASiR and iDose. CONCLUSIONS Improved quantitative measurements in images reconstructed with iterative reconstruction compared to FBP are not equivalent to improved diagnostic image accuracy.
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Alshamari M, Geijer M, Norrman E, Lidén M, Krauss W, Jendeberg J, Magnuson A, Geijer H. Impact of iterative reconstruction on image quality of low-dose CT of the lumbar spine. Acta Radiol 2017; 58:702-709. [PMID: 28157395 DOI: 10.1177/0284185116669870] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Iterative reconstruction (IR) is a recent reconstruction algorithm for computed tomography (CT) that can be used instead of the standard algorithm, filtered back projection (FBP), to reduce radiation dose and/or improve image quality. Purpose To evaluate and compare the image quality of low-dose CT of the lumbar spine reconstructed with IR to conventional FBP, without further reduction of radiation dose. Material and Methods Low-dose CT on 55 patients was performed on a Siemens scanner using 120 kV tube voltage, 30 reference mAs, and automatic dose modulation. From raw CT data, lumbar spine CT images were reconstructed with a medium filter (B41f) using FBP and four levels of IR (levels 2-5). Five reviewers scored all images on seven image quality criteria according to the European guidelines on quality criteria for CT, using a five-grade scale. A side-by-side comparison was also performed. Results There was significant improvement in image quality for IR (levels 2-4) compared to FBP. According to visual grading regression, odds ratios of all criteria with 95% confidence intervals for IR2, IR3, IR4, and IR5 were: 1.59 (1.39-1.83), 1.74 (1.51-1.99), 1.68 (1.46-1.93), and 1.08 (0.94-1.23), respectively. In the side-by-side comparison of all reconstructions, images with IR (levels 2-4) received the highest scores. The mean overall CTDIvol was 1.70 mGy (SD 0.46; range, 1.01-3.83 mGy). Image noise decreased in a linear fashion with increased strength of IR. Conclusion Iterative reconstruction at levels 2, 3, and 4 improves image quality of low-dose CT of the lumbar spine compared to FPB.
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Affiliation(s)
- Muhammed Alshamari
- Department of Radiology, School of Medical Sciences, Örebro University, Örebro, Sweden
| | - Mats Geijer
- Department of Radiology, School of Medical Sciences, Örebro University, Örebro, Sweden
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Lund University, Sweden
| | - Eva Norrman
- Department of Medical Physics, School of Medical Sciences, Örebro University, Örebro, Sweden
| | - Mats Lidén
- Department of Radiology, School of Medical Sciences, Örebro University, Örebro, Sweden
| | - Wolfgang Krauss
- Department of Radiology, School of Medical Sciences, Örebro University, Örebro, Sweden
| | - Johan Jendeberg
- Department of Radiology, School of Medical Sciences, Örebro University, Örebro, Sweden
| | - Anders Magnuson
- Clinical Epidemiology and Biostatistics, School of Medical Sciences, Örebro University, Örebro, Sweden
| | - Håkan Geijer
- Department of Radiology, School of Medical Sciences, Örebro University, Örebro, Sweden
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Joshi A, Gislason-Lee AJ, Keeble C, Sivananthan UM, Davies AG. Can image enhancement allow radiation dose to be reduced whilst maintaining the perceived diagnostic image quality required for coronary angiography? Br J Radiol 2017; 90:20160660. [PMID: 28124572 DOI: 10.1259/bjr.20160660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE The aim of this research was to quantify the reduction in radiation dose facilitated by image processing alone for percutaneous coronary intervention (PCI) patient angiograms, without reducing the perceived image quality required to confidently make a diagnosis. METHODS Incremental amounts of image noise were added to five PCI angiograms, simulating the angiogram as having been acquired at corresponding lower dose levels (10-89% dose reduction). 16 observers with relevant experience scored the image quality of these angiograms in 3 states-with no image processing and with 2 different modern image processing algorithms applied. These algorithms are used on state-of-the-art and previous generation cardiac interventional X-ray systems. Ordinal regression allowing for random effects and the delta method were used to quantify the dose reduction possible by the processing algorithms, for equivalent image quality scores. RESULTS Observers rated the quality of the images processed with the state-of-the-art and previous generation image processing with a 24.9% and 15.6% dose reduction, respectively, as equivalent in quality to the unenhanced images. The dose reduction facilitated by the state-of-the-art image processing relative to previous generation processing was 10.3%. CONCLUSION Results demonstrate that statistically significant dose reduction can be facilitated with no loss in perceived image quality using modern image enhancement; the most recent processing algorithm was more effective in preserving image quality at lower doses. Advances in knowledge: Image enhancement was shown to maintain perceived image quality in coronary angiography at a reduced level of radiation dose using computer software to produce synthetic images from real angiograms simulating a reduction in dose.
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Affiliation(s)
- Anuja Joshi
- 1 Division of Biomedical Imaging, University of Leeds, Leeds, UK
| | | | - Claire Keeble
- 1 Division of Biomedical Imaging, University of Leeds, Leeds, UK.,2 Division of Epidemiology and Biostatistics, University of Leeds, Leeds, UK
| | | | - Andrew G Davies
- 1 Division of Biomedical Imaging, University of Leeds, Leeds, UK
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Saffari SE, Löve Á, Fredrikson M, Smedby Ö. Regression models for analyzing radiological visual grading studies--an empirical comparison. BMC Med Imaging 2015; 15:49. [PMID: 26515510 PMCID: PMC4627379 DOI: 10.1186/s12880-015-0083-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 09/21/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND For optimizing and evaluating image quality in medical imaging, one can use visual grading experiments, where observers rate some aspect of image quality on an ordinal scale. To analyze the grading data, several regression methods are available, and this study aimed at empirically comparing such techniques, in particular when including random effects in the models, which is appropriate for observers and patients. METHODS Data were taken from a previous study where 6 observers graded or ranked in 40 patients the image quality of four imaging protocols, differing in radiation dose and image reconstruction method. The models tested included linear regression, the proportional odds model for ordinal logistic regression, the partial proportional odds model, the stereotype logistic regression model and rank-order logistic regression (for ranking data). In the first two models, random effects as well as fixed effects could be included; in the remaining three, only fixed effects. RESULTS In general, the goodness of fit (AIC and McFadden's Pseudo R (2)) showed small differences between the models with fixed effects only. For the mixed-effects models, higher AIC and lower Pseudo R (2) was obtained, which may be related to the different number of parameters in these models. The estimated potential for dose reduction by new image reconstruction methods varied only slightly between models. CONCLUSIONS The authors suggest that the most suitable approach may be to use ordinal logistic regression, which can handle ordinal data and random effects appropriately.
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Affiliation(s)
- S Ehsan Saffari
- Department of Medical and Health Sciences (IMH), Linköping University, Linköping, Sweden. .,Sabzevar University of Medical Sciences, Sabzevar, Iran.
| | - Áskell Löve
- Department of Diagnostic Radiology, Lund University, Clinical Sciences, Lund, Sweden. .,Department of Radiology, Landspitali University Hospital, Reykjavik and Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
| | - Mats Fredrikson
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
| | - Örjan Smedby
- Department of Medical and Health Sciences (IMH), Linköping University, Linköping, Sweden. .,KTH Royal Institute of Technology, School of Technology and Health, Alfred Nobels allé 10, SE-141 52, Huddinge, Stockholm, Sweden.
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