INTRODUCTION Lumbar spine radiography is considered as having a high radiation dose compared to o... more INTRODUCTION Lumbar spine radiography is considered as having a high radiation dose compared to other planar radiography examinations. The aim of this study was to investigate the feasibility of replacing an antiscatter grid with an air gap technique to achieve dose reduction for lateral lumbar spine radiography while maintaining image quality on a direct digital radiography (DDR) system. METHODS In phase 1, an experimental study using an anthropomorphic phantom identified the optimal airgap technique. In phase 2, lateral projections of the lumbar spine were performed on 50 patients randomly assigned equally into a control group (using the antiscatter grid) and an experimental group (using the airgap technique). The dose area product (DAP) was recorded, keeping other variables constant. Image quality evaluation was performed by 5 radiologists performing Absolute Visual Grading Analysis (VGA) using an image quality score tool, with resultant scores analysed using Visual Grading Characteristics (VGC). RESULTS A 10 cm airgap in conjunction with a source to image distance (SID) of 121 cm was found as the optimal airgap technique. The clinical application of this technique resulted in a statistically significant (p < 0.05) reduction in DAP of 72%. Image quality scores were higher for the antiscatter grid but variation between the two techniques was not significant (p > 0.05). CONCLUSION Replacing the antiscatter grid with an airgap technique in lateral lumbar spine digital radiography, provides a significant dose reduction whilst still maintaining diagnostic image quality. IMPLICATIONS FOR PRACTICE The airgap technique is a simple and easy technique to implement and radiographers should find no difficulties in applying it, as It involves no additional cost and no additional equipment.
The intent of the review was to identify different methodological approaches used to calculate th... more The intent of the review was to identify different methodological approaches used to calculate the planning target volume (PTV) margin for head and neck patients treated with volumetric arc therapy (VMAT), and whether the necessary factors to calculate the margin size with the selected formula were used. A comprehensive, systematic search of related studies was done using the Hydi search engine and different databases: MEDLINE, PubMed, CINAHL, ProQuest (Nursing and Allied Health), Scopus, ScienceDirect and tipsRO. The literature search included studies published between January 2007 and December 2020. Eligibility screening was performed by two reviewers. A total of seven studies were found. All the reviewed studies used the Van Herk formula to measure the PTV margin. None of the studies incorporated the systematic errors of target volume delineation in the PTV equation. Inter-fraction translational errors were assessed in all the studies, whilst intra-fraction errors were only inclu...
The use of cadavers for medical education purposes and for radiology research methodologies which... more The use of cadavers for medical education purposes and for radiology research methodologies which involve subjective image quality evaluation of anatomical criteria is well documented. The aim of this study was to quantify the impact of cadaver tissue preservation in producing MR images that are representative of living tissue by comparing the visualisation of anatomical structures of the ankle obtained from live and cadaver (fresh frozen and Thiel embalmed) specimens through a visual grading analysis (VGA) study. Methods: A VGA study was conducted on an image data set consisting of 4 coronal proton density weighted (PDw) sequences obtained from ankles of a live patient and those of a cadaveric specimen, of which the right ankle was frozen and the left Thiel embalmed. Results: Comparison of the image quality scores obtained from: the live patient vs. the Thiel specimen indicate a significant difference (p 0.05) between the scores in favour of the Thiel specimen; between the live patient vs. the frozen specimen indicate a significant difference (p 0.05) in favour of the frozen specimen and between the frozen vs. the Thiel specimen indicate a significant difference (p 0.05) in favour of the Thiel specimen. Conclusions: The advantages of the use of cadavers (frozen or Thiel embalmed) has been shown to also apply for use with proton density (PD) MR imaging. The preservation of cadavers especially using Thiel is a suitable alternative for MRI optimisation and protocol development purposes.
Purpose: To analyse whether the screening performance parameters of the Maltese National Breast S... more Purpose: To analyse whether the screening performance parameters of the Maltese National Breast Screening Programme first screening round met requirements set by European standards. The association between screening age and results of screening performance parameters was also investigated. Method: Quantitative methodology was used to review examinations of women who were recalled for a technical recall or further assessment rates. All accessible members of the population recalled during the first round were retrospectively reviewed resulting in a sample of 2300 recalled examinations. Results: Malta's first screening round met the European Guidelines recommendations for technical repeat rate (0.26%), early recall rate (0.45%), breast cancer detection rate (13.77 per 1000 women) and Positive Predictive Value of screening test (7.58%). However, local recall rate (18.53%) and further assessment rate (18.27%) were higher than recommended. The Chi square test showed a statistically significant difference (p<0.05) in recall rates between the compared age groups, as younger women (51-55 years) were more likely to have a negative diagnosis after the initial mammogram whereas older women (56-60 years) were more likely to be recalled. There was no age discrepancy (p>0.05) in local breast cancer detection rate and positive predictive value of screening test. Conclusion: Although the Maltese first screening round performed well, this study found deficiencies in recall and further assessment rates, which according to literature may result in psychological morbidity and inefficient use of screening resources. This study also concluded that when a cohort is analysed, age is not as significant as the screening round itself (first/subsequent).
IEEE EUROCON 2019 -18th International Conference on Smart Technologies
Medical imaging is an important medical diagnostic tool that provides visual information of the i... more Medical imaging is an important medical diagnostic tool that provides visual information of the interior of the human body. In recent years computer-aided detection/diagnosis (CAD) systems became a key component of routine clinical practice in several medical areas, such as mammography and colonoscopy. However, research on brain CAD systems is still limited compared to other areas. This paper presents a solution that uses image processing techniques on brain computed tomography (CT) scans to create a CAD system that detects fresh bleeds. The system also features a basic classification method that distinguishes between an intra-axial and an extra-axial haemorrhage with the only limitation being subarachnoid haemorrhage (SAH), which is not always properly classified due to its complex structure. The techniques implemented include noise reduction methods, morphological operations and segmentation algorithms. The developed CAD system was tested on 36 brain CT sets obtained from the general hospital in Malta. Results show that the system achieves a sensitivity of 94.4%, a specificity of 94.4%, a precision of 91.259% and a classification accuracy of 88.89%.
Poster: "ECR 2015 / A-605 / B. Patient safety in CT: radiation dose and CM administration&qu... more Poster: "ECR 2015 / A-605 / B. Patient safety in CT: radiation dose and CM administration" by: "F. Zarb; Msida/MT"
Objectives To evaluate visual grading characteristics (VGC) and ordinal regression analysis durin... more Objectives To evaluate visual grading characteristics (VGC) and ordinal regression analysis during head CT optimisation as a potential alternative to visual grading assessment (VGA), traditionally employed to score anatomical visualisation. Methods Patient images (n=66) were obtained using current and optimised imaging protocols from two CT suites: a 16-slice scanner at the national Maltese centre for trauma and a 64-slice scanner in a private centre. Local resident radiologists (n=6) performed VGA followed by VGC and ordinal regres-sion analysis. Results VGC alone indicated that optimised protocols had similar image quality as current protocols. Ordinal logistic regression analysis provided an in-depth evaluation, criterion by criterion allowing the selective implementation of the protocols. The local radiology review panel supported the implementation of optimised protocols for brain CT examina-tions (including trauma) in one centre, achieving radiation dose reductions ranging fro...
INTRODUCTION Lumbar spine radiography is considered as having a high radiation dose compared to o... more INTRODUCTION Lumbar spine radiography is considered as having a high radiation dose compared to other planar radiography examinations. The aim of this study was to investigate the feasibility of replacing an antiscatter grid with an air gap technique to achieve dose reduction for lateral lumbar spine radiography while maintaining image quality on a direct digital radiography (DDR) system. METHODS In phase 1, an experimental study using an anthropomorphic phantom identified the optimal airgap technique. In phase 2, lateral projections of the lumbar spine were performed on 50 patients randomly assigned equally into a control group (using the antiscatter grid) and an experimental group (using the airgap technique). The dose area product (DAP) was recorded, keeping other variables constant. Image quality evaluation was performed by 5 radiologists performing Absolute Visual Grading Analysis (VGA) using an image quality score tool, with resultant scores analysed using Visual Grading Characteristics (VGC). RESULTS A 10 cm airgap in conjunction with a source to image distance (SID) of 121 cm was found as the optimal airgap technique. The clinical application of this technique resulted in a statistically significant (p < 0.05) reduction in DAP of 72%. Image quality scores were higher for the antiscatter grid but variation between the two techniques was not significant (p > 0.05). CONCLUSION Replacing the antiscatter grid with an airgap technique in lateral lumbar spine digital radiography, provides a significant dose reduction whilst still maintaining diagnostic image quality. IMPLICATIONS FOR PRACTICE The airgap technique is a simple and easy technique to implement and radiographers should find no difficulties in applying it, as It involves no additional cost and no additional equipment.
The intent of the review was to identify different methodological approaches used to calculate th... more The intent of the review was to identify different methodological approaches used to calculate the planning target volume (PTV) margin for head and neck patients treated with volumetric arc therapy (VMAT), and whether the necessary factors to calculate the margin size with the selected formula were used. A comprehensive, systematic search of related studies was done using the Hydi search engine and different databases: MEDLINE, PubMed, CINAHL, ProQuest (Nursing and Allied Health), Scopus, ScienceDirect and tipsRO. The literature search included studies published between January 2007 and December 2020. Eligibility screening was performed by two reviewers. A total of seven studies were found. All the reviewed studies used the Van Herk formula to measure the PTV margin. None of the studies incorporated the systematic errors of target volume delineation in the PTV equation. Inter-fraction translational errors were assessed in all the studies, whilst intra-fraction errors were only inclu...
The use of cadavers for medical education purposes and for radiology research methodologies which... more The use of cadavers for medical education purposes and for radiology research methodologies which involve subjective image quality evaluation of anatomical criteria is well documented. The aim of this study was to quantify the impact of cadaver tissue preservation in producing MR images that are representative of living tissue by comparing the visualisation of anatomical structures of the ankle obtained from live and cadaver (fresh frozen and Thiel embalmed) specimens through a visual grading analysis (VGA) study. Methods: A VGA study was conducted on an image data set consisting of 4 coronal proton density weighted (PDw) sequences obtained from ankles of a live patient and those of a cadaveric specimen, of which the right ankle was frozen and the left Thiel embalmed. Results: Comparison of the image quality scores obtained from: the live patient vs. the Thiel specimen indicate a significant difference (p 0.05) between the scores in favour of the Thiel specimen; between the live patient vs. the frozen specimen indicate a significant difference (p 0.05) in favour of the frozen specimen and between the frozen vs. the Thiel specimen indicate a significant difference (p 0.05) in favour of the Thiel specimen. Conclusions: The advantages of the use of cadavers (frozen or Thiel embalmed) has been shown to also apply for use with proton density (PD) MR imaging. The preservation of cadavers especially using Thiel is a suitable alternative for MRI optimisation and protocol development purposes.
Purpose: To analyse whether the screening performance parameters of the Maltese National Breast S... more Purpose: To analyse whether the screening performance parameters of the Maltese National Breast Screening Programme first screening round met requirements set by European standards. The association between screening age and results of screening performance parameters was also investigated. Method: Quantitative methodology was used to review examinations of women who were recalled for a technical recall or further assessment rates. All accessible members of the population recalled during the first round were retrospectively reviewed resulting in a sample of 2300 recalled examinations. Results: Malta's first screening round met the European Guidelines recommendations for technical repeat rate (0.26%), early recall rate (0.45%), breast cancer detection rate (13.77 per 1000 women) and Positive Predictive Value of screening test (7.58%). However, local recall rate (18.53%) and further assessment rate (18.27%) were higher than recommended. The Chi square test showed a statistically significant difference (p<0.05) in recall rates between the compared age groups, as younger women (51-55 years) were more likely to have a negative diagnosis after the initial mammogram whereas older women (56-60 years) were more likely to be recalled. There was no age discrepancy (p>0.05) in local breast cancer detection rate and positive predictive value of screening test. Conclusion: Although the Maltese first screening round performed well, this study found deficiencies in recall and further assessment rates, which according to literature may result in psychological morbidity and inefficient use of screening resources. This study also concluded that when a cohort is analysed, age is not as significant as the screening round itself (first/subsequent).
IEEE EUROCON 2019 -18th International Conference on Smart Technologies
Medical imaging is an important medical diagnostic tool that provides visual information of the i... more Medical imaging is an important medical diagnostic tool that provides visual information of the interior of the human body. In recent years computer-aided detection/diagnosis (CAD) systems became a key component of routine clinical practice in several medical areas, such as mammography and colonoscopy. However, research on brain CAD systems is still limited compared to other areas. This paper presents a solution that uses image processing techniques on brain computed tomography (CT) scans to create a CAD system that detects fresh bleeds. The system also features a basic classification method that distinguishes between an intra-axial and an extra-axial haemorrhage with the only limitation being subarachnoid haemorrhage (SAH), which is not always properly classified due to its complex structure. The techniques implemented include noise reduction methods, morphological operations and segmentation algorithms. The developed CAD system was tested on 36 brain CT sets obtained from the general hospital in Malta. Results show that the system achieves a sensitivity of 94.4%, a specificity of 94.4%, a precision of 91.259% and a classification accuracy of 88.89%.
Poster: "ECR 2015 / A-605 / B. Patient safety in CT: radiation dose and CM administration&qu... more Poster: "ECR 2015 / A-605 / B. Patient safety in CT: radiation dose and CM administration" by: "F. Zarb; Msida/MT"
Objectives To evaluate visual grading characteristics (VGC) and ordinal regression analysis durin... more Objectives To evaluate visual grading characteristics (VGC) and ordinal regression analysis during head CT optimisation as a potential alternative to visual grading assessment (VGA), traditionally employed to score anatomical visualisation. Methods Patient images (n=66) were obtained using current and optimised imaging protocols from two CT suites: a 16-slice scanner at the national Maltese centre for trauma and a 64-slice scanner in a private centre. Local resident radiologists (n=6) performed VGA followed by VGC and ordinal regres-sion analysis. Results VGC alone indicated that optimised protocols had similar image quality as current protocols. Ordinal logistic regression analysis provided an in-depth evaluation, criterion by criterion allowing the selective implementation of the protocols. The local radiology review panel supported the implementation of optimised protocols for brain CT examina-tions (including trauma) in one centre, achieving radiation dose reductions ranging fro...
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