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Computed tomography dose optimisation in cystic fibrosis:A review

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World journal of Radiology 2016年第4期8卷 331-341页

作者： Helena Ferris Maria Twomey Fiachra Moloney Siobhan B o'Neill Kevin Murphy owen j o'connor Michael Maher Department of Radiology Cork University Hospital

Cystic fibrosis(CF)is the most common autosomal recessive disease of the Caucasian population worldwide,with respiratory disease remaining the most relevant source of morbidity and *** tomography(CT)is frequently used for monitoring disease complications and *** the last fifteen years there has been a six-fold increase in the use of CT,which has lead to a growing concern in relation to cumulative radiation *** challenge to the medical profession is to identify dose reduction strategies that meet acceptable image quality,but fulfil the requirements of a diagnostic quality ***-optimisation,particularly in CT,is essential as it reduces the chances of patients receiving cumulative radiation doses in excess of 100 m Sv,a dose deemed significant by the United Nations Scientific Committee on the Effects of Atomic *** review article explores the current trends in imaging in CF with particular emphasis on new developments in dose optimisation.

关键词： Cystic fibrosis Dose optimization Computed tomography Dose Ionising radiation Kalydeco

Computed tomography and patient risk:Facts,perceptions and uncertainties

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World journal of Radiology 2016年第12期8卷 902-915页

作者： Stephen P Power Fiachra Moloney Maria Twomey Karl james owen j o'connor Michael M Maher Department of Radiology Cork University Hospital

Since its introduction in the 1970s, computed tomography(CT) has revolutionized diagnostic decision-making. one of the major concerns associated with the widespread use of CT is the associated increased radiation exposure incurred by patients. The link between ionizing radiation and the subsequent development of neoplasia has been largely based on extrapolating data from studies of survivors of the atomic bombs dropped in japan in 1945 and on assessments of the increased relative risk of neoplasia in those occupationally exposed to radiation within the nuclear industry. However, the association between exposure to low-dose radiation from diagnostic imaging examinations and oncogenesis remains unclear. With improved technology, significant advances have already been achieved with regards to radiation dose reduction. There are several dose optimization strategies available that may be readily employed including omitting unnecessary images at the ends of acquired series, minimizing the number of phases acquired, and the use of automated exposure control as opposed to fixed tube current techniques. In addition, new image reconstruction techniques that reduce radiation dose have been developed in recent years with promising results. These techniques use iterative reconstruction algorithms to attain diagnostic quality images with reduced image noise at lower radiation doses.

关键词： Computed tomography Radiation dose Iterative reconstruction Neoplasia Carcinogenesis

Effects of oral contrast on dose in abdominopelvic computed tomography with pure iterative reconstruction

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World journal of Radiology 2016年第9期8卷 809-815页

作者： Kevin P Murphy Liam j Healy Lee Crush Maria Twomey Fiachra Moloney Sylvia Sexton owen j o'connor Michael M Maher Department of Radiology Cork University Hospital

AIM To assess the effect of neutral(NC) and positive(PC) oral contrast use on patient dose in low-dose abdominal computed tomography(CT).METHoDS Low-dose clinically indicated CTs were performed on 79 Crohn's patients(35 = PC, 1 L 2% gastrografin; 44 = NC, 1.5 L polyethylene glycol). Scanner settings for both acquisitions were identical apart from 25 s difference in intravenous contrast timing. Body mass index(BMI), scan-ranges, dose-length product and size-specific dose estimated were recorded. Data was reconstructed with pure model-based iterative reconstruction. Image quality was objectively and subjectively analysed. Data analysis was performed with Statistical Package for Social *** Higher doses were seen in neutral contrast CTs(107.60 ± 78.7 m ***, 2.47 ± 1.21 m Gy vs 85.65 ± 58.2 m ***, 2.18 ± 0.96 m Gy). The differencehad both NC and PC investigations. Image-quality assessment yielded 6952 datapoints. NC image quality was significantly superior(P objective noise, objective signal to noise ratio, subjective spatial resolution, subjective contrast resolution, diagnostic acceptability) at all levels. NC bowel distension was significantly(P of polyethylene glycol as a neutral oC agent leads to higher radiation doses than standard positive contrast studies, in low dose abdominal CT imaging. This is possibly related to the osmotic effect of the agent resulting in larger intraluminal fluid volumes and resultant increased overall beam attenuation.

关键词： Radiation dose Low dose computed tomography Abdominal imaging oral contrast Computed tomography

Ultra-low-dose chest computed tomography with model-based iterative reconstruction in the analysis of solid pulmonary nodules:A prospective study

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World journal of Radiology 2024年第11期16卷 668-677页

作者： Patrick W o'Regan Antonia Harold-Barry Alexander T o'Mahony Claire Crowley Stella joyce Niamh Moore owen j o'connor Michael T Henry David j Ryan Michael M Maher Department of Radiology School of MedicineUniversity College CorkCork T12 AK54Ireland Department of Radiology Cork University HospitalCork T12 DC4AIreland Department of Radiology Mercy University HospitalCork T12WE28Ireland Department of Respiratory Medicine Cork University HospitalCork T12 DC4AIreland

BACKGRoUND Incidental pulmonary nodules are an increasingly common finding on computed tomography(CT)scans of the thorax due to the exponential rise in CT examin-ations in everyday *** majority of incidental pulmonary nodules are benign and correctly identifying the small number of malignant nodules is ***-low-dose CT(ULDCT)has been shown to be effective in diagnosis of respiratory pathology in comparison with traditional standard dose *** hypothesis was that ULDCT chest combined with model-based iterative reconstruction(MBIR)is comparable to standard dose CT(SDCT)chest in the analysis of pulmonary nodules with significant reduction in radiation *** To prospectively compare ULDCT chest combined with MBIR with SDCT chest in the analysis of solid pulmonary *** A prospective cohort study was conducted on adult patients(n=30)attending a respiratory medicine outpatient clinic in a tertiary referral university hospital for surveillance of previously detected indeterminate pulmonary nodules on SDCT *** study involved the acquisition of a reference SDCT chest followed immediately by an ULDCT *** identification,nodule characterisation,nodule measurement,objective and subjective image quality and radiation dose were compared between ULDCT with MBIR and SDCT *** one hundred solid nodules were detected on ULDCT chest and 98 on SDCT *** was no significant difference in the characteristics of correctly identified nodules when comparing SDCT chest to ULDCT chest ***-to-noise ratio was significantly increased in the ULDCT chest in all areas except in the paraspinal muscle at the maximum cardiac diameter level(Pjective image quality score for overall diagnostic acceptability was 8.9/*** mean dose length product,computed tomography volume dose index and effective dose for the ULDCT chest protocol were 5.592 ***,0.16 mGy and 0.08 mSv *** were sign

关键词： Ultra-low dose computed tomography Solid pulmonary nodules Computed tomography methods Radiation dosage Adult human

Cumulative radiation exposure from diagnostic imaging in intensive care unit patients

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World journal of Radiology 2016年第4期8卷 419-427页

作者： Fiachra Moloney Daniel Fama Maria Twomey Ruth o'Leary Conor Houlihane Kevin P Murphy Siobhan B o'Neill owen j o'connor Dorothy Breen Michael M Maher Department of Radiology Cork University Hospital Department of Anesthesia Cork University Hospital

AIM:To quantify cumulative effective dose of intensive care unit(ICU)patients attributable to diagnostic ***:This was a prospective,interdisciplinary study conducted in the ICU of a large tertiary referral and level 1 trauma *** and clinical data including age,gender,date of ICU admission,primary reason for ICU admission,APACHE Ⅱ score,length of stay,number of days intubated,date of death or discharge,and re-admission data was collected on all patients admitted over a 1-year *** overall radiation exposure was quantified by the cumulative effective radiation dose(CED)in millisieverts(mS v)and calculated using reference effective doses published by the United Kingdom National Radiation Protection *** patients were selected for ***:A total of 2737 studies were performedin 421 *** total CED was 1704 m Sv with a median CED of 1.5 mS v(IQR 0.04-6.6 mS v).Total CED in pediatric patients was 74.6 mS v with a median CED of 0.07 mS v(IQR 0.01-4.7 mS v).Chest radiography was the most commonly performed examination accounting for 83% of all studies but only 2.7% of total *** tomography(CT)accounted for 16% of all studies performed and contributed 97% of total *** patients received a statistically significant higher dose [median CED 7.7 mS v(IQR 3.5-13.8 mS v)] than medical [median CED 1.4 m Sv(IQR 0.05-5.4 m Sv)] and surgical [median CED 1.6 mS v(IQR 0.04-7.5 mS v)] *** of stay in ICU [oR = 1.12(95%CI:1.079-1.157)] was identified as an independent predictor of receiving a CED greater than 15 mS ***:Trauma patients and patients with extended ICU admission times are at increased risk of higher *** should be minimized where feasible,especially in young patients.

关键词： Cumulative effective dose Pediatric patients Computed tomography Radiation dose Intensive care unit

C-reactive protein and radiographic findings of lower respiratory tract infection in infants

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World journal of Radiology 2017年第4期9卷 206-211页

作者： Maria Twomey Hannah Fleming Fiachra Moloney Kevin P Murphy Lee Crush Siobhan B o’Neill oisin Flanagan Karl james Conor Bogue owen j o’connor Michael M Maher Department of Radiology Cork University HospitalWiltonT12 DC4A CorkIreland

AIM To evaluate the association between C-reactive protein(CRP) and radiological evidence of lower respiratory tract infection(LRTI) in *** All patients aged less than 4 years who presented with suspected lower respiratory tract infection,who received a peri-presentation chest radiograph and CRP blood measurement over an 18-mo period were included in the ***,gender,source of referral,CRP,white cell count,neutrophil count along with the patients' symptoms and radiologist's report were *** Three hundred and eleven patients met the *** chest radiographs were more common in patients with elevated CRP levels(P ologic signs of LRTI were identified in 73.7% of chest radiographs when a patient had a CRP level between 50-99 mg/*** levels were a better predictor of positive chest radiograph findings for those aged greater than I year compared to those 1 year or *** CRP may be used in patients with suspected LRTI diagnosis to select those who are likely to have positive findings on chest radiograph,thus reducing unnecessary chest radiographs.

关键词： Chest radiograph C-reactive protein Chest infection Respiratory infection Pediatric

Integrative multi-omics and systems bioinformatics in translational neuroscience:A data mining perspective

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journal of Pharmaceutical Analysis 2023年第8期13卷 836-850页

作者： Lance M.o'connor Blake A.o'connor Su Bin Lim jialiu Zeng Chih Hung Lo College of Biological Sciences University of MinnesotaMinneapolisMN55455USA School of Pharmacy University of WisconsinMadisonWI53705USA Department of Biochemistry and Molecular Biology Ajou University School of MedicineSuwon16499South Korea Lee Kong Chian School of Medicine Nanyang Technological UniversitySingapore308232Singapore

Bioinformatic analysis of large and complex omics datasets has become increasingly useful in modern day biology by providing a great depth of information,with its application to neuroscience termed *** mining of omics datasets has enabled the generation of new hypotheses based on differentially regulated biological molecules associated with disease mechanisms,which can be tested experimentally for improved diagnostic and therapeutic targeting of neurodegenerative ***,integrating multi-omics data using a systems bioinformatics approach will advance the understanding of the layered and interactive network of biological regulation that exchanges systemic knowledge to facilitate the development of a comprehensive human brain *** this review,we first summarize data mining studies utilizing datasets from the individual type of omics analysis,including epigenetics/epigenomics,transcriptomics,proteomics,metabolomics,lipidomics,and spatial omics,pertaining to Alzheimer's disease,Parkinson's disease,and multiple *** then discuss multi-omics integration approaches,including independent biological integration and unsupervised integration methods,for more intuitive and informative interpretation of the biological data obtained across different omics *** further assess studies that integrate multi-omics in data mining which provide convoluted biological insights and offer proof-of-concept proposition towards systems bioinformatics in the reconstruction of brain ***,we recommend a combination of high dimensional bioinformatics analysis with experimental validation to achieve translational neuroscience applications including biomarker discovery,therapeutic development,and elucidation of disease *** conclude by providing future perspectives and opportunities in applying integrative multi-omics and systems bioinformatics to achieve precision phenotyping of neurodegenerative diseases and towards personaliz

关键词： Multi-omics integration Systems bioinformatics Data mining Human brain profile reconstruction Translational neuroscience

Numerical investigation into water entry problems of a flat plate with air pockets

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journal of ocean Engineering and Science 2023年第4期8卷 386-400页

作者： Casey o’connor Saeed Mohajernasab Nagi Abdussamie National Centre for Maritime Engineering and Hydrodynamics Australian Maritime CollegeUniversity of TasmaniaLauncestonTasmaniaAustralia

Computational Fluid Dynamics(CFD)investigations into water entry problems of a rigid flat plate with air pockets were systematically *** Volume of Fluid(VoF)model was utilised to capture localised slamming phenomena that occur during,and post-impact *** model’s geometry was modified to include a pocket on the slamming impact surface to investigate the effect of air entrapment on the magnitude and distribution of slamming forces and pressures.A parametric study was conducted on the geometric parameters of the modelled pocket by altering its area,depth,and volume to exam-ine the response of slamming force and pressure loading under several impact *** numerical results of slamming forces and pressures were in good agreement with experimental drop test measure-ments(with relative error of-6%and 7%for the magnitude of slamming force and pressure,respectively).The numerical results proved that the peak pressure is proportional to the magnitude of impact velocity squared(p maxαv^(2)).

关键词： Marine structures Slamming Air entrapment Computationalﬂuid dynamics Drop tests

Dominant species of mid-elevation grasslands of the uKhahlamba-Drakensberg Park are predicted to be largely immune to climate change

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journal of Mountain Science 2023年第9期20卷 2468-2486页

作者： Debbie jEWITT Craig D.MoRRIS Tim G.o’connor Michelle j.TEDDER Ezemvelo KZN Wildlife Scientific ServicesPO Box 13053Cascades 3202South Africa School of Animal Plant and Environmental SciencesUniversity of the WitwatersrandJohannesburgPrivate Bag X3WITS 2050South Africa Agricultural Research Council-Animal Production(ARC-AP) ℅School of Life Sciences University of KwaZulu-NatalPrivate Bag X01Scottsville 3209PietermaritzburgSouth Africa School of Life Sciences University of KwaZulu-NatalPrivate Bag X01Scottsville 3209PietermaritzburgSouth Africa

Anticipating global change impact on natural vegetation,especially in poorly researched systems,requires an understanding of the environmental factors that most strongly influence the organisation of plant communities at different *** environmental relations of plant communities in the Drakensberg mountains of South Africa remain poorly *** study investigated the influence of selected environmental determinants on the dominant species of plant community organisation in this *** order to provide an overview of the influence of the environment on botanical composition and plant diversity,this study,conducted as four discrete exercises,investigated the interplay of altitude,aspect and slope on the abundance of selected species,and to examine the influence of latitude,geological substrate and local topography on species *** diversity showed no pattern of response to investigated environmental *** composition was related to temperature and solarradiation *** altitude sites facing east were distinct for non-graminoid *** and latitude exerted a pronounced effect on species composition,confounded by longitude and precipitation *** substrate,in concert with slope steepness and orientation,influenced composition,restricting the abundance but not distribution of some *** individualistic responses were found for C_3,C_4,and non-graminoid species in relation to altitude,slope and *** and aspect mediate the effects of altitude and hence temperature for some *** study has demonstrated the complexity of drivers influencing species and compositional distribution in the Drakensberg and permits a preliminary consideration of potential changes in the composition and dominance structure of mid-elevation grasslands in response to climate *** dominant grass species were widespread across environmental gradients,occupying currently warm,cool,moist and dry habitats

关键词： Drakensberg Environmental gradients Grasslands Mountain biodiversity Vegetation