ORCID Profile
0000-0003-4048-5121
Current Organisations
The University of Edinburgh
,
Bond University
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Publisher: Elsevier BV
Date: 06-2023
Publisher: SAGE Publications
Date: 02-02-2021
Abstract: This article analyses how the financial literacy of elderly people affects their decisions on the adoption of various financial strategies. Multiple mediator models with bootstrap techniques are used to identify the mediating mechanisms of financial concerns that transmit the effects of financial literacy onto specific financial strategies. We find (1) financial concerns mediate the majority of financial literacy-strategy nexuses specifically, financially illiterate people are more likely to have financial concerns and are more likely to cut back on spending, seek job opportunities, increase debts and downsize or sell their residence as a result (2) financially literate people are more likely to seek professional financial advice, purchase a life annuity, contribute more to superannuation and invest more conservatively, regardless of their concerns. Our findings suggest professional advisors and robo-advisor developers take into account financial concerns when recommending advice. JEL Classification: D14, J14, J26, I31, G11
Publisher: Informa UK Limited
Date: 06-2012
Publisher: Human Kinetics
Date: 02-2020
Abstract: Sprint capacity is an important attribute for team-sport athletes, yet the most appropriate method to analyze it is unclear. Purpose : To examine the relationship between sprint workloads using relative versus absolute thresholds and lower-body soft-tissue and bone-stress injury incidence in professional Australian rules football. Methods : Fifty-three professional Australian rules football athletes’ noncontact soft-tissue and bone-stress lower-body injuries (N = 62) were recorded, and sprint workloads were quantified over ∼18 months using the global positioning system. Sprint volume (m) and exposures (n) were determined using 2 methods: absolute ( .9 km·h −1 ) and relative (≥75%, ≥80%, ≥85%, ≥90%, ≥95% of maximal velocity). Relationships between threshold methods and injury incidence were assessed using logistic generalized additive models. Incidence rate ratios and model performances’ area under the curve were reported. Results : Mean (SD) maximal velocity for the group was 31.5 (1.4), range 28.6 to 34.9 km·h −1 . In comparing relative and absolute thresholds, 75% maximal velocity equated to ~1.5 km·h −1 below the absolute speed threshold, while 80% and 85% maximal velocity were 0.1 and 1.7 km·h −1 above the absolute speed threshold, respectively. Model area under the curve ranged from 0.48 to 0.61. Very low and very high cumulative sprint loads ≥80% across a 4-week period, when measured relatively, resulted in higher incidence rate ratios (2.54–3.29), than absolute thresholds (1.18–1.58). Discussion : Monitoring sprinting volume relative to an athlete’s maximal velocity should be incorporated into athlete monitoring systems. Specifically, quantifying the distance covered at % maximal velocity will ensure greater accuracy in determining sprint workloads and associated injury risk.
Publisher: Elsevier BV
Date: 08-1997
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2018
Publisher: Springer Science and Business Media LLC
Date: 30-03-2017
DOI: 10.1007/S00256-017-2630-9
Abstract: To assess the quality and accuracy of metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) for the diagnosis of lumbosacral neuropathies in patients with metallic implants in the pelvis. Twenty-two subjects with lumbosacral neuropathy following pelvic instrumentation underwent 1.5-T MARS MRI including optimized axial intermediate-weighted and STIR turbo spin echo sequences extending from L5 to the ischial tuberosity. Two readers graded the visibility of the lumbosacral trunk, sciatic, femoral, lateral femoral cutaneous, and obturator nerves and the nerve signal intensity of nerve, architecture, caliber, course, continuity, and skeletal muscle denervation. Clinical examination and electrodiagnostic studies were used as the standard of reference. Descriptive, agreement, and diagnostic performance statistics were applied. Lumbosacral plexus visibility on MARS MRI was good (4) or very good (3) in 92% of cases with 81% exact agreement and a Kendall's W coefficient of 0.811. The obturator nerve at the obturator foramen and the sciatic nerve posterior to the acetabulum had the lowest visibility, with good or very good ratings in only 61% and 77% of cases respectively. The reader agreement for nerve abnormalities on MARS MRI was excellent, ranging from 95.5 to 100%. MARS MRI achieved a sensitivity of 86%, specificity of 67%, positive predictive value of 95%, and negative predictive value of 40%, and accuracy of 83% for the detection of neuropathy. MARS MRI yields high image quality and diagnostic accuracy for the assessment of lumbosacral neuropathies in patients with metallic implants of the pelvis and hips.
Publisher: Human Kinetics
Date: 11-2020
Abstract: Context : Exercise in hot environments increases body temperature and thermoregulatory strain. However, little is known regarding the magnitude of effect that ambient temperature ( T a ), relative humidity (RH), and solar radiation in idually have on team-sport athletes. Purpose : To determine the effect of these in idual heat-stress variables on team-sport training performance and recovery. Methods : Professional Australian Rules Football players (N = 45) undertook 8-wk preseason training producing a total of 579 outdoor field-based observations with T a , RH, and solar radiation recorded at every training session. External load (distance covered, in m/min percentage high-speed running [%HSR] .4 km/h) was collected via a global positioning system. Internal load (ratings of perceived exertion and heart rate) and recovery (subjective ratings of well-being and heart-rate variability [root mean square of the successive differences]) were monitored throughout the training period. Mixed-effects linear models analyzed relationships between variables using standardized regression coefficients. Results : Increased solar-radiation exposure was associated with reduced distance covered (−19.7 m/min, P .001), %HSR (−10%, P .001) during training and rMSSD 48 h posttraining (−16.9 ms, P = .019). Greater RH was associated with decreased %HSR (−3.4%, P = .010) but increased percentage duration % HR max (3.9%, P .001), ratings of perceived exertion (1.8 AU, P .001), and self-reported stress 24 h posttraining (−0.11 AU, P = .002). In contrast, higher T a was associated with increased distance covered (19.7 m/min, P .001) and %HSR (3.5%, P = .005). Conclusions : The authors show the importance of considering the in idual factors contributing to thermal load in isolation for team-sport athletes and that solar radiation and RH reduce work capacity during team-sport training and have the potential to slow recovery between sessions.
Publisher: Elsevier BV
Date: 05-2022
Publisher: Springer Science and Business Media LLC
Date: 23-07-2018
DOI: 10.1007/S00330-018-5591-Z
Abstract: To test the hypothesis that MRI of the ankle with a 10-min 3D CAIPIRINHA SPACE TSE protocol is at least equivalent for the detection of painful conditions when compared to a 20-min 2D TSE standard of reference protocol. Following institutional review board approval and informed consent, 70 symptomatic subjects underwent 3T MRI of the ankle. Six axial, sagittal and coronal intermediate-weighted (IW) and fat-saturated T2-weighted (T2FS) 2D TSE (total acquisition time, 20 min), and two sagittal isotropic IW and T2FS 3D CAIPIRINHA TSE (10 min) pulse sequence prototypes were obtained. Following randomization and anonymization, two musculoskeletal radiologists evaluated the 2D and 3D datasets independently. Descriptive statistics, inter-reader reliability, inter-method concordance, diagnostic definitiveness tests were applied. P-values < 0.05 were considered significant. Raters diagnosed 116 cartilage defects with 2D and 109 with 3D MRI, 35 ligament tears with 2D and 65 with 3D MRI, 18 tendon tears with 2D and 20 with 3D MRI, and 137 osseous abnormalities with 2D and 149 with 3D MRI. The inter-reader agreement was high for 2D (Kendall W, 0.925) and 3D MRI (W, 0.936) (p < 0.05), as was the inter-method concordance (W, 0.919). The diagnostic definitiveness of readers was higher for 3D MRI than 2D MRI in 10-27% of the time, while the reverse was true in 7-11% of the time (p < 0.01). The performance of 10-min 3D CAIPIRINHA SPACE MRI for the detection of painful ankle conditions is similar to that of a 20-min 2D TSE MRI reference standard. • CAIPIRINHA Acceleration facilitates isotropic 3D MRI of the Ankle in 10 min. • 10-min 3D CAIPIRINHA MRI and 20-min 2D TSE MRI have similar performance. • 3D CAIPIRINHA SPACE MRI afforded higher diagnostic definitiveness of readers.
Publisher: Springer Science and Business Media LLC
Date: 06-01-2021
DOI: 10.1186/S40537-020-00394-7
Abstract: Record linkage is the process of finding matches and linking records from different data sources so that the linked records belong to the same entity. There is an increasing number of applications of record linkage in statistical, health, government and business organisations to link administrative, survey, population census and other files to create a complete set of information for more complete and comprehensive analysis. To make valid inferences using a linked file, it has become increasingly important to have effective and efficient methods for linking data from different sources. Therefore, it becomes necessary to assess the ability of a linking method to achieve high accuracy or to compare between methods with respect to accuracy. This motivates the development of a method for assessing the linking process and facilitating decisions about which linking method is likely to be more accurate for a particular linking task. This paper proposes a Markov Chain based Monte Carlo simulation approach, MaCSim for assessing a linking method and illustrates the utility of the approach using a realistic synthetic dataset received from the Australian Bureau of Statistics to avoid privacy issues associated with using real personal information. A linking method applied by MaCSim is also defined. To assess the defined linking method, correct re-link proportions for each record are calculated using our developed simulation approach. The accuracy is determined for a number of simulated datasets. The analyses indicated promising performance of the proposed method MaCSim of the assessment of accuracy of the linkages. The computational aspects of the methodology are also investigated to assess its feasibility for practical use.
Publisher: Wiley
Date: 14-04-2019
DOI: 10.1111/ACFI.12362
Publisher: Wiley
Date: 24-08-2018
DOI: 10.1002/JMRI.26241
Abstract: Ten-minute MRI of the pediatric knee can add value through increased cost-effectiveness and decreased sedation needs but requires validation of its clinical efficacy. To determine the arthroscopy-based diagnostic accuracy and interreader reliability of 10-min 3D Controlled Aliasing In Parallel Imaging Results In Higher Acceleration (CAIPIRINHA) turbo spin echo (TSE) MRI with two isotropic pulse sequences for the diagnosis of internal derangement in children with painful knee conditions. Prospective. Sixty children. 3T, gradient echo-based scout with automatic anatomical landmark recognition and plane prescription, 3D CAIPIRINHA SPACE TSE. Three fellowship-trained musculoskeletal radiologists evaluated the MRI studies independently and resolved discrepancies through consensus. Outcome variables included image quality, motion artifacts, meniscal abnormalities, anterior and posterior cruciate ligament tears, and cartilage lesions. Arthroscopic surgery served as the standard of reference, which was performed after 37 (range, 1-143) days post-MRI. Diagnostic accuracy analysis of MRI with arthroscopic surgery as the standard of reference. Reliability analysis through calculation of interreader agreements with kappa statistics. All studies were suitable for diagnostic interpretation with good-to-very-good image quality ratings and little-to-no motion degradation ratings in the majority of cases. The sensitivities/specificities/accuracies of 3D CAIPIRINHA TSE MRI were 0.93/0.96/0.94 for 15/60 (25%) medial meniscal tears, 0.95/0.92/0.94 for 21/60 (35%) lateral meniscal tears, 0.83/1.00/0.92 for 6/60 (17%) discoid menisci, 1.00/0.98/0.99 for 16/60 (27%) anterior cruciate ligament tears, 1.0/1.0/1.0 for 2/60 (3%) posterior cruciate ligament tears, 1.00/1.00/1.00 for 5/60 (8%) osteochondritis dissecans lesions, 0.71/0.96/0.84 for 48 (13%) defects in 360 cartilage segments, and 0.85/0.97/0.91 overall. The interreader agreements were overall good-to-very-good (kappa, 0.72-1.00). The clinical use of 10-min 3D CAIPIRINHA TSE MRI of the knee in children with painful knee conditions yields an overall high arthroscopy-validated diagnostic accuracy of 91% and good-to-very good interreader reliability for the diagnosis of internal knee derangements. 1 Technical Efficacy: Stage 6 J. Magn. Reson. Imaging 2019 :e139-e151.
Publisher: Wiley
Date: 26-12-2015
DOI: 10.1111/JON.12325
Abstract: To determine the feasibility of apparent diffusion coefficient (ADC)-based thermometry to assess intraventricular temperature in children. ADC maps were generated from diffusion tensor imaging data, which were acquired with diffusion gradients along 20 noncollinear directions using a b-value of 1000 s/mm(2) . The intraventricular temperature was calculated based on intraventricular ADC values and the mode method as previously reported. The calculated intraventricular temperature was validated with an estimated brain temperature based on temporal artery temperature measurements. We included 120 children in this study (49 females, 71 males, mean age 6.63 years), 15 consecutive children for each of the following age groups: 0-1, 1-2, 2-4, 4-6, 6-8, 8-10, 10-14, and 14-18 years. Forty-three children had a normal brain MRI and 77 children had an abnormal brain scan. Polynomial fitting to the temperature distribution and subsequent calculation of mode values was performed. A correlation coefficient and a coefficient of determination were calculated between ADC calculated temperatures and estimated brain temperatures. Linear regression analysis was performed to investigate the two temperature measures. ADC-based intraventricular temperatures ranged between 31.5 and 39.6 °C, although estimated brain temperatures ranged between 36.3 and 38.1 °C. The difference between the temperatures is larger for children with more than 8,000 voxels within the lateral ventricles compared to children with less than 8,000 voxels. The correlation coefficient between ADC-based temperatures and the estimated brain temperatures is .1, the respective R(2) is .01 indicating that 1% of the changes in estimated brain temperatures are attributable to corresponding changes in ADC-based temperature measurements (P = .275). ADC-based thermometry has limited application in the pediatric population mainly due to a small ventricular size.
Publisher: Oxford University Press (OUP)
Date: 08-02-2011
DOI: 10.1111/J.1467-9876.2010.00751.X
Abstract: Standard paired comparison models are widely used in circumstances where a measure of preference is available on a sequence or collection of pairwise comparisons between a group of objects or treatments. Typically, the measure of preference observations takes the form of simple binary outcomes, indicating which of the two objects or treatments in a particular comparison is preferred. Common ex les of such situations include models of choice behaviour in politics or marketing, comparisons of medical treatments or in the realm of sports rankings. We investigate situations where the observed measure of preference for the paired comparisons is instead a continuous outcome indicating not simply the direction of preference but the degree of preference as well in particular, we present, as a motivating ex le, a ranking analysis of the top 12 international limited overs cricket teams, with an appropriately defined margin of victory in in idual matches playing the role of the measure of preference. We propose a new method, which is termed moderated paired comparisons, that is based on fitting a penalized likelihood model to the observed margins of victory. Importantly, the structure of the penalty function chosen allows for the model to assign differential importance to the information that is contained solely in the dichotomous win–loss outcome of a match as against that contained in the actual margin of the victory.
Publisher: Springer Science and Business Media LLC
Date: 25-06-2021
DOI: 10.1186/S13244-021-01020-7
Abstract: The purpose of our retrospective study was to assess the termination rate and the image quality of MR exams performed in claustrophobic patients under medical hypnosis, as compared to patients undergoing MR under spontaneous breathing general anesthesia. Our study was approved by the ethics committee. The “hypnosis group” included consecutive patients that had previously interrupted an MR exam because of claustrophobia. The “control group” included patients undergoing MR under pharmacologic sedation. Two experienced radiologists assessed, randomly, independently and blinded the image quality of the two groups using a symmetrical Likert scale: 0 = non-diagnostic images 1 = bad image quality 2 = fair image quality 3 = good image quality 4 = very good image quality. Descriptive statistics was performed. Eighty patients were included, equally distributed between the two groups. Every patient was able to complete the MR exam. Ratings 3 and 4 represented the majority of ratings. Both readers rated the MR exams with score 3 or 4 in 66.25% (53/80) of MR exams. Only 5% (4/80) of MR exams were rated below score 2. The majority of the MR exams showed good or very good image quality. No significant difference was found in image quality between the two ( p = 0.06) groups. The agreement between the two readers according to the k score was 0.105. Medical hypnosis is a valid alternative to spontaneous breathing general anesthesia in patients unable to undergo MR due to claustrophobia, allowing good quality images.
Publisher: Elsevier BV
Date: 06-2002
DOI: 10.1016/S0197-4580(01)00327-X
Abstract: There is evidence that increased blood concentrations of homocysteine may be a risk factor for Alzheimer's disease. (E)-4-hydroxy-2-nonenal (HNE) is a neurotoxic product of lipid peroxidation that is increased in the ventricular fluid and brains of patients with Alzheimer's disease. We measured the concentrations of homocysteine, HNE, vitamin B(12) and folate in the plasma of 27 patients with Alzheimer's disease and 25 control subjects. There was a statistically significant increase in the plasma concentration of homocysteine (P < 0.001) and HNE (P < 0.001) in the Alzheimer's disease patients compared to the control group. There was a significant decrease in the plasma concentration of vitamin B(12) (P < 0.001) and folate (P = 0.002) in the Alzheimer's group compared to the controls. There was a significant positive correlation between the plasma concentrations of homocysteine and HNE in the patients with Alzheimer's disease (r = 0.661, P < 0.001). A significant negative correlation was found between the plasma concentration of homocysteine and the plasma concentrations of vitamin B(12) (r = -0.605, P = 0.0006) and folate (r = 0.586, P = 0.001). We also measured the concentrations of homocysteine, HNE, vitamin B(12) and folate in the cerebrospinal fluid (CSF) of 8 patients with Alzheimer's disease compared to 6 control subjects. The concentrations of homocysteine (P = 0.032) and HNE (P = 0.001) were significantly higher in the CSF of Alzheimer's patients than in the control subjects. There were significant positive correlations between the CSF concentrations of homocysteine and HNE (r = 0.924, P = 0.001). There was also a significant positive correlation between the plasma concentration of homocysteine and the CSF concentrations of homocysteine (r = 0.850, P = 0.007) and HNE (r = 0.092, P = 0.002). These results demonstrate that there is a relationship between increased homocysteine concentrations and increased HNE concentrations in Alzheimer's disease.
Publisher: Human Kinetics
Date: 10-2020
Abstract: Little is known about the effect of preceding endurance-exercise bouts on subsequent resistance-training (RT) performance in team-sport players. Purpose : To examine the effect of prior skills/endurance training and different recovery time periods on subsequent same-day RT performance in professional Australian football players. Methods : Sport-specific endurance-running loads (duration [in minutes], total distance [in meters], mean speed [in meters per minute], high-speed running km·h −1 , and relative high-speed running [ % and % of maximal velocity]) were obtained for 46 professional Australian football players for each training session across an entire competitive season. RT was prescribed in 3 weekly mesocycles with tonnage (in kilograms) lifted recorded as RT performance. Endurance and RT sessions were interspersed by different recovery durations: ∼20 min and 1, 2, and 3 h. Fixed- and mixed-effect linear models assessed the influence of skills/endurance-running loads on RT performance. Models also accounted for season period (preseason vs in-season) and recovery duration between concurrent training bouts. Results : An increase in high-speed running and distance covered % and % of maximal velocity had the greatest reductions on RT performance. In-season total distance covered displayed greater negative effects on subsequent RT performance compared with preseason, while ∼20-min recovery between skills/endurance and RT was associated with greater reductions in RT performance, compared with 1-, 2-, and 3-h recovery. Conclusions : Sport-specific endurance-running loads negatively affect subsequent same-day RT performance, and this effect is greater in-season and with shorter recovery durations between bouts.
Publisher: Wiley
Date: 30-09-2020
DOI: 10.1111/ACFI.12545
Publisher: Oxford University Press (OUP)
Date: 09-1997
Abstract: Inference in the presence of nuisance parameters is often carried out by using the χ2-approximation to the profile likelihood ratio statistic. However, in small s les, the accuracy of such procedures may be poor, in part because the profile likelihood does not behave as a true likelihood, in particular having a profile score bias and information bias which do not vanish. To account better for nuisance parameters, various researchers have suggested that inference be based on an additively adjusted version of the profile likelihood function. Each of these adjustments to the profile likelihood generally has the effect of reducing the bias of the associated profile score statistic. However, these adjustments are not applicable outside the specific parametric framework for which they were developed. In particular, it is often difficult or even impossible to apply them where the parameter about which inference is desired is multidimensional. In this paper, we propose a new adjustment function which leads to an adjusted profile likelihood having reduced score and information biases and is readily applicable to a general parametric framework, including the case of vector-valued parameters of interest. Ex les are given to examine the performance of the new adjusted profile likelihood in small s les, and also to compare its performance with other adjusted profile likelihoods.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 21-06-2022
Abstract: The diagnosis of periprosthetic shoulder infection (PSI) in patients with a painful arthroplasty is challenging. Magnetic resonance imaging (MRI) may be helpful, but shoulder implant-induced metal artifacts degrade conventional MRI. Advanced metal artifact reduction (MARS) improves the visibility of periprosthetic bone and soft tissues. The purpose of our study was to determine the reliability, repeatability, and diagnostic performance of advanced MARS-MRI findings for diagnosing PSI. Between January 2015 and December 2019, we enrolled consecutive patients suspected of having PSI at our academic hospital. All 89 participants had at least 1-year clinical follow-up and underwent standardized clinical, radiographic, and laboratory evaluations and advanced MARS-MRI. Two fellowship-trained musculoskeletal radiologists retrospectively evaluated the advanced MARS-MRI studies for findings associated with PSI in a blinded and independent fashion. Both readers repeated their evaluations after a 2-month interval. Interreader reliability and intrareader repeatability were assessed with κ coefficients. The diagnostic performance of advanced MARS-MRI for PSI was quantified using sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC). When applying the International Consensus Meeting (ICM) 2018 criteria, of the 89 participants, 22 (25%) were deemed as being infected and 67 (75%) were classified as being not infected (unlikely to have PSA and not requiring a surgical procedure during 1-year follow-up). The interreader reliability and intrareader repeatability of advanced MARS-MRI findings, including lymphadenopathy, joint effusion, synovitis, extra-articular fluid collection, a sinus tract, rotator cuff muscle edema, and periprosthetic bone resorption, were good (κ = 0.61 to 0.80) to excellent (κ 0.80). Lymphadenopathy, complex joint effusion, and edematous synovitis had sensitivities of %, specificities of %, odds ratios of .6, and AUC values of .90 for diagnosing PSI. The presence of all 3 findings together yielded a PSI probability of %, per logistic regression analysis. Our study shows the clinical utility of advanced MARS-MRI for diagnosing PSI when using the ICM 2018 criteria as the reference standard. Although the reliability and diagnostic accuracy were high, these conclusions are based on our specific advanced MARS-MRI protocol interpreted by experienced musculoskeletal radiologists. Investigations with larger s le sizes are needed to confirm these results. Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.
Publisher: Informa UK Limited
Date: 16-01-2018
Publisher: Elsevier BV
Date: 09-2006
Publisher: Wiley
Date: 30-10-2015
DOI: 10.1111/JON.12310
Abstract: To determine if axial T2-weighted imaging can serve as screening tool for pediatric brain imaging. We retrospectively evaluated consecutive brain magnetic resonance imaging (MRI) data of 161 children (74 girls) with a mean age of 7.44 ± 5.71 years. Standard of reference was the final report of neuroradiology attendings. Three readers with different levels of experience were blinded for clinical diagnoses and study indications. First, readers studied only the axial T2-weighted screening sequence. Second, they studied all available anatomical and functional MRI sequences as performed per standard protocol for each clinical indication. The readings were classified as normal or abnormal. Sensitivity and specificity were measured. Axial T2 screening yielded a sensitivity of 77-88% and a specificity of 92%. The full studies/data sets had a sensitivity of 89-95% and a specificity of 86-93%. Nineteen of 167 studies were acquired for acute and 148 of 167 studies for nonacute clinical indication. Twenty-five false-negative diagnoses paneled in three groups were made by all readers together. Readers misread four of 19 studies with acute and 21 of 148 studies with nonacute clinical indication. Four of 21 misread studies with nonacute indications harbored unexpected findings needing management. Axial T2 screening can detect pediatric brain abnormalities with high sensitivity and specificity and can possibly replace CT as screening tool if the reading physician is aware of possible limitations itfalls. The level of experience influences sensitivity and specificity. Adding diffusion-weighted imaging and susceptibility-weighted imaging to a 3-dimensional T2-weighted sequence would most likely further increase sensitivity and specificity.
Publisher: Informa UK Limited
Date: 02-01-2023
Publisher: Informa UK Limited
Date: 27-02-2022
Publisher: Wiley
Date: 03-2001
DOI: 10.2307/3316051
Publisher: Radiological Society of North America (RSNA)
Date: 11-2018
DOI: 10.1148/RADIOL.2018173007
Abstract: Purpose To test the hypothesis that synthetic MRI of the knee generates accurate and repeatable quantitative maps and produces morphologic MR images with similar quality and detection rates of structural abnormalities than does conventional MRI. Materials and Methods Data were collected prospectively between January 2017 and April 2018 and were retrospectively analyzed. An International Society for Magnetic Resonance in Medicine-National Institute of Standards and Technology phantom was used to determine the accuracy of T1, T2, and proton density (PD) quantification. Statistical models were applied for correction. Fifty-four participants (24 men, 30 women mean age, 40 years range, 18-62 years) underwent synthetic and conventional 3-T MRI twice on the same day. Fifteen of 54 participants (28%) repeated the protocol within 9 days. The intra- and interday agreements of quantitative cartilage measurements were assessed. Contrast-to-noise (CNR) ratios, image quality, and structural abnormalities were assessed on corresponding synthetic and conventional images. Statistical analyses included the Wilcoxon test, χ
Publisher: Elsevier BV
Date: 07-1998
Publisher: Microbiology Society
Date: 2005
Abstract: Escherichia coli were isolated from the faeces of 266 in iduals living in the Canberra region of Australia. The isolates were characterized for their ECOR group membership (A, B1, B2 or D) and for the presence of 29 virulence-associated traits. Overall, 19·5 % of the strains were members of group A, 12·4 % B1, 45·1 % B2 and 22·9 % D. The frequency with which strains belonging to the four ECOR groups were observed varied with the age and sex of the hosts from which they were isolated. In males, the probability of isolating A or D strains increased with host age, whilst the probability of detecting a group B2 strain declined. In females, the probability of recovering A or B2 strains increased with increasing host age and there was a concomitant decline in the likelihood of isolating B1 or D strains. Of the 29 virulence-associated traits examined, 24 were detected in more than one strain. The likelihood of detecting most traits varied with a strain's ECOR membership, with the exception of afa / draBC , astA , cvaC , eaeA , iss and iutA , for which there was no statistically significant evidence of an association with ECOR group. The frequency with which fimH , iha , eaeA , iroN , hlyD , iss , ompT and K1 were detected in a strain depended on the age or sex of the host from which the strain was isolated. In group B2 strains many of the virulence traits were non-randomly associated, with some co-occurring in a strain less often than expected by chance, whilst others were co-associated. In 17 cases, the extent to which two virulence traits were co-associated was found to depend on host sex and age. The results of this study suggest that the morphological, physiological and dietary differences that occur among human in iduals of different sex or age may influence the distribution of E. coli genotypes.
Publisher: Oxford University Press (OUP)
Date: 1993
Publisher: ACM Press
Date: 2004
Publisher: Springer Science and Business Media LLC
Date: 07-12-2017
DOI: 10.1007/S00330-017-5153-9
Abstract: To assess high-bandwidth and compressed sensing-(CS)-SEMAC turbo spin echo (TSE) techniques for metal artifact reduction MRI of total ankle arthroplasty (TAA) implants. Following institutional approval and consent, 40 subjects with TAA implants underwent 1.5-T MRI prospectively. Evaluations included bone-implant interfaces, anatomical structures, abnormal findings and differential diagnoses before and after MRI. AUCs of P-P plots were used to determine superiority. Statistical differences were evaluated with McNemar and chi-square tests. P-values ≤ 0.05 were considered significant. CS-SEMAC TSE was superior to high-bandwidth TSE in showing the bone-implant interfaces (AUC=0.917), periprosthetic bone, tendons and joint capsule (AUC=0.337-0.766), bone marrow oedema (43 % difference, p=0.041), interface osteolysis (63 %, p=0.015), tendinopathy (62 %, p=0.062), periprosthetic fractures (60 %, p=0.250), synovitis (43 %, p=0.250), as well as reader confidence for bone marrow oedema (p=<0.001), fracture (p=0.001), interface osteolysis (p=0.003), synovitis (p=0.027) and tendinopathy (p=0.034). The number of differential diagnoses in symptomatic subjects after the MRI with CS-SEMAC decreased from 3 (1-4) to 1 (1-2) (p<0.001). MRI of TAA implants with CS-SEMAC improves the diagnosis of interface osteolysis, periprosthetic bone marrow oedema, fractures and tendinopathy when compared to high-BW TSE, and has a positive effect on patient management. • High-bandwidth TSE and compressed sensing SEMAC improve MRI of ankle arthroplasty implants. • Compressed sensing SEMAC improves bone-implant interfaces, periprosthetic bone, tendons and joint capsule visibility. • Compressed sensing SEMAC improves the diagnosis of osteolysis, tendinopathy, fractures and synovitis. • MRI decreases the number of clinical differential diagnoses of painful ankle arthroplasty implants.
Publisher: Wiley
Date: 20-09-2017
DOI: 10.1111/ACFI.12298
Publisher: Wiley
Date: 03-10-2016
Abstract: The purpose of this study was to determine the value of resistive index (RI) variability in predicting cerebrovascular complications during extracorporeal membrane oxygenation (ECMO). This retrospective study included 36 infants treated by ECMO. The RI was measured on daily transfontanellar duplex sonography, obtained first without fontanel compression and then after gentle compression with the transducer. The age at ECMO cannulation, sex, gestational age at birth, method of delivery, indication, and type and duration of ECMO were recorded. There was a statistically significant difference in RI variability in infants who developed cerebrovascular complications as opposed to those who did not (P = .002). Resistive index variability of 10% or greater on any day was associated with an increased risk for cerebrovascular complications (P = .0482 χ Resistive index variability of 10% or greater on any day had a statistically significant risk of cerebrovascular complication development. Extracorporeal membrane oxygenation cannulation at younger than 3 days conferred an increased risk of cerebrovascular complications.
Publisher: Informa UK Limited
Date: 02-2009
Publisher: Informa UK Limited
Date: 12-2016
DOI: 10.1057/JORS.2016.30
Publisher: Wiley
Date: 30-10-2023
DOI: 10.1002/AJB2.16241
Publisher: Oxford University Press (OUP)
Date: 12-2006
Publisher: Radiological Society of North America (RSNA)
Date: 06-2021
Publisher: Wiley
Date: 09-2000
DOI: 10.2307/3315962
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.FAS.2018.09.005
Abstract: Restoration of anatomical relationship between talus and tibia is crucial for longevity of total ankle replacement (TAR). Weight-bearing (WB) radiographs are the standard for evaluating the sagittal balance alignment, but are prone to rotational misalignment and altered measurements. Metal artifact reduction sequence (MARS) MRI allows visualization of periprosthetic landmarks and alignment of the image plane to the true sagittal axis of the implant. The purpose of this study was to compare TAR sagittal balance measurements on MARS MRI and WB radiographs. Twenty-three subjects with TAR [10 men/13 women, age 60 (41-73) years 13 (3-24) months post-op] underwent MARS MRI and standard lateral WB radiographs. Standardized MARS MR images were aligned to the sagittal talar component axis. Three observers performed sagittal balance alignment measurements twice in an independent, random and blinded fashion. Lateral Talar Station (LTS), tibial axis-to-talus (T-T) ratio and normalized tibial axis-to-lateral-process (T-L) distance were measured. Concordance correlation coefficients (CCC) and intraclass correlation coefficients (ICC) were used for statistical analysis. In addition, mixed effects linear models were employed to assess overall concordance of the two image types. The intraobserver agreement was excellent for radiographic (CCC=0.96) and MRI (CCC=0.90-0.97) measurements. Interobserver agreements were good-to-excellent with overall slightly higher agreements for MRI (ICC=0.78-0.94) than radiography (ICC=0.78-0.90) measurements. The T-T ratios of radiographs and MRI showed a high degree of concordance, whereas LTS was significantly lower on MRI when compared with radiographs, and T-L distance showed notable disagreement between the two imaging types. Sagittal balance measurements performed on standardized weight-bearing radiographs and standardized MARS MRI demonstrate substantial correlation and similarity. Given its high intra and interobserver agreement, MARS MRI may be helpful for the evaluation of TAR sagittal balance. Level II - Prospective Comparative Study.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Steven Stern.