Landspítali University Hospital Research Archive
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A CT-based method to compute femur remodelling after total hip arthroplasty
No full textTo access publisher's full text version of this article click on the hyperlink belowBone remodelling after total hip arthroplasty has been largely observed and investigated. Most studies rely on projective images and only few obtain 3D information with limited spatial resolution. This study proposes a method to provide quantitative, 3D high-resolution data about femur bone density variations, by means of CT volume processing. This would offer a tool for further research and clinical studies. Five patients subjected to primary, cementless total hip arthroplasty were considered. Calibrated CT volumes were acquired before, just after surgery and 1 yr later. Bone remodelling hinders accurate alignment of femur volumes acquired after a year; instead, prosthesis stem remains unchanged. Thus, after metal artefact reduction, prosthesis was segmented, and stem-based accurate alignment was obtained. A test to exclude prosthesis migration was performed by considering specific femur anatomical landmarks. Bone density error due to artefact reduction and realignment was estimated. Quantitative differences in bone mineral density were computed for each voxel, providing a resolution of about 1 mm. Preliminary results showed that the femur underwent consistent remodelling after a year. Widespread bone density losses appeared in those areas where strain-adaptive remodelling is normally expected, particularly about the calcar. Conversely, distal areas with clear stem-bone contact showed considerable density gains
Predicting body mass index and isometric leg strength using soft tissue distributions from computed tomography scans
No full textTo access publisher's full text version of this article click on the hyperlink belowThis paper describes the interconnections and predictive value between Body Mass Index (BMI), Isometric Leg Strength (ISO) and soft tissue distribution from mid-thigh Computed Tomography (CT) scans using Machine Learning (ML) regression and classification algorithms. A novel methodology for soft tissue patient specific CT profile called Nonlinear Trimodal Regression Analysis (NTRA) was developed using radiodensitomentric distribution from a CT scan. This method defines 11 parameters used as input features for Tree-Based ML algorithms in order to apply regression and classification on BMI and ISO. K_fold Cross-Validation with k = 10 is applied to obtain several models to choose the best one using the higher coefficient of determination (R-2) as an evaluator of the quality of regression prediction. Following this, BMI and ISO are divided into 3 and 5 classes and the same methodology is used to classify them. For this analysis, an accuracy parameter is calculated to evaluate the quality of the results. The max R-2 is 88.9 for the BMI and it is obtained using the Gradient-Boosting Algorithm. The best accuracy was 76.1 for 3 classes and 73.1 for 5 classes. The best results obtained for ISO are R-2 = 66.5 and an accuracy of 65.5 for the 3 classes classification. Furthermore, the connective tissue assumes high importance in the prediction process. In this methodological study the feasibility of a ML approach was tested with good results, in order to show a novel approach to study the correlation between physiology parameters and imaging.United States Department of Health & Human Services
National Institutes of Health (NIH) - USA
NIA Intramural Research Program, Hjartavernd (Icelandic Heart Association)
Althingi (Icelandic Parliament
A poor appetite or ability to eat and its association with physical function amongst community-dwelling older adults: age, gene/environment susceptibility-Reykjavik study
Get PDFTo access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadA poor appetite or ability to eat and its association with physical function have not been explored considerably amongst community-dwelling older adults. The current study examined whether having an illness or physical condition affecting one's appetite or ability to eat is associated with body composition, muscle strength, or physical function amongst community-dwelling older adults. This is a secondary analysis of cross-sectional data from the age, gene/environment susceptibility-Reykjavik study (n = 5764). Illnesses or physical conditions affecting one's appetite or ability to eat, activities of daily living, current level of physical activity, and smoking habits were assessed with a questionnaire. Fat mass, fat-free mass, body mass index, knee extension strength, and grip strength were measured, and the 6-m walk test and timed up-and-go test were administered. Individuals who reported illnesses or physical conditions affecting their appetite or ability to eat were considered to have a poor appetite. The associations of appetite or the ability to eat with body composition and physical function were analysed with stepwise linear regression models. A total of 804 (14%) individuals reported having conditions affecting their appetite or ability to eat and had a significantly lower fat-free mass and body mass index, less grip strength, and poorer physical function than did those without any conditions affecting their appetite or ability to eat. Although the factors reported to affect one's appetite or ability to eat are seldom considered severe, their strong associations with physical function suggest that any condition affecting one's appetite or ability to eat requires attention.European Horizon 2020 PROMISS Project "PRevention Of Malnutrition In Senior Subjects in the EU
Sjúklingatilfelli frá Tannlæknadeild Háskóla Íslands - Partagerð
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Sjúklingatilfelli frá Tannlæknadeild Háskóla Íslands - Krónu- og brúargerð, tannfylling
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Specialist training for cardiothoracic surgery in the Nordic countries.
No full textTo access publisher's full text version of this article click on the hyperlink belowSweden, Denmark, Finland, Norway, and Iceland form the 5 culturally uniform Nordic countries. Each of the countries owns a high-standard tradition of individual steering in cardiothoracic education aiming at securing the needs and features of the local area. Indisputably, mastering a Nordic language and applying a high-standard individual steering in education ensure that a dedicated trainee is selected to the cardiothoracic program in accordance with the needs and features of the local area.Competitive State Research Financing of the Expert Responsibility area of Tampere University Hospital, Tampere Finlan
Atopy Modifies the Association Between Inhaled Corticosteroid Use and Lung Function Decline in Patients with Asthma.
Get PDFTo access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadBackground: Inhaled corticosteroids (ICSs) are the mainstay of asthma treatment, but response to medication is variable. Patients with allergic inflammation generally show a better short-term response to ICSs; however, studies on predictors of long-term response are few.
Objective: To assess whether allergic sensitization can modify the association between ICS use and lung function decline over 20 years in adult asthma.
Methods: We used data from the 3 clinical examinations of the European Community Respiratory Health Survey. We measured ICS use (no use, and use for 8 years) and FEV1 decline among subjects with asthma over the 2 periods between consecutive examinations. We conducted a cohort study combining data of the 2 periods (906 observations from 745 subjects) to assess whether the association between ICS use and FEV1 decline was modified by allergic sensitization (IgE > 0.35 kU/L for any of house-dust mite, timothy grass, cat, or Cladosporium).
Results: FEV1 decline was similar for non-ICS users, as well as ICS users for less than 1.3 years, with and without allergic sensitization. However, among subjects on ICSs for a longer period, sensitization was associated with an attenuated decline (Pinteraction = .006): in the group treated for more than 8 years, FEV1 decline was on average 27 mL/y (95% CIBonferroni-adjusted, 11-42) lower for subjects with sensitization compared with nonsensitized subjects.
Conclusions: Our study suggests that biomarkers of atopy can predict a more favorable long-term response to ICSs. Randomized controlled studies are needed to confirm these findings.European Union's Horizon 2020 Research and Innovation programm
Impact of the 10-valent pneumococcal conjugate vaccine on hospital admissions in children under three years of age in Iceland.
Get PDFTo access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadIntroduction: Pneumococcus is an important respiratory pathogen. The 10-valent pneumococcal vaccine (PHiD-CV) was introduced into the Icelandic vaccination programme in 2011. The aim was to estimate the impact of PHiD-CV on paediatric hospitalisations for respiratory tract infections and invasive disease.
Methods: The 2005-2015 birth-cohorts were followed until three years of age and hospitalisations were recorded for invasive pneumococcal disease (IPD), meningitis, sepsis, pneumonia and otitis media. Hospitalisations for upper- and lower respiratory tract infections (URTI, LRTI) were used as comparators. The 2005-2010 birth-cohorts were defined as vaccine non-eligible cohorts (VNEC) and 2011-2015 birth-cohorts as vaccine eligible cohorts (VEC). Incidence rates (IR) were estimated for diagnoses, birth-cohorts and age groups, and incidence rate ratios (IRR) between VNEC and VEC were calculated assuming Poisson variance. Cox regression was used to estimate the hazard ratio (HR) of hospitalisation between VNEC and VEC.
Results: 51,264 children were followed for 142,315 person-years, accumulating 1,703 hospitalisations for the respective study diagnoses. Hospitalisations for pneumonia decreased by 20% (HR 0.80, 95%CI:0.67-0.95) despite a 32% increase in admissions for LRTI (HR 1.32, 95%CI:1.14-1.53). Hospital admissions for culture-confirmed IPD decreased by 93% (HR 0.07, 95%CI:0.01-0.50) and no hospitalisations for IPD with vaccine-type pneumococci were observed in the VEC. Hospitalisations for meningitis and sepsis did not change. A decrease in hospital admissions for otitis media was observed, but did not coincide with PHiD-CV introduction.
Conclusion: Following the introduction of PHiD-CV in Iceland, hospitalisations for pneumonia and culture confirmed IPD decreased. Admissions for other LRTIs and URTIs increased during this period.GlaxoSmithKline
Landspitali University Hospital Research Fun
Incidence of myeloproliferative neoplasms - trends by subgroup and age in a population-based study in Sweden.
No full textTo access publisher's full text version of this article click on the hyperlink belowBackground: The reported incidence of Philadelphia-negative myeloproliferative neoplasms (MPNs) differs substantially between previous reports, likely due to true regional differences in incidence and/or variations in the quality and coverage of the cancer registers.
Objective: We therefore assessed MPN incidence in Sweden during recent years using prospectively collected information captured in Swedish health registers.
Methods: Patients with MPNs were identified through the Swedish Cancer Register and Swedish Blood Cancer Register between 2000 and 2014. Information on the Swedish population was obtained from the Human Mortality Database. Crude and age-standardized incidence rates of MPNs with 95% confidence intervals (CIs) were calculated.
Results: A total of 6281 MPN cases were reported to the Swedish Cancer Register and Swedish Blood Cancer Register during 2000-2014. The age-standardized, to the Swedish population in 2000, incidence for all MPNs was 4.45 (95% confidence interval [CI] 4.34-4.56)/100 000 person-years. The age-standardized incidence for polycythemia vera was 1.48 (1.42-1.54), for essential thrombocythemia 1.60 (1.53-1.66) and for primary myelofibrosis 0.52 (0.48-0.56)/100 000 person-years, respectively. The incidence rate of MPNs was substantially higher in the older compared to the younger age groups. The incidence increased during the study period, likely to do better reporting and increasing age of the general population.
Conclusion: The reported MPN incidences in our study, which were in the higher interval of previously published studies, are likely more accurate compared to previous reports due to the population-based setting and high level of coverage in the Swedish Cancer and Blood Cancer Registers.Karolinska Institutet
United States Department of Health & Human Services
National Institutes of Health (NIH) - USA
NIH National Cancer Institute (NCI)
Stockholm County Council
Swedish Research Council
Blodcancerfonden
Cancer Research Foundations of Radiumhemme