16 research outputs found
Assessment of accuracy of non-rigid registration algorithms for follow-up treatment NSCLC imaging (Conference Abstract)
Assessment of overlap between high FDG-uptake areas in deformed pre-treatment and post-treatment PET scans (Conference Abstract)
Dietary Glycemic Load and Glycemic Index and Risk of Coronary Heart Disease and Stroke in Dutch Men and Women: The EPIC-MORGEN Study
BACKGROUND: The associations of glycemic load (GL) and glycemic index (GI) with the risk of cardiovascular diseases (CVD) are not well-established, particularly in men, and may be modified by gender. OBJECTIVE: To assess whether high dietary GL and GI increase the risk of CVD in men and women. METHODS: A large prospective cohort study (EPIC-MORGEN) was conducted within the general Dutch population among 8,855 men and 10,753 women, aged 21-64 years at baseline (1993-1997) and free of diabetes and CVD. Dietary intake was assessed with a validated food-frequency questionnaire and GI and GL were calculated using Foster-Powell's international table of GI. Information on morbidity and mortality was obtained through linkage with national registries. Cox proportional hazards analysis was performed to estimate hazard ratios (HRs) for incident coronary heart disease (CHD) and stroke, while adjusting for age, CVD risk factors, and dietary factors. RESULTS: During a mean follow-up of 11.9 years, 581 CHD cases and 120 stroke cases occurred among men, and 300 CHD cases and 109 stroke cases occurred among women. In men, GL was associated with an increased CHD risk (adjusted HR per SD increase, 1.17 [95% CI, 1.02-1.35]), while no significant association was found in women (1.09 [0.89-1.33]). GI was not associated with CHD risk in both genders, while it was associated with increased stroke risk in men (1.27 [1.02-1.58]) but not in women (0.96 [0.75-1.22]). Similarly, total carbohydrate intake and starch intake were associated with a higher CHD risk in men (1.23 [1.04-1.46]; and 1.24 [1.07-1.45]), but not in women. CONCLUSION: Among men, high GL and GI, and high carbohydrate and starch intake, were associated with increased risk of CVD
Alcohol intake in relation to non-fatal and fatal coronary heart disease and stroke: EPIC-CVD case-cohort study.
To investigate the association between alcohol consumption (at baseline and over lifetime) and non-fatal and fatal coronary heart disease (CHD) and stroke
Alcohol intake in relation to non-fatal and fatal coronary heart disease and stroke : EPIC-CVD case-cohort study
OBJECTIVE To investigate the association between alcohol consumption (at baseline and over lifetime) and non-fatal and fatal coronary heart disease (CHD) and stroke. DESIGN Multicentre case-cohort study. SETTING A study of cardiovascular disease (CVD) determinants within the European Prospective Investigation into Cancer and nutrition cohort (EPIC-CVD) from eight European countries. PARTICIPANTS 32 549 participants without baseline CVD, comprised of incident CVD cases and a subcohort for comparison. MAIN OUTCOME MEASURES Non-fatal and fatal CHD and stroke (including ischaemic and haemorrhagic stroke). RESULTS There were 9307 non-fatal CHD events, 1699 fatal CHD, 5855 non-fatal stroke, and 733 fatal stroke. Baseline alcohol intake was inversely associated with non-fatal CHD, with a hazard ratio of 0.94 (95% confidence interval 0.92 to 0.96) per 12 g/day higher intake. There was a J shaped association between baseline alcohol intake and risk of fatal CHD. The hazard ratios were 0.83 (0.70 to 0.98), 0.65 (0.53 to 0.81), and 0.82 (0.65 to 1.03) for categories 5.0-14.9 g/day, 15.0-29.9 g/day, and 30.0-59.9 g/day of total alcohol intake, respectively, compared with 0.1-4.9 g/ day. In contrast, hazard ratios for non-fatal and fatal stroke risk were 1.04 (1.02 to 1.07), and 1.05 (0.98 to 1.13) per 12 g/day increase in baseline alcohol intake, respectively, including broadly similar findings for ischaemic and haemorrhagic stroke. Associations with cardiovascular outcomes were broadly similar with average lifetime alcohol consumption as for baseline alcohol intake, and across the eight countries studied. There was no strong evidence for interactions of alcohol consumption with smoking status on the risk of CVD events. CONCLUSIONS Alcohol intake was inversely associated with non-fatal CHD risk but positively associated with the risk of different stroke subtypes. This highlights the opposing associations of alcohol intake with different CVD types and strengthens the evidence for policies to reduce alcohol consumption.Peer reviewe
Validation of nonrigid registration in pretreatment and follow-up PET/CT scans for quantification of tumor residue in lung cancer patients
Nonrigid registrations of pre- and postradiotherapy (RT) PET/CT scans of NSCLC patients were performed with different algorithms and validated tracking internal landmarks. Dice overlap ratios (DR) of high FDG-uptake areas in registered PET/CT scans were then calculated to study patterns of relapse. For 22 patients, pre- and post-RT PET/CT scans were registered first rigidly and then nonrigidly. For three patients, two types (based on Demons or Morphons) of nonrigid registration algorithms each with four different parameter settings were applied and assessed using landmark validation. The two best performing methods were tested on all patients, who were then classified into three groups: large (Group 1), minor (Group 2) or insufficient improvement (Group 3) of registration accuracy. For Group 1 and 2, DRs between high FDG-uptake areas in pre- and post-RT PET scans were determined. Distances between corresponding landmarks on deformed pre-RT and post-RT scans decreased for all registration methods. Differences between Demons and Morphons methods were smaller than 1 mm. For Group 1, landmark distance decreased from 9.5 ± 2.1 mm to 3.8 ± 1.2 mm (mean ± 1 SD, p < 0.001), and for Group 3 from 13.6 ± 3.2 mm to 8.0 ± 2.2 mm (p=0.02). No significant change was observed for Group 2 where distances decreased from 5.6 ± 1.3 mm to 4.5 ± 1.1 mm (p=0.02). DRs of high FDG-uptake areas improved significantly after nonrigid registration for most patients in Group 1. Landmark validation of nonrigid registration methods for follow-up CT imaging in NSCLC is necessary. Nonrigid registration significantly improves matching between pre- and post-RT CT scans for a subset of patients, although not in all patients. Hence, the quality of the registration needs to be assessed for each patient individually. Successful nonrigid registration increased the overlap between pre- and post-RT high FDG-uptake regions
Validation of nonrigid registration in pretreatment and follow‐up PET/CT scans for quantification of tumor residue in lung cancer patients
T 2 mapping of cerebrospinal fluid : 3 T versus 7 T
OBJECT: Cerebrospinal fluid (CSF) T 2 mapping can potentially be used to investigate CSF composition. A previously proposed CSF T 2-mapping method reported a T 2 difference between peripheral and ventricular CSF, and suggested that this reflected different CSF compositions. We studied the performance of this method at 7 T and evaluated the influence of partial volume and B 1 and B 0 inhomogeneity. MATERIALS AND METHODS: T 2-preparation-based CSF T 2-mapping was performed in seven healthy volunteers at 7 and 3 T, and was compared with a single echo spin-echo sequence with various echo times. The influence of partial volume was assessed by our analyzing the longest echo times only. B 1 and B 0 maps were acquired. B 1 and B 0 dependency of the sequences was tested with a phantom. RESULTS: T 2,CSF was shorter at 7 T compared with 3 T. At 3 T, but not at 7 T, peripheral T 2,CSF was significantly shorter than ventricular T 2,CSF. Partial volume contributed to this T 2 difference, but could not fully explain it. B 1 and B 0 inhomogeneity had only a very limited effect. T 2,CSF did not depend on the voxel size, probably because of the used method to select of the regions of interest. CONCLUSION: CSF T 2 mapping is feasible at 7 T. The shorter peripheral T 2,CSF is likely a combined effect of partial volume and CSF composition
Phase contrast MRI measurements of net cerebrospinal fluid flow through the cerebral aqueduct are confounded by respiration
BACKGROUND: Net cerebrospinal fluid (CSF) flow through the cerebral aqueduct may serve as a marker of CSF production in the lateral ventricles, and changes that occur with aging and in disease. PURPOSE: To investigate the confounding influence of the respiratory cycle on net CSF flow and stroke volume measurements. STUDY TYPE: Cross-sectional study. SUBJECTS: Twelve young, healthy subjects (seven male, age range 19-39 years, average age 28.3 years). FIELD STRENGTH/SEQUENCE: Phase contrast MRI (PC-MRI) measurements were performed at 7T, with and without respiratory gating on expiration and on inspiration. All measurements were repeated. ASSESSMENT: Net CSF flow and stroke volume in the aqueduct, over the cardiac cycle, was determined. STATISTICAL TESTS: Repeatability was determined using the intraclass correlation coefficient (ICC) and linear regression analysis between the repeated measurements. Repeated measures analysis of variance (ANOVA) was performed to compare the measurements during inspiration/expiration/no gating. Linear regression analysis was performed between the net CSF flow difference (inspiration minus expiration) and stroke volume. RESULTS: Net CSF flow (average ± standard deviation) was 0.64 ± 0.32 mL/min (caudal) during expiration, 0.12 ± 0.49 mL/min (cranial) during inspiration, and 0.31 ± 0.18 mL/min (caudal) without respiratory gating. Respiratory gating did not affect stroke volume measurements (41 ± 18, 42 ± 19, 42 ± 19 μL/cycle for expiration, no respiratory gating and inspiration, respectively). Repeatability was best during inspiration (ICC = 0.88/0.56/-0.31 for gating on inspiration/expiration/no gating). A positive association was found between average stroke volume and net flow difference between inspiration and expiration (R = 0.678/0.605, P = 0.015/0.037 for the first/second repeated measurement). DATA CONCLUSION: Measured net CSF flow is confounded by respiration effects. Therefore, net CSF flow measurements with PC-MRI cannot in isolation be directly linked to CSF production. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018
De-implementation strategy to Reduce the Inappropriate use of urinary and intravenous CATheters study protocol for the RICAT-study
BACKGROUND: Urinary and (peripheral and central) intravenous catheters are widely used in hospitalized patients. However, up to 56% of the catheters do not have an appropriate indication and some serious complications with the use of these catheters can occur. The main objective of our quality improvement project is to reduce the use of catheters without an appropriate indication by 25-50%, and to evaluate the affecting factors of our de-implementation strategy. METHODS: In a multicenter, prospective interrupted time series analysis, several interventions to avoid inappropriate use of catheters will be conducted in seven hospitals in the Netherlands. Firstly, we will define a list of appropriate indications for urinary and (peripheral and central) intravenous catheters, which will restrict the use of catheters and urge catheter removal when the indication is no longer appropriate. Secondly, after the baseline measurements, the intervention will take place, which consists of a kick-off meeting, including a competitive feedback report of the baseline measurements, and education of healthcare workers and patients. Additional strategies based on the baseline data and local conditions are optional. The primary endpoint is the percentage of catheters with an inappropriate indication on the day of data collection before and after the de-implementation strategy. Secondary endpoints are catheter-related infections or other complications, catheter re-insertion rate, length of hospital (and ICU) stay and mortality. In addition, the cost-effectiveness of the de-implementation strategy will be calculated. DISCUSSION: This study aims to reduce the use of urinary and intravenous catheters with an inappropriate indication, and as a result reduce the catheter-related complications. If (cost-) effective it provides a tool for a nationwide approach to reduce catheter-related infections and other complications. TRIAL REGISTRATION: Dutch trial registry: NTR6015 . Registered 9 August 2016