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2.
Public Health ; 222: 154-159, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37544126

RESUMO

OBJECTIVES: Conventional cigarette smoking increases inflammation and white blood cell (WBC) counts. However, there have been limited studies on the relationship between heated cigarette smoking and WBC counts. This study aimed to examine this relationship using nationally representative population-based health data. STUDY DESIGN: This was a population-based cross-sectional study. METHODS: The Korea National Health and Nutrition Examination Survey database was used to analyze this relationship. Data related to sex, age, body mass index (BMI), WBC count, and smoking history were obtained from the database. The smoking-related questionnaires included smoking status, smoking type (heated or conventional cigarettes), and smoking amount. The summary statistics of the WBC counts were calculated according to sex, smoking status, and smoking type. In addition, the exposure-response relationship between the smoking amount and WBC count was examined by smoking type, controlling for sex, age, and BMI. RESULTS: In total, 9747 WBC measurements were used in the analyses. WBC count increased in conventional cigarette smokers, while there was no significant difference in WBC count between heated cigarette smokers and non-smokers. The WBC count showed a positive dose-response relationship with the smoking amount in both conventional and heated cigarette smokers. CONCLUSIONS: The results confirm that conventional cigarette smoking increases WBC counts. Furthermore, the results suggest that heated cigarette smoking does not lead to a significant increase in WBC counts, although it indicates a potential dose-response relationship with WBC count. Further research with larger sample sizes is needed to confirm whether these results reflect true associations.


Assuntos
Fumar Cigarros , Humanos , Estudos Transversais , Inquéritos Nutricionais , Fumar Cigarros/epidemiologia , Contagem de Leucócitos , Leucócitos
3.
BMC Public Health ; 23(1): 1082, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37280555

RESUMO

BACKGROUND: Toybox is a kindergarten-based intervention program that targets sedentary behavior, snacking and drinking habits, as well as promoting physical activity in an effort to improve healthy energy balance-related behaviors among children attending kindergartens in Malaysia. The pilot of this program was conducted as a randomized controlled trial (RCT) involving 837 children from 22 intervention kindergartens and 26 control kindergartens respectively. This paper outlines the process evaluation of this intervention. METHODS: We assessed five process indicators: recruitment, retention, dosage, fidelity, and satisfaction for the Toybox program. Data collection was conducted via teachers' monthly logbooks, post-intervention feedback through questionnaires, and focus group discussions (FGD) with teachers, parents, and children. Data were analyzed using quantitative and qualitative data analysis methods. RESULTS: A total of 1072 children were invited. Out of the 1001 children whose parents consented to join, only 837 completed the program (Retention rate: 88.4%). As high as 91% of the 44 teachers and their assistants engaged positively in one or more of the process evaluation data collection methods. In terms of dosage and fidelity, 76% of parents had received newsletters, tip cards, and posters at the appropriate times. All teachers and their assistants felt satisfied with the intervention program. However, they also mentioned some barriers to its implementation, including the lack of suitable indoor environments to conduct activities and the need to make kangaroo stories more interesting to captivate the children's attention. As for parents, 88% of them were satisfied with the family-based activities and enjoyed them. They also felt that the materials provided were easy to understand and managed to improve their knowledge. Lastly, the children showed positive behaviors in consuming more water, fruits, and vegetables. CONCLUSIONS: The Toybox program was deemed acceptable and feasible to implement by the parents and teachers. However, several factors need to be improved before it can be expanded and embedded as a routine practice across Malaysia.


Assuntos
Obesidade Infantil , Pré-Escolar , Humanos , Avaliação de Programas e Projetos de Saúde , Malásia , Obesidade Infantil/prevenção & controle , Instituições Acadêmicas , Comportamentos Relacionados com a Saúde , Pais/educação
4.
Med J Malaysia ; 78(1): 54-60, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36715192

RESUMO

INTRODUCTION: The Brunei Dialysis and Transplant Registry (BDTR) recorded data on patients with end-stage kidney disease (ESKD) from 2011 to 2020, mainly for planning of services and benchmarking of standards. We report the trends of epidemiologic and performance parameters, compare performances between modalities of Kidney Replacement Therapy and evaluate the survival of ESKD patients over the 10-year period. MATERIALS AND METHODS: Three groups of data were analysed from the BDTR over the 10-year period. Epidemiological data, blood parameters and dialysis are key performance indicators. RESULTS: There are increments in prevalence and incidence of treated ESKD patients in Brunei over 10 years, especially with haemodialysis (HD). The projected prevalence and incidence showed an anticipated annual increase of 42.2 per million population (pmp) and 9.9 pmp respectively. Diabetes mellitus (DM) (79%) was the main cause of ESKD. HD (86%), peritoneal dialysis (PD) (9%) and transplant (5%) were the main modalities of kidney replacement therapy in 2020. Cumulative results over the decade showed significant improvements in serum phosphate, peritonitis rates and HD blood flow rates. PD patients have better survival rates, lower systolic blood pressure and better adequacy. PD survival (patient survival of 91%, 73% and 56% at 1, 3 and 5 years respectively) was superior to HD survival (86% and 64% at 1 and 2 years, respectively), but patient demographics (age and DM status) were different. The 2020 dataset showed satisfactory anaemia management but mineral bone disease management was sub-optimal. Seventy percent of prevalent HD patients had arteriovenous fistula access. Thirty-two percent and fifty-two percent of HD and PD patients, respectively, achieved target dialysis adequacy. Peritonitis rate was 0.3 episodes per patient year. CONCLUSION: Brunei has a high incidence and prevalence of treated ESKD in the last decade, especially DM-related ESKD. This study has identified many specific areas to be targeted for improvements and provided evidence for further proliferation of PD and transplant preference policy.


Assuntos
Falência Renal Crônica , Transplante de Rim , Peritonite , Humanos , Brunei/epidemiologia , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/terapia , Diálise Renal
5.
Clin Radiol ; 77(2): 88-95, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34598790

RESUMO

The pattern of metastases in prostate cancer (PC) is evolving. Increased use of imaging, newer imaging techniques with higher sensitivity for disease detection and patients receiving multiple lines of novel therapies with increased life expectancy are likely to be contributory. Awareness of metastatic disease patterns improves early diagnosis, accurate staging, and initiation of appropriate therapy, and can inform prognostic information and anticipate potential disease complications. The aim of this review is to document the spectrum of metastases in PC including emerging and unusual patterns, and to highlight the role of novel imaging including prostate-specific membrane antigen (PSMA)-positron-emission tomography (PET) and whole-body magnetic resonance imaging (WB-MRI) to improve diagnostic and response assessment accuracy.


Assuntos
Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Imagem Corporal Total/métodos , Humanos , Masculino , Próstata/diagnóstico por imagem
6.
Br J Cancer ; 125(11): 1462-1465, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34316019

RESUMO

The National Cancer Imaging Translational Accelerator (NCITA) is creating a UK national coordinated infrastructure for accelerated translation of imaging biomarkers for clinical use. Through the development of standardised protocols, data integration tools and ongoing training programmes, NCITA provides a unique scalable infrastructure for imaging biomarker qualification using multicentre clinical studies.


Assuntos
Biomarcadores Tumorais/metabolismo , Testes Diagnósticos de Rotina/métodos , Neoplasias/diagnóstico por imagem , Humanos , Projetos de Pesquisa , Reino Unido
7.
Clin Radiol ; 76(10): 715-727, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33934876

RESUMO

Whole-body magnetic resonance imaging (MRI) is now a crucial tool for the assessment of the extent of systemic malignant bone disease and response to treatment, and forms part of national and international recommendations for imaging patients with myeloma or metastatic prostate cancer. Recent developments in scanners have enabled acquisition of good-quality whole-body MRI data within 45 minutes on modern MRI systems from all main manufacturers. This provides complimentary morphological and functional whole-body imaging; however, lack of prior experience and acquisition times required can act as a barrier to adoption in busy radiology departments. This article aims to tackle the former by reviewing the indications and providing guidance for technical delivery and clinical interpretation of whole-body MRI for patients with malignant bone disease.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/patologia , Imageamento por Ressonância Magnética/métodos , Guias de Prática Clínica como Assunto , Imagem Corporal Total/métodos , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Humanos
8.
J Hosp Infect ; 102(3): 337-342, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30500386

RESUMO

This study explored how cultural values affected Health Belief Model (HBM) components and the influenza vaccine uptake among nurses across three Asian populations using a survey conducted in 2017 (N = 3971). The vaccination coverages were 33.5% (Brunei), 35.6% (Hong Kong) and 69.5% (Singapore). Three HBM components (perceived susceptibility, perceived benefits and cues to action) were positively associated with vaccination. A direct negative link and an indirect positive link via HBM were observed between collectivism and vaccination, whereas a negative indirect link via HBM between power distance and vaccination was observed. Cultural values, notably collectivism, advanced HBM to study nurses' vaccination.


Assuntos
Cultura , Conhecimentos, Atitudes e Prática em Saúde , Influenza Humana/prevenção & controle , Enfermeiras e Enfermeiros/psicologia , Cobertura Vacinal , Vacinação/psicologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brunei , Infecção Hospitalar/prevenção & controle , Estudos Transversais , Transmissão de Doença Infecciosa/prevenção & controle , Feminino , Hong Kong , Humanos , Influenza Humana/transmissão , Masculino , Pessoa de Meia-Idade , Singapura , Adulto Jovem
9.
Int J Behav Nutr Phys Act ; 15(1): 36, 2018 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-29618384

RESUMO

BACKGROUND: The interpretation of previous studies on the association of physical activity and sedentary behaviour with psychological health is limited by the use of mostly self-reported physical activity and sedentary behaviour, and a focus on Western populations. We aimed to explore the association of self-reported and devise-based measures of physical activity and sedentary behaviour domains on psychological distress in an urban multi-ethnic Asian population. METHODS: From a population-based cross-sectional study of adults aged 18-79 years, data were used from an overall sample (n = 2653) with complete self-reported total physical activity/sedentary behaviour and domain-specific physical activity data, and a subsample (n = 703) with self-reported domain-specific sedentary behaviour and accelerometry data. Physical activity and sedentary behaviour data were collected using the Global Physical Activity Questionnaire (GPAQ), a domain-specific sedentary behaviour questionnaire and accelerometers. The Kessler Screening Scale (K6) and General Health Questionnaire (GHQ-12) were used to assess psychological distress. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals, adjusted for socio-demographic and lifestyle characteristics. RESULTS: The sample comprised 45.0% men (median age = 45.0 years). The prevalence of psychological distress based on the K6 and GHQ-12 was 8.4% and 21.7%, respectively. In the adjusted model, higher levels of self-reported moderate-to-vigorous physical activity (MVPA) were associated with significantly higher odds for K6 (OR = 1.47 [1.03-2.10]; p-trend = 0.03) but not GHQ-12 (OR = 0.97 [0.77-1.23]; p-trend = 0.79), when comparing the highest with the lowest tertile. Accelerometry-assessed MVPA was not significantly associated with K6 (p-trend = 0.50) nor GHQ-12 (p-trend = 0.74). The highest tertile of leisure-time physical activity, but not work- or transport-domain activity, was associated with less psychological distress using K6 (OR = 0.65 [0.43-0.97]; p-trend = 0.02) and GHQ-12 (OR = 0.72 [0.55-0.93]; p-trend = 0.01). Self-reported sedentary behaviour was not associated with K6 (p-trend = 0.90) and GHQ-12 (p-trend = 0.33). The highest tertile of accelerometry-assessed sedentary behaviour was associated with significantly higher odds for K6 (OR = 1.93 [1.00-3.75]; p-trend = 0.04), but not GHQ-12 (OR = 1.34 [0.86-2.08]; p-trend = 0.18). CONCLUSIONS: Higher levels of leisure-time physical activity and lower levels of accelerometer-based sedentary behaviour were associated with lower psychological distress. This study underscores the importance of assessing accelerometer-based and domain-specific activity in relation to mental health, instead of solely focusing on total volume of activity.


Assuntos
Acelerometria , Povo Asiático , Exercício Físico , Comportamento Sedentário , Estresse Psicológico/epidemiologia , População Urbana , Adolescente , Adulto , Idoso , Estudos Transversais , Etnicidade , Feminino , Humanos , Estilo de Vida , Modelos Logísticos , Masculino , Saúde Mental , Pessoa de Meia-Idade , Autorrelato , Singapura/epidemiologia , Estresse Psicológico/fisiopatologia , Inquéritos e Questionários , Adulto Jovem
10.
J Magn Reson ; 288: 37-42, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29414062

RESUMO

MRI volume coils can be represented by equivalent lumped element circuits and for a variety of these circuit configurations analytical design equations have been presented. The unification of several volume coil topologies results in a two-dimensional gridded equivalent lumped element circuit which compromises the birdcage resonator, its multiple endring derivative but also novel structures like the capacitive coupled ring resonator. The theory section analyzes a general two-dimensional circuit by noting that its current distribution can be decomposed into a longitudinal and an azimuthal dependency. This can be exploited to compare the current distribution with a transfer function of filter circuits along one direction. The resonances of the transfer function coincide with the resonance of the volume resonator and the simple analytical solution can be used as a design equation. The proposed framework is verified experimentally against a novel capacitive coupled ring structure which was derived from the general circuit formulation and is proven to exhibit a dominant homogeneous mode. In conclusion, a unified analytical framework is presented that allows determining the resonance frequency of any volume resonator that can be represented by a two dimensional meshed equivalent circuit.

11.
Oncogene ; 36(34): 4951, 2017 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-28604745

RESUMO

This corrects the article DOI: 10.1038/onc.2011.331.

12.
Magn Reson Imaging ; 38: 71-76, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28038964

RESUMO

INTRODUCTION: To assess if parameters in intravoxel incoherent motion (IVIM) and diffusion tensor imaging (DTI) can be used to evaluate early renal fibrosis in a mouse model of diabetic nephropathy. MATERIALS & METHODS: In a population of 38 male CD1 mice (8weeks old, 20-30g), streptozotocin induced diabetes was created in 20 mice via a single intraperitoneal injection of streptozotocin at 150mg/kg, while 18 mice served as control group. IVIM parameters were acquired at 0, 12 and 24weeks after injection of streptozotocin using a range of b values from 0 to 1200s/mm2. DTI parameters were obtained using 12 diffusion directions and lower b values of 0, 100 and 400s/mm2. DTI and IVIM parameters were obtained using region of interests drawn over the renal parenchyma. Histopathological analysis of the right kidney was performed in all mice. Results were analyzed using an unpaired t-test with P<0.05 considered statistically significant. RESULTS: Renal cortex fractional anisotropy (FA) was significantly lower in the diabetes group at week 12 as compared with the control group. Renal cortex apparent diffusion coefficient and tissue diffusivity were significantly higher in the diabetes group at week 12 compared with the control group at 12weeks. Blood flow was significantly decreased at the renal medulla at 24weeks. Histopathological analysis confirmed fibrosis in the diabetes group at 24weeks. CONCLUSION: FA is significantly reduced in diabetic nephropathy. FA might serve a potential role in the detection and therapy monitoring of early diabetic nephropathy.


Assuntos
Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/patologia , Imagem de Tensor de Difusão/métodos , Nefropatias/diagnóstico por imagem , Nefropatias/patologia , Imageamento por Ressonância Magnética/métodos , Animais , Modelos Animais de Doenças , Fibrose/diagnóstico por imagem , Fibrose/patologia , Rim/diagnóstico por imagem , Rim/patologia , Nefropatias/complicações , Masculino , Camundongos , Movimento (Física)
13.
Phys Med Biol ; 61(24): N667-N680, 2016 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-27893459

RESUMO

The bi-exponential intravoxel-incoherent-motion (IVIM) model for diffusion-weighted MRI (DWI) fails to account for differential T 2 s in the model compartments, resulting in overestimation of pseudodiffusion fraction f. An extended model, T2-IVIM, allows removal of the confounding echo-time (TE) dependence of f, and provides direct compartment T 2 estimates. Two consented healthy volunteer cohorts (n = 5, 6) underwent DWI comprising multiple TE/b-value combinations (Protocol 1: TE = 62-102 ms, b = 0-250 mm-2s, 30 combinations. Protocol 2: 8 b-values 0-800 mm-2s at TE = 62 ms, with 3 additional b-values 0-50 mm-2s at TE = 80, 100 ms; scanned twice). Data from liver ROIs were fitted with IVIM at individual TEs, and with the T2-IVIM model using all data. Repeat-measures coefficients of variation were assessed for Protocol 2. Conventional IVIM modelling at individual TEs (Protocol 1) demonstrated apparent f increasing with longer TE: 22.4 ± 7% (TE = 62 ms) to 30.7 ± 11% (TE = 102 ms); T2-IVIM model fitting accounted for all data variation. Fitting of Protocol 2 data using T2-IVIM yielded reduced f estimates (IVIM: 27.9 ± 6%, T2-IVIM: 18.3 ± 7%), as well as T 2 = 42.1 ± 7 ms, 77.6 ± 30 ms for true and pseudodiffusion compartments, respectively. A reduced Protocol 2 dataset yielded comparable results in a clinical time frame (11 min). The confounding dependence of IVIM f on TE can be accounted for using additional b/TE images and the extended T2-IVIM model.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Fígado/anatomia & histologia , Modelos Teóricos , Adulto , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes
14.
J Hosp Infect ; 94(2): 133-42, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27546456

RESUMO

Seasonal influenza vaccine uptake rate of healthcare workers (HCWs) varies widely from <5% to >90% worldwide. Perception of vaccine efficacy and side-effects are conventional factors affecting the uptake rates. These factors may operate on a personal and social level, impacting the attitudes and behaviours of HCWs. Vaccination rates were also under the influence of the occurrence of other non-seasonal influenza pandemics such as avian influenza. Different strategies have been implemented to improve vaccine uptake, with important ones including the enforcement of the local authority's recommendations, promulgation of practice guidelines, and mandatory vaccination polices. Practised in some regions in North America, mandatory policies have led to higher vaccination rate, but are not problem-free. The effects of conventional educational programmes and campaigns are in general of modest impact only. Availability of convenient vaccination facilities, such as mobile vaccination cart, and role models of senior HCWs receiving vaccination are among some strategies which have been observed to improve vaccination uptake rate. A multi-faceted approach is thus necessary to persuade HCWs to participate in a vaccination programme, especially in areas with low uptake rate.


Assuntos
Infecção Hospitalar/prevenção & controle , Pessoal de Saúde , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Vacinação/estatística & dados numéricos , Atitude do Pessoal de Saúde , Política de Saúde , Humanos , Vacinas contra Influenza/imunologia , América do Norte
15.
Obes Rev ; 17(5): 467-81, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26990220

RESUMO

Prolonged sedentary behaviour has been associated with various detrimental health risks. Workplace sitting is particularly important, providing it occupies majority of total daily sedentary behaviour among desk-based employees. The aim of this systematic review and meta-analysis was to examine the effectiveness of workplace interventions overall, and according to different intervention strategies (educational/behavioural, environmental and multi-component interventions) for reducing sitting among white-collar working adults. Articles published through December 2015 were identified in five online databases and manual searches. Twenty-six controlled intervention studies published between 2003 and 2015 of 4568 working adults were included. All 26 studies were presented qualitatively, and 21 studies with a control group without any intervention were included in the meta-analysis. The pooled intervention effect showed a significant workplace sitting reduction of -39.6 min/8-h workday (95% confidence interval [CI]: -51.7, -27.5), favouring the intervention group. Multi-component interventions reported the greatest workplace sitting reduction (-88.8 min/8-h workday; 95% CI: -132.7, -44.9), followed by environmental (-72.8 min/8-h workday; 95% CI: -104.9, -40.6) and educational/behavioural strategies -15.5 min/8-h workday (95% CI:-22.9,-8.2). Our study found consistent evidence for intervention effectiveness in reducing workplace sitting, particularly for multi-component and environmental strategies. Methodologically rigorous studies using standardized and objectively determined outcomes are warranted. © 2016 World Obesity.


Assuntos
Local de Trabalho , Comportamento , Humanos , Saúde Ocupacional , Fatores de Tempo
16.
Trauma Case Rep ; 6: 1-7, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29942851

RESUMO

Adult perianal impalement injuries are uncommon but can carry high morbidity and mortality. We report a case of a penetrating perineal trauma in a construction worker highlighting an innovative use of a Sengstaken tube to control his pelvic bleeding, as well as the operative management of his sphincteric injury. This article illustrates principles of effective acute care and discusses a diagnostic approach to evaluating a potentially complex injury, as well as the decision-making process with regard to fecal diversion and choice of sphincteric repair.

17.
Indoor Air ; 25(6): 631-40, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25557769

RESUMO

UNLABELLED: We conducted a comprehensive humidifier disinfectant exposure characterization for 374 subjects with lung disease who presumed their disease was related to humidifier disinfectant use (patient group) and for 303 of their family members (family group) for an ongoing epidemiological study. We visited the homes of the registered patients to investigate disinfectant use characteristics. Probability of exposure to disinfectants was determined from the questionnaire and supporting evidence from photographs demonstrating the use of humidifier disinfectant, disinfectant purchase receipts, any residual disinfectant, and the consistency of their statements. Exposure duration was estimated as cumulative disinfectant use hours from the questionnaire. Airborne disinfectant exposure intensity (µg/m(3)) was estimated based on the disinfectant volume (ml) and frequency added to the humidifier per day, disinfectant bulk level (µg/ml), the volume of the room (m(3)) with humidifier disinfectant, and the degree of ventilation. Overall, the distribution patterns of the intensity, duration, and cumulative exposure to humidifier disinfectants for the patient group were higher than those of the family group, especially for pregnant women and patients ≤6 years old. Further study is underway to evaluate the association between the disinfectant exposures estimated here with clinically diagnosed lung disease. PRACTICAL IMPLICATIONS: Retrospective exposure to household humidifier disinfectant as estimated here can be used to evaluate associations with clinically diagnosed lung disease due to the use of humidifier disinfectant in Korea. The framework, with modifications to account for dispersion and use patterns, can also be potentially adapted to assessment of other household chemical exposures.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Desinfetantes/análise , Umidificadores , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Poluição do Ar em Ambientes Fechados/efeitos adversos , Criança , Pré-Escolar , Desinfetantes/efeitos adversos , Feminino , Humanos , Pneumopatias/epidemiologia , Pneumopatias/etiologia , Masculino , Pessoa de Meia-Idade , Gravidez , República da Coreia/epidemiologia , Estudos Retrospectivos , Adulto Jovem
18.
Phys Med Biol ; 60(2): N9-20, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25559552

RESUMO

Respiratory motion commonly confounds abdominal diffusion-weighted magnetic resonance imaging, where averaging of successive samples at different parts of the respiratory cycle, performed in the scanner, manifests the motion as blurring of tissue boundaries and structural features and can introduce bias into calculated diffusion metrics. Storing multiple averages separately allows processing using metrics other than the mean; in this prospective volunteer study, median and trimmed mean values of signal intensity for each voxel over repeated averages and diffusion-weighting directions are shown to give images with sharper tissue boundaries and structural features for moving tissues, while not compromising non-moving structures. Expert visual scoring of derived diffusion maps is significantly higher for the median than for the mean, with modest improvement from the trimmed mean. Diffusion metrics derived from mono- and bi-exponential diffusion models are comparable for non-moving structures, demonstrating a lack of introduced bias from using the median. The use of the median is a simple and computationally inexpensive alternative to complex and expensive registration algorithms, requiring only additional data storage (and no additional scanning time) while returning visually superior images that will facilitate the appropriate placement of regions-of-interest when analysing abdominal diffusion-weighted magnetic resonance images, for assessment of disease characteristics and treatment response.


Assuntos
Algoritmos , Imagem de Difusão por Ressonância Magnética/métodos , Processamento de Imagem Assistida por Computador/métodos , Respiração , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Movimento (Física)
19.
Phys Med Biol ; 60(4): 1681-96, 2015 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-25633183

RESUMO

A commercial active breathing coordinator (ABC) device, employed to hold respiration at a specific level for a predefined duration, was successfully adapted for magnetic resonance imaging (MRI) use for the first time. Potential effects of the necessary modifications were assessed and taken into account. Automatic MR acquisition during ABC breath holding was achieved. The feasibility of MR-ABC thoracic and abdominal examinations together with the advantages of imaging in repeated ABC-controlled breath holds were demonstrated on healthy volunteers. Five lung cancer patients were imaged under MR-ABC, visually confirming the very good intra-session reproducibility of organ position in images acquired with the same patient positioning as used for computed tomography (CT). Using identical ABC settings, good MR-CT inter-modality registration was achieved. This demonstrates the value of ABC, since application of T1, T2 and diffusion weighted MR sequences provides a wider range of contrast mechanisms and additional diagnostic information compared to CT, thus improving radiotherapy treatment planning and assessment.


Assuntos
Suspensão da Respiração , Imageamento por Ressonância Magnética/métodos , Técnicas de Imagem de Sincronização Respiratória/métodos , Humanos , Imageamento por Ressonância Magnética/instrumentação , Masculino , Posicionamento do Paciente , Técnicas de Imagem de Sincronização Respiratória/instrumentação , Transdutores
20.
Occup Med (Lond) ; 65(1): 72-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25324483

RESUMO

BACKGROUND: Occupational exposure is estimated to contribute 15% to the burden of chronic obstructive pulmonary disease (COPD). Welding fumes are suspected to accelerate the decline of lung function and development of COPD. AIMS: To examine the relationship between welding fume exposure and COPD in Korean shipyard welders. METHODS: The study involved a group of male welders working at two shipyards who underwent an annual health examination in 2010. Subjects completed a questionnaire about smoking habits and occupational history and a pulmonary function test (PFT) was carried out with strict quality control measures. Welding fume exposure concentrations were estimated using 884 measurements taken between 2002 and 2009 in one of the shipyards. Multiple linear and logistic regression was employed to evaluate the association between cumulative fume exposure and lung function parameters, controlling for age, height and cigarette smoking. RESULTS: Two hundred and forty subjects participated, with a mean age of 48 and mean work duration of 15 years. The mean cumulative fume exposure was 7.7mg/m(3). The prevalence of COPD was 15%. FEV1 and FVC showed non-significant negative correlations with cumulative fume exposure. Odds ratios of COPD were significantly elevated for the middle (3.9; 95% CI 1.4-13.3) and high exposure groups (3.8; 95% CI 1.03-16.2) compared with the low fume exposure group. CONCLUSIONS: Our findings support an association between welding fume exposure and increased risk of COPD. Further prospective study is needed to investigate whether this is a causal relationship.


Assuntos
Gases/efeitos adversos , Exposição por Inalação/estatística & dados numéricos , Exposição Ocupacional/estatística & dados numéricos , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Soldagem , Adulto , Humanos , Exposição por Inalação/efeitos adversos , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/epidemiologia , Exposição Ocupacional/efeitos adversos , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/etiologia , Inquéritos e Questionários
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