Elevated body weight in adolescence is strongly associated with early cardiovascular disease, but... more Elevated body weight in adolescence is strongly associated with early cardiovascular disease, but whether this association is traceable to weight in early adulthood, or to weight gain with subsequent high adult weight is not known. Using data from the Swedish CArdioPulmonary bioImage Study (SCAPIS
Background: Early detection of coronary atherosclerosis using coronary computed tomography angiog... more Background: Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies. We used CCTA to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population. Methods: We recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (ie, no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Noncontrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment (defined as no atherosclerosis, 1% to 49% stenosis, or ≥50% stenosis). External validity of prevalence estimates was evaluated using...
Objectives Previous large studies of contrast-induced or post-contrast acute kidney injury (CI-AK... more Objectives Previous large studies of contrast-induced or post-contrast acute kidney injury (CI-AKI/PC-AKI) have been observational, and mostly retrospective, often with patients undergoing non-enhanced CT as controls. This carries risk of inclusion bias that makes the true incidence of PC-AKI hard to interpret. Our aim was to determine the incidence of PC-AKI in a large, randomly selected cohort, comparing the serum creatinine (Scr) changes after contrast medium exposure with the normal intraindividual fluctuation in Scr. Methods In this prospective study of 1009 participants (age 50–65 years, 48% females) in the Swedish CArdioPulmonary bioImage Study (SCAPIS), with estimated glomerular filtration rate (eGFR) ≥ 50 mL/min, all received standard dose intravenous iohexol at coronary CT angiography (CCTA). Two separate pre-CCTA Scr samples and a follow-up sample 2–4 days post-CCTA were obtained. Change in Scr was statistically analyzed and stratification was used in the search of possib...
Background Digital tomosynthesis (DTS) might be a low-dose/low-cost alternative to computed tomog... more Background Digital tomosynthesis (DTS) might be a low-dose/low-cost alternative to computed tomography (CT). Purpose To investigate DTS relative to CT for surveillance of incidental, solid pulmonary nodules. Material and Methods Recruited from a population study, 106 participants with indeterminate solid pulmonary nodules on CT underwent surveillance with concurrently performed CT and DTS. Nodule size on DTS was assessed by manual diameter measurements and semi-automatic nodule segmentations were independently performed on CT. Measurement agreement was analyzed according to Bland–Altman with 95% limits of agreement (LoA). Detection of nodule volume change > 25% by DTS in comparison to CT was evaluated with receiver operating characteristics (ROC). Results A total of 81 nodules (76%) were assessed as measurable on DTS by two independent observers. Inter- and intra-observer LoA regarding change in average diameter were ± 2 mm. Calculation of relative volume change on DTS resulted i...
Emphysema may be used for subclassification of chronic obstructive pulmonary disease (COPD) and i... more Emphysema may be used for subclassification of chronic obstructive pulmonary disease (COPD) and is also a risk factor for lung cancer. Emphysema can be directly visualized by low dose computed tomography (CT). As visual assessment of emphysema is time-consuming, our aim was to detect emphysema by quantitative densitometry (% Low Attenuation Value below -950 Hounsfield Units, LAV950) using the software CTPulmo3D (Syngo.via, Siemens Healthineers). Participants from the pilot study of The Swedish CArdioPulmonary Bioimage Study (SCAPIS) with visually detected emphysema (n=100, 56 males and 44 females) and 100 matched controls (gender, age, height and weight) without emphysema were included in this study. In more than 80% of the participants the emphysema was visually graded as mild (1% to ≤25% of the lung parenchyma). Inter- and intraobserver variability for visual assessment of emphysema was reliable with Krippendorff alpha values ranging from 0.80 to 0.85. Patients with emphysema were more obstructive (FEV1/FVC 0.72 versus 0.78) and had a higher tobacco burden (27 versus 20 pack-years) compared to the matched controls. The mean difference in LAV950 between matched pairs of emphysema and controls was -0.1% (CI -1.3 to 1.2%), limits of agreement from -12.3 to 12.1%. When defining emphysema as LAV950 being ≥ 10%, the sensitivity of finding emphysema was 27%. In conclusion, visual assessment of emphysema is reliable. Quantitative measurements of LAV950 by the software used in this study were not able to distinguish patients with or without visually detected mild emphysema. Other quantitative methods need to be evaluated for use in large-scale studies.
Background It is not clear if the European Systematic Coronary Risk Evaluation algorithm is usefu... more Background It is not clear if the European Systematic Coronary Risk Evaluation algorithm is useful for identifying prevalent subclinical atherosclerosis in a population of apparently healthy individuals. Our aim was to explore the association between the risk estimates from Systematic Coronary Risk Evaluation and prevalent subclinical atherosclerosis. Design The design of this study was as a cross-sectional analysis from a population-based study cohort. Methods From the general population, the Swedish Cardiopulmonary Bioimage Study randomly invited individuals aged 50–64 years and enrolled 13,411 participants mean age 57 (standard deviation 4.3) years; 46% males between November 2013–December 2016. Associations between Systematic Coronary Risk Evaluation risk estimates and coronary artery calcification and plaques in the carotid arteries by using imaging data from a computed tomography of the heart and ultrasonography of the carotid arteries were examined. Results Coronary calcifica...
IntroductionBreathlessness is common in the population, especially in women and associated with a... more IntroductionBreathlessness is common in the population, especially in women and associated with adverse health outcomes. Obesity (body mass index (BMI) >30 kg/m2) is rapidly increasing globally and its impact on breathlessness is unclear.MethodsThis population-based study aimed primarily to evaluate the association of current BMI and self-reported change in BMI since age 20 with breathlessness (modified Research Council score ≥1) in the middle-aged population. Secondary aims were to evaluate factors that contribute to breathlessness in obesity, including the interaction with spirometric lung volume and sex.ResultsWe included 13 437 individuals; mean age 57.5 years; 52.5% women; mean BMI 26.8 (SD 4.3); mean BMI increase since age 20 was 5.0 kg/m2; and 1283 (9.6%) reported breathlessness. Obesity was strongly associated with increased breathlessness, OR 3.54 (95% CI, 3.03 to 4.13) independent of age, sex, smoking, airflow obstruction, exercise level and the presence of comorbiditie...
Rationale and Objectives: Emphysema is a hallmark of chronic obstructive pulmonary disease. The p... more Rationale and Objectives: Emphysema is a hallmark of chronic obstructive pulmonary disease. The primary aim of this study was to investigate inter-and intraobserver agreement of visual assessment of mild emphysema in low-dose multidetector computed tomography of subjects in the pilot SCAPIS in order to certify consistent detection of mild emphysema. The secondary aim was to investigate the performance of quantitative densitometric measurements in the cohort. Materials and Methods: Participants with emphysema (n = 100, 56 males and 44 females) reported in the electronic case report form of pilot SCAPIS and 100 matched controls (gender, age, height, and weight) without emphysema were included. To assess interobserver variability the randomized examinations were evaluated by two thoracic radiologists. For intraobserver variability three radiologists re-evaluated randomized examinations which they originally evaluated. The results were evaluated statistically by Krippendorff's a. The dataset was also assessed quantitively for % lung attenuation value À950 HU (LAV950), mean lung density and total lung volume by commercially available software. Results: Emphysema was visually scored as mild and Krippendorff's a was 0.8 for both the inter-and intraobserver agreement regarding presence of emphysema and approaching 0.8 regarding presence and extent of emphysema by location in the upper lobes. Mean LAV950 was not different between the emphysematous and the nonemphysematous participants; 8.3% and 8.4%, respectively. Conclusion: The inter-and intraobserver agreement for visual detection of mild emphysema in low-dose multidetector computed tomography was good. Surprisingly, quantitative analysis could not reliably identify participants with mild emphysema, which hampers the use of automatic evaluation.
Elevated body weight in adolescence is strongly associated with early cardiovascular disease, but... more Elevated body weight in adolescence is strongly associated with early cardiovascular disease, but whether this association is traceable to weight in early adulthood, or to weight gain with subsequent high adult weight is not known. Using data from the Swedish CArdioPulmonary bioImage Study (SCAPIS
International Journal of Chronic Obstructive Pulmonary Disease
Background: The aim of this study was to estimate the occupational burden of airflow limitation, ... more Background: The aim of this study was to estimate the occupational burden of airflow limitation, chronic airflow limitation, COPD, and emphysema. Materials and methods: Subjects aged 50-64 years (n=1,050) were investigated with forced expiratory volume in 1 s (FEV 1) and forced vital capacity (FVC). Airflow limitation was defined as FEV 1 /FVC ,0.7 before bronchodilation. Chronic airflow limitation was defined after bronchodilation either according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) as FEV 1 /FVC ,0.7 or according to the lower limit of normal (LLN) approach as FEV 1 /FVC , LLN. COPD was defined as chronic airflow limitation (GOLD) in combination with dyspnea, wheezing, or chronic bronchitis. Emphysema was classified according to findings from computed tomography of the lungs. Occupational exposure was defined as selfreported occupational exposure to vapor, gas, dust, or fumes (VGDF). Odds ratios (OR) were calculated in models adjusted for age, gender, and smoking; population-attributable fractions and 95% CI were also calculated. Results: There were significant associations between occupational exposure to VGDF and COPD (OR 2.7, 95% CI 1.4-51), airflow limitation (OR 1.8, 95% CI 1.3-2.5), and emphysema (OR 1.8, 95% CI 1.1-3.1). The associations between occupational exposure to VGDF and chronic airflow limitation were weaker, and for the OR, the CIs included unity. The populationattributable fraction for occupational exposure to VGDF was 0.37 (95% CI 0.23-0.47) for COPD and 0.23 (95% CI 0.05-0.35) for emphysema. Conclusion: The occupational burden of COPD and computed tomography-verified emphysema is substantial.
This study aims to estimate the relationship between non-alcoholic fatty liver disease (NAFLD) an... more This study aims to estimate the relationship between non-alcoholic fatty liver disease (NAFLD) and measures of atherosclerotic cardiovascular disease (ASCVD), and to determine to what extent such relationships are modified by metabolic risk factors. Methods The study was conducted in the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) pilot cohort (n = 1015, age 50-64 years, 51.2% women). NAFLD was defined as computed tomography liver attenuation 40 Hounsfield Units, excluding other causes of liver fat. Coronary artery calcification score (CACS) was assessed using the Agatston method. Carotid plaques and intima media thickness (IMT) were measured by ultrasound. Metabolic status was based on assessments of glucose homeostasis, serum lipids, blood pressure and inflammation. A propensity score model was used to balance NAFLD and non NAFLD groups with regards to potential confounders and associations between NAFLD status and ASCVD variables in relation to metabolic status were examined by logistic and generalized linear regression models.
Background Computed tomography colonography (CTC) is an accepted complement or alternative to opt... more Background Computed tomography colonography (CTC) is an accepted complement or alternative to optical colonoscopy (OC) but its implementation is incompletely analyzed, and technical performance varies between centers. Purpose To evaluate implementation, indications, and technical performance of CTC in Sweden and to evaluate compliance to international guidelines. Material and Methods A structured, self-assessed questionnaire regarding implementation and technical performance of CTC was sent to all eligible radiology departments in Sweden. Eighty-six out of 89 departments replied. Comparisons were made with similar national surveys from 2004 and 2009. Results The number of centers performing CTC gradually increased from 23 in 2004 to 77 in 2016. In parallel, centers performing barium enema (BE) examinations have decreased from 89 in 2004 to 13 in 2016. Main reasons stated for still performing BE were lack of resources regarding CTC/OC. Main reasons for not performing CTC were lack of...
Breathlessness is associated with major adverse health outcomes and is twice as common in women a... more Breathlessness is associated with major adverse health outcomes and is twice as common in women as men in the general population. We evaluated whether this is related to their lower absolute lung volumes. Cross-sectional analysis of the population-based Swedish CardioPulmonarybioImage Study (SCAPIS) Pilot, including static spirometry and diffusing capacity (n = 1,013; 49% women). Breathlessness was measured using the modified Medical Research Council (mMRC) scale and analyzed using ordinal logistic regression adjusting for age, pack-years of smoking, body mass index, chronic airway limitation, asthma, chronic bronchitis, depression and anxiety in all models. Breathlessness was twice as common in women as in men; adjusted odds ratio (OR) 2.20 (95% confidence interval, 1.32-3.66). Lower absolute lung volumes were associated with increased breathlessness prevalence in both men and women. The sex difference in breathlessness was unchanged when adjusting for lung function in %predicted, ...
Computed Tomography (CT) allows detailed studies of body composition and its association with met... more Computed Tomography (CT) allows detailed studies of body composition and its association with metabolic and cardiovascular disease. The purpose of this work was to develop and validate automated and manual image processing techniques for detailed and efficient analysis of body composition from CT data. The study comprised 107 subjects examined in the Swedish CArdioPulmonary BioImage Study (SCAPIS) using a 3-slice CT protocol covering liver, abdomen, and thighs. Algorithms were developed for automated assessment of liver attenuation, visceral (VAT) and subcutaneous (SAT) abdominal adipose tissue, thigh muscles, subcutaneous, subfascial (SFAT) and intermuscular adipose tissue. These were validated using manual reference measurements. SFAT was studied in selected subjects were the fascia lata could be visually identified (approx. 5%). In addition, precision of manual measurements of intra-(IPAT) and retroperitoneal adipose tissue (RPAT) and deep-and superficial SAT was evaluated using repeated measurements. Automated measurements correlated strongly to manual reference measurements. The SFAT depot showed the weakest correlation (r = 0.744). Automated VAT and SAT measurements were slightly, but significantly overestimated (≤4.6%, p ≤ 0.001). Manual segmentation of abdominal sub-depots showed high repeatability (CV ≤ 8.1%, r ≥ 0.930). We conclude that the low dose CT-scanning and automated analysis makes the setup suitable for large-scale studies. Studies of body composition can improve the understanding of for example type-2 diabetes (T2D) and cardiovascular disease (CVD) and their prediction and prevention. Medical imaging techniques, such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) can be used for detailed studies of human body composition. These techniques are often used to quantify liver fat, muscle, and adipose tissue distribution. Increased liver fat can be estimated from liver attenuation measured by CT and is believed to be crucial component in development of dyslipidemia associated with obesity. Abdominal adipose tissue is often separated into subcutaneous and intra-abdominal, or visceral adipose tissue, (SAT and VAT, respectively) 1-6 as these are known to have different associations to glucose tolerance 7 and thereby to T2D and CVD risk. More recently the importance of further separating these into sub-depots has gained attention. The VAT depot can be separated into intraand retroperitoneal adipose tissue 8-10 (IPAT and RPAT, respectively) and the SAT can be separated into deep and superficial depots (DSAT and SSAT, respectively). DSAT and SSAT have been found to differ in structure and function 5, 11, 12 , in association to insulin resistance 5, 12 , and in triglyceride saturation 12, 13. Quantification of thigh composition, in terms of muscle and adipose tissue sub-depots has also been found of importance in metabolic studies 14-17. CT creates images in absolute Hounsfield units (HU) but exposes the subject to ionizing radiation limiting the number of slices that can be obtained. The Swedish CardioPulmonary bioImage Study (SCAPIS) 18 , has a primary aim to study cardiovascular and pulmonary disease for which CT angiography and CT of the lungs are preferred methods. The study also includes CT imaging of liver, abdominal adipose tissue and thighs for the purpose of detailed body composition phenotyping. It aims to include 30,000 study subjects in the age range 50 to 64 years in
International journal of chronic obstructive pulmonary disease, 2017
In epidemiological studies, items about physician-diagnosed COPD are often used. There is a lack ... more In epidemiological studies, items about physician-diagnosed COPD are often used. There is a lack of validation and standardization of these items. In a general population-based study, 1,050 subjects completed a questionnaire and performed spirometry, including forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) after inhalation of 400 µg of salbutamol. COPD was defined as the ratio of FEV1/FVC <0.7 after bronchodilation. Physician-diagnosed COPD was defined as an affirmative answer to the single item: "Have you ever had COPD diagnosed by a physician?", physician-diagnosed COPD/emphysema as an affirmative answer to any of the two single items; "Have you ever had COPD diagnosed by a physician?" or "Have you ever been told by a physician that you have emphysema?", physician-diagnosed chronic bronchitis as an affirmative answer to; "Have you ever been told by a physician that you have chronic bronchitis?" and physician-d...
Elevated body weight in adolescence is strongly associated with early cardiovascular disease, but... more Elevated body weight in adolescence is strongly associated with early cardiovascular disease, but whether this association is traceable to weight in early adulthood, or to weight gain with subsequent high adult weight is not known. Using data from the Swedish CArdioPulmonary bioImage Study (SCAPIS
Background: Early detection of coronary atherosclerosis using coronary computed tomography angiog... more Background: Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies. We used CCTA to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population. Methods: We recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (ie, no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Noncontrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment (defined as no atherosclerosis, 1% to 49% stenosis, or ≥50% stenosis). External validity of prevalence estimates was evaluated using...
Objectives Previous large studies of contrast-induced or post-contrast acute kidney injury (CI-AK... more Objectives Previous large studies of contrast-induced or post-contrast acute kidney injury (CI-AKI/PC-AKI) have been observational, and mostly retrospective, often with patients undergoing non-enhanced CT as controls. This carries risk of inclusion bias that makes the true incidence of PC-AKI hard to interpret. Our aim was to determine the incidence of PC-AKI in a large, randomly selected cohort, comparing the serum creatinine (Scr) changes after contrast medium exposure with the normal intraindividual fluctuation in Scr. Methods In this prospective study of 1009 participants (age 50–65 years, 48% females) in the Swedish CArdioPulmonary bioImage Study (SCAPIS), with estimated glomerular filtration rate (eGFR) ≥ 50 mL/min, all received standard dose intravenous iohexol at coronary CT angiography (CCTA). Two separate pre-CCTA Scr samples and a follow-up sample 2–4 days post-CCTA were obtained. Change in Scr was statistically analyzed and stratification was used in the search of possib...
Background Digital tomosynthesis (DTS) might be a low-dose/low-cost alternative to computed tomog... more Background Digital tomosynthesis (DTS) might be a low-dose/low-cost alternative to computed tomography (CT). Purpose To investigate DTS relative to CT for surveillance of incidental, solid pulmonary nodules. Material and Methods Recruited from a population study, 106 participants with indeterminate solid pulmonary nodules on CT underwent surveillance with concurrently performed CT and DTS. Nodule size on DTS was assessed by manual diameter measurements and semi-automatic nodule segmentations were independently performed on CT. Measurement agreement was analyzed according to Bland–Altman with 95% limits of agreement (LoA). Detection of nodule volume change > 25% by DTS in comparison to CT was evaluated with receiver operating characteristics (ROC). Results A total of 81 nodules (76%) were assessed as measurable on DTS by two independent observers. Inter- and intra-observer LoA regarding change in average diameter were ± 2 mm. Calculation of relative volume change on DTS resulted i...
Emphysema may be used for subclassification of chronic obstructive pulmonary disease (COPD) and i... more Emphysema may be used for subclassification of chronic obstructive pulmonary disease (COPD) and is also a risk factor for lung cancer. Emphysema can be directly visualized by low dose computed tomography (CT). As visual assessment of emphysema is time-consuming, our aim was to detect emphysema by quantitative densitometry (% Low Attenuation Value below -950 Hounsfield Units, LAV950) using the software CTPulmo3D (Syngo.via, Siemens Healthineers). Participants from the pilot study of The Swedish CArdioPulmonary Bioimage Study (SCAPIS) with visually detected emphysema (n=100, 56 males and 44 females) and 100 matched controls (gender, age, height and weight) without emphysema were included in this study. In more than 80% of the participants the emphysema was visually graded as mild (1% to ≤25% of the lung parenchyma). Inter- and intraobserver variability for visual assessment of emphysema was reliable with Krippendorff alpha values ranging from 0.80 to 0.85. Patients with emphysema were more obstructive (FEV1/FVC 0.72 versus 0.78) and had a higher tobacco burden (27 versus 20 pack-years) compared to the matched controls. The mean difference in LAV950 between matched pairs of emphysema and controls was -0.1% (CI -1.3 to 1.2%), limits of agreement from -12.3 to 12.1%. When defining emphysema as LAV950 being ≥ 10%, the sensitivity of finding emphysema was 27%. In conclusion, visual assessment of emphysema is reliable. Quantitative measurements of LAV950 by the software used in this study were not able to distinguish patients with or without visually detected mild emphysema. Other quantitative methods need to be evaluated for use in large-scale studies.
Background It is not clear if the European Systematic Coronary Risk Evaluation algorithm is usefu... more Background It is not clear if the European Systematic Coronary Risk Evaluation algorithm is useful for identifying prevalent subclinical atherosclerosis in a population of apparently healthy individuals. Our aim was to explore the association between the risk estimates from Systematic Coronary Risk Evaluation and prevalent subclinical atherosclerosis. Design The design of this study was as a cross-sectional analysis from a population-based study cohort. Methods From the general population, the Swedish Cardiopulmonary Bioimage Study randomly invited individuals aged 50–64 years and enrolled 13,411 participants mean age 57 (standard deviation 4.3) years; 46% males between November 2013–December 2016. Associations between Systematic Coronary Risk Evaluation risk estimates and coronary artery calcification and plaques in the carotid arteries by using imaging data from a computed tomography of the heart and ultrasonography of the carotid arteries were examined. Results Coronary calcifica...
IntroductionBreathlessness is common in the population, especially in women and associated with a... more IntroductionBreathlessness is common in the population, especially in women and associated with adverse health outcomes. Obesity (body mass index (BMI) >30 kg/m2) is rapidly increasing globally and its impact on breathlessness is unclear.MethodsThis population-based study aimed primarily to evaluate the association of current BMI and self-reported change in BMI since age 20 with breathlessness (modified Research Council score ≥1) in the middle-aged population. Secondary aims were to evaluate factors that contribute to breathlessness in obesity, including the interaction with spirometric lung volume and sex.ResultsWe included 13 437 individuals; mean age 57.5 years; 52.5% women; mean BMI 26.8 (SD 4.3); mean BMI increase since age 20 was 5.0 kg/m2; and 1283 (9.6%) reported breathlessness. Obesity was strongly associated with increased breathlessness, OR 3.54 (95% CI, 3.03 to 4.13) independent of age, sex, smoking, airflow obstruction, exercise level and the presence of comorbiditie...
Rationale and Objectives: Emphysema is a hallmark of chronic obstructive pulmonary disease. The p... more Rationale and Objectives: Emphysema is a hallmark of chronic obstructive pulmonary disease. The primary aim of this study was to investigate inter-and intraobserver agreement of visual assessment of mild emphysema in low-dose multidetector computed tomography of subjects in the pilot SCAPIS in order to certify consistent detection of mild emphysema. The secondary aim was to investigate the performance of quantitative densitometric measurements in the cohort. Materials and Methods: Participants with emphysema (n = 100, 56 males and 44 females) reported in the electronic case report form of pilot SCAPIS and 100 matched controls (gender, age, height, and weight) without emphysema were included. To assess interobserver variability the randomized examinations were evaluated by two thoracic radiologists. For intraobserver variability three radiologists re-evaluated randomized examinations which they originally evaluated. The results were evaluated statistically by Krippendorff's a. The dataset was also assessed quantitively for % lung attenuation value À950 HU (LAV950), mean lung density and total lung volume by commercially available software. Results: Emphysema was visually scored as mild and Krippendorff's a was 0.8 for both the inter-and intraobserver agreement regarding presence of emphysema and approaching 0.8 regarding presence and extent of emphysema by location in the upper lobes. Mean LAV950 was not different between the emphysematous and the nonemphysematous participants; 8.3% and 8.4%, respectively. Conclusion: The inter-and intraobserver agreement for visual detection of mild emphysema in low-dose multidetector computed tomography was good. Surprisingly, quantitative analysis could not reliably identify participants with mild emphysema, which hampers the use of automatic evaluation.
Elevated body weight in adolescence is strongly associated with early cardiovascular disease, but... more Elevated body weight in adolescence is strongly associated with early cardiovascular disease, but whether this association is traceable to weight in early adulthood, or to weight gain with subsequent high adult weight is not known. Using data from the Swedish CArdioPulmonary bioImage Study (SCAPIS
International Journal of Chronic Obstructive Pulmonary Disease
Background: The aim of this study was to estimate the occupational burden of airflow limitation, ... more Background: The aim of this study was to estimate the occupational burden of airflow limitation, chronic airflow limitation, COPD, and emphysema. Materials and methods: Subjects aged 50-64 years (n=1,050) were investigated with forced expiratory volume in 1 s (FEV 1) and forced vital capacity (FVC). Airflow limitation was defined as FEV 1 /FVC ,0.7 before bronchodilation. Chronic airflow limitation was defined after bronchodilation either according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) as FEV 1 /FVC ,0.7 or according to the lower limit of normal (LLN) approach as FEV 1 /FVC , LLN. COPD was defined as chronic airflow limitation (GOLD) in combination with dyspnea, wheezing, or chronic bronchitis. Emphysema was classified according to findings from computed tomography of the lungs. Occupational exposure was defined as selfreported occupational exposure to vapor, gas, dust, or fumes (VGDF). Odds ratios (OR) were calculated in models adjusted for age, gender, and smoking; population-attributable fractions and 95% CI were also calculated. Results: There were significant associations between occupational exposure to VGDF and COPD (OR 2.7, 95% CI 1.4-51), airflow limitation (OR 1.8, 95% CI 1.3-2.5), and emphysema (OR 1.8, 95% CI 1.1-3.1). The associations between occupational exposure to VGDF and chronic airflow limitation were weaker, and for the OR, the CIs included unity. The populationattributable fraction for occupational exposure to VGDF was 0.37 (95% CI 0.23-0.47) for COPD and 0.23 (95% CI 0.05-0.35) for emphysema. Conclusion: The occupational burden of COPD and computed tomography-verified emphysema is substantial.
This study aims to estimate the relationship between non-alcoholic fatty liver disease (NAFLD) an... more This study aims to estimate the relationship between non-alcoholic fatty liver disease (NAFLD) and measures of atherosclerotic cardiovascular disease (ASCVD), and to determine to what extent such relationships are modified by metabolic risk factors. Methods The study was conducted in the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) pilot cohort (n = 1015, age 50-64 years, 51.2% women). NAFLD was defined as computed tomography liver attenuation 40 Hounsfield Units, excluding other causes of liver fat. Coronary artery calcification score (CACS) was assessed using the Agatston method. Carotid plaques and intima media thickness (IMT) were measured by ultrasound. Metabolic status was based on assessments of glucose homeostasis, serum lipids, blood pressure and inflammation. A propensity score model was used to balance NAFLD and non NAFLD groups with regards to potential confounders and associations between NAFLD status and ASCVD variables in relation to metabolic status were examined by logistic and generalized linear regression models.
Background Computed tomography colonography (CTC) is an accepted complement or alternative to opt... more Background Computed tomography colonography (CTC) is an accepted complement or alternative to optical colonoscopy (OC) but its implementation is incompletely analyzed, and technical performance varies between centers. Purpose To evaluate implementation, indications, and technical performance of CTC in Sweden and to evaluate compliance to international guidelines. Material and Methods A structured, self-assessed questionnaire regarding implementation and technical performance of CTC was sent to all eligible radiology departments in Sweden. Eighty-six out of 89 departments replied. Comparisons were made with similar national surveys from 2004 and 2009. Results The number of centers performing CTC gradually increased from 23 in 2004 to 77 in 2016. In parallel, centers performing barium enema (BE) examinations have decreased from 89 in 2004 to 13 in 2016. Main reasons stated for still performing BE were lack of resources regarding CTC/OC. Main reasons for not performing CTC were lack of...
Breathlessness is associated with major adverse health outcomes and is twice as common in women a... more Breathlessness is associated with major adverse health outcomes and is twice as common in women as men in the general population. We evaluated whether this is related to their lower absolute lung volumes. Cross-sectional analysis of the population-based Swedish CardioPulmonarybioImage Study (SCAPIS) Pilot, including static spirometry and diffusing capacity (n = 1,013; 49% women). Breathlessness was measured using the modified Medical Research Council (mMRC) scale and analyzed using ordinal logistic regression adjusting for age, pack-years of smoking, body mass index, chronic airway limitation, asthma, chronic bronchitis, depression and anxiety in all models. Breathlessness was twice as common in women as in men; adjusted odds ratio (OR) 2.20 (95% confidence interval, 1.32-3.66). Lower absolute lung volumes were associated with increased breathlessness prevalence in both men and women. The sex difference in breathlessness was unchanged when adjusting for lung function in %predicted, ...
Computed Tomography (CT) allows detailed studies of body composition and its association with met... more Computed Tomography (CT) allows detailed studies of body composition and its association with metabolic and cardiovascular disease. The purpose of this work was to develop and validate automated and manual image processing techniques for detailed and efficient analysis of body composition from CT data. The study comprised 107 subjects examined in the Swedish CArdioPulmonary BioImage Study (SCAPIS) using a 3-slice CT protocol covering liver, abdomen, and thighs. Algorithms were developed for automated assessment of liver attenuation, visceral (VAT) and subcutaneous (SAT) abdominal adipose tissue, thigh muscles, subcutaneous, subfascial (SFAT) and intermuscular adipose tissue. These were validated using manual reference measurements. SFAT was studied in selected subjects were the fascia lata could be visually identified (approx. 5%). In addition, precision of manual measurements of intra-(IPAT) and retroperitoneal adipose tissue (RPAT) and deep-and superficial SAT was evaluated using repeated measurements. Automated measurements correlated strongly to manual reference measurements. The SFAT depot showed the weakest correlation (r = 0.744). Automated VAT and SAT measurements were slightly, but significantly overestimated (≤4.6%, p ≤ 0.001). Manual segmentation of abdominal sub-depots showed high repeatability (CV ≤ 8.1%, r ≥ 0.930). We conclude that the low dose CT-scanning and automated analysis makes the setup suitable for large-scale studies. Studies of body composition can improve the understanding of for example type-2 diabetes (T2D) and cardiovascular disease (CVD) and their prediction and prevention. Medical imaging techniques, such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) can be used for detailed studies of human body composition. These techniques are often used to quantify liver fat, muscle, and adipose tissue distribution. Increased liver fat can be estimated from liver attenuation measured by CT and is believed to be crucial component in development of dyslipidemia associated with obesity. Abdominal adipose tissue is often separated into subcutaneous and intra-abdominal, or visceral adipose tissue, (SAT and VAT, respectively) 1-6 as these are known to have different associations to glucose tolerance 7 and thereby to T2D and CVD risk. More recently the importance of further separating these into sub-depots has gained attention. The VAT depot can be separated into intraand retroperitoneal adipose tissue 8-10 (IPAT and RPAT, respectively) and the SAT can be separated into deep and superficial depots (DSAT and SSAT, respectively). DSAT and SSAT have been found to differ in structure and function 5, 11, 12 , in association to insulin resistance 5, 12 , and in triglyceride saturation 12, 13. Quantification of thigh composition, in terms of muscle and adipose tissue sub-depots has also been found of importance in metabolic studies 14-17. CT creates images in absolute Hounsfield units (HU) but exposes the subject to ionizing radiation limiting the number of slices that can be obtained. The Swedish CardioPulmonary bioImage Study (SCAPIS) 18 , has a primary aim to study cardiovascular and pulmonary disease for which CT angiography and CT of the lungs are preferred methods. The study also includes CT imaging of liver, abdominal adipose tissue and thighs for the purpose of detailed body composition phenotyping. It aims to include 30,000 study subjects in the age range 50 to 64 years in
International journal of chronic obstructive pulmonary disease, 2017
In epidemiological studies, items about physician-diagnosed COPD are often used. There is a lack ... more In epidemiological studies, items about physician-diagnosed COPD are often used. There is a lack of validation and standardization of these items. In a general population-based study, 1,050 subjects completed a questionnaire and performed spirometry, including forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) after inhalation of 400 µg of salbutamol. COPD was defined as the ratio of FEV1/FVC <0.7 after bronchodilation. Physician-diagnosed COPD was defined as an affirmative answer to the single item: "Have you ever had COPD diagnosed by a physician?", physician-diagnosed COPD/emphysema as an affirmative answer to any of the two single items; "Have you ever had COPD diagnosed by a physician?" or "Have you ever been told by a physician that you have emphysema?", physician-diagnosed chronic bronchitis as an affirmative answer to; "Have you ever been told by a physician that you have chronic bronchitis?" and physician-d...
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Papers by John Brandberg