| 1. |
- Persson, Jan, 1962, et al.
(författare)
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Fully covered stents are similar to semi-covered stents with regard to migration in palliative treatment of malignant strictures of the esophagus and gastric cardia : results of a randomized controlled trial.
- 2017
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Ingår i: Surgical Endoscopy. - : Springer Science and Business Media LLC. - 0930-2794 .- 1432-2218. ; 31:10, s. 4025-4033
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Stent migration is a significant clinical problem in palliation of malignant strictures in the esophagus and gastro-esophageal junction (GEJ). We have compared a newer design of a fully-covered stent to a widely used semi-covered stent using migration >20 mm as the primary outcome variable. Effects on dysphagia, quality of life (QoL) and re-intervention frequency were also investigated.METHODS: Patients with dysphagia due to non-curable esophagus/GEJ cancer were randomized to receive either a more recent design of a fully-covered stent (n = 48) or a conventional semi-covered stent (n = 47). Chest x-ray, dysphagia and QoL were studied at baseline, one week, four weeks and three months thereafter.RESULTS: There were no significant differences either in stent migration distance or in the migration frequency. Stent migration during the total study period occurred in 37.2 % in the semi-covered group compared to 20.0 % for the fully-covered group. Dysphagia was measured with Watson and Ogilvie scores and with the dysphagia module in the QoL scale (QLQ-OG25). On average, there was a tendency to better dysphagia relief for the fully-covered design as scored with the two latter dysphagia instruments (p= 0.081 and p= 0.067) at three months and towards more re-interventions in the semi-covered group (p= 0.083).CONCLUSION: In spite of its somewhat lower intrinsic radial force, the fully-covered stent was comparable to the conventional semi-covered stent with regard to stent migration. The data further suggest a potential benefit of the fully-covered stent in improving dysphagia in patients with longer life expectancy.
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| 2. |
- Engström, Gunnar, et al.
(författare)
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The Swedish CArdioPulmonary BioImage Study : objectives and design
- 2015
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 278:6, s. 645-659
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Tidskriftsartikel (refereegranskat)abstract
- Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.
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| 3. |
- Arvidsson, Jonathan, et al.
(författare)
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Image Fusion of Reconstructed Digital Tomosynthesis Volumes From a Frontal and a Lateral Acquisition
- 2016
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 169:1-4, s. 410-415
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Tidskriftsartikel (refereegranskat)abstract
- Digital tomosynthesis (DTS) has been used in chest imaging as a low radiation dose alternative to computed tomography (CT). Traditional DTS shows limitations in the spatial resolution in the out-of-plane dimension. As a first indication of whether a dual-plane dual-view (DPDV) DTS data acquisition can yield a fair resolution in all three spatial dimensions, a manual registration between a frontal and a lateral image volume was performed. An anthropomorphic chest phantom was scanned frontally and laterally using a linear DTS acquisition, at 120 kVp. The reconstructed image volumes were resampled and manually co-registered. Expert radiologist delineations of the mediastinal soft tissues enabled calculation of similarity metrics in regard to delineations in a reference CT volume. The fused volume produced the highest total overlap, implying that the fused volume was a more isotropic 3D representation of the examined object than the traditional chest DTS volumes.
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| 4. |
- Bech-Hanssen, Odd, 1956, et al.
(författare)
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Pulsed-Wave Doppler Recordings in the Proximal Descending Aorta in Patients with Chronic Aortic Regurgitation: Insights from Cardiovascular Magnetic Resonance
- 2018
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Ingår i: Journal of the American Society of Echocardiography. - : Elsevier BV. - 0894-7317. ; 31:3
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Tidskriftsartikel (refereegranskat)abstract
- The pulsed-wave Doppler recording in the descending aorta (PWD DAO ) is one of the parameters used in grading aortic regurgitation (AR) severity. The aim of the present study was to investigate the assessment of chronic AR by PWD DAO with insights from cardiovascular magnetic resonance (CMR). Methods: This prospective study comprised 40 patients investigated with echocardiography and CMR within 4 hours either prior to valve surgery (n = 23) or as part of their follow-up (n = 17) due to moderate or severe AR. End-diastolic flow velocity (EDFV) and the diastolic velocity time integral (dVTI) were measured. The appearance of diastolic forward flow (DFF) was noted. Phase-contrast flow rate curves were obtained in the DAO. Results: Twenty-five patients had severe and eight had moderate AR by echocardiography (seven were indeterminate). The EDFV was below the recommended threshold ( > 20 cm/sec) in 13 patients (52%) with severe AR. Lowering the EDFV threshold ( > 13 cm/sec) and with a dVTI threshold > 13 cm showed negative likelihood ratios of 0.27 and 0.09, respectively. Detection of DFF with PWD DAO identified a nonuniform velocity profile by CMR with positive and negative likelihood ratios of 7.0 and 0.19, respectively. The relation between EDFV and DAO regurgitant volume (DAO-RVol CMR ) was strong in patients without (R = 0.88) and weak in patients with DFF (R = 0.49). The DAO-RVol CMR as a percent of the total RVol CMR decreased with increasing ascending aorta (AAO) size and increased with increasing AR severity. Conclusions: Our findings suggest that PWD DAO provides semiquantitative parameters useful to assess chronic AR severity. The limitations are related to nonuniform velocity contour and variable degree of lower body contribution, which depends on AR severity but also on the AAO size.
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| 5. |
- Gao, Sinsia, 1966, et al.
(författare)
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Evaluation of the Integrative Algorithm for Grading Chronic Aortic and Mitral Regurgitation Severity Using the Current American Society of Echocardiography Recommendations: To Discriminate Severe from Moderate Regurgitation.
- 2018
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Ingår i: Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography. - : Elsevier BV. - 1097-6795. ; 31:9
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Tidskriftsartikel (refereegranskat)abstract
- The recently published integrative algorithms for echocardiographic grading of native aortic regurgitation (AR) and mitral regurgitation (MR) by the American Society of Echocardiography are consensus based and have not been evaluated. Thus, the aims of the present study were to investigate the feasibility of individual parameters and to evaluate the ability of the algorithms to discriminate severe from moderate regurgitation.This prospective study comprised 93 patients with chronic AR (n=45) and MR (n=48). All patients underwent echocardiography and cardiovascular magnetic resonance within 4hours. The algorithms were evaluated using two different definitions for severe regurgitation: (1) a cardiovascular magnetic resonance standard indicating future need for valve surgery and (2) a clinical standard using patients who underwent valve surgery with proven postoperative left ventricular reverse remodeling and improved functional class (AR/MR, n = 26/26).The feasibility of the criteria in the first step of the algorithm was higher (AR/MR, 95%/91%) compared with the second step using quantitative Doppler parameters (74%/57%). For the AR algorithm, sensitivity was 95% and specificity 44%, whereas for the MR algorithm, sensitivity was 73% and specificity 92%. Among patients with benefit of surgery, the algorithms correctly identified 77%, misclassified 8%, and were inconclusive in 15% of the patients with AR; the corresponding figures were 73%, 15%, and 12% in the patients with MR.Using cardiovascular magnetic resonance as reference, the recommended algorithms for grading of regurgitation have the ability to rule out severe AR and rule in severe MR. The quantitative Doppler methods are hampered by feasibility issues, and our findings suggest that the decision regarding surgical intervention in symptomatic patients with discordant or inconclusive echocardiographic grading should be based on a consolidated assessment of clinical and multimodality findings.
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| 6. |
- Polte, Christian Lars, et al.
(författare)
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Characterization of Chronic Aortic and Mitral Regurgitation Undergoing Valve Surgery Using Cardiovascular Magnetic Resonance.
- 2017
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Ingår i: The American journal of cardiology. - : Elsevier BV. - 1879-1913 .- 0002-9149. ; 119:12, s. 2061-2068
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Tidskriftsartikel (refereegranskat)abstract
- Grading of chronic aortic regurgitation (AR) and mitral regurgitation (MR) by cardiovascular magnetic resonance (CMR) is currently based on thresholds, which are neither modality nor quantification method specific. Accordingly, this study sought to identify CMR-specific and quantification method-specific thresholds for regurgitant volumes (RVols), RVol indexes, and regurgitant fractions (RFs), which denote severe chronic AR or MR with an indication for surgery. The study comprised patients with moderate and severe chronic AR (n= 38) and MR (n= 40). Echocardiography and CMR was performed at baseline and in all operated AR/MR patients (n= 23/25) 10 ± 1months after surgery. CMR quantification of AR: direct (aortic flow) and indirect method (left ventricular stroke volume [LVSV]- pulmonary stroke volume [PuSV]); MR: 2 indirect methods (LVSV- aortic forward flow [AoFF]; mitral inflow [MiIF]- AoFF). All operated patients had severe regurgitation and benefited from surgery, indicated by a significant postsurgical reduction in end-diastolic volume index and improvement or relief of symptoms. The discriminatory ability between moderate and severe AR was strong for RVol >40ml, RVol index >20ml/m(2), and RF >30% (direct method) and RVol >62ml, RVol index >31ml/m(2), and RF >36% (LVSV-PuSV) with a negative likelihood ratio ≤ 0.2. In MR, the discriminatory ability was very strong for RVol >64ml, RVol index >32ml/m(2), and RF >41% (LVSV-AoFF) and RVol >40ml, RVol index >20ml/m(2), and RF >30% (MiIF-AoFF) with a negative likelihood ratio < 0.1. In conclusion, CMR grading of chronic AR and MR should be based on modality-specific and quantification method-specific thresholds, as they differ largely from recognized guideline criteria, to assure appropriate clinical decision-making and timing of surgery.
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| 7. |
- Polte, Christian Lars, et al.
(författare)
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Mitral regurgitation quantification by cardiovascular magnetic resonance: a comparison of indirect quantification methods
- 2015
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Ingår i: The International Journal of Cardiovascular Imaging. - : Springer Science and Business Media LLC. - 1569-5794 .- 1573-0743. ; 31:6, s. 1223-31
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Tidskriftsartikel (refereegranskat)abstract
- Quantification of mitral regurgitation (MR) using cardiovascular magnetic resonance can be achieved by three indirect methods. The aims of the study were to determine their agreement, observer variability and effect on grading MR severity. The study comprised 16 healthy volunteers and 36 MR patients. Quantification was performed using the 'standard' [left ventricular stroke volume (LVSV)-aortic forward flow (AoFF)], 'volumetric' [LVSV-right ventricular stroke volume (RVSV)] and 'flow' method [mitral inflow (MiIF)-AoFF]. In healthy volunteers without MR, LVSV was larger than AoFF (mean difference ±SD: 12 ± 6 ml, P < 0.0001). Only small differences were found between LVSV-RVSV (3 ± 6 ml) and MiIF-AoFF (1 ± 5 ml). In patients, mitral regurgitant volumes (MRVs)/fractions (MRFs) were larger (P < 0.0001) using the 'standard' method (90 ± 31 ml/51 ± 11%) compared with the 'volumetric' (76 ± 30 ml/42 ± 11%) and 'flow' method (70 ± 32 ml/44 ± 15%). Inter-observer variability was lowest for the 'flow' and highest for the 'volumetric' method, while intra-observer variability was similar for all three methods. In 29 operated patients with severe MR, MRVs were above the guideline threshold (≥60 ml) in 100, 86 and 83% of the cases, and MRFs were above the threshold (≥50%) in 76, 32 and 48% of the cases, when using the 'standard', 'volumetric' and 'flow' method respectively. In conclusion, the choice of method can affect the grading of MR severity and thereby eventually the clinical decision-making and timing of surgery.
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| 8. |
- Thoren, Fredrik, 1959, et al.
(författare)
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CT colonography: implementation, indications, and technical performance - a follow-up national survey.
- 2019
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 60:3, s. 271-277
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Tidskriftsartikel (refereegranskat)abstract
- 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 suitable software, lack of machine/reading time, and lack of experience. The majority of centers follow international CTC guidelines. An important exception is fecal tagging, which was implemented in only 63% of the centers. Incomplete OC remains a major indication for CTC, while preoperative CTC in colorectal cancer and follow-up after diverticulitis have emerged as new indications. Conclusion CTC today is well implemented in routine healthcare but still lacking in capacity. Indications have expanded over time, and most departments perform "state of the art" CTC, although fecal tagging is incompletely implemented.
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| 9. |
- Torén, Kjell, 1952, et al.
(författare)
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Vital capacity and COPD: the Swedish CArdioPulmonary bioImage Study (SCAPIS)
- 2016
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Ingår i: International Journal of Chronic Obstructive Pulmonary Disease. - : Informa UK Limited. - 1178-2005. ; 11:1, s. 927-933
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Tidskriftsartikel (refereegranskat)abstract
- Background: Spirometric diagnosis of chronic obstructive pulmonary disease (COPD) is based on the ratio of forced expiratory volume in 1 second (FEV1)/vital capacity (VC), either as a fixed value <0.7 or below the lower limit of normal (LLN). Forced vital capacity (FVC) is a proxy for VC. The first aim was to compare the use of FVC and VC, assessed as the highest value of FVC or slow vital capacity (SVC), when assessing the FEV1/VC ratio in a general population setting. The second aim was to evaluate the characteristics of subjects with COPD who obtained a higher SVC than FVC. Methods: Subjects (n=1,050) aged 50-64 years were investigated with FEV1, FVC, and SVC after bronchodilation. Global Initiative for Chronic Obstructive Lung Disease (GOLD) COPDFVC was defined as FEV1/FVC <0.7, GOLDCOPD(VC) as FEV1/VC <0.7 using the maximum value of FVC or SVC, LLNCOPDFVC as FEV1/FVC below the LLN, and LLNCOPDVC as FEV1/VC below the LLN using the maximum value of FVC or SVC. Results: Prevalence of GOLDCOPD(FVC) was 10.0% (95% confidence interval [CI] 8.2-12.0) and the prevalence of LLNCOPDFVC was 9.5% (95% CI 7.8-11.4). When estimates were based on VC, the prevalence became higher; 16.4% (95% CI 14.3-18.9) and 15.6% (95% CI 13.5-17.9) for GOLDCOPD(VC) and LLNCOPDVC, respectively. The group of additional subjects classified as having COPD based on VC, had lower FEV1, more wheeze and higher residual volume compared to subjects without any COPD. Conclusion: The prevalence of COPD was significantly higher when the ratio FEV1/VC was calculated using the highest value of SVC or FVC compared with using FVC only. Subjects classified as having COPD when using the VC concept were more obstructive and with indications of air trapping. Hence, the use of only FVC when assessing airflow limitation may result in a considerable under diagnosis of subjects with mild COPD.
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| 10. |
- Arvidsson, Jonathan, 1986, et al.
(författare)
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Automated estimation of in-plane nodule shape in chest tomosynthesis images
- 2015
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Ingår i: International Federation for Medical and Biological Engineering Proceedings. - Cham : Springer International Publishing. - 1680-0737. - 9783319129679 ; 48, s. 20-23
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Konferensbidrag (refereegranskat)abstract
- The purpose of this study was to develop an automated segmentation method for lung nodules in chest tomo-synthesis images. A number of simulated nodules of different sizes and shapes were created and inserted in two different locations into clinical chest tomosynthesis projections. The tomosynthesis volumes were then reconstructed using standard cone beam filtered back projection, with 1 mm slice interval. For the in-plane segmentation, the central plane of each nodule was selected. The segmentation method was formulated as an optimization problem where the nodule boundary corresponds to the minimum of the cost function, which is found by dynamic programming. The cost function was composed of terms related to pixel intensities, edge strength, edge direction and a smoothness constraint. The segmentation results were evaluated using an overlap measure (Dice index) of nodule regions and a distance measure (Hausdorff distance) between true and segmented nodule. On clinical images, the nodule segmentation method achieved a mean Dice index of 0.96 ± 0.01, and a mean Hausdorff distance of 0.5 ± 0.2 mm for isolated nodules and for nodules close to other lung structures a mean Dice index of 0.95 ± 0.02 and a mean Hausdorff distance of 0.5 ± 0.2 mm. The method achieved an acceptable accuracy and may be useful for area estimation of lung nodules.
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