| 1. |
- Lagerstrand, Kerstin M, et al.
(författare)
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Importance of through-plane heart motion correction for the assessment of aortic regurgitation severity using phase contrast magnetic resonance imaging
- 2021
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Ingår i: Magnetic Resonance Imaging. - : Elsevier BV. - 0730-725X. ; 84, s. 69-75
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To elucidate the influence of through-plane heart motion on the assessment of aortic regurgitation (AR) severity using phase contrast magnetic resonance imaging (PC-MRI). Approach: A patient cohort with chronic AR (n = 34) was examined with PC-MRI. The regurgitant volume (RVol) and fraction (RFrac) were extracted from the PC-MRI data before and after through-plane heart motion correction and was then used for assessment of AR severity. Results: The flow volume errors were strongly correlated to aortic diameter (R = 0.80, p < 0.001) with median (IQR 25%;75%): 16 (14; 17) ml for diameter>40mm, compared with 9 (7; 10) ml for normal aortic size (p < 0.001). RVol and RFrac were underestimated (uncorrected:64 +/- 37 ml and 39 +/- 17%; corrected:76 +/- 37 ml and 44 +/- 15%; p < 0.001) and similar to 20% of the patients received lower severity grade without correction. Conclusion: Through-plane heart motion introduces relevant flow volume errors, especially in patients with aortic dilatation that may result in underestimation of the severity grade in patients with chronic AR.
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| 2. |
- Meltzer, Carin, et al.
(författare)
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Surveillance of small, solid pulmonary nodules at digital chest tomosynthesis: data from a cohort of the pilot Swedish CArdioPulmonary bioImage Study (SCAPIS)
- 2021
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 62:3, s. 348-359
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Tidskriftsartikel (refereegranskat)abstract
- 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 in wide inter- and intra-observer LoA in the order of +/- 100% and +/- 50%. Comparing relative volume change between DTS and CT resulted in LoA of -58% to 67%. The area under the ROC curve regarding the ability of DTS to detect volumetric changes > 25% on CT was 0.58 (95% confidence interval [CI] = 0.40-0.76) and 0.50 (95% CI = 0.35-0.66) for the two observers. Conclusion The results of the present study show that measurement variability limits the agreement between DTS and CT regarding nodule size change for small solid nodules.
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| 3. |
- Molnar, David, et al.
(författare)
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Artificial intelligence based automatic quantification of epicardial adipose tissue suitable for large scale population studies
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- To develop a fully automatic model capable of reliably quantifying epicardial adipose tissue (EAT) volumes and attenuation in large scale population studies to investigate their relation to markers of cardiometabolic risk. Non-contrast cardiac CT images from the SCAPIS study were used to train and test a convolutional neural network based model to quantify EAT by: segmenting the pericardium, suppressing noise-induced artifacts in the heart chambers, and, if image sets were incomplete, imputing missing EAT volumes. The model achieved a mean Dice coefficient of 0.90 when tested against expert manual segmentations on 25 image sets. Tested on 1400 image sets, the model successfully segmented 99.4% of the cases. Automatic imputation of missing EAT volumes had an error of less than 3.1% with up to 20% of the slices in image sets missing. The most important predictors of EAT volumes were weight and waist, while EAT attenuation was predicted mainly by EAT volume. A model with excellent performance, capable of fully automatic handling of the most common challenges in large scale EAT quantification has been developed. In studies of the importance of EAT in disease development, the strong co-variation with anthropometric measures needs to be carefully considered.
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| 4. |
- Pesonen, Ida, et al.
(författare)
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High prevalence of interstitial lung abnormalities in middle-aged never-smokers
- 2023
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Ingår i: ERJ Open Research. - : European Respiratory Society. - 2312-0541. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Interstitial lung abnormalities (ILA) are incidental findings on chest computed tomography (CT). These patterns can present at an early stage of fibrotic lung disease. Our aim was to estimate the prevalence of ILA in the Swedish population, in particular in never-smokers, and find out its association with demographics, comorbidities and symptoms.METHODS: Participants were recruited to the Swedish CArdioPulmonary BioImage Study (SCAPIS), a population-based survey including men and women aged 50-64 years performed at six university hospitals in Sweden. CT scan, spirometry and questionnaires were performed. ILA were defined as cysts, ground-glass opacities, reticular abnormality, bronchiectasis and honeycombing.FINDINGS: Out of 29 521 participants, 14 487 were never-smokers and 14 380 were men. In the whole population, 2870 (9.7%) had ILA of which 134 (0.5%) were fibrotic. In never-smokers, the prevalence was 7.9% of which 0.3% were fibrotic. In the whole population, age, smoking history, chronic bronchitis, cancer, coronary artery calcium score and high-sensitive C-reactive protein were associated with ILA. Both ILA and fibrotic ILA were associated with restrictive spirometric pattern and impaired diffusing capacity of the lung for carbon monoxide. However, individuals with ILA did not report more symptoms compared with individuals without ILA.INTERPRETATION: ILA are common in a middle-aged Swedish population including never-smokers. ILA may be at risk of being underdiagnosed among never-smokers since they are not a target for screening.
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| 5. |
- Truedsson, Frida, et al.
(författare)
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Importance of complex blood flow in the assessment of aortic regurgitation severity using phase contrast magnetic resonance imaging.
- 2021
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Ingår i: The international journal of cardiovascular imaging. - : Springer Science and Business Media LLC. - 1875-8312 .- 1569-5794 .- 1573-0743. ; 37, s. 3561-3572
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to investigate if and how complex flow influences the assessment of aortic regurgitation (AR) using phase contrast MRI in patients with chronic AR. Patients with moderate (n=15) and severe (n=28) chronic AR were categorized into non-complex flow (NCF) or complex flow (CF) based on the presence of systolic backward flow volume. Phase contrast MRI was performed repeatedly at the level of the sinotubular junction (Ao1) and 1cm distal to the sinotubular junction (Ao2). All AR patients were assessed to have non-severe AR or severe AR (cut-off values: regurgitation volume (RVol)≥60ml and regurgitation fraction (RF)≥50%) in both measurement positions. The repeatability was significantly lower, i.e. variation was larger, for patients with CF than for NCF (≥12±12% versus≥6±4%, P≤0.03). For patients with CF, the repeatability was significantly lower at Ao2 compared to Ao1 (≥21±20% versus≥12±12%, P≤0.02), as well as the assessment of regurgitation (RVol: 42±34ml versus 54±42ml, P<0.001; RF: 30±18% versus 34±16%, P=0.01). This was not the case for patients with NCF. The frequency of patients that changed in AR grade from severe to non-severe when the position of the measurement changed from Ao1 to Ao2 was higher for patients with CF compared to NCF (RVol: 5/26 (19%) versus 1/17 (6%), P=0.2; RF: 4/26 (15%) versus 0/17 (0%), P=0.09). Our study shows that complex flow influences the quantification of chronic AR, which can lead to underestimation of AR severity when using PC-MRI.
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| 6. |
- Vikgren, Jenny, 1957, et al.
(författare)
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Visual and Quantitative Evaluation of Emphysema: A Case-Control Study of 1111 Participants in the Pilot Swedish CArdioPulmonary BioImage Study (SCAPIS)
- 2020
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Ingår i: Academic Radiology. - : Elsevier BV. - 1076-6332 .- 1878-4046. ; 27:5, s. 636-643
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Tidskriftsartikel (refereegranskat)abstract
- 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 α. The dataset was also assessed quantitively for % lung attenuation value −950 HU (LAV950), mean lung density and total lung volume by commercially available software. Results: Emphysema was visually scored as mild and Krippendorff's α 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. © 2019 The Association of University Radiologists
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| 7. |
- Baubeta Fridh, Erik, et al.
(författare)
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Comparison of Magnetic Resonance Angiography and Digital Subtraction Angiography for the Assessment of Infrapopliteal Arterial Occlusive Lesions, Based on the TASC II Classification Criteria
- 2020
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Ingår i: Diagnostics (Basel). - : MDPI. - 2075-4418. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- This paper aimed to study the agreement and repeatability, both intra- and interobserver, of infrapopliteal lesion assessment with magnetic resonance angiography (MRA), using the TransAtlantic Inter-Society Consensus (TASC) II criteria, with perioperative digital subtraction angiography (DSA) as a reference. Sixty-eight patients with an MRA preceding an endovascular infrapopliteal revascularization were included. Preoperative MRAs and perioperative DSAs were evaluated in random order by three independent observers using the TASC II classification. The results were analyzed using visual grading characteristics (VGC) analysis and Krippendorffs alpha. No systematic difference was found between modalities: area under the VGC curve (AUC(VGC)) = 0.48 (p = 0.58) or intraobserver; AUC(VGC) for Observer 1 and 2 respectively, 0.49 (p = 0.85) and 0.53 (p = 0.52) for MRA compared with 0.54 (p = 0.30) and 0.49 (p = 0.81) for DSA. Interobserver differences were seen: AUC(VGC) of 0.63 (p < 0.01) for DSA and 0.80 (p < 0.01) for MRA. These results were confirmed using Krippendorffs alpha for the three observers showing 0.13 (95% confidence interval (CI) -0.07-0.31) for MRA and 0.39 (95% CI 0.23-0.53) for DSA. Poor interobserver agreement was also found in the choice of a target vessel on preoperative MRA: Krippendorffs alpha = 0.19 (95% CI 0.01-0.36). In conclusion, infrapopliteal lesions can be reliably determined on preoperative MRA, but interobserver variability regarding the choice of a target vessel is a major concern that appears to affect the overall TASC II grade.
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| 8. |
- Johnsson, Åse (Allansdotter), 1966, et al.
(författare)
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Extracolonic Findings-Identification at Low-Dose CTC.
- 2021
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 195:3-4, s. 188-197
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Tidskriftsartikel (refereegranskat)abstract
- In contrast to optical colonoscopy, computed tomography colonography (CTC) has the ability to reveal pathology outside of the colon. While identification of colorectal lesions at CTC requires only limited radiation dose, the detection of abnormalities in extracolonic soft tissue requires more radiation. The purpose of this study was to investigate the influence of ultra-low-dose (ULD) CTC on the detection and characterisation of extracolonic findings. In a prospective study 49 patients with colorectal symptoms were examined with CTC adding a ULD series (mean effective dose 0.9±0.4mSv) to the normal unenhanced standard dose (SD) series (mean effective dose 3.6±1.2mSv). Five radiologists individually and blindly evaluated the ULD, followed by evaluation of the SD after ≥9weeks (median 35weeks). A ViewDEX-based examination protocol was used, including a confidence scale and a graded assessment of need for follow-up according to the CTC Reporting and Data System (C-RADS E0-E4). The reference findings comprised the combined information from CTC (ULD, SD and contrast-enhanced CTC series) and a 4-year radiological and clinical follow-up. For the overall detection of reference findings (E2-E4) we found a statistically significant difference in favour of SD. This, however, was not the case when looking at classification of possibly important/important reference findings (E3-E4). Our results suggest that CTC with ULD (0.9mSv) is comparable to SD (3.6mSv) for identification of clinically relevant extracolonic pathology, but there is a large inter-observer variability.
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| 9. |
- Lagerstrand, Kerstin M, et al.
(författare)
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Reliable phase-contrast flow volume magnetic resonance measurements are feasible without adjustment of the velocity encoding parameter
- 2020
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Ingår i: Journal of Medical Imaging. - 2329-4310 .- 2329-4302. ; 7:6
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To show that adjustment of velocity encoding (VENC) for phase-contrast (PC) flow volume measurements is not necessary in modern MR scanners with effective background velocity offset corrections. Approach: The independence on VENC was demonstrated theoretically, but also experimentally on dedicated phantoms and on patients with chronic aortic regurgitation (n = 17) and one healthy volunteer. All PC measurements were performed using a modern MR scanner, where the pre-emphasis circuit but also a subsequent post-processing filter were used for effective correction of background velocity offset errors. Results: The VENC level strongly affected the velocity noise level in the PC images and, hence, the estimated peak flow velocity. However, neither the regurgitant blood flow volume nor the mean flow velocity displayed any clinically relevant dependency on the VENC level. Also, the background velocity offset was shown to be close to zero (
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| 10. |
- Ludwigs, Karin, et al.
(författare)
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Poor inter-observer agreement in anatomical classifications of infrapopliteal arterial disease due to mandatory selection of only one target artery
- 2023
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 64:3, s. 1298-1306
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Tidskriftsartikel (refereegranskat)abstract
- Background Established anatomical classifications of infrapopliteal arterial lesion severity are based on assessment of only one target artery, not including all infrapopliteal arteries although multivessel revascularization is common. Purpose To investigate the reproducibility of one of these classifications and a new aggregated score. Material and Methods A total of 68 patients undergoing endovascular infrapopliteal revascularization at Sahlgrenska University Hospital during 2008-2016 were included. Preoperative magnetic resonance angiographies (MRA) and digital subtraction angiographies (DSA) were evaluated by three blinded observers in random order, using the infrapopliteal TransAtlantic Inter-Society Consensus (TASC) II classification. An aggregated score, the Infrapopliteal Total Atherosclerotic Burden (I-TAB) score, including all infrapopliteal arteries, was constructed and used for comparison. Results Inter-observer agreement on lesion severity for each evaluated artery was good; Krippendorff's alpha for MRA 0.64-0.79 and DSA 0.66-0.84. Inter-observer agreement on TASC II grade, based on the selected target artery as stipulated, was poor; Krippendorff's alpha 0.14 (95% confidence interval [CI]=-0.05 to 0.30) for MRA and 0.48 (95% CI=0.33-0.61) for DSA. Inter-observer agreement for the new I-TAB score was good; Krippendorff's alpha 0.76 (95% CI=0.70-0.81) for MRA and 0.79 (95% CI=0.74-0.84) for DSA. Conclusion Reproducible assessment of infrapopliteal lesion severity can be achieved for separate arteries with both MRA and DSA using the TASC II definitions. However, poor inter-observer agreement in selecting the target artery results in low reproducibility of the overall infrapopliteal TASC II grade. An aggregated score, such as I-TAB, results in less variability and may provide a more robust evaluation tool of atherosclerotic disease severity.
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