| 1. |
- Alshamari, Muhammed, 1975-, et al.
(författare)
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Impact of iterative reconstruction on image quality of low-dose CT of the lumbar spine
- 2017
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Ingår i: Acta Radiologica. - London : Sage Publications. - 0284-1851 .- 1600-0455. ; 58:6, s. 702-709
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Tidskriftsartikel (refereegranskat)abstract
- Background: Iterative reconstruction (IR) is a recent reconstruction algorithm for computed tomography (CT) that can be used instead of the standard algorithm, filtered back projection (FBP), to reduce radiation dose and/or improve image quality.Purpose: To evaluate and compare the image quality of low-dose CT of the lumbar spine reconstructed with IR to conventional FBP, without further reduction of radiation dose.Material and Methods: Low-dose CT on 55 patients was performed on a Siemens scanner using 120 kV tube voltage, 30 reference mAs, and automatic dose modulation. From raw CT data, lumbar spine CT images were reconstructed with a medium filter (B41f) using FBP and four levels of IR (levels 2-5). Five reviewers scored all images on seven image quality criteria according to the European guidelines on quality criteria for CT, using a five-grade scale. A side-by-side comparison was also performed.Results: There was significant improvement in image quality for IR (levels 2-4) compared to FBP. According to visual grading regression, odds ratios of all criteria with 95% confidence intervals for IR2, IR3, IR4, and IR5 were: 1.59 (1.39-1.83), 1.74 (1.51-1.99), 1.68 (1.46-1.93), and 1.08 (0.94-1.23), respectively. In the side-by-side comparison of all reconstructions, images with IR (levels 2-4) received the highest scores. The mean overall CTDIvol was 1.70 mGy (SD 0.46; range, 1.01-3.83 mGy). Image noise decreased in a linear fashion with increased strength of IR.Conclusion: Iterative reconstruction at levels 2, 3, and 4 improves image quality of low-dose CT of the lumbar spine compared to FPB.
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| 2. |
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| 3. |
- Alshamari, Muhammed, 1975-, et al.
(författare)
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Low dose CT of the lumbar spine compared with radiography : a study on image quality with implications for clinical practice
- 2016
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Ingår i: Acta Radiologica. - London, United Kingdom : Sage Publications. - 0284-1851 .- 1600-0455. ; 57:5, s. 602-611
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lumbar spine radiography is often performed instead of CT for radiation dose concerns.Purpose: To compare image quality and diagnostic information from low dose lumbar spine CT at an effective dose of about 1 mSv with lumbar spine radiography.Material and Methods: Fifty-one patients were examined by both methods. Five reviewers scored all examinations on eight image quality criteria using a five-graded scale and also assessed three common pathologic changes.Results: Low dose CT scored better than radiography on the following: sharp reproduction of disc profile and vertebral end-plates (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3-2.5), intervertebral foramina and pedicles (OR, 4.3; 95% CI, 3.1-5.9), intervertebral joints (OR, 139; 95% CI, 59-326), spinous and transverse processes (OR, 7.0; 95% CI, 4.3-11.2), sacro-iliac joints (OR, 4.2; 95% CI, 3.2-5.7), reproduction of the adjacent soft tissues (OR, 2.9; 95% CI, 2.1-4.0), and absence of any obscuring superimposed gastrointestinal gas and contents (OR, 188; 95% CI, 66-539). Radiography scored better on sharp reproduction of cortical and trabecular bone (OR, 0.3; 95% CI, 0.2-0.4). The reviewers visualized disk degeneration, spondylosis/diffuse idiopathic skeletal hyperostosis (DISH) and intervertebral joint osteoarthritis more clearly and were more certain with low dose CT. Mean time to review low dose CT was 204 s (95% CI, 194-214 s.), radiography 152 s (95% CI, 146-158 s.). The effective dose for low dose CT was 1.0-1.1 mSv, for radiography 0.7 mSv.Conclusion: Low dose lumbar spine CT at about 1 mSv has superior image quality to lumbar spine radiography with more anatomical and diagnostic information.
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| 4. |
- Andersson, Karin M., 1989-, et al.
(författare)
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Visual grading evaluation of commercially available metal artefact reduction techniques in hip prosthesis computed tomography
- 2016
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Ingår i: British Journal of Radiology. - London, United Kingdom : British Institute of Radiology. - 0007-1285 .- 1748-880X. ; 89:1063
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To evaluate metal artefact reduction (MAR) techniques from four computed tomography (CT) vendors in hip prosthesis imaging.Methods: Bilateral hip prosthesis phantom images, obtained by using MAR algorithms for single energy CT data or dual energy CT (DECT) data and by monoenergetic reconstructions of DECT data, were visually graded by five radiologists using ten image quality criteria. Comparisons between the MAR images and a reference image were performed for each scanner separately. Ordinal probit regression analysis was used.Results: The MAR algorithms in general improved the image quality based on the majority of the criteria (up to between 8/10 and 10/10) with a statistically improvement in overall image quality (P<0.001). However, degradation of image quality, such as new artefacts, was seen in some cases. A few monoenergetic reconstruction series improved the image quality (P<0.004) for one of the DECT scanners, but it was only improved for some of the criteria (up to 5/10). Monoenergetic reconstructions resulted in worse image quality for the majority of the criteria (up to 7/10) for the other DECT scanner.Conclusions: The MAR algorithms improved the image quality of the hip prosthesis CT images. However, since additional artefacts and degradation of image quality were seen in some cases, all algorithms should be carefully evaluated for every clinical situation. Monoenergetic reconstructions were in general concluded to be insufficient for reducing metal artifacts. Advances in knowledge: Qualitative evaluation of the usefulness of several MAR techniques from different vendors in CT imaging of hip prosthesis.
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| 5. |
- Dreifaldt, Mats, 1959-, et al.
(författare)
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Pedicled versus skeletonized internal thoracic artery grafts : a randomized trial
- 2021
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Ingår i: Asian cardiovascular & thoracic annals. - : Medikaru Toribyun. - 1816-5370 .- 0218-4923. ; 29:6, s. 490-497
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Concerns have been raised regarding whether skeletonization of the internal thoracic artery could damage the graft and thereby reduces its patency. The objective of this study was to compare patency rates at mid- and long-term follow-up between pedicled and skeletonized left internal thoracic artery grafts.METHODS: This randomized controlled trial included 109 patients undergoing coronary artery bypass surgery. The patients were assigned to receive either one pedicled or one skeletonized left internal thoracic artery graft to the left anterior descending artery. Follow-up was performed at 3 years with conventional angiography, and at 8 years with computed tomography angiography. Differences between patency rates were analyzed with Fisher's exact test and a generalized linear model.RESULTS: The patency rates for pedicled and skeletonized left internal thoracic artery grafts were 46/48 (95.8%) versus 47/52 (90.4%), p = 0.44 at 3 years, and 40/43 (93.0%) versus 37/41 (90.2%), p = 0.71 at 8 years, respectively. The difference in patency rates for pedicled and skeletonized grafts was 5.4% (95% confidence interval: -4.2-14.5) at 3 years and 2.8% (95% confidence interval: -9.9-14.1) at 8 years. All failed grafts, except for one with a localized stenosis, were anastomosed to native coronary arteries with a stenosis less than 70%. Three patients suffered sternal wound infections (two in the pedicled group, one in the skeletonized group).CONCLUSIONS: The skeletonization technique can be used without jeopardizing the patency of the left internal thoracic artery. The most important factor in graft failure was target artery stenosis below 70%.
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| 6. |
- Dreifaldt, Mats, 1959-, et al.
(författare)
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The no-touch saphenous vein is an excellent alternative conduit to the radial artery 8 years after coronary artery bypass grafting : A randomized trial
- 2021
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - : Elsevier. - 0022-5223 .- 1097-685X. ; 161:2, s. 624-630
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Tidskriftsartikel (refereegranskat)abstract
- Background: In 2004, a prospective randomized trial demonstrated that after 3 years, saphenous veins (SVs) harvested with a no touch (NT) technique had a greater patency than radial grafts for coronary bypass surgery. Here we report the 8-year follow-up data of this trial.Methods: The trial included 108 patients undergoing coronary artery bypass grafting (CABG). Each patient was assigned to receive 1 NT SV and 1 radial artery (RA) graft to either the left or right coronary territory to complement the left internal thoracic artery (LITA). Sequential grafting was common, so overall graft patency as well as the patency of each anastomosis were assessed.Results: Angiography was performed in 84 patients (78%) at mean of 97 months postoperatively. Graft patency were high and similar for both NT and RA: 86% for NT versus 79% for RA (P = .22). The patency of coronary anastomoses was significantly higher with the NT SV grafts (91% vs 81%; P = .046). The NT grafts also had excellent patency in coronary arteries with <90% stenosis (93% patency) and in coronary arteries of small diameter (87% patency) or with mild calcification (88% patency). Patency for the LITA was 92%.Conclusions: NT SV grafts have excellent patency similar to that of RA grafts after 8 years. In addition, NT SV grafts can be used in situations that are not ideal for RA grafts.
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| 7. |
- Engstrand, Per, 1955-, et al.
(författare)
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Improved refining energy efficiency in thermo-mechanical pulping by means of collimated wood chipping – from solid mechanics to full scale evaluation
- 2016
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Ingår i: PaperWeek Canada 2016 Conference <em>February 1 to 5, 2016, Montreal</em>.
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Konferensbidrag (refereegranskat)abstract
- The wood chipping process was never optimized with regard to high yield pulping processes as thermomechanical pulping (TMP) and chemithermomechanical pulping (CTMP). It is generally believed that wood chips for pulping should be produced in such a way that the degree of damage is minimized and that the chip dimensional distribution should be as narrow as possible. Since the TMP and CTMP processes were developed in the 60-ies and 70-ies, compression screw as well as roll nip equipment have been developed to pretreat wood chips as a way to reduce refining energy consumption to given fiber and pulp properties and also in order to improve impregnation. The general conclusions are that a combination of shear and compression in the tangential or radial direction of the wood initiates cracks that later in the refiner will enhance and optimize fiber separation and also fiber property development. The idea with the collimated chipping technology is to utilize the wood chipper as a tool, combining cutting of wood logs to wood chips with a pretreatment of the chips by creating cracks that would enhance fiber separation, fiber surface development as well as chip-impregnation. In this case the compression is performed in the wood fiber direction, in which direction wood actually is weakest when it comes to compression induced cracking. The maximization of the amount of cracks in wood-chips is performed by optimizing the knife angle (or spout angle) in the chipper, to what we call collimated chipping (according to a patent owned by CCT AB). This presentation describes a theoretical background and two demonstration scale studies performed by SCA Forest Products at their Ortviken mill. One conclusion drawn, based on two-month test period with three weeks of collimated chipping, was that specific refining energy reduction was around 100 kWh/adt of the 1400 kWh/adt used in primary stage double disc refining. Most probably the potential is higher if the whole system is optimized. Tests were performed at constant production rate and energy was reduced by reducing power to constant freeness, leading to similar tensile and light scattering levels. The deliberately increased forces created in the wood chipper by means of an optimized (increased) edge angle caused more problems with knife holder equipment than normally, as well as increased vibrations. These problems will have to be solved for future long-term implementation of the technique.
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| 8. |
- Ahlstrand, Erik, 1974-, et al.
(författare)
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Visual scoring of chest CT at hospital admission predicts hospitalization time and intensive care admission in Covid-19
- 2021
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Ingår i: Infectious Diseases. - : Taylor & Francis. - 2374-4235 .- 2374-4243. ; 53:8, s. 622-632
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Chest CT is prognostic in Covid-19 but there is a lack of consensus on how to report the CT findings. A chest CT scoring system, ÖCoS, was implemented in clinical routine on 1 April 2020, in Örebro Region, Sweden. The ÖCoS-severity score measures the extent of lung involvement. The objective of the study was to evaluate the ÖCoS scores as predictors of the clinical course of Covid-19.METHODS: Population based study including data from all hospitalized patients with Covid-19 in Örebro Region during March to July 2020. We evaluated the correlations between CT scores at the time of admission to hospital and intensive care in relation to hospital and intensive care length of stay (LoS), intensive care admission and death. C-reactive protein and lymphocyte count were included as covariates in multivariate regression analyses.RESULTS: In 381 included patients, the ÖCoS-severity score at admission closely correlated to hospital length of stay, and intensive care admission or death. At admission to intensive care, the ÖCoS-severity score correlated with intensive care length of stay. The ÖCoS-severity score was superior to basic inflammatory biomarkers in predicting clinical outcomes.CONCLUSION: Chest CT visual scoring at admission to hospital predicted the clinical course of Covid-19 pneumonia.
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| 9. |
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| 10. |
- Albin, Maria, et al.
(författare)
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0253 Hairdressers are occupationally exposed to ortho- and meta- toluidine
- 2014
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Ingår i: Occupational and Environmental Medicine. - : BMJ. - 1470-7926 .- 1351-0711. ; 71 Suppl 1, s. 32-33
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Konferensbidrag (refereegranskat)abstract
- Hairdressing work is classified as carcinogenic based on excess risk for bladder cancer. We aimed at evaluating if current hairdressers are exposed to established/suspected bladder carcinogens (aromatic amines) and indicate possible sources of exposure.
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| 11. |
- Alobeidi, Hanan, et al.
(författare)
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Minimizing contrast media dose in CT pulmonary angiography with high-pitch technique
- 2020
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Ingår i: British Journal of Radiology. - : John Wiley & Sons. - 0007-1285 .- 1748-880X. ; 93:1111
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To perform CT pulmonary angiography (CTPA) using a minimal amount of iodinated contrast media.METHODS: 47 patients (25 females) with mean age 69 years (range 41-82 years) referred for contrast-enhanced chest CT were prospectively included in this Phase IV clinical drug trial. All participants underwent a study specific CTPA in addition to the chest CT. The participants received 80 mg I/kg body weight Iohexol contrast media using a preparatory saline bolus, a dual flow contrast/saline bolus and a saline flush, and a scanner protocol with 80 kVp dual source high-pitch mode. Three readers independently assessed the image quality on the 3-point scale non-diagnostic, adequate or good-excellent image quality. Additionally, the pulmonary arterial contrast opacification was measured.RESULTS: On average, the patients received 16.8 ml Iohexol 350 mg I/mL (range 12-20 ml). Mean patient weight was 71 kg (range 50-85 kg). Identically for all readers, pulmonary embolism (PE) was detected in 1/47 participants. The median number of examinations visually scored concerning pulmonary embolism as good-excellent was 47/47 (range 44-47); adequate 0/47 (0-3) and non-diagnostic 0/47 (range 0-0). The proportion adequate or better examinations was for all readers 47/47, 100% [95% confidence interval 92-100%]. The mean attenuation ± standard deviation in the pulmonary trunk was 325 ± 72 Hounsfield unit (range 165-531 Hounsfield unit).CONCLUSIONS: Diagnostic CTPA with 17 ml contrast media is possible in non-obese patients using low kVp, high pitch and carefully designed contrast media administration.ADVANCES IN KNOWLEDGE: By combining several procedures in a CTPA protocol, the contrast media dose can be minimized.
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| 12. |
- Arbeus, Mikael, et al.
(författare)
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Five-year patency for the no-touch saphenous vein and the left internal thoracic artery in on- and off-pump coronary artery bypass grafting
- 2021
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Ingår i: Journal of cardiac surgery. - : Wiley-Blackwell Publishing Inc.. - 0886-0440 .- 1540-8191. ; 36:10, s. 3702-3708
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Randomized trials show high long-term patency for no-touch saphenous vein grafts in coronary artery bypass grafting. The patency rate in off-pump coronary bypass surgery for these grafts has not been investigated. Our center participated in the CORONARY randomized trial, NCT00463294. This is a study aimed to assess the patency of no-touch saphenous veins in on- versus off-pump coronary bypass surgery at five-year follow-up.METHODS: Fifty-six patients were included. Forty of 49 patients, alive at 5 years, participated in this follow-up. There were 21 and 19 patients in the on- and off-pump groups respectively. No-touch saphenous veins were used to bypass all targets and in some cases the left anterior descending artery. Graft patency according to distal anastomosis was evaluated with computed tomography angiography.RESULTS: The five-year patency rate was 123/139 (88.5%). The patency for the no-touch vein grafts was 57/64 (89.1%) in the on-pump versus 37/45 (82.2%) in the off-pump group. All left internal thoracic arteries except for one, 29/30 (96.6%), were patent. All vein grafts used to bypass the left anterior descending and the diagonal arteries were patent 32/32. The lowest patency rate for the saphenous veins was to the right coronary territory, particularly in off-pump surgery (80.0% vs. 62.5% for the on- respective off-pump groups).CONCLUSIONS: Comparable 5-year patency for the no-touch saphenous veins and the left internal thoracic arteries to the left anterior descending territory in both on- and off-pump coronary artery bypass grafting. Graft patency in off-pump CABG is lower to the right coronary artery.
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| 13. |
- Arkitektur & teknik, Årskurs 2, et al.
(författare)
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På fötter genom England 2016
- 2016
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Denna resedagbok är en del av Arkitektur och teknik-studenternas förberedelse för årskurs 3 och särskilt en träning i att söka, upptäcka och iakkta arkitekturens komplexa sammanhang och de värden som kan skapas genom arkitektur. Under studieresan byggs ett grundmaterial till dagboken upp genom förberedda presentationer, gemensamma analyser, undersökande skisser och konstnärliga övningar. Studieresan följs upp och bearbetas vid seminarier och genom korsläsning av texter där studenterna uppmanas till ett personligt reflekterande hållningssätt. På så sätt blir dagboken ett levande dokument som visar vår glädje och nyfikenhet över de många broar och byggnader vi upplevt tillsammans, och ett dokument som vill locka oss och alla läsare till vidare upptäcktsfärder.
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| 14. |
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| 15. |
- Björkenheim, Anna, 1980-, et al.
(författare)
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Right ventricular lead perforation with iatrogenic injury to an intercostal artery causing haemothorax after pacemaker implant
- 2024
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Ingår i: BMJ Case Reports. - : BMJ Publishing Group Ltd. - 1757-790X. ; 17:2
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Tidskriftsartikel (refereegranskat)abstract
- A woman in her 80s experienced a life-threatening complication of pacemaker implant consisting of subacute right ventricular lead perforation causing iatrogenic injury to an intercostal artery, resulting in a large haemothorax. A CT scan confirmed active bleeding from the fourth intercostal artery. The patient underwent cardiothoracic surgery via a median sternotomy approach, during which the source of the bleeding was sealed, a new epicardial lead was positioned, and the original lead was extracted. This case emphasises the potentially severe consequences of pacemaker lead perforation and secondary injury to adjacent structures. It underscores the importance of early recognition and timely intervention, preferably in a tertiary specialist unit equipped for cardiothoracic surgery and confirms the value of pacemaker interrogation and CT scans for diagnosis.
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| 16. |
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| 17. |
- Carrasco, Cristhian, et al.
(författare)
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Arabinosylated phenolics obtained from SO2-steam-pretreated sugarcane bagasse
- 2012
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575. ; 87:12, s. 1723-1726
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Tidskriftsartikel (refereegranskat)abstract
- A pentose-rich hydrolysate fraction obtained by extraction of steam-pretreated sugarcane bagasse was analysed with regard to dissolved phenolics. The liquid obtained after steam pretreatment (2% SO2 (w/w) at 190 degrees C for 5 min) was divided into two parts: one containing dissolved compounds originating from hemicellulose (with xylose as the dominating compound), and the other containing predominantly dissolved compounds originating from lignin. Using nuclear magnetic resonance, the main dissolved compounds originating from lignin were identified as the glycosylated aromatics, 5-O-(trans-feruloyl)-L-Arabinofuranose and 5-O-(trans-coumaroyl)-L-Arabinofuranose, together with p-coumaric acid and small amounts of more common free phenolics such as p-hydroxybenzaldehyde, p-hydroxybenzoic acid and vanillin. The phenolic compounds were analysed and quantified using reversed-phase high-performance liquid chromatography. The findings show that SO2 steam explosion opened up new degradation pathways during lignin degradation. Copyright (c) 2012 Society of Chemical Industry
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| 18. |
- Carrasco, Cristhian, et al.
(författare)
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SO2-catalysed steam pretreatment of quinoa stalks
- 2015
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575. ; 90:1, s. 64-71
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDQuinoa is a pseudo-cereal grown predominantly in South America. The quinoa stalks are lignocellulosic residues, which have a limited use today. The objective of the current study was to assess the potential of this material as a source of monosaccharides for fermentation purposes by means of steam pretreatment giving sugars from the hemicellulose part, and enzymatic hydrolysis of the solid fraction obtained. SO2 catalysed steam pretreatment was carried out with a holding time of 5min at temperatures between 180 and 220 degrees C. The pretreatment was carried out at two different scales, a small reactor of size 0.5L and a somewhat larger reactor of size 10L, to allow comparison of scale effects in the pretreatment. RESULTSThe highest xylose yield in the liquid phase, obtained after pretreatment at 210 degrees C, was 80%. In the smaller scale unit, longer residence times were needed. The enzymatic hydrolysis, at an enzyme loading of 15 FPU g(-1) glucan and a WIS loading of 2%, resulted in a glucose yield of 70% based on the original glucan. The overall sugar yield, including the xylan hydrolysed in the enzymatic treatment, at dilute conditions was 75%. CONCLUSIONSSO2 catalysed pretreatment of quinoa straw followed by enzymatic hydrolysis gave a relatively good sugar yield. However, the yield obtained was somewhat lower than previously reported for similar materials, such as wheat straw and sugarcane bagasse, steam pretreated with SO2. (c) 2013 Society of Chemical Industry
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| 19. |
- Carrasco, Cristhian, et al.
(författare)
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SO2-catalyzed steam pretreatment and fermentation of enzymatically hydrolyzed sugarcane bagasse
- 2010
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Ingår i: Enzyme and Microbial Technology. - : Elsevier BV. - 0141-0229. ; 46:2, s. 64-73
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Tidskriftsartikel (refereegranskat)abstract
- Sugarcane bagasse is a lignocellulosic residue obtained from sugarcane milling, and a potentially interesting raw material that can be used for fuel ethanol production. In the present study, bagasse was steam pretreated at temperatures between 180 and 205 ◦C, with holding times of 5–10 min using SO2 as a catalyst to determine conditions that provide a good recovery of pentoses and a suitable material for enzymatic hydrolysis. Pretreatment conducted at 190 ◦C for 5 min gave a pentose yield of 57%, with only minor amounts of degradation compounds formed. Commercial cellulolytic enzymes were used to hydrolyze the obtained fiber fractions after pretreatment at different water-insoluble solid contents (2%, 5% and 8% WIS). The overall highest sugar yield achieved from bagasse was 87% at 2% WIS. Fermentation tests were made on both the pentose-rich hemicellulose hydrolysate obtained from the pretreatment, and the enzymatic hydrolysates obtained from the fiber fractions using the xylose-fermenting strain of Saccharomyces cerevisiae TMB3400, as well as the natural xylose-utilizing yeast Pichia stipitis CBS 6054. The pretreatment hydrolysates produced at 2% WIS as well as the enzymatic hydrolysates showed a complete glucose fermentability indicating a low toxicity to the yeasts. The best xylose conversion (more than 60%) was achieved by the strain TMB3400 at 2% WIS.
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| 20. |
- Carrasco, Cristhian, et al.
(författare)
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Steam pretreatment and fermentation of the straw material "Paja Brava" using simultaneous saccharification and co-fermentation.
- 2011
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Ingår i: Journal of Bioscience and Bioengineering. - : Elsevier BV. - 1347-4421 .- 1389-1723. ; 111, s. 167-174
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Tidskriftsartikel (refereegranskat)abstract
- Pretreatment, enzymatic hydrolysis and simultaneous saccharification and fermentation (SSF) of the South American straw material Paja Brava were investigated. Suitable process conditions for an SO(2)-catalyzed steam pretreatment of the material were determined and assessed by enzymatic digestibility of obtained fiber slurries for 72h at a water insoluble solids (WIS) content of 2%. The best pretreatment conditions obtained (200°C, 5min holding time and 2.5% SO(2)) gave an overall glucose yield following enzymatic hydrolysis of more than 90%, and a xylose yield of about 70%. Simultaneous saccharification and co-fermentation of glucose and xylose (SSCF) of the pretreated material using the xylose-fermenting strain Saccharomyces cerevisiae TMB3400 was examined at WIS contents between 5% and 10%. In agreement with previous studies on other materials, the overall ethanol yield and also the xylose conversion decreased somewhat with increasing WIS content in the SSCF. In batch SSCF, the xylose conversion obtained was almost 100% at 5% WIS content, but decreased to 69% at 10% WIS. The highest ethanol concentration obtained for a WIS content of 10% was about 40g/L, corresponding to a yield of 0.41g/g in a fed-batch SSCF. The Paja Brava material has previously been found difficult to hydrolyze in a dilute-acid process. However, the SSCF results obtained here show that similar sugar yields and fermentation performance can be expected from Paja Brava as from materials such as wheat straw, corn stover or sugarcane bagasse.
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| 21. |
- Danielson, Mats, et al.
(författare)
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A Process for Participatory Democracy in Electronic Government
- 2008
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Ingår i: Journal of Multi-Criteria Decision Analysis. - : Wiley. - 1057-9214 .- 1099-1360. ; 15:1-2, s. 15-30
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a project and case study integrating decision methods into democratic processes. The case discussed is a set of three complicated decisions in a municipality in Sweden. The decisions had been postponed on several occasions prior to bringing in the method described in the paper. The method employed consists of two main parts. The interaction part contains the communication channels directed to the stakeholders. The decision-process part consists of a three-layered working process model. As a part of the method, the project was highly visible on the web. Citizens were encouraged to submit material to the project. All intermediate results of the process were continuously published, enhancing transparency. For each decision, the analysis consisted of comparing all alternatives, taking the respective criteria into account as weighted or ranked by the participants. A method for recording compromises analytically was also used. The purpose was not to replace the political process but to support it in a structured way.
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| 22. |
- Fazlinovic, Sanin, et al.
(författare)
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Outcome and survival after open heart surgery for adults with congenital heart disease - a single center experience
- 2021
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 55:6, s. 345-353
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Tidskriftsartikel (refereegranskat)abstract
- Introduction. Congenital heart disease (CHD) is the most common type of birth defect today. The adult congenital heart disease (ACHD) population is constantly growing and becoming older and more patients require cardiac surgery. The objective of this study was to review the surgical outcome of the open heart procedures performed on ACHD patients in the last 10 years at Sahlgrenska University Hospital (SUH) through a retrospective descriptive cohort study. Methods. A retrospective data collection was performed for 421 patients who underwent a total of 439 surgical procedures between 2009 and 2018 at the Cardiothoracic department in SUH. The primary outcomes were early (<30 days) and late survival. Secondary outcomes were postoperative complications and independent risk factors for postoperative complications. Results. 30-day mortality was 1.9%. Long-term survival after 3, 5 and 10 years were 96% +/- 1, 94.3% +/- 1.3 and 92.4% +/- 1.8. 82 major complications occurred after 46 procedures (11.6%). The most common major complication was re-exploration due to hemorrhage. Risk factors for major complications were acute surgery and prolonged extracorporeal circulation time. 173 minor complications occurred after 90 procedures (22.5%). The most common minor complication was prolonged intensive care unit stay (>48 h). Conclusion. This study presents satisfactory early and midterm survival. The survival and frequency of major postoperative complications are well in line with what other studies have presented. Patients undergoing resternotomies had no increased risk for mortality or postoperative complications.
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| 23. |
- Frankó, Balázs, et al.
(författare)
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Removal of Water-Soluble Extractives Improves the Enzymatic Digestibility of Steam-Pretreated Softwood Barks
- 2018
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Ingår i: Applied Biochemistry and Biotechnology. - : Springer Science and Business Media LLC. - 0273-2289 .- 1559-0291. ; 184:2, s. 599-615
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Tidskriftsartikel (refereegranskat)abstract
- Softwood bark contains a large amounts of extractives—i.e., soluble lipophilic (such as resin acids) and hydrophilic components (phenolic compounds, stilbenes). The effects of the partial removal of water-soluble extractives before acid-catalyzed steam pretreatment on enzymatic digestibility were assessed for two softwood barks—Norway spruce and Scots pine. A simple hot water extraction step removed more than half of the water-soluble extractives from the barks, which improved the enzymatic digestibility of both steam-pretreated materials. This effect was more pronounced for the spruce than the pine bark, as evidenced by the 30 and 11% glucose yield improvement, respectively, in the enzymatic digestibility. Furthermore, analysis of the chemical composition showed that the acid-insoluble lignin content of the pretreated materials decreased when water-soluble extractives were removed prior to steam pretreatment. This can be explained by a decreased formation of water-insoluble “pseudo-lignin” from water-soluble bark phenolics during the acid-catalyzed pretreatment, which otherwise results in distorted lignin analysis and may also contribute to the impaired enzymatic digestibility of the barks. Thus, this study advocates the removal of extractives as the first step in the processing of bark or bark-rich materials in a sugar platform biorefinery.
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| 24. |
- Galbe, Mats, et al.
(författare)
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Production of ethanol from biomass - Research in Sweden
- 2005
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Ingår i: Journal of Scientific and Industrial Research. - 0022-4456. ; 64:11, s. 905-919
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Tidskriftsartikel (refereegranskat)abstract
- Ethanol produced from various lignocellulosic materials such as wood, agricultural and forest residues has the potential to be a valuable substitute for, or complement to, gasoline. This paper reviews the research activities in Sweden on development of the technology for ethanol production from lignocellulosics. The paper focuses on hemicellulose and cellulose hydrolysis and fermentation as well as on process integration and techno-economic evaluation of the overall process.
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| 25. |
- Hahn-Hägerdal, Bärbel, et al.
(författare)
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Bio-ethanol - the fuel of tomorrow from the residues of today
- 2006
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Ingår i: Trends in Biotechnology. - : Elsevier BV. - 0167-7799. ; 24:12, s. 549-556
-
Forskningsöversikt (refereegranskat)abstract
- The increased concern for the security of the oil supply and the negative impact of fossil fuels on the environment, particularly greenhouse gas emissions, has put pressure on society to find renewable fuel alternatives. The most common renewable fuel today is ethanol produced from sugar or grain (starch); however, this raw material base will not be sufficient. Consequently, future large-scale use of ethanol will most certainly have to be based on production from lignocellulosic materials. This review gives an overview of the new technologies required and the advances achieved in recent years to bring lignocellulosic ethanol towards industrial production. One of the major challenges is to optimize the integration of process engineering, fermentation technology, enzyme engineering and metabolic engineering.
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| 26. |
- Hansson, Lars-Olof, et al.
(författare)
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Performance evaluation of a turbidimetric cystatin C assay on different high-throughput platforms
- 2010
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Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 70:5, s. 347-353
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Tidskriftsartikel (refereegranskat)abstract
- Objective. The goal with this study was to evaluate the analytical performance of a new cystatin C immunoassay (Tina-quant (R) a Cystatin C, Roche Diagnostics GmbH). The evaluation was carried out at four centers according to a standardized protocol. Material and methods. The Tina-quant (R) a Cystatin C is a latex particle-enhanced immunoturbidimetric assay. Roche cobas (R) 6000, MODULAR ANALYTICS SWA and COBAS INTEGRA (R) instruments were included in the study. Method comparison studies were carried out against two turbidimetric methods (Dako Cystatin C, Gentian Cystatin C), and one nephelometric method (Siemens N-Latex Cystatin C). Results. Linearity was proven throughout the measuring range from 0.4 to 8 mg/L. Within-run CVs ranged from 0.7-2.8%, and total CVs from 1.4-4.7 % (concentration range 0.6-3.9 mg/L). Comparable results were obtained with paired serum and Li-heparinate plasma samples. Good agreement was achieved in the comparisons between the Tina-quant (R) a Cystatin C assay and the other commercially available cystatin C assays, two different turbidimetric methods (slope range 0.88-1.04, intercept < 0.17 mg/L, r >= 0.993) and one nephelometric assay (slope range 0.90-1.05, intercept < 0.21 mg/L, r >= 0.986). Conclusions. The Tina-quant (R) a Cystatin C assay was shown to be precise and accurate with proven linearity over the measuring range. Good comparability was obtained with other commercially available assays for the determination of cystatin C. The Tina-quant (R) a Cystatin C assay is very well suited for clinical use on routine clinical chemistry analysers to detect renal dysfunction with a 24 h availability.
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| 27. |
- Hellstrandh Jorstig, Stina, 1978-, et al.
(författare)
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Determination of Right Ventricular Volume by Combining Echocardiographic Distance Measurements
- 2016
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Ingår i: Echocardiography. - Hoboken, USA : Wiley-Blackwell Publishing Inc.. - 0742-2822 .- 1540-8175. ; 33:6, s. 844-853
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Tidskriftsartikel (refereegranskat)abstract
- Background: The position of the right ventricle (RV), often partly behind the sternum, implies difficulties to image the RV free wall using transthoracic echocardiography (TTE) and consequently limits the possibilities of stroke volume calculations. The aim of this study was to evaluate whether the volume of the right ventricle (RV) can be determined by combining TTE distance measurements that do not need the RV free wall to be fully visualized.Methods: The RV volume was approximated by an ellipsoid composed of three distances. Distance measurements, modeled RV stroke volumes (RVSV), and RV ejection fraction (RVEF) were compared to reference values obtained from cardiac magnetic resonance (CMR) imaging for 12 healthy volunteers.Results: Inter-modality comparisons showed that distance measurements were significantly underestimated in TTE compared to CMR. The modeled RV volumes using TTE distance measurements were underestimated compared to reference CMR volumes. There was, however, for TTE an agreement between modeled RVSV and left ventricular stroke volumes determined by biplane Simpson's rule. Similar agreement was shown between modeled RVSV based on CMR distance measurements and the CMR reference. Regarding RVEF, further studies including patients with a wider range of RVEF are needed to evaluate the method.Conclusion: In conclusion, the ellipsoid model of the RV provides good estimates of RVSVs, but volumes based on distance measurements from different modalities cannot be used interchangeably.
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| 28. |
- Håkansson, Alexander, et al.
(författare)
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Compassion focused therapy : a transdiagnostic approach to counteract shame and self-criticism in the treatment of individuals with chronic pain and comorbid emotional problems
- 2015
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Konferensbidrag (refereegranskat)abstract
- Introduction: Chronic pain affects people worldwide. Depression and anxiety are common comorbid problems and are many times associated with pervasive problems with self-image, shame and self-criticism. Recently, Compassion Focused Therapy (CFT) has received increasing clinical and scientific interest as a means to counteract shame, self-criticism and isolation. CFT integrates influences from affective neuroscience, Buddhism, attachment theory, evolution theory and cognitive behavioral theories. The focus in CFT is on increasing individuals' ability to experience warmth, acceptance and community in relation to themselves as well as to and from others. Therefore, CFT may be a promising approach to address self-criticism and shame in chronic patients with comorbid emotional problems.Method: This study employs a Single Case Experimental Design (N=6) to examine whether a 7 week, Internet delivered, CFT can lead to increased self-compassion, reduced shame, self-criticism, depression and anxiety symptoms in patients with chronic pain and comorbid anxiety and depression.Results: The results showed treatments effects on all variables of varying magnitude.Discussion: The results add to the growing body of research that CFT affects several problem areas, and can be delivered via the Internet. While the results are encouraging, variations in treatment results and methodological restrictions indicate need for further research.
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| 29. |
- Ingberg, Edvin, 1988-, et al.
(författare)
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RT-PCR cycle threshold value in combination with visual scoring of chest computed tomography at hospital admission predicts outcome in COVID-19
- 2022
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Ingår i: Infectious Diseases. - : Taylor & Francis. - 2374-4235 .- 2374-4243. ; 54:6, s. 431-440
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: COVID-19 has a most variable prognosis. Several risk factors for an unfavourable outcome have been identified including extensive lung involvement on chest CT and high viral load estimated by RT-PCR cycle threshold (Ct) values. We investigated Ct value for outcome prediction, relation between Ct value and extent of lung involvement on chest CT and the combination of Ct value and chest CT lung involvement to predict outcome in COVID-19.METHODS: Population-based retrospective study on all patients (n = 286) hospitalised for COVID-19 in Örebro Region, Sweden, between 1 March and 31 August 2020. Nasopharyngeal samples and chest CT at hospital admission were evaluated in relation to outcome of COVID-19.RESULTS: Both Ct value and chest CT lung involvement were independently associated with risk for ICU admission or death. Lung involvement was superior as a single parameter, but addition of Ct value increased the prediction performance. Ct value was especially useful to identify patients with high risk for severe disease despite limited lung involvement.CONCLUSIONS: The addition of RT-PCR Ct value to the assessment of lung involvement on chest CT adds valuable prognostic information in COVID-19. We believe that this information can be used to support clinical decision-making when managing COVID-19 patients.
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| 30. |
- Jendeberg, Johan, 1972-, et al.
(författare)
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Differentiation of distal ureteral stones and pelvic phleboliths using a convolutional neural network
- 2021
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Ingår i: Urolithiasis. - : Springer Berlin/Heidelberg. - 2194-7228 .- 2194-7236. ; 49, s. 41-49
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Tidskriftsartikel (refereegranskat)abstract
- The objectives were to develop and validate a Convolutional Neural Network (CNN) using local features for differentiating distal ureteral stones from pelvic phleboliths, compare the CNN method with a semi-quantitative method and with radiologists' assessments and to evaluate whether the assessment of a calcification and its local surroundings is sufficient for discriminating ureteral stones from pelvic phleboliths in non-contrast-enhanced CT (NECT). We retrospectively included 341 consecutive patients with acute renal colic and a ureteral stone on NECT showing either a distal ureteral stone, a phlebolith or both. A 2.5-dimensional CNN (2.5D-CNN) model was used, where perpendicular axial, coronal and sagittal images through each calcification were used as input data for the CNN. The CNN was trained on 384 calcifications, and evaluated on an unseen dataset of 50 stones and 50 phleboliths. The CNN was compared to the assessment by seven radiologists who reviewed a local 5 × 5 × 5 cm image stack surrounding each calcification, and to a semi-quantitative method using cut-off values based on the attenuation and volume of the calcifications. The CNN differentiated stones and phleboliths with a sensitivity, specificity and accuracy of 94%, 90% and 92% and an AUC of 0.95. This was similar to a majority vote accuracy of 93% and significantly higher (p = 0.03) than the mean radiologist accuracy of 86%. The semi-quantitative method accuracy was 49%. In conclusion, the CNN differentiated ureteral stones from phleboliths with higher accuracy than the mean of seven radiologists' assessments using local features. However, more than local features are needed to reach optimal discrimination.
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| 31. |
- Jendeberg, Johan, 1972-
(författare)
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Non-enhanced single-energy computed tomography of urinary stones
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Computed tomography (CT) is the mainstay imaging method for urinary stones.The aim of this thesis was to optimize the information obtained from the initial CT scan to allow a well-founded diagnosis and prognosis, and to guide the clinician as early and as far as possible in the further treatment of urinary stone disease.We examined CT scan parameters with regards to their importance for prediction of spontaneous ureteral stone passage, the impact of interreader variability of stone size estimates on this prediction, and the predictive accuracy of a semi-automated, three-dimensional (3D) segmentation algorithm. We also developed and tested the ability of a machine learning algorithm to classify pelvic calcifications into ureteral stones and phleboliths.Using single-energy CT, three quantitative methods for classification of stone composition into uric acid and non-uric acid stones in vivo were prospectively validated, using dual-energy CT as reference.Our results show that spontaneous ureteral stone passage can be predicted with high accuracy, with knowledge of stone size and position. The interreader variability in the size estimation has a large impact on the predicted outcome, but can be eliminated through a 3D segmentation algorithm. Which size estimate we use is of minor importance, but it is important that we use the chosen estimate consistently. A machine learning algorithm can differentiate distal ureteral stones from phleboliths, but more than local features are needed to reach optimal discrimination.A single-energy CT method can distinguish uric acid from non-uric acid stones in vivo with accuracy comparable to dual-energy CT.In conclusion, single-energy CT not only detects a urinary stone, but can also provide us with a prediction regarding spontaneous stone passage and a classification of stone type into uric acid and non-uric acid.
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| 32. |
- Jendeberg, Johan, 1972-, et al.
(författare)
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Prediction of spontaneous ureteral stone passage : Automated 3D-measurements perform equal to radiologists, and linear measurements equal to volumetric
- 2018
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Ingår i: European Radiology. - : Springer. - 0938-7994 .- 1432-1084. ; 28:6, s. 2474-2483
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To compare the ability of different size estimates to predict spontaneous passage of ureteral stones using a 3D-segmentation and to investigate the impact of manual measurement variability on the prediction of stone passage.METHODS: We retrospectively included 391 consecutive patients with ureteral stones on non-contrast-enhanced CT (NECT). Three-dimensional segmentation size estimates were compared to the mean of three radiologists' measurements. Receiver-operating characteristic (ROC) analysis was performed for the prediction of spontaneous passage for each estimate. The difference in predicted passage probability between the manual estimates in upper and lower stones was compared.RESULTS: The area under the ROC curve (AUC) for the measurements ranged from 0.88 to 0.90. Between the automated 3D algorithm and the manual measurements the 95% limits of agreement were 0.2 ± 1.4 mm for the width. The manual bone window measurements resulted in a > 20 percentage point (ppt) difference between the readers in the predicted passage probability in 44% of the upper and 6% of the lower ureteral stones.CONCLUSIONS: All automated 3D algorithm size estimates independently predicted the spontaneous stone passage with similar high accuracy as the mean of three readers' manual linear measurements. Manual size estimation of upper stones showed large inter-reader variations for spontaneous passage prediction.KEY POINTS:• An automated 3D technique predicts spontaneous stone passage with high accuracy.• Linear, areal and volumetric measurements performed similarly in predicting stone passage.• Reader variability has a large impact on the predicted prognosis for stone passage.
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| 33. |
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| 34. |
- Jendeberg, Johan, 1972-, et al.
(författare)
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Single-energy CT predicts uric acid stones with accuracy comparable to dual-energy CT-prospective validation of a quantitative method
- 2021
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Ingår i: European Radiology. - : Springer. - 0938-7994 .- 1432-1084. ; 31:8, s. 5980-5989
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To prospectively validate three quantitative single-energy CT (SE-CT) methods for classifying uric acid (UA) and non-uric acid (non-UA) stones.METHODS: Between September 2018 and September 2019, 116 study participants were prospectively included in the study if they had at least one 3-20-mm urinary stone on an initial urinary tract SE-CT scan. An additional dual-energy CT (DE-CT) scan was performed, limited to the stone of interest. Additionally, to include a sufficient number of UA stones, eight participants with confirmed UA stone on DE-CT were retrospectively included. The SE-CT stone features used in the prediction models were (1) maximum attenuation (maxHU) and (2) the peak point Laplacian (ppLapl) calculated at the position in the stone with maxHU. Two prediction models were previously published methods (ppLapl-maxHU and maxHU) and the third was derived from the previous results based on the k-nearest neighbors (kNN) algorithm (kNN-ppLapl-maxHU). The three methods were evaluated on this new independent stone dataset. The reference standard was the CT vendor's DE-CT application for kidney stones.RESULTS: Altogether 124 participants (59 ± 14 years, 91 men) with 106 non-UA and 37 UA stones were evaluated. For classification of UA and non-UA stones, the sensitivity, specificity, and accuracy were 100% (37/37), 97% (103/106), and 98% (140/143), respectively, for kNN-ppLapl-maxHU; 95% (35/37), 98% (104/106), and 97% (139/143) for ppLapl-maxHU; and 92% (34/37), 94% (100/106), and 94% (134/143) for maxHU.CONCLUSION: A quantitative SE-CT method (kNN-ppLapl-maxHU) can classify UA stones with accuracy comparable to DE-CT.KEY POINTS:• Single-energy CT is the first-line diagnostic tool for suspected renal colic.• A single-energy CT method based on the internal urinary stone attenuation distribution can classify urinary stones into uric acid and non-uric acid stones with high accuracy.• This immensely increases the availability of in vivo stone analysis.
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| 35. |
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| 36. |
- Jendeberg, Johan, 1972-, et al.
(författare)
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Size matters : The width and location of a ureteral stone accurately predict the chance of spontaneous passage
- 2017
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Ingår i: European Radiology. - : Springer. - 0938-7994 .- 1432-1084. ; 27:11, s. 4775-4785
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To determine how to most accurately predict the chance of spontaneous passage of a ureteral stone using information in the diagnostic non-enhanced computed tomography (NECT) and to create predictive models with smaller stone size intervals than previously possible.METHODS: Retrospectively 392 consecutive patients with ureteric stone on NECT were included. Three radiologists independently measured the stone size. Stone location, side, hydronephrosis, CRP, medical expulsion therapy (MET) and all follow-up radiology until stone expulsion or 26 weeks were recorded. Logistic regressions were performed with spontaneous stone passage in 4 weeks and 20 weeks as the dependent variable.RESULTS: The spontaneous passage rate in 20 weeks was 312 out of 392 stones, 98% in 0-2 mm, 98% in 3 mm, 81% in 4 mm, 65% in 5 mm, 33% in 6 mm and 9% in ≥6.5 mm wide stones. The stone size and location predicted spontaneous ureteric stone passage. The side and the grade of hydronephrosis only predicted stone passage in specific subgroups.CONCLUSION: Spontaneous passage of a ureteral stone can be predicted with high accuracy with the information available in the NECT. We present a prediction method based on stone size and location.KEY POINTS: • Non-enhanced computed tomography can predict the outcome of ureteral stones. • Stone size and location are the most important predictors of spontaneous passage. • Prediction models based on stone width or length and stone location are introduced. • The observed passage rates for stone size in mm-intervals are reported. • Clinicians can make better decisions about treatment.
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| 37. |
- Johansson, Sara, et al.
(författare)
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Implications of differences in macromolecular composition of stem fractions for processing of Scots pine
- 2015
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Ingår i: Wood Science and Technology. - : Springer Science and Business Media LLC. - 1432-5225 .- 0043-7719. ; 49:5, s. 1037-1054
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Tidskriftsartikel (refereegranskat)abstract
- Use of wood feedstocks for sugar-based biorefineries requires suitable treatments of the various tree fractions to optimize yields. In the current study, stem wood fractions (sapwood, heartwood and knotwood) were sampled at different heights from well-documented Scots pine trees taken from two contrasting stands. The fractions were assessed in terms of chemical composition, response to SO2-catalysed steam pretreatment and enzymatic digestibility. There were significant differences in total extractive contents between the fractions, where the heartwood fractions had an extractive content 1-3 wt% higher than sapwood (corresponding to a relative increase of 20-60 %) for samples at the same height. In contrast, the differences in macromolecular carbohydrate contents between the fractions were smaller and mainly insignificant. One exception was the xylan content, which was higher in heartwood than in sapwood at the same tree height (a relative difference of 10-15 %). Steam pretreatment resulted in a clearly higher degree of hydrolysis for sapwood than for heartwood at the same conditions. However, at optimal pretreatment temperatures a higher total sugar yield was in fact obtained for heartwood, showing the importance of tuning the process conditions for the respective wood fractions.
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| 38. |
- Jorstig, Stina, 1978-, et al.
(författare)
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Distance and area measurement of the right atrium and ventricle by echocardiography and cardiac magnetic resonance imaging : do we measure the same thing?
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Purpose: It has previously been shown that stroke volumes measured by transthoracic echocardiography (TTE) are underestimated, compared to cardiac magnetic resonance (CMR) imaging. The purpose of this study was to evaluate differences in distance and area measurements of the right atrium (RA) and the right ventricle (RV) by TTE and CMR.Methods: TTE examinations and CMR examinations were subsequently performed in 12 healthy volunteers. Three distances (RAL - right atrial length, RVIT3 - right ventricular inflow tract, RVLAX - right ventricular long axis) and one area (RVA - right ventricular area) were measured in TTE and CMR. Stroke volumes were also calculated using conventional methods available on each modality. Both intramodality and intermodality comparisons were performed based on measurements from three observers. One of the observers performed measurements in both TTE and CMR.Results: Intermodality comparisons showed that all distance and area measurements were significantly smaller using TTE (Table 1). Two of the measurements, RVIT3 and RVA, differed at about 50%. Calculated stroke volumes showed, consistent with previous results, that the TTE stroke volumes are substantially underestimated compared to CMR volumes. Intramodality variations of distance and area measurements were considerably smaller (Table 1).Conclusions: Our results show that RV distances and areas measured by TTE are smaller compared to CMR, probably due to differences in defining the endocardial borders. These differences subsequently result in smaller stroke volumes when using TTE. Caution should be taken when comparing distances, areas and volumes measured by TTE and CMR.
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| 39. |
- Jorstig, Stina Hellstrand, 1978-, et al.
(författare)
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A study to determine the contribution to right ventricle stroke volume from pulmonary and tricuspid valve displacement volumes
- 2015
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 35:4, s. 283-290
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Describing the systolic function of the right ventricle (RV) is a difficult task due to the complex shape and orientation of the RV. The purpose of this study was to investigate the extent to which the volumes encompassed by the pulmonary and tricuspid valve displacements contribute to the total right ventricle stroke volume (RVSV).METHODS: Twelve healthy volunteers were examined using cardiac magnetic resonance (CMR). Two series of time-resolved axially rotated MR images were acquired that encompassed the tricuspid valve and the pulmonary valve, respectively. The volume related to each valve movement, the tricuspid plane displacement (TPD) and the pulmonary plane displacement (PPD), was determined by delineation in diastole and systole. These volumes, RVSVTPD and RVSVPPD , were compared to the stroke volume to determine the contributions to the total stroke volume from the TPD and the PPD. The remaining volume of the total RVSV was referred to as RVSVOther . An initial in vitro study was carried out to validate the accuracy of volume measurements using axially rotated images.RESULTS: In vitro measurements indicated that the method for volumetric measurements using axially rotated images was a very accurate one, with a mean difference of 0·04 ± 0·10 ml. The in vivo measurements of RVSVTPD , RVSVPPD and RVSVOther were 45 ± 10%, 13 ± 2% and 42 ± 11%, respectively.CONCLUSIONS: Right ventricle stroke volume is determined by different individual volume changes as follows: RVSVTPD together with RVSVOther contributes to almost the entire RVSV in nearly equal proportions, while RVSVPPD contributes only a small amount and is approximately 30% of either RVSVTPD or RVSVOther.
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| 40. |
- Jorstig, Stina, 1978-
(författare)
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On the assessment of right ventricular function using cardiac magnetic resonance imaging and echocardiography
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) imaging are two commonly used imaging modalities for evaluating the size and function of the heart. There are advantages and disadvantages associated with both modalities when examining the right ventricle (RV).The RV is positioned partly behind the sternum and lung, sometimes causing shadows in the TTE images. This along with the complex shape of the RV makes volume calculations challenging by 2D TTE. CMR is considered to be the reference method for volume calculations of the ventricles. The valve separating the RV from the right atrium is however often oblique compared to the valve separating the left ventricle from the left atrium. This complicates RV volume calculations using conventional CMR short-axis stack images. The aim of this thesis was to find ways to improve the RV stroke volume and ejection fraction calculations using TTE and CMR.A method, transferring the position of the tricuspid plane from RV long-axis images to short-axis images, was developed to improve the separation of the right atrium from the RV when calculating RV stroke volumes by CMR. The method provided calculations of RV stroke volumes with good agreement to reference volumes. Further, the movements contributing to the RV stroke volume was studied aiming to find new ways of calculating RV stroke volumes and ejection fraction by TTE. A model for RV stroke volume and ejection fraction calculations was evaluated showing underestimation of stroke volumes by TTE compared to CMR, which probably depend on differences in distance measurements using the two modalities. The model provided, however, promising results for ejection fraction calculations which was validated in a study of 37 participants that covered a wide range of EF.
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| 41. |
- Jorstig, Stina, 1978-, et al.
(författare)
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Right ventricular ejection fraction measurements using two-dimensional transthoracic echocardiography by applying an ellipsoid model
- 2017
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Ingår i: Cardiovascular Ultrasound. - : BioMed Central. - 1476-7120. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- Background: There is today no established approach to estimate right ventricular ejection fraction (RVEF) using 2D transthoracic echocardiography (TTE). The aim of this study was to evaluate a new method for RVEF calculations using 2D TTE and compare the results with cardiac magnetic resonance (CMR) imaging and tricuspid annular plane systolic excursion (TAPSE).Methods: A total of 37 subjects, 25 retrospectively included patients and twelve healthy volunteers, were included to give a wide range of RVEF. The right ventricle (RV) was modeled as a part of an ellipsoid enabling calculation of the RV volume by combining three distance measurements. RVEF calculated according to the model, RVEFTTE, were compared with reference CMR-derived RVEF, RVEFCMR. Further, TAPSE was measured in the TTE images and the correlations were calculated between RVEFTTE, TAPSE and RVEFCMR.Results: The mean values were RVEFCMR = 43 +/- 12% (range 20-66%) and RVEFTTE = 50 +/- 9% (range 34-65%). There was a high correlation (r = 0.80, p < 0.001) between RVEFTTE and RVEFCMR. Bland-Altman analysis showed a mean difference between RVEFCMR and RVEFTTE of 6 percentage points (ppt) with limits of agreement from -11 to 23 ppt. The mean value for TAPSE was 19 +/- 5 mm and the correlation between TAPSE and RVEFCMR was moderate (r = 0.54, p < 0.001). The correlation between RVEFTTE and RVEFCMR was significantly higher (p < 0.05) than the correlation between TAPSE and RVEFCMR.Conclusions: The ellipsoid model shows promise for RVEF calculations using 2D TTE for a wide range of RVEF, providing RVEF estimates that were significantly better correlated to RVEF obtained from CMR compared to TAPSE.
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| 42. |
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| 43. |
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| 44. |
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| 45. |
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| 46. |
- Krauss, Wolfgang, 1973-, et al.
(författare)
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Radiomics from multisite MRI and clinical data to predict clinically significant prostate cancer
- 2024
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Ingår i: Acta Radiologica. - : Sage Publications. - 0284-1851 .- 1600-0455. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Magnetic resonance imaging (MRI) is useful in the diagnosis of clinically significant prostate cancer (csPCa). MRI-derived radiomics may support the diagnosis of csPCa. PURPOSE: To investigate whether adding radiomics from biparametric MRI to predictive models based on clinical and MRI parameters improves the prediction of csPCa in a multisite-multivendor setting.MATERIAL AND METHODS: Clinical information (PSA, PSA density, prostate volume, and age), MRI reviews (PI-RADS 2.1), and radiomics (histogram and texture features) were retrieved from prospectively included patients examined at different radiology departments and with different MRI systems, followed by MRI-ultrasound fusion guided biopsies of lesions PI-RADS 3-5. Predictive logistic regression models of csPCa (Gleason score ≥7) for the peripheral (PZ) and transition zone (TZ), including clinical data and PI-RADS only, and combined with radiomics, were built and compared using receiver operating characteristic (ROC) curves.RESULTS: In total, 456 lesions in 350 patients were analyzed. In PZ and TZ, PI-RADS 4-5 and PSA density, and age in PZ, were independent predictors of csPCa in models without radiomics. In models including radiomics, PI-RADS 4-5, PSA density, age, and ADC energy were independent predictors in PZ, and PI-RADS 5, PSA density and ADC mean in TZ. Comparison of areas under the ROC curve (AUC) for the models without radiomics (PZ: AUC = 0.82, TZ: AUC = 0.80) versus with radiomics (PZ: AUC = 0.82, TZ: AUC = 0.82) showed no significant differences (PZ: P = 0.366; TZ: P = 0.171).CONCLUSION: PSA density and PI-RADS are potent predictors of csPCa. Radiomics do not add significant information to our multisite-multivendor dataset.
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| 47. |
- Larsson, Mats, 1951-, et al.
(författare)
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Mot en ny värld : Yngre stenålder i Sverige 4000-1700 f.KR
- 2012. - 1
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Denna bok tar avstamp i den omvälvning som skedde för 6000 år sedan när människor övergick från att huvudsakligen ha varit jägare och fiskare till att bli bönder. I boken belyses och dsikuteras denna utveckling i ett långtidsperspektiv som sträcker sig från ca 4000 f.Kr. till ca 1700 f.Kr. Två kapitel i boken behandlar också natruvetenskapliga undersökningar och hur dessa på många avgörande sätt bidrar till förståelsen för hur månniksor levde och dog för många tusen år sedan.
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| 48. |
- Larsson, Mats, 1951-, et al.
(författare)
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Paths towards a new world : Neolithic Sweden
- 2014. - 1
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- This book is about new results frpm Archaeological research and excavations during the last 10 years. In the book new data is dicussed and how thhis changes our viiew of the period 5000-1700 BC. The whole of Sweden is discussed; from Scania to Lapland and the evidence is interpreted and compared with the older evidence. Two chapters discusses the evidence from sceintific Archaeology as well as the enviromental changes during the period.
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| 49. |
- Lidén, Annika, et al.
(författare)
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Genetic counselling for cancer and risk perception
- 2003
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 42:7, s. 726-734
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Tidskriftsartikel (refereegranskat)abstract
- The main aim was to investigate risk perception and psychological distress in individuals attending genetic counselling. A consecutive series of 86 individuals with a diagnosis and/or family history of breast, ovarian or colorectal cancer was included. Risk assessments were performed before and immediately after genetic counselling and at a one-year follow-up. Psychological distress was assessed 1 week before, and 6 weeks, 6 months and 1 year after genetic counselling. The number of individuals who correctly-estimated the general risk in the population increased significantly from 35%, before to 82% after counselling (p < 0.001). One year later, data on general risk estimates showed a significant reduction of the number of correct estimations to 51%, compared with directly after the counselling (p < 0.005). In total, 54% estimated their own lifetime risk correctly after the counselling, compared with 17% before (p < 0.001) (those with a cancer diagnosis estimated the risk of their children developing cancer). One year later, the number of correct estimations had dropped to 28%. Before the counselling, the majority of the participants overestimated both the general risk and their own/children's risk. The participants experienced moderate levels of psychological distress before the counselling and a decrease of anxiety afterwards (p < 0.02). However, half of the participants reported moderate or high distress. There were no differences in psychological distress between those who estimated their risk/ children's risk as low, moderate or high or between those who over-, under- or correctly estimated their own/children's risk. Further investigations are needed to develop and adjust the risk information provided to the individual in order to avoid misunderstanding, especially as this information is going to be revealed to family members Counselling support should be offered to those individuals who experience psychological distress.
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| 50. |
- Lidén, Mats, 1976-
(författare)
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A new method for predicting uric acid composition in urinary stones using routine single-energy CT
- 2018
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Ingår i: Urolithiasis. - : Springer. - 2194-7228 .- 2194-7236. ; 46:4, s. 325-332
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Tidskriftsartikel (refereegranskat)abstract
- Urinary stones composed of uric acid can be treated medically. Prediction of uric acid stone type is, therefore, desirable when a urinary stone is diagnosed with unenhanced CT. The purpose of the present study was to describe single-energy thin slice quantitative CT parameters of urinary stones correlated to chemical stone type and to develop a method to distinguish pure uric acid stones (UA) from other stones (non-UA/Mix). Unenhanced thin slice single-energy CT images of 126 urinary stones (117 patients) with known chemical stone type were retrospectively included in the study. Among the included stones, 22 were UA and 104 were non-UA/Mix. The included CT images and Laplacian filtered images of the stones were quantitatively analyzed using operator-independent methods. A post hoc classification method for pure UA stones was created using a combination of cutoff values for the peak attenuation and peak point Laplacian. The stone types differed in most quantitative image characteristics including mean attenuation (p < 0.001), peak attenuation (p < 0.001), and peak point Laplacian (p < 0.001). The sensitivity for the post hoc-developed peak attenuation-peak point Laplacian method for classifying pure UA stones was 95% [21/22, 95% CI (77-100%)] and the specificity was 99% [103/104, 95% CI (95-100%)]. In conclusion, quantitative image analysis of thin slice routine single-energy CT images is promising for predicting pure UA content in urinary stones, with results comparable to double energy methods.
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