| 1. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 2. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 3. |
- Appel, Carl-Fredrik, et al.
(författare)
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Transcatheter versus surgical treatment for aortic stenosis : Patient selection and early outcome
- 2012
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa Healthcare. - 1401-7431 .- 1651-2006. ; 46:5, s. 301-307
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. To describe short-term clinical and echocardiography outcomes in patients undergoing transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). To explore patient selection criteria for treatment with TAVI. Design. TAVI patients (n = 45) were matched to SAVR patients (n = 45) with respect to age within +/- 10 years, sex and systolic left ventricular function. Results. TAVI patients were older, 82 +/- 8 versus 78 +/- 5 years (p = 0.005) and they had higher logEuroSCORE, 16 +/- 11% versus 8 +/- 4% (p andlt; 0.001). There were no significant differences in 30 days mortality, stroke and myocardial infarction. TAVI patients received less erythrocyte (53% vs. 78%, p = 0.03) and thrombocyte (7% vs. 27%, p = 0.02) transfusions. Postoperative atrial fibrillation was less common (18% vs. 60%, p andlt; 0.001) in the TAVI group. Paravalvular regurgitation was more common in TAVI patients (87% vs. 0%, p andlt; 0.001) and 27% had access site complications. Aortic transvalvular velocity was 2.3 +/- 0.4 m/s versus 2.6 +/- 0.5 m/s (p = 0.002) and mean valve pressure gradient was 12 +/- 4 mmHg versus 15 +/- 5 mmHg (p = 0.01) in the TAVI and SAVR groups, respectively. Twenty-nine (64%) of the TAVI patients had logEuroSCORE andlt; 15%. Conclusions. Both TAVI and SAVR have good short term clinical outcome with excellent hemodynamic result. In clinical practice, factors other than high logEuroSCORE play an important role in patient selection for TAVI.
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| 4. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 5. |
- Ahn, Henrik, et al.
(författare)
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An implantable pressure sensor for long-term wireless monitoring of cardiac function- first study in man
- 2016
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Ingår i: Journal of Cardiovascular Diseases & Diagnosis. - : Omics Publishing Group. - 2329-9517. ; 4:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Heart failure is a huge health problem. The possibility of long-term monitoring heart function more accurately in these patients has gained increasing interest. The primary aim of this study was to see if a wireless pressure sensor can be safely implanted to give accurate and reproducible long-term intracardiac pressure recordings. Another aim was to see if there are any adverse effects connected with the implant. A control group was included for comparison of clinical data.Methods: Forty patients with heart failure, 31 scheduled for open heart surgery and 9 for transcatheter aortic valve replacement (TAVR) were included to test the safety and feasibility of the Titan™ pressure sensor. The patients were randomized to the implant or control group.Findings: Initial sensor measurements showed very good correlation with reference pressure values from a fluid-filled catheter, and there was no need for calibration of the sensor. At the 6-month follow-up 11 patients had been wearing the implant for >1 year with a median time of 560 days. Ten of these had adequate sensor function. Compared to the control group there was no difference in adverse clinical events and the overall number of complications was low.Conclusions: This first study in man on a new implantable wireless hemodynamic monitor showed favorable results regarding our primary endpoints; accuracy of recordings over time and safety profile. The technology has great potential for monitoring at home since it is easy to use in the out-patient setting.
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| 6. |
- Ahn, Henrik Casimir, 1949-, et al.
(författare)
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A New Total Artificial Heart Concept Allowing Replacement or Support of the Native Heart
- 2018
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Ingår i: Journal of Clinical & Experimental Cardiology. - Los Angeles, United States : Omics Publishing Group. - 2155-9880. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- A total artificial heart (TAH) is typically used to bridge the time to heart transplantation. A device designed by Robert Jarvik has been improved through the years and under the name of Syncardia™ this has been the most successful commercially available TAH so far. Since 2008 the Carmat™ heart has been under development in Europe. The Scandinavian Real Heart™ is based on a unique physiological concept where the atrio-ventricular valve plane is of utmost importance in the pumping function of the heart. It consists of two identical parts driven separately by independent motors and in this first animal study we have used one part as a left ventricular assist device. This new concept makes the device flexible as it may be used not only as a TAH but also as a separate pump for left or right ventricular assist.
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| 7. |
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| 8. |
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| 9. |
- Ahn, Henrik Casimir, et al.
(författare)
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Can predilatation in transcatheter aortic valve implantation be omitted? - a prospective randomized study
- 2016
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Ingår i: Journal of Cardiothoracic Surgery. - : BIOMED CENTRAL LTD. - 1749-8090. ; 11:124
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Tidskriftsartikel (refereegranskat)abstract
- Background: The use of a balloon expandable stent valve includes balloon predilatation of the aortic stenosis before valve deployment. The aim of the study was to see whether or not balloon predilatation is necessary in transcatheter aortic valve replacement (TAVI). Methods: Sixty consecutive TAVI patients were randomized to the standard procedure or to a protocol where balloon predilatation was omitted. Results: There were no significant differences between the groups regarding early hemodynamic results or complication rates. Conclusions: TAVI can be performed safely without balloon predilatation and with the same early results as achieved with the standard procedure including balloon predilatation. The reduction in the number of pacing periods required may be beneficial for the patient.
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| 10. |
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| 11. |
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| 12. |
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| 13. |
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Ahn, Henrik Casimir, et al.
(författare)
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Transvenous Implantation of a Stent Valve in Patients With Degenerated Mitral Prostheses and Native Mitral Stenosis
- 2016
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Ingår i: Annals of Thoracic Surgery. - : Elsevier. - 0003-4975 .- 1552-6259. ; 101:6, s. 2279-2284
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The purpose of this study was to report the use of a transvenous transseptal approach using a stent valve in patients with degenerated biological mitral valve prostheses, regurgitation after mitral repair, and native mitral stenosis.METHODS: Ten patients (median age, 74 years; range, 20-89 years; 5 men and 5 women) with degenerated mitral bioprosthetic valves (n = 7), failed mitral repair (n = 1), or calcified native stenotic valves (n = 2) underwent transvenous implantation of a stent valve.RESULTS: The procedure was initially successful in all patients. Predilation was performed for balloon sizing only in the 2 patients with native mitral stenosis. The stent valve was deployed during 1 period of rapid pacing. A guidewire, as a loop from the right femoral vein and through the left ventricular apex, facilitated a good angle and secure positioning of the stent valve. An ultrasonographically guided puncture of the apex was carried out in 6 patients, and in the other 4 we performed a minithoracotomy before apical puncture. All valves were implanted in a good position with improved function and without significant paravalvular leakage (PVL). There were no periprocedural deaths. The 30-day survival was 80% (8 of 10 patients), and 60% (6 of 10) of patients were still alive a median time of 290 days after the procedure.CONCLUSIONS: Transvenous transseptal implantation of a stent valve was performed in 10 patients with mitral valve disease, with good early functional results. These high-risk patients must be carefully selected by a multidisciplinary team because the procedure carries a high mortality.
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| 18. |
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| 19. |
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| 20. |
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Babic, Ankica, 1960-, et al.
(författare)
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Case Based Reasoning in a Web Based Decision Support System for Thoracic Surgery
- 2013
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Ingår i: IFMBE Proceedings 41. - Cham : Springer. - 9783319008455 - 9783319008462 ; , s. 1413-1416
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Konferensbidrag (refereegranskat)abstract
- Case Based Reasoning (CBR) methodology provides means of collecting patients cases and retrieving them following the clinical criteria. By studying previously treated patients with similar backgrounds, the physician can get a better base for deciding on treatment for a current patient and be better prepared for complications that might occur during and after surgery. This could be taken advantage of when there is not enough data for a statistical analysis, but electronic patient records that provide all the relevant information to assure a timely and accurate clinical insight into a patient particular situation.We have developed and implemented a CBR engine using the Nearest Neighbor algorithm. A patient case is represented as a combination of perioperative variable values and operation reports. Physicians could review a selected number of cases by browsing through the electronic patient record and operational narratives which provides an exhaustive insight into the previously treated cases. An evaluation of the search algorithm suggests a very good functionality.
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| 25. |
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| 26. |
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| 27. |
- Baranowski, Jacek, et al.
(författare)
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A simplified protocol for transcatheter aortic valve implantation that reduces procedure-related risk
- 2016
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Ingår i: Journal of Cardiovascular Diseases & Diagnosis. - : Omics Publishing Group. - 2329-9517. ; 4:3
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Transcatheter Aortic Valve Implantation is now a well-established procedure and continuous development has improved the technique. The object of this paper is to describe the successive steps taken at our department to improve our protocol, resulting in a more effective and patient-safe procedure.Design: An echo-guided method for aortic cusp alignment was used in 229 patients. In 139 patients pre-dilatation was excluded from the protocol. In the last 47 of the patients we exchanged the stiff guide-wire in the left ventricle with a soft wire for valve placement.Results: There was a significant decrease in the use of contrast medium during the period with 90% of patients receiving less than 50 ml contrast and 35% no contrast at all. In more than half the patients we only used rapid pacing in association with deployment of the stent valve. We had six cases ofpericardial bleeding due to penetration of the stiff guide wire through the left ventricular (LV) wall. This complication was avoided in all subsequent patients where we exchanged the stiff catheter to a soft guidewire in the ascending aorta before introduction of the wire and stent valve into the LV.Conclusions: We have successively modified our standard protocol for implantation of a balloon-expandable transcatheter aortic valve. This has simplified the procedure and reduced the risk for certain procedure-related complications.
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| 28. |
- Baranowski, Jacek, et al.
(författare)
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Echo-guided presentation of the aortic valve minimises contrast exposure in transcatheter valve recipients
- 2011
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Ingår i: Catheterization and cardiovascular interventions. - : Wiley. - 1522-1946 .- 1522-726X. ; 77:2, s. 272-275
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: We have developed a method using transthoracic echocardiography in establishing optimal visualization of the aortic root, to reduce the amount of contrast medium used in each patient. BACKGROUND: During transcatheter aortic valve implantation, it is necessary to obtain an optimal fluoroscopic projection for deployment of the valve showing the aortic ostium with the three cusps aligned in the beam direction. This may require repeat aortic root angiograms at this stage of the procedure with a high amount of contrast medium with a risk of detrimental influence on renal function. METHODS: We studied the conventional way and an echo guided way to optimize visualisation of the aortic root. Echocardiography was used initially allowing easier alignment of the image intensifier with the transducer's direction. RESULTS: Contrast volumes, radiation/fluoroscopy exposure times, and postoperative creatinine levels were significantly less in patients having the echo-guided orientation of the optimal fluoroscopic angles compared with patients treated with the conventional approach. CONCLUSION: We present a user-friendly echo-guided method to facilitate fluoroscopy adjustment during transcatheter aortic valve implantation. In our series, the amounts of contrast medium and radiation have been significantly reduced, with a concomitant reduction in detrimental effects on renal function in the early postoperative phase.
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| 29. |
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| 30. |
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| 31. |
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| 32. |
- Boivie, Patrik, 1976-
(författare)
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Cerebrovascular accidents associated with aortic manipulation during cardiac surgery
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Despite the successful development in cardiac surgery, cerebrovascular accidents (CVA) remain a devastating complication. Aortic atherosclerosis has been identified as a major risk factor for CVA. The present thesis addresses this question in relation to aortic manipulation during cardiac surgery, being divided into a clinical (I-II) and an experimental part (III-V). Material and methods: Consecutive cardiac surgery cases (n=2641) were analyzed. Patients with CVA were extracted from a database designed to monitor clinical symptoms. Patient records were used to confirm clinical data and diagnosis. Subdivision was made into three groups: control subjects, immediate, and delayed CVA, being analyzed for neurological symptoms (I). Patients with CVA who also had been investigated with computer tomography (CT) (n=77) were further evaluated in terms of hemispheric and vascular distribution of lesions. The CT-findings were compared with CVA symptoms (II). An aortic perfusion model was developed using cadaver aorta onto which multiple cross-clamp manipulations were applied (III). Washout samples of perfusate were analyzed by computerized image processing and with subdivision into different particle spectra. The model was further developed with the introduction of intraluminal manipulation from cannula and intra-aortic filter (IV). A technique for macro-anatomic mapping of plaque distribution of cadaver thoracic aorta was developed (V). Variation in plaque density was analyzed in different anatomical segments, monitored by digital image analysis. Hazards associated with surgical manipulation were studied by superimposing cannulation and cross-clamp sites onto the aortic maps in a blinded fashion. Results: The incidence of immediate and delayed CVA was 3.0% and 0.9%, respectively. Aortic quality was a strongly associated with immediate but not delayed CVA. Left-sided symptoms of immediate CVA were significantly more frequent than of the contra-lateral side. Positive signs on CT were seen in 66% of the CVA patients. Right-hemispheric lesions were more frequent compared with the contra-lateral side and the middle-cerebral artery territory dominated. Aortic cross-clamping produced a substantial output of particulate matter. Manipulation by intra-aortic filter produced a significant washout of embolic particles that escaped the filter, although some particles were captured. Cannulation was an additional source of embolic material. In terms of plaque distribution was the anterior wall of the ascending part and arch of the aorta more affected than its posterior side. However, observing a plaque in the anterior wall of this aortic segment predicted to 83% a concomitant plaque in the posterior wall. Increased age correlated positively with plaque density. The theoretical chance of interfering with a plaque during cannulation and/or clamp positioning was 45.8%. Conclusions: Both CT scans and clinical symptoms confirmed that CVA after cardiac surgery had a right-hemispheric predominance. The perfusion model resulted in a profound output of material during cross-clamp maneuvers. The intra-aortic filter successfully collected particles but also generated embolic debris on its own. Aortic cannulation was an additional source of embolic debris. Plaques were frequently found in the cadaveric aorta, and there was a high risk of plaque interference during surgical manipulation. As expected, plaque density was age-dependent.
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| 33. |
- Casimir Ahn, Henrik, et al.
(författare)
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Long-term left ventricular support in patients with a mechanical aortic valve
- 2013
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Ingår i: Scandinavian Cardiovascular Journal. - : INFORMA HEALTHCARE, TELEPHONE HOUSE, 69-77 PAUL STREET, LONDON EC2A 4LQ, ENGLAND. - 1401-7431 .- 1651-2006. ; 47:4, s. 236-239
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. The presence of a mechanical prosthesis has been regarded as an increased risk of thromboembolic complications and as a relative contraindication for a left ventricular assist device (LVAD). Five patients in our center had a mechanical aortic valve at the time of device implantation and were studied regarding thromboembolic complications. Design. Five patients operated upon with an LVAD (1 HeartMate I (TM), 4 HeartMate II (TM)) between 2002 and 2011 had a mechanical aortic valve at the time of implantation. The first patient had a patch closure of the aortic valve. In four patients, the prosthesis was left in place. Anticoagulants included aspirin, warfarin, and clopidogrel. Results. The average and accumulated treatment times were 150 and 752 days, respectively. Three of the five patients showed early signs of valve thrombosis on echo with concomitant valve dysfunction. Four patients were transplanted without thromboembolic events during pump treatment. One patient died from a hemorrhagic stroke after 90 days on the LVAD. Conclusions. The strategy of leaving a mechanical heart valve in place at the time of LVAD implantation in five patients led to valvular thrombosis in three but did not provoke embolic events. It increased the complexity of postoperative anticoagulation.
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| 34. |
- Dahlström, Örjan, et al.
(författare)
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Clustering as a data mining method in a Web-based system for thoracic surgery
- 2001
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Ingår i: Journal of the Medical Informatics Association. Symposium Supplement. - Washington : Hanley&Belfus. - 1560535369 ; , s. 888-
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Konferensbidrag (refereegranskat)abstract
- Cluster analysis is one way of data mining from large amounts of information. Being able to perform series of analyses, varying clinical criteria and requests, expected results of the clustering might be truly rewarding. Instead of having a few hypotheses prepared and tested, medical experts can be surprised by obtaining a set of hypotheses to further validate and work on.Internet technologies enable a substantial flexibility that can be taken advantage of when implementing a Web-based tool. Division of Medical Informatics together with Linkoping Heart Center of the Linkoping University is developing procedures for multivariate clustering within the Web-based AssistMe1 system.
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| 35. |
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| 36. |
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| 37. |
- Fors, Carina, et al.
(författare)
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Analysis of breathing-related variations in ECG-triggered laser Doppler perfusion signals measured on the beating heart during surgery
- 2006
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Ingår i: Computers in cardiology. - 0276-6574. ; 33, s. 181-184
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Tidskriftsartikel (refereegranskat)abstract
- Laser Doppler perfusion monitoring (LDPM) is amethod to assess microvascular perfusion. A modified,ECG-triggered LDPM system has been developed tomeasure myocardial perfusion with minimum influencefrom heart motion. With this method, one systolic (PLS)and one diastolic (PLD) perfusion value is obtained.The aim of this study was to analyse breathing-relatedvariations in PLS and PLD measured during open-heartsurgery. The phase delays between PLS, PLD, meanarterial blood pressure (MAP), heart rate and, indirectly,the respiration were determined.MAP tended to be in phase with or precede thevariations in PLD, i.e., PLD was at a maximum at the endof inspiration or at the beginning of expiration. No clearrelation between PLS and any of the other signals couldbe found.
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| 38. |
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| 39. |
- Fors, Carina, 1978-
(författare)
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Evaluation of a Laser Doppler System for Myocardial Perfusion Monitoring
- 2007
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Coronary artery bypass graft (CABG) surgery is a common treatment for patients with coronary artery disease. A potential complication of CABG is myocardial ischemia or infarction. In this thesis, a method - based on laser Doppler flowmetry (LDF) - for detection of intra- and postoperative ischemia by myocardial perfusion monitoring is evaluated.LDF is sensitive to motion artifacts. In previous studies, a method for reduction of motion artifacts when measuring on the beating heart has been developed. By using the ECG as a reference, the perfusion signal is measured in intervals during the cardiac cycle where the cardiac motion is at a minimum, thus minimizing the artifacts in the perfusion signal.The aim of this thesis was to investigate the possibilities to use the ECG-triggered laser Doppler system for continuous monitoring of myocardial perfusion in humans during and after CABG surgery. Two studies were performed. In the first study, changes in myocardial perfusion during CABG surgery were investigated (n = 13), while the second study focused on postoperative measurements (n = 13). In addition, an ECG-triggering method was implemented and evaluated.It was found that the large variations in myocardial perfusion during CABG surgery could be monitored with the ECG-triggered laser Doppler system. Furthermore, a perfusion signal of good quality could be registered postoperatively from the closed chest in ten out of thirteen patients. In eight out of ten patients, a proper signal was obtained also the following morning, i.e., about 20 hours after probe insertion. The results show that respiration and blood pressure can have an influence on the perfusion signal.In conclusion, the results indicate that the method is able to detect fluctuations in myocardial perfusion under favourable circumstances. However, high heart rate, abnormal cardiac motion, improper probe attachment and limitations in the ECG-triggering method may result in variations in the perfusion signal that are not related to tissue perfusion.
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| 40. |
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| 41. |
- Fors, Carina, 1978-, et al.
(författare)
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Online Laser Doppler Measurements of Myocardial Perfusion
- 2008
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Ingår i: IFMBE Proceedings 22,2008. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783540892076 - 9783540892083 ; , s. 1718-1721
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Konferensbidrag (refereegranskat)abstract
- Laser Doppler perfusion monitoring is a suitable method for microvascular blood perfusion measurements. When used on a moving tissue or organ, the Doppler signal arising from the moving blood cells may be distorted. ECG triggering of the laser Doppler signal can be used for reducing the influence from movements during measurements on the beating heart. The aim of this study was to determine the most appropriate triggering intervals during the cardiac cycle for online measurements. Recordings from thirteen coronary artery bypass graft (CABG) patients were included in the study. During surgery, the fibre-optic probe was passed through the chest wall and sutured to the left anterior ventricular wall with the probe tip inserted 3–5 mm into the myocardium. After the patient arrived at the intensive care unit a second measurement was initiated and lasted for about two hours. Before the probe was removed a third measurement was performed for about 5 minutes the following morning. A total of 97 data sequences were analysed and the intervals of low and stable perfusion signal were compared to the positions of the T and P peaks in the ECG.It was found that the most appropriate time intervals were in late systole at the T peak [−3, 9] ms and just before the P peak [−28, -10] ms in late diastole. However, the position of these intervals may vary between individuals, because of e.g., abnormal cardiac motion. With the use of the appropriate interval online measurement of the myocardial perfusion on a beating heart appears possible.
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| 42. |
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| 43. |
- Granfeldt, Hans, et al.
(författare)
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A single center experience with the HeartMate II (TM) Left Ventricular Assist Device (LVAD)
- 2009
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 43:6, s. 360-365
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. Left ventricular assist devices (LVAD), used in the setting bridge-to-transplantation and destination therapy, for patients with deteriorating severe heart failure are continuously developing. The second generation, the axial flow pumps, have been introduced since some years. Design. Eleven consecutive patients, seven male, with severe heart failure due to ischemic cardiomyopathy (n = 5), dilated cardiomyopathy (n = 5) and cytotoxic ethiology (n = 1) were implanted with the HeartMate-II (TM). They were preoperatively treated with inotropic support (n = 9), ventricular assist device (n = 2) and mechanical ventilation (n = 4). Results. Eight patients were bridged to transplant after median 155 days (range, 65 to 316 days). One patient is ongoing for 748 days, intended for destination therapy. Ten of eleven patients were discharged after median 64 days (range, 40 to 105 days). Four patients were reoperated due to bleeding. Two embolic events were recorded. One perioperative death. Conclusion. Eleven HM-II (TM) LVADs have been implanted in our institution with good early results. Eight patients were successfully bridged to heart transplantation. One patient is intended for destination therapy and is ongoing since November 2006. In these severely ill patients, this technique offers a good chance surviving until heart transplantation. In selected cases the technique also offers the possibility of a permanent support and longevity.
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| 44. |
- Granfeldt, Hans, et al.
(författare)
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Experience with the Impella (R) recovery axial-flow system for acute heart failure at three cardiothoracic centers in Sweden
- 2009
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 43:4, s. 233-239
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. The Impella (R) recovery axial-flow system is a mechanical assist system for use in acute heart failure. This retrospective study reports the use of the device at three cardiothoracic units in Sweden. Design. Fifty patients (35 men, mean age 55.8 years, range 26 to 84 years) underwent implantation of 26 Impella (R) LP 2.5/5.0 (support-time 0.1 to 14 days), 16 Impella (R) LD (support-time 1 to 7 days) and 8 Impella (R) RD (support-time 0.1 to 8 days) between 2003 and 2007. Implantation was performed because of postcardiotomy heart failure (surgical group, n=33) or for various states of heart failure in cardiological patients (non-surgical group, n=17). The intention for the treatments was mainly to use the pump as a obridge-to-recoveryo. Results. Early mortality in the surgical and non-surgical groups was 45% and 23%, respectively. Complications included infection, 36% and right ventricular failure, 28%. Cardiac output and cardiac power output postoperatively were significantly higher among survivors than non-survivors. Conclusions. The Impella (R) recovery axial-flow system facilitates treatment in acute heart failure. Early intervention in patients with acute heart failure and optimized hemodynamics in the post-implantation period seem to be of importance for long-term survival. Insufficient early response to therapy should urge to consider further treatment options.
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| 45. |
- Granfeldt, Hans, 1960-, et al.
(författare)
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Long-term Quality-of-Life (QoL) in patients with progressive chronic heart failure after surgical ventricular restoration with passive ventricular constraint (CorCap-CSDTM) : Comparison with a patient-matched reference group from the general population
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: Chronic heart failure have a poor prognosis with high morbidity and reduced quality of life. Ventricular constraint, the CorCap Cardiac Support Device (CSD) has been introduced with the intention of inducing reverse remodeling. Studies have shown sustained improvement in left ventricular dimensions and function after three years, but quality-of-life (QoL) has been poorly studied. Methods and Results: Since 2003, 26 patients with chronic progressive heart failure met the inclusion criteria for CSD. They were prospectively followed each year for five years postoperatively. Nineteen patients were scheduled for concomitant cardiac surgery. In a cross-sectional study, 18 patients were investigated regarding QoL using SF-36. A reference group was randomly selected from the Swedish SF-36 general population reference group. One-year survival for CSD-patients was 86%, three-year survival was 76%. After a mean follow-up time after surgery of 3.9 years (range; 0.9 to 7 years), no difference in QoL measured with SF-36 was found. Echocardiographic dimensions and QoL improved significantly after three years for isolated CSD patients. Conclusions: QoL in patients operated with CSD, measured with SF-36-questionnaire, more than three years after implantation, is comparable to a matched general population reference group. In the CSD group alone, QoL improved significantly after three years.
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| 46. |
- Granfeldt, Hans, et al.
(författare)
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Risk Factor Analysis of Swedish Left Ventricular Assist Device (LVAD) Patients
- 2003
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Ingår i: Annals of Thoracic Surgery. - : Elsevier. - 0003-4975 .- 1552-6259. ; 76:6, s. 1993-1998
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Tidskriftsartikel (refereegranskat)abstract
- Background. The use of left ventricular assist devices (LVADs) is established as a bridge to heart transplantation. Methods. All Swedish patients on the waiting list for heart transplantation, treated with LVAD since 1993 were retrospectively collected into a database and analyzed in regards to risk factors for mortality and morbidity. Results. Fifty-nine patients (46 men) with a median age of 49 years (range, 14 to 69 years), Higgins score median of 9 (range, 3 to 15), EuroScore median of 10 (range, 5 to 17) were investigated. Dominating diagnoses were dilated cardiomyopathy in 61% (n = 36) and ischemic cardiomyopathy in 18.6% (n = 11). The patients were supported with LVAD for a median time of 99.5 days (range, 1 to 873 days). Forty-five (76%) patients received transplants, and 3 (5.1%) patients were weaned from the device. Eleven patients (18.6%) died during LVAD treatment. Risk factor analysis for mortality before heart transplantation showed significance for a high total amount of autologous blood transfusions (p < 0.001), days on mechanical ventilation postoperatively (p < 0.001), prolonged postoperative intensive care unit stay (p = 0.007), and high central venous pressure 24 hours postoperatively and at the final measurement (p = 0.03 and 0.01, respectively). Mortality with LVAD treatment was 18.6% (n = 11). High C-reactive protein (p = 0.001), low mean arterial pressure (p = 0.03), and high cardiac index (p = 0.03) preoperatively were risk factors for development of right ventricular failure during LVAD treatment. Conclusions. The Swedish experience with LVAD as a bridge to heart transplantation was retrospectively collected into a database. This included data from transplant and nontransplant centers. Figures of mortality and morbidity in the database were comparable to international experience. Specific risk factors were difficult to define retrospectively as a result of different protocols for follow-up among participating centers. © 2003 by The Society of Thoracic Surgeons.
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| 47. |
- Granfeldt, Hans, et al.
(författare)
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The Linkoping-Lund surgical experience with the HeartMate left ventricular assist system
- 1995
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 59:Suppl. 1, s. 52-55
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Tidskriftsartikel (refereegranskat)abstract
- Four transplant candidates fulfilling the Food and Drug Administration criteria for a permanent left ventricular assist device received a pneumatic HeartMate system as a bridge to heart transplantation. All patients survived and were fully rehabilitated at the time of transplantation, which was carried out 2 to 6 months after the initial operation. There were no major complications associated with the procedures. We are impressed by the effectiveness and safety of the device.
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| 48. |
- Granfeldt, Hans, 1960-
(författare)
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The use of mechanical circulatory support and passive ventricular constraint in patients with acute and chronic heart failure
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Many patients are diagnosed as having chronic heart failure (CHF) and apart from the fact that daily activities are impaired, they are great consumers of health care, and the prognosis is poor. The distinction between acute heart failure (AHF) and CHF may be difficult and is more a question of time rather than severity. The “gold standard” treatment for end‐stage heart failure is heart transplantation. Due to organ shortage this is reserved for selected patients only. Since the introduction of mechanical circulatory support (MCS) more and more patients with progressive CHF have been bridged‐to‐heart‐transplantation. There are MCS systems available for both short‐ and long‐term support. Newer concepts such as ventricular constraint to prevent ventricular remodelling are on the way. We have investigated short‐ (ImpellaTM) and long‐term (HeartMateTM I and II) MCS and ventricular constraint (CorCapTM CSD) as treatment concepts for all forms of heart failure, the aims being: bridge‐to‐decision, bridge‐to‐transplant and extended therapy, called “destination therapy” (DT).Methods and results: In Paper I, the use of HM‐ITM pulsatile MCS in bridge‐to‐transplantation patients in Sweden was retrospectively investigated regarding outcome and risk factors for mortality and morbidity. Fifty‐nine patients were treated between 1993 and 2002. The dominating diagnosis was dilated cardiomyopathy in 61%. Median support time was 99.5 days. 18.6% died before transplantation. Four patients needed RV assist due to right ventricular failure. Haemorrhage was an issue. Six patients (10%) suffered a cerebrovascular thromboembolic lesion. 15% developed driveline infection. 45% of the MCS patients were discharged home while on pump treatment. Massive blood transfusion was a predictor for mortality and morbidity, p<0.001.In Paper II the second generation long‐term MCS, the continuous axial flow pump HM‐IITM, was prospectively evaluated for mortality and morbidity. Eleven patients, from 2005 until 2008, were consecutively included at our institution. One patient received the pump for DT. The median pump time was 155 days. Survival to transplantation was 81.8%. Ten patients could be discharged home before transplantation after a median time of 65 days.Paper III investigated the Swedish experience and outcome of short‐term axial flow MCS, the ImpellaTM, in patients with AHF. Fifty patients were collected between 2003 and 2007 and divided into two groups: 1. Surgical group (n=33) with cardiogenic shock after cardiac surgery; and 2. Non‐surgical group (n=17), patients with AHF due to acute coronary syndromes with cardiogenic shock (53%) and myocarditis (29%). The 1‐year survival was 36% and 70%, respectively. 52% were reoperated because of bleeding. Predictors for survival at 30 days were preoperatively placed IABP (p=0.01), postoperatively cardiac output at 12 hours and Cardiac Power Output at 6 and 12 hours.In Paper IV we evaluated the use and long term outcome of ventricular constraint CorCapTM CSD. Since 2003, 26 consecutive patients with chronic progressive heart failure were operated with CSD via sternotomy (n=25) or left mini‐thoracotomy (n=1). Seven patients were operated with CorCapTM only. Nineteen patients had concomitant cardiac surgery. There were three early and three late deaths. The remaining cohort (n=18) was investigated in a cross‐sectional study regarding QoL with SF‐36. There was no difference in QoL measured with SF‐36 after a mean 3‐years follow up period, when compared to an age‐ and sex‐matched control group from the general population. The one‐year survival was 86%, and after three years 76%. Echocardiographic dimensions had improved significantly after three years.Conclusion: In our unit, a non‐transplanting medium‐sized cardiothoracic department, short‐ and long‐term MCS (ImpellaTM resp. HMTM) in patients with acute or chronic HF have been used with good results. The use of ventricular constraint early in the course of the disease is a good adjunct to other treatment options in progressive chronic HF patients.
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| 49. |
- Haraldsson, Henrik, et al.
(författare)
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Assessment of Reynolds stress components and turbulent pressure loss using 4D flow MRI with extended motion encoding
- 2018
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Ingår i: Magnetic Resonance in Medicine. - : WILEY. - 0740-3194 .- 1522-2594. ; 79:4, s. 1962-1971
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Tidskriftsartikel (refereegranskat)abstract
- PurposeTo measure the Reynolds stress tensor using 4D flow MRI, and to evaluate its contribution to computed pressure maps. MethodsA method to assess both velocity and Reynolds stress using 4D flow MRI is presented and evaluated. The Reynolds stress is compared by cross-sectional integrals of the Reynolds stress invariants. Pressure maps are computed using the pressure Poisson equationboth including and neglecting the Reynolds stress. ResultGood agreement is seen for Reynolds stress between computational fluid dynamics, simulated MRI, and MRI experiment. The Reynolds stress can significantly influence the computed pressure loss for simulated (eg, -0.52% vs -15.34% error; Pamp;lt;0.001) and experimental (eg, 30611 vs 203 +/- 6 Pa; Pamp;lt;0.001) data. A 54% greater pressure loss is seen at the highest experimental flow rate when accounting for Reynolds stress (Pamp;lt;0.001). Conclusion4D flow MRI with extended motion-encoding enables quantification of both the velocity and the Reynolds stress tensor. The additional information provided by this method improves the assessment of pressure gradients across a stenosis in the presence of turbulence. Unlike conventional methods, which are only valid if the flow is laminar, the proposed method is valid for both laminar and disturbed flow, a common presentation in diseased vessels. Magn Reson Med 79:1962-1971, 2018. (c) 2017 International Society for Magnetic Resonance in Medicine.
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