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1.
  • Aaltonen, H. L., et al. (författare)
  • Deposition of inhaled nanoparticles is reduced in subjects with COPD and correlates with the extent of emphysema : Proof of concept for a novel diagnostic technique
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 38:6, s. 1008-1014
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: The diagnosis of chronic obstructive pulmonary disease (COPD) is often based on spirometry, which is not sensitive to early emphysema. We have recently described a method for assessing distal airspace dimensions by measuring recovery of nanoparticles in exhaled air after a single-breath inhalation followed by breath-hold. Recovery refers to the non-deposited particle fraction. The aim of this study was to explore differences in the recovery of exhaled nanoparticles in subjects with COPD and never-smoking controls. A secondary aim was to determine whether recovery correlates with the extent of emphysema. Method: A total of 19 patients with COPD and 19 controls underwent three repeats of single-breath nanoparticle inhalation followed by breath-hold. Particle concentrations in the inhaled aerosol, and in an alveolar sample exhaled after breath-hold, were measured to obtain recovery. Findings: The patients with COPD had a significantly higher mean recovery than controls, 0·128 ± 0·063 versus 0·074 ± 0·058; P = 0·010. Also, recovery correlated significantly with computed tomography (CT) densitometry variables (P<0·01) and diffusing capacity for carbon monoxide (DL,CO; P = 0·002). Interpretation: Higher recovery for emphysema patients, relative to controls, is explained by larger diffusion distances in enlarged distal airspaces. The nanoparticle inhalation method shows potential to be developed towards a tool to diagnose emphysema.
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2.
  • Ahlander, Britt-Marie, 1954-, et al. (författare)
  • An echo-planar imaging sequence is superior to a steady-state free precession sequence for visual as well as quantitative assessment of cardiac magnetic resonance stress perfusion
  • 2017
  • Ingår i: Clinical Physiology and Functional Imaging. - : Blackwell Publishing. - 1475-0961 .- 1475-097X. ; 37:1, s. 52-61
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: To assess myocardial perfusion, steady-state free precession cardiac magnetic resonance (SSFP, CMR) was compared with gradient-echo-echo-planar imaging (GRE-EPI) using myocardial perfusion scintigraphy (MPS) as reference.METHODS: Cardiac magnetic resonance perfusion was recorded in 30 patients with SSFP and in another 30 patients with GRE-EPI. Timing and extent of inflow delay to the myocardium was visually assessed. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated. Myocardial scar was visualized with a phase-sensitive inversion recovery sequence (PSIR). All scar positive segments were considered pathologic. In MPS, stress and rest images were used as in clinical reporting. The CMR contrast wash-in slope was calculated and compared with the stress score from the MPS examination. CMR scar, CMR perfusion and MPS were assessed separately by one expert for each method who was blinded to other aspects of the study.RESULTS: Visual assessment of CMR had a sensitivity for the detection of an abnormal MPS at 78% (SSFP) versus 91% (GRE-EPI) and a specificity of 58% (SSFP) versus 84% (GRE-EPI). Kappa statistics for SSFP and MPS was 0·29, for GRE-EPI and MPS 0·72. The ANOVA of CMR perfusion slopes for all segments versus MPS score (four levels based on MPS) had correlation r = 0·64 (SSFP) and r = 0·96 (GRE-EPI). SNR was for normal segments 35·63 ± 11·80 (SSFP) and 17·98 ± 8·31 (GRE-EPI), while CNR was 28·79 ± 10·43 (SSFP) and 13·06 ± 7·61 (GRE-EPI).CONCLUSION: GRE-EPI displayed higher agreement with the MPS results than SSFP despite significantly lower signal intensity, SNR and CNR.
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4.
  • Asp, Anna M., et al. (författare)
  • Cardiac remodelling and functional alterations in mild-to-moderate renal dysfunction: Comparison with healthy subjects
  • 2015
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 35:3, s. 223-230
  • Tidskriftsartikel (refereegranskat)abstract
    • © 2014 The Authors. Introduction: Left ventricular (LV) hypertrophy (LVH) and reduced LV function correlate with poor prognosis in patients with chronic kidney disease (CKD). Our aim is to investigate whether mild-to-moderate CKD is associated with cardiac abnormalities. Methods: Echocardiography, including tissue Doppler imaging, was performed in 103 patients with CKD at stages 2-3 and 4-5, and in 53 healthy controls. The systolic (s′) and diastolic myocardial velocity (e′), and the transmitral diastolic flow velocity (E) were measured, and E/e′ was calculated. Results: Patients with chronic kidney disease had higher mean E/e′ than controls (mean E/e′: controls 5·00 ± 1·23 versus CKD 4-5 6·36 ± 1·71, P < 0·001 and versus CKD 2-3 5·69 ± 1·47, P = 0·05), indicating altered diastolic function in the patients. The CKD groups showed lower longitudinal systolic function than controls, as assessed by atrio-ventricular plane displacement and s′ (mean s′: controls 11·5 ± 1·9 cm s < sup > -1 < /sup > versus CKD 4-5 10·4 ± 2·1 cm s < sup > -1 < /sup > , P = 0·03 and versus CKD 2-3 10·4 ± 2·1 cm s < sup > -1 < /sup > , P = 0·02). The prevalence of LVH was higher in patients with CKD than in controls (controls 13% versus CKD 4-5 37%, P = 0·006 and versus CKD 2-3 30%, P = 0·03). Conclusion: Alterations in systolic and diastolic myocardial function can be seen in mild-to-moderate CKD compared with controls, indicating that cardiac involvement starts early in CKD, which may be a precursor of premature cardiac morbidity.
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5.
  • Bhat, Misha, et al. (författare)
  • Fetal iGRASP cine CMR assisting in prenatal diagnosis of complicated cardiac malformation with impact on delivery planning
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:4, s. 231-235
  • Tidskriftsartikel (refereegranskat)abstract
    • Limited visualisation of the fetal heart and vessels by fetal ultrasound due to suboptimal fetal position, patient habitus and skeletal calcification may lead to missed diagnosis, overdiagnosis and parental uncertainty. Counseling and delivery planning may in those cases also be tentative. The recent fetal cardiac magnetic resonance (CMR) reconstruction method utilising tiny golden angle iGRASP (iterative Golden-angle RAdial Sparse Parallel MRI) allows for cine imaging of the fetal heart for use in clinical practice. This case describes an unbalanced common atrioventricular canal where limited ultrasound image quality and visibility of the aortic arch precluded confirming or ruling out presence of a ventricular septal defect. Need of prostaglandins or neonatal intervention was thus uncertain. Cardiovascular magnetic resonance imaging confirmed ultrasound findings and added value by ruling out a significant ventricular septal defect and diagnosing arch hypoplasia. This confirmed the need of patient relocation for delivery at a paediatric cardiothoracic surgery centre and prostaglandins could be initiated before the standard postnatal ultrasound. The applied CMR method can thus improve diagnosis of complicated fetal cardiac malformation and has direct clinical impact. This article is protected by copyright. All rights reserved.
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6.
  • Bidhult, Sebastian, et al. (författare)
  • A new vessel segmentation algorithm for robust blood flow quantification from two-dimensional phase-contrast magnetic resonance images
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:5, s. 327-338
  • Tidskriftsartikel (refereegranskat)abstract
    • Blood flow measurements in the ascending aorta and pulmonary artery from phase-contrast magnetic resonance images require accurate time-resolved vessel segmentation over the cardiac cycle. Current semi-automatic segmentation methods often involve time consuming manual correction, relying on user experience for accurate results. The purpose of this study was to develop a semi-automatic vessel segmentation algorithm with shape constraints based on manual vessel delineations for robust segmentation of the ascending aorta and pulmonary artery, to evaluate the proposed method in healthy volunteers and patients with heart failure and congenital heart disease, to validate the method in a pulsatile flow phantom experiment, and to make the method freely available for research purposes. Algorithm shape constraints were extracted from manual reference delineations of the ascending aorta (n=20) and pulmonary artery (n=20) and were included into a semi-automatic segmentation method only requiring manual delineation in one image. Bias and variability (bias±SD) for flow volume of the proposed algorithm versus manual reference delineations were 0·0±1·9ml in the ascending aorta (n=151; 7 healthy volunteers; 144 heart failure patients) and -1·7±2·9 ml in the pulmonary artery (n=40; 25 healthy volunteers; 15 patients with atrial septal defect). Inter-observer bias and variability were lower (p=0·008) for the proposed semi-automatic method (-0·1±0·9ml) compared to manual reference delineations (1·5±5·1ml). Phantom validation showed good agreement between the proposed method and timer-and-beaker flow volumes (0·4±2·7ml). In conclusion, the proposed semi-automatic vessel segmentation algorithm can be used for efficient analysis of flow and shunt volumes in the aorta and pulmonary artery. This article is protected by copyright. All rights reserved.
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8.
  • Brolin, Gustav, et al. (författare)
  • The accuracy of quantitative parameters in Tc-99m-MAG3 dynamic renography : a national audit based on virtual image data
  • 2016
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 36:2, s. 146-154
  • Tidskriftsartikel (refereegranskat)abstract
    • Assessment of image analysis methods and computer software used in Tc-99m-MAG3 dynamic renography is important to ensure reliable study results and ultimately the best possible care for patients. In this work, we present a national multicentre study of the quantification accuracy in Tc-99m-MAG3 renography, utilizing virtual dynamic scintigraphic data obtained by Monte Carlo-simulated scintillation camera imaging of digital phantoms with time-varying activity distributions. Three digital phantom studies were distributed to the participating departments, and quantitative evaluation was performed with standard clinical software according to local routines. The differential renal function (DRF) and time to maximum renal activity (T-max) were reported by 21 of the 28 Swedish departments performing Tc-99m-MAG3 studies as of 2012. The reported DRF estimates showed a significantly lower precision for the phantom with impaired renal uptake than for the phantom with normal uptake. The T-max estimates showed a similar trend, but the difference was only significant for the right kidney. There was a significant bias in the measured DRF for all phantoms caused by different positions of the left and right kidney in the anterior-posterior direction. In conclusion, this study shows that virtual scintigraphic studies are applicable for quality assurance and that there is a considerable uncertainty associated with standard quantitative parameters in dynamic Tc-99m-MAG3 renography, especially for patients with impaired renal function.
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9.
  • Brønd, Jan Christian, et al. (författare)
  • The ActiGraph counts processing and the assessment of vigorous activity.
  • 2019
  • Ingår i: Clinical physiology and functional imaging. - : Wiley. - 1475-097X .- 1475-0961. ; 39:4, s. 276-283
  • Tidskriftsartikel (refereegranskat)abstract
    • The purpose of this study was to investigate the effect of different band-pass filters on the measurement bias with ActiGraph counts during high speed running and for estimating free-living vigorous physical activity (VPA). Two alternative band-pass filters were designed, extending the original frequency range from 0·29 to 1·66Hz (AG) to 0·29-4Hz (AC4) and 0·29-10Hz (AC10). Sixty-two subjects in three age groups participated in a structured locomotion protocol consisting of multiple walking and running speeds. The time spent in free-living VPA using the three different band-pass filters were evaluated in 1121 children. Band-pass filter specific intensity cut-points from both linear regression and ROC analysis was identified from a calibration experiment using indirect calorimetry. The ActiGraph GT3X+ device recording raw acceleration at 30Hz was used in all experiments. The linear association between counts and running speed was negative for AG but positive for AC4 and AC10 across all age groups. The time spent in free-living VPA was similar for all band-pass filters. Considering higher frequency information in the generation of ActiGraph counts with a hip/waist worn device reduces the measurement bias with running above 10km·h-1 . However, additional developments are required to accurately capture all VPA, including intermittent activities.
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10.
  • Bytyçi, Ibadete, et al. (författare)
  • Compromised left atrial function and increased size predict raised cavity pressure : a systematic review and meta-analysis
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 39:5, s. 297-307
  • Forskningsöversikt (refereegranskat)abstract
    • Aim: This meta-analysis assesses left atrial (LA) cavity and myocardial function measurements that predict pulmonary capillary wedge pressure (PCWP).Methods: PubMed-MEDLINE, EMBASE, Scopus, Google Scholar and the Cochrane Central Registry were searched up to December 2018 for studies on the relationship of LA diameter, LA indexed volume (LAVI max, LAVI min), peak atrial longitudinal (PALS), peak atrial contraction (PACS) strain and total emptying fraction (LAEF) with PCWP. Eighteen studies with 1343 patients were included. sensitivity and specificity (with 95% CI) for evaluation of diagnostic accuracy and the best cut-off values for different LA indices in predicting raised PCWP were estimated using summary receiver operating characteristic analysis.Results: The pooled analysis showed association between PCWP and LA diameter: Cohen's d = 0 center dot 87, LAVI max: d = 0 center dot 92 and LAVI min: d = 1 center dot 0 (P<0 center dot 001 for all). A stronger correlation was found between PCWP and PALS: d = 1 center dot 26, and PACS: d = 1 center dot 62, total EF d = 1 center dot 22 (P<0 center dot 0001 for all). PALS <= 19% had a summary sensitivity of 80% (65-90) and summary specificity of 77% (52-92), positive likelihood ratio (LR+) 3 center dot 74, negative likelihood ratio (LR-) DOR > 15 center dot 1 whereas LAVI >= 34 ml m(-2) had summary sensitivity of 75% (55-89) and summary specificity 77% (57-90), with LR+ >3, LR- 0 center dot 32 and DOR >10 center dot 1.Conclusions: Compromised LA myocardial function and increased size predict raised cavity pressure. These results should assist in optimum follow-up of patients with fluctuating LA pressure.
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11.
  • Carlén, Anna, et al. (författare)
  • Loaded treadmill walking and cycle ergometry to assess work capacity : a retrospective comparison in 424 firefighters.
  • 2017
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 37:1, s. 37-44
  • Tidskriftsartikel (refereegranskat)abstract
    • The fitness of firefighters is regularly evaluated using exercise tests. We aimed to compare, with respect to age and body composition, two test modalities for the assessment work capacity. A total of 424 Swedish firefighters with cycle ergometer (CE) and treadmill (TM) tests available from Jan 2004 to Dec 2010 were included. We compared results from CE (6 min at 200 W, 250 W or incremental ramp exercise) with TM (6 min at 8° inclination, 4·5 km h(-1) or faster, wearing 24-kg protective equipment). Oxygen requirements were estimated by prediction equations. It was more common to pass the TM test and fail the supposedly equivalent CE test (20%), than vice versa (0·5%), P<0·001. Low age and tall stature were significant predictors of passing both CE and TM tests (P<0·05), while low body mass predicted accomplishment of TM test only (P = 0·006). Firefighters who passed the TM but failed the supposedly equivalent CE test within 12 months had significantly lower body mass, lower BMI, lower BSA and shorter stature than did those who passed both tests. Calculated oxygen uptake was higher in TM tests compared with corresponding CE tests (P<0·001). Body constitution affected approval differently depending on the test modality. A higher approval rate in TM testing suggests lower cardiorespiratory requirements compared with CE testing, even though estimated oxygen uptake was higher during TM testing. The relevance of our findings in relation to the occupational demands needs reconsidering.
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12.
  • Carlsson, Marcus, et al. (författare)
  • Heart filling exceeds emptying during late ventricular systole in patients with systolic heart failure and healthy subjects – a cardiac MRI study
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:3, s. 192-200
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Total heart volume (THV) within the pericardium is not constant throughout the cardiac cycle and THV would intuitively be lowest at end systole. We have, however, observed a phase shift between ventricular outflow and atrial inflow which causes the minimum THV to occur before end systole. The aims were to explain the mechanism of the late-systolic net inflow to the heart and determine whether this net inflow is affected by increased cardiac output or systolic heart failure. Methods and Results: Healthy controls (n = 21) and patients with EF<35% (n = 14) underwent magnetic resonance imaging with flow measurements in vessels to and from the heart, and this was repeated in nine controls during 140 μgram kg−1 min−1 adenosine infusion. Minimum THV occurred 78 ± 6 ms before end of systolic ejection (8 ± 1% of the cardiac cycle) in controls. The late-systolic net inflow was 12·3 ± 1·1 ml or 6·0 ± 0·5% of total stroke volume (TSV). Cardiac output increased 66 ± 8% during adenosine but late-systolic net inflow to the heart did not change (P = 0·73). In patients with heart failure, late-systolic net inflow of the heart′s left side was lower (3·4 ± 0·5%) compared to healthy subjects (5·3 ± 0·6%, P = 0·03). Conclusions: Heart size increases before end systole due to a late-systolic net inflow which is unaffected by increased cardiac output. This may be explained by inertia of blood that flows into the atria generated by ventricular systole. The lower late-systolic net inflow in patients with systolic heart failure may be a measure of decreased ventricular filling due to decreased systolic function, thus linking systolic to diastolic dysfunction.
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13.
  • Carlsson, Marcus, et al. (författare)
  • Submaximal adenosine-induced coronary hyperaemia with 12 h caffeine abstinence: implications for clinical adenosine perfusion imaging tests.
  • 2015
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 35:1, s. 49-56
  • Tidskriftsartikel (refereegranskat)abstract
    • Adenosine is widely used as a vasodilator agent in myocardial perfusion imaging. Caffeine inhibits the effect, but the time of caffeine abstinence needed is under discussion and varies from 12 to 24 h. Therefore, our aim was to examine whether the time of caffeine abstinence affects the hyperaemic response using quantification of coronary sinus flow (CS F) with cardiac magnetic resonance (CMR) during adenosine infusion.
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14.
  • da Silva, Cristina, et al. (författare)
  • Hemodynamic outcomes of transcatheter aortic valve implantation with the CoreValve system : an early assessment
  • 2015
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 35:3, s. 216-222
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and Aims: Transcatheter aortic valve implantation (TAVI) is an established method for the treatment of high-risk patients with aortic stenosis (AS). The beneficial effects of TAVI in cardiac hemodynamics have been described in recent studies, but those investigations were mostly performed after an interval of more than 6 months following aortic valve implantation. The aim of this study is to investigate the acute and short-term alterations in hemodynamic conditions using the echocardiography outcomes in patients undergoing TAVI. Methods and Results: A total of 60 patients (26 males, 34 females; age 84·7 ± 5·8) who underwent TAVI with CoreValve system were included in the study. Echocardiography was performed before hospital discharge and at 3 months follow-up. As expected, TAVI was associated with an immediate significant improvement in aortic valve area (AVA) (from 0·64 ± 0·16 cm2 to 1·67 ± 0·41 cm2, P-value<0·001) and mean gradient (from 51·9 ± 15·4 mmHg to 8·8 ± 3·8 mmHg, P-value<0·001). At 3-month follow-up, systolic LV function was augmented (EF: 50 ± 14% to 54 ± 11%, P-value = 0·024). Left ventricle (LV) mass and left atrium (LA) volume were significantly reduced (LV mass index from 126·5 ± 30·5 g m-2 to 102·4 ± 32·4 g m-2; LA index from 42·9 ± 17·3 ml m-2 to 33·6 ± 10·6 ml m-2; P-value<0·001 for both). Furthermore, a decrement in systolic pulmonary artery pressure (SPAP) from 47·5 ± 13·5 mmHg to 42·5 ± 11·2 mmHg, P-value = 0·02 was also observed. Despite the high incidence of paravalvular regurgitation (PVR) (80%), most of the patients presented mild or trace PVR and no significant progress of the regurgitation grade was seen after 3 months. Conclusion: This study demonstrates that the beneficial effects of TAVI in cardiac function and hemodynamics occur already after a short period following aortic valve implantation.
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15.
  • Davidsson, Anette, et al. (författare)
  • Influence of reconstruction algorithms on image quality in SPECT myocardial perfusion imaging
  • 2017
  • Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 37:6, s. 655-662
  • Tidskriftsartikel (refereegranskat)abstract
    • INTRODUCTION: We investigated if image- and diagnostic quality in SPECT MPI could be maintained despite a reduced acquisition time adding Depth Dependent Resolution Recovery (DDRR) for image reconstruction. Images were compared with filtered back projection (FBP) and iterative reconstruction using Ordered Subsets Expectation Maximization with (IRAC) and without (IRNC) attenuation correction (AC).MATERIALS AND METHODS: Stress- and rest imaging for 15 min was performed on 21 subjects with a dual head gamma camera (Infinia Hawkeye; GE Healthcare), ECG-gating with 8 frames/cardiac cycle and a low-dose CT-scan. A 9 min acquisition was generated using five instead of eight gated frames and was reconstructed with DDRR, with (IRACRR) and without AC (IRNCRR) as well as with FBP. Three experienced nuclear medicine specialists visually assessed anonymized images according to eight criteria on a four point scale, three related to image quality and five to diagnostic confidence. Statistical analysis was performed using Visual Grading Regression (VGR).RESULTS: Observer confidence in statements on image quality was highest for the images that were reconstructed using DDRR (P<0·01 compared to FBP). Iterative reconstruction without DDRR was not superior to FBP. Interobserver variability was significant for statements on image quality (P<0·05) but lower in the diagnostic statements on ischemia and scar. The confidence in assessing ischemia and scar was not different between the reconstruction techniques (P = n.s.).CONCLUSION: SPECT MPI collected in 9 min, reconstructed with DDRR and AC, produced better image quality than the standard procedure. The observers expressed the highest diagnostic confidence in the DDRR reconstruction.
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16.
  • De Geer, Jakob, et al. (författare)
  • Large variation in blood flow between left ventricular segments, as detected by adenosine stress dynamic CT perfusion.
  • 2015
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 35:4, s. 291-300
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Dynamic cardiac CT perfusion (CTP) is based on repeated imaging during the first-pass contrast agent inflow. It is a relatively new method that still needs validation.PURPOSE: To evaluate the variation in adenosine stress dynamic CTP blood flow as compared to (99m) Tc SPECT. Secondarily, to compare manual and automatic segmentation.METHODS: Seventeen patients with manifest coronary artery disease were included. Nine were excluded from evaluation for various reasons. All patients were examined with dynamic stress CTP and stress/rest SPECT. CTP blood flow was compared with SPECT on a per segment basis. Results for manual and automated AHA segmentation were compared.RESULTS: CTP showed a positive correlation with SPECT, with correlation coefficients of 0·38 and 0·41 for manual and automatic segmentation, respectively (P<0·0001). There was no significant difference between the correlation coefficients of the manual and automated segmentation procedures (P = 0·75). The average per individual global CTP blood flow value for normal segments varied by a factor of 1·9 (manual and automatic segmentation). For the whole patient group, the CTP blood flow value in normal segments varied by a factor of 2·9/2·7 (manual/automatic segmentation). Within each patient, the average per segment blood flow in normal segments varied by a factor of 1·3-2·0/1·2-2·1 (manual/automatic segmentation).CONCLUSION: A positive but rather weak correlation was found between CTP and (99m) Tc SPECT. Large variations in CTP blood flow suggest that a cut-off value for stress myocardial blood flow is inadequate to detect ischaemic segments. Dynamic CTP is hampered by a limited coverage.
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17.
  • Frieberg, Petter, et al. (författare)
  • Simulation of aortopulmonary collateral flow in Fontan patients for use in prediction of interventional outcomes
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-097X .- 1475-0961. ; 38:4, s. 622-629
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Patients with complex congenital heart disease may need to be converted to a Fontan circulation with systemic venous return surgically connected to the pulmonary circulation. These patients frequently form aortopulmonary collaterals (APC), that is arterial inflows to the pulmonary artery vascular tree. The aim of this study was to develop a method to calculate the effect of APC on the pulmonary flow distribution based on magnetic resonance imaging (MRI) measurements and computational fluid dynamics simulations in order to enable prediction of interventional outcomes in Fontan patients.Methods: Patient-specific models of 11 patients were constructed in a 3D-design software based on MRI segmentations. APC flow was quantified as the difference between pulmonary venous flow and pulmonary artery flow, measured by MRI. A method was developed to include the modulating effect of the APC flow by calculating the patient-specific relative pulmonary vascular resistance. Simulations, including interventions with a Y-graft replacement and a stent dilatation, were validated against MRI results.Results: The bias between simulated and MRI-measured fraction of blood to the left lung was 29 53%. Including the effects of the APC flow in the simulation (n = 6) reduced simulation error from 98 70% to 52 63%. Preliminary findings in two patients show that the effect of surgical and catheter interventions could be predicted using the demonstrated methods.Conclusions: The work demonstrates a novel method to include APC flow in predictive simulations of Fontan hemodynamics. APC flow was found to have a significant contribution to the pulmonary flow distribution in Fontan patients.
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18.
  • Garpered, Sabine, et al. (författare)
  • Measurement of airway inflammation in current smokers by positron emission tomography
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:6, s. 393-398
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Accumulation of activated neutrophilic leucocytes is known to increase uptake of F-18-fluorodeoxyglucose (F-18-FDG) into lung tissue. Available evidence suggests that smokers and subjects with chronic obstructive pulmonary disease (COPD) have neutrophilic inflammation in peripheral airways. The aim of this study was to examine whether current smokers have higher lung tissue uptake of F-18-FDG than never-smokers when correcting for air fraction of the lungs. Methods We prospectively recruited 33 current smokers and 33 never-smokers among subjects referred for diagnosis or staging of cancer, other than lung cancer, with combined positron emission tomography/computed tomography (PET/CT) with F-18-FDG. Subjects with focal F-18-FDG uptake or focal CT abnormalities in the lungs were excluded. The lungs were segmented in the CT image, and lung density measured. F-18-FDG uptake was measured in the corresponding volume and corrected for air fraction. Results Lung uptake of F-18-FDG, corrected for air fraction, was 12 center dot 5 and 8 per cent higher in the right and left lungs, respectively, in current smokers than in never-smokers (P<0 center dot 05). Conclusion Abnormal lung tissue uptake of F-18-FDG may be masked by reduced lung density if the uptake is not related to air fraction. Increased uptake of F-18-FDG in lung tissue in current smokers relative to never-smokers may reflect inflammation in peripheral airways. Measurements of F-18-FDG uptake in the lung tissue may be useful for animal and human studies of airways disease in COPD and the relation between airway and systemic inflammation.
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19.
  • Genberg, Margareta, et al. (författare)
  • Commonly used reference values underestimate oxygen uptake in healthy, 50-year-old Swedish women.
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 38:1, s. 25-33
  • Tidskriftsartikel (refereegranskat)abstract
    • Cardiopulmonary exercise testing (CPET) is the gold standard among clinical exercise tests. It combines a conventional stress test with measurement of oxygen uptake (VO2 ) and CO2 production. No validated Swedish reference values exist, and reference values in women are generally understudied. Moreover, the importance of achieved respiratory exchange ratio (RER) and the significance of breathing reserve (BR) at peak exercise in healthy individuals are poorly understood. We compared VO2 at maximal load (peakVO2 ) and anaerobic threshold (VO2@AT ) in healthy Swedish individuals with commonly used reference values, taking gender into account. Further, we analysed maximal workload and peakVO2 with regard to peak RER and BR. In all, 181 healthy, 50-year-old individuals (91 women) performed CPET. PeakVO2 was best predicted using Jones et al. (100·5%), while SHIP reference values underestimated peakVO2 most: 112·5%. Furthermore, underestimation of peakVO2 in women was found for all studied reference values (P<0·001) and was largest for SHIP: women had 128% of predicted peakVO2 , while men had 104%. PeakVO2 was similar in subjects with peak RER of 1-1·1 and RER > 1·1 (2 328·7 versus 2 176·7 ml min(-1) , P = 0·11). Lower BR (≤30%) related to significantly higher peakVO2 (P<0·001). In conclusion, peakVO2 was best predicted by Jones. All studied reference values underestimated oxygen uptake in women. No evidence for demanding RER > 1·1 in healthy individuals was found. A lowered BR is probably a normal response to higher workloads in healthy individuals.
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20.
  • Gustafsson, Agneta, et al. (författare)
  • A visual grading study for different administered activity levels in bone scintigraphy
  • 2015
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 35:3, s. 231-236
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: The aim of the study is to assess the administered activity levels versus visual-based image quality using visual grading regression (VGR) including an assessment of the newly stated image criteria for whole-body bone scintigraphy.Materials and methods: A total of 90 patients was included and grouped in three levels of administered activity: 400, 500 and 600 MBq. Six clinical image criteria regarding image quality was formulated by experienced nuclear medicine physicians. Visual grading was performed in all images, where three physicians rated the fulfilment of the image criteria on a four-step ordinal scale. The results were analysed using VGR. A count analysis was also made where the total number of counts in both views was registered.Results: The administered activity of 600 MBq gives significantly better image quality than 400 MBq in five of six criteria (P<005). Comparing the administered activity of 600 MBq to 500 MBq, four criteria of six show significantly better image quality (P<005). The administered activity of 500 MBq gives no significantly better image quality than 400 Mbq (P<005). The count analysis shows that none of the three levels of administrated activity fulfil the recommendations by the EANM.Conclusion: There was a significant improvement in perceived image quality using an activity level of 600 MBq compared to lower activity levels in whole-body bone scintigraphy for the gamma camera equipment end set-up used in this study. This type of visual-based grading study seems to be a valuable tool and easy to implement in the clinical environment.
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21.
  • Hagman, Carina, et al. (författare)
  • Measuring breathing patterns and respiratory movements with the respiratory movement measuring instrument
  • 2016
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 36:5, s. 414-420
  • Tidskriftsartikel (refereegranskat)abstract
    • INTRODUCTION: The respiratory movement measuring instrument (RMMI) is a laser-based non-invasive technique to measure breathing patterns and respiratory movements (RMs). Little knowledge is known about the ability of the RMMI to measure breathing patterns and the correlation between RMs and breathing volumes.OBJECTIVES: One aim was to investigate whether the RMMI could discriminate between normal versus abdominal versus high costal breathing patterns in different body positions. A second aim was to determine the correlation between RMs and breathing volumes in different body positions.METHOD: Twenty adult, healthy subjects (10 women) were included in the study. The RMMI was used to study the above-mentioned breathing patterns in supine, sitting and standing positions. A subgroup of 12 subjects (6 women) simultaneously performed measurements of breathing volumes while RMs were recorded.RESULTS: The RMMI was able to discriminate between different breathing patterns in different body positions (P<0·001). The upper thoracic contribution to RMs in the sitting position was 47% for natural breathing, 32% for abdominal breathing and 64% for high costal breathing; similar results were found in the supine and standing positions. A strong correlation was observed between RMs as measured by the RMMI and different breathing volumes in all three body positions (Spearman's rho 0·86-1·00).CONCLUSION: The RMMI can be used to measure and analyse different breathing patterns in different body positions, and the correlation between measured RMs and breathing volumes is strong.
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22.
  • Hagström, Linn, et al. (författare)
  • Impact of age and sex on normal left heart structure and function
  • 2017
  • Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 37:6, s. 759-766
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Accurate age- and sex-related normal reference values of ventricular structure and function are important to determine the level of dysfunction in patients. The aim of this study therefore was to document normal age range sex-related measurements of LV structural and functional measurements to serve such purpose.METHODS: We evaluated left ventricular structure and function in 293 healthy subjects between 20 and 90 years with equally distributed gender. Doppler echocardiography was used including measure of both systolic and diastolic functions.RESULTS: Due to systolic LV function, only long axis function correlated with age (r = 0·55, P<0·01) and the correlation was stronger in females. Concerning diastolic function, there was a strong age correlation in all parameters used (r = 0·40-0·74, P<0·001). Due to LV structural changes over age, females showed a larger reduction in end-diastolic volumes, but no or trivial difference in wall thickness after the age of 60 years.CONCLUSION: Age is associated with significant normal changes in left ventricular structure and function, which should be considered when deciding on normality. These changes are related to systemic arterial changes as well as body stature, thus reflecting overall body ageing process. Furthermore, normal cardiac ageing in females might partly explain the higher prevalence of heart failure with preserved ejection in females.
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23.
  • Hansen, Tomas, et al. (författare)
  • Total atherosclerotic burden measured by magnetic resonance imaging is related to five-year decline in cognitive function
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 38:3, s. 373-377
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective: The aim of this study was to explore whether total atherosclerotic burden is related to future decline in performance on cognitive tests.Methods: The total atherosclerotic burden (TAS) was assessed by whole‐body magnetic resonance angiography (WBMRA) in 305 subjects at age 70 in the study Prospective Investigation of Vasculature in Uppsala Seniors (PIVUS). The mini‐mental state examination (MMSE) and trail making tests (TMT) A and B were evaluated at ages 75 and 80 in 190 of those subjects. No subject with a diagnosis of dementia was included in the sample.Results: MMSE did not change during the 5 years of follow‐up, while TMT A and B increased by 4 and 7 s, respectively. TAS at age 70 was significantly related to the individual change in TMT B (P<0·0001) between age 75 and 80, when adjusted for sex, education level, TMT B at age 75 and Framingham score at age 70. No such relationship was seen for the change in TMT A (P = 0·10). The relationship between TAS and the change in MMSE was of borderline significance (P = 0·025).Conclusion: A relationship was found between the total atherosclerotic burden and future decline in performance on TMT B, highlighting a role of global atherosclerosis in the cognitive decline seen during ageing.
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24.
  • Henein, Michael Y., et al. (författare)
  • Can Doppler echocardiography estimate raised pulmonary capillary wedge pressure provoked by passive leg lifting in suspected heart failure?
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 39:2, s. 128-134
  • Tidskriftsartikel (refereegranskat)abstract
    • AIMS: Non-invasive estimation of left ventricular filling pressure (LVFP) during stress is important for explaining exertional symptoms in patients with heart failure (HF). The aim of this study was to evaluate ability of Doppler echocardiographic measures of elevated LVFP with passive leg lifting (PLL) in patients with suspected HF.METHODS: Twenty-nine patients with clinical signs of HF who underwent simultaneous Doppler echocardiography and right heart catheterization (RHC) at rest and during PLL were consecutively investigated. Seventeen patients had normal PCWP (≤15 mmHg) at rest and during PLL and 12 with normal PCWP at rest but >15 mmHg with PLL. Conventional echo and 2D strain were used to assess early diastolic blood flow velocity (E), LV strain rate during early diastole (LVSRe), left atrial SR during atrial contraction (LASRa) and myocardial tissue Doppler velocities to assess lateral e' and further calculate E/e' and E/LVSRe and their relationship with PCWP, at rest and during PLL.RESULTS: Resting LAVI (β = 0·45, P = 0·009) and LASRa (β = -0·51, P = 0·004) were independently related to PCWP during PLL. Also, LASRa (β = -0·77, P<0·001), E/e' (β = 0·40, P = 0·04) and E/LVSRe (β = 0·47, P = 0·021) during PLL correlated with PCWP during PLL. Multiple regression analysis identified E/LVSRe (β = 0·46, P = 0·001) and LASRa (β = -0·58, P = 0·002) during PLL as being independently associated with PCWP during PLL.CONCLUSION: Left atrial volume and myocardial contraction (LASRa) at rest both predict unstable LV filling pressures measured as raised PCWP when provoked by PLL. Furthermore, LASRa at PLL seems to have the strongest association to PCWP during PLL.
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25.
  • Henein, Michael Y, et al. (författare)
  • Right and left heart dysfunction predict mortality in pulmonary hypertension
  • 2017
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 37:1, s. 45-51
  • Tidskriftsartikel (refereegranskat)abstract
    • In pulmonary hypertension (PH), the right heart dysfunction is a strong predictor of adverse clinical outcome, while the role of the left heart is not fully determined. The aim of this study was to identify predictors of mortality in precapillary PH including measures of both right and left heart function. We studied 34 patients (mean age 64 ± 13, range 31-82 years, 24 females) with precapillary PH, all of whom underwent detailed Doppler echocardiographic examination of the right and left heart function using conventional and speckle-tracking echocardiography. Patients were followed up for up to 8 years (mean 4·2 ± 1·9 years). At follow-up, 16 patients survived. Left ventricular (LV) filling time (P = 0·007), pulmonary artery acceleration time (P = 0·009), right atrial pressure (RAP) (P<0·001) and tricuspid regurgitation (TR) severity (P = 0·007) were worse in the deceased group. RV global longitudinal strain (GLS) (P = 0·001), RAP (P≤0·001), LV filling time (P<0·001) and TR severity (P<0·001) were the most accurate predictors, having the largest AUC (>0·65) and carried the highest risk for mortality (P<0·001 for all). The strongest predictors of mortality in precapillary PH indirectly reflect both left and right heart dysfunction including atrial structure and function disturbances. While an interaction pattern is observed, it needs to be confirmed in a larger cohort.
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26.
  • Henriksen, Egil, et al. (författare)
  • Associations of left atrial volumes and Doppler filling indices with left atrial function in acute myocardial infarction
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : WILEY. - 1475-0961 .- 1475-097X. ; 39:1, s. 85-92
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent findings suggest that left atrial (LA) function is more strongly related to adverse prognosis than LA volumes. We aimed to evaluate the associations between LA volumes and Doppler filling indices with LA function. Echocardiographic LA volumes (LAVs), mitral valve early (MV-E) and late (MV-A) peak flow velocities, and mitral atrioventricular plane tissue-Doppler early (TD-e ') and late (TD-a ') peak velocities were obtained in 320 patients with acute myocardial infarction (AMI) free from atrial fibrillation and more than moderate valvular disease. LA function was estimated as the LA emptying fraction (LAEF), that is 100x (LAVmax-LAVmin)/LAVmax. LA reservoir volume was calculated as LAVmax-LAVmin and LA transit volume as LV stroke volume-reservoir volume. In restricted cubic spline regression analyses with multivariable adjustment, a reduced LAEF was strongly associated with smaller reservoir volume, larger transit volume, LAVmax, LAVpreA and especially LAVmin. MV-E linearly increased with a lower LAEF, whereas MV-A decreased but only below LAEF levels of approximately 45%. The resulting E/A ratio showed a sudden increase in LAEF levels below similar to 45%. Lower TD-a ' was linearly associated with a lower LAEF. In conclusion, a reduced atrial function was associated with smaller LA reservoir volume, larger LA transit volume, lower TD-a ', a non-linear decrease in MV-A and a non-linear increase in E/A. Our findings are likely a reflection of the adaptation to sustain LV filling volume and counteracting a rise in pulmonary venous pressure in face of an enhanced LV end-diastolic pressure.
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27.
  • Henriksson, Peter, et al. (författare)
  • Microvascular capillary assessment in relation to forearm blood flow
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : WILEY. - 1475-0961 .- 1475-097X. ; 39:5, s. 322-326
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective To study whether vascular reactivity as assessed by the methods forearm blood flow (FBF) and postocclusive reactive hyperaemia (PRH) in the nail fold was related as a measure of endothelium-dependent vasodilation in the microcirculation. Methods Microvascular reactivity was assessed in forearm blood flow and in the nail fold by vital capillaroscopy of individual microvessels as postocclusive reactive hyperaemia. Vascular reactivity was assessed at baseline (n = 25) as well as after infusion of acetylcholine and of sodium nitroprusside (n = 13). We also performed a multivariate regression analysis to assess whether forearm blood flow or flow-mediated dilatation related to postocclusive reactive hyperaemia. Results This study showed a distinct microvascular response to both acetylcholine (endothelium-dependent vasodilation) and sodium nitroprusside (endothelium-independent vasodilation) during forearm blood flow assessment and postocclusive reactive hyperaemia assessment in the nail fold (n = 13). These changes were inversely related (r- = -0 center dot 57; P<0 center dot 05). Conclusions Forearm blood flow was inversely correlated to postocclusive reactive hyperaemia. Postocclusive reactive hyperaemia was shortened after infusion with both acetylcholine and sodium nitroprusside. This occurred in parallel with the expected increase in forearm blood flow, conceivably reflecting that both methods can be used to assess endothelium-dependent vasodilation in the microcirculation.
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28.
  • Hjelmgren, Ola, et al. (författare)
  • Comparison between magnetic resonance imaging and B-mode ultrasound in detecting and estimating the extent of human carotid atherosclerosis
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 38:2, s. 296-303
  • Tidskriftsartikel (refereegranskat)abstract
    • Background In MRI studies of carotid plaques, ultrasound is used to find plaques, which are later imaged using MRI. The performance in plaque detection has not been compared between the modalities. The aim of the current study was to compare the performance of MRI and ultrasound in detecting carotid artery plaques and measuring extent of atherosclerosis. Methods Subjects with at least one plaque (height >= 2.5mm) on ultrasound were imaged using MRI. The number of plaques and their height was measured in both modalities; plaque area and volume were analysed on ultrasound and MRI, respectively. Results Thirty-eight subjects were included. MRI detected plaques in 95% of carotid arteries with a plaque height of 2.5 mm on ultrasound and in all carotid arteries with a plaque exceeding >= 2.5 mm. MRI detected 53% of the plaques with a height below 2.5mm. The plaque height measured with both techniques correlated significantly, 0.59, P<0.0001. Ultrasound-derived plaque height and plaque area correlated similarly to MRI-derived plaque volume, r = 0.52; P<0.0001 and r = 0.47; P = 0.001, respectively. Conclusions We conclude that MRI has a similar sensitivity to ultrasound in finding carotid artery plaques that are 2.5 mm or higher. In smaller plaques, MRI detects fewer plaques. Multiple carotid plaques seen on ultrasound most often are a misinterpretation of the anatomy and correspond to a single plaque. Plaque height on ultrasound is comparable to plaque height on MRI and correlates fairly well with plaque volume on MRI making it an interesting proxy for plaque burden.
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29.
  • Hjelmgren, Ola, et al. (författare)
  • Inverse association between size of the lipid-rich necrotic core and vascularization in human carotid plaques
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 38:2, s. 326-331
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose To study the relationship between the size of the lipid-rich necrotic core measured by MRI (magnetic resonance imaging) and the level of plaque vascularization measured by contrast-enhanced ultrasound, in human carotid plaques. Further, to compare the size of lipid-rich necrotic core from MRI to plaque echogenicity. Methods Thirty-one subjects with carotid plaques underwent standard B-mode ultrasound, contrast-enhanced ultrasound and MRI. The lipid-rich necrotic core was quantified using MRI. Contrast-enhanced ultrasound was used to measure carotid plaque vascularization. Standard B-mode ultrasound was used to measure plaque echogenicity as greyscale median. Results The amount of lipid-rich necrotic core correlated inversely with the degree of plaque vascularization (r = -0.40, P = 0.03). There were no correlations between the degree of plaque vascularization and the amount of fibrous tissue or calcifications. There were no correlations between greyscale median and the lipid-rich necrotic core, fibrous tissue or calcifications. Conclusions We show that more dense plaque vascularization is associated with a lower plaque content of lipid-rich necrotic core. A large lipid-rich necrotic core and high plaque vascularization are both proposed as predictors of vulnerability, and our finding is therefore odds with some earlier observations. Our finding can be explained by the fact that the necrotic core of the plaque contains no viable tissue and therefore less of the plaque can be vascularized if the lipid-rich necrotic core is large. Our study suggests that the true relation between plaque vascularization and other indices of vulnerability is more complex than initially thought.
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30.
  • Hysing, Per, et al. (författare)
  • Prevalence and prognostic impact of electrocardiographic abnormalities in outpatients with extracardiac artery disease
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : WILEY. - 1475-0961 .- 1475-097X. ; 38:5, s. 823-829
  • Tidskriftsartikel (refereegranskat)abstract
    • Identifying cardiac disease in patients with extracardiac artery disease (ECAD) is essential for clinical decision-making. Electrocardiography (ECG) is an easily accessible tool to unmask subclinical cardiac disease and to risk stratify patient with or without manifest cardiovascular disease (CV). We aimed to examine the prevalence and prognostic impact of ECG changes in outpatients with ECAD. Outpatients with carotid or lower extremity artery disease (n = 435) and community-based controls (n = 397) underwent resting ECG. The patients were followed during a median of 4.8 years for CV events (hospitalization or death caused by ischaemic heart disease, cardiac arrest, heart failure, or stroke). ECG abnormalities were classified according to the Minnesota Code. Major (33% versus 15%, P<0.001) but not minor ECG abnormalities (23% versus 26%, P = 0.42) were significantly more common in patients versus controls. During the follow-up, 141 patients experienced CV events. Both major ECG abnormalities [hazard ratio (HR) 1.58, 95% confidence interval (CI) 1.11-2.25, P = 0.012] and any ECG abnormalities (HR 1.57, 95% CI 1.06-2.33, P = 0.024) were significantly associated with CV events after adjustment for potential risk factors. In conclusion, ECG abnormalities were common in these outpatients with ECAD. Major and any ECG abnormalities were independent predictors of CV events. Addition of easily accessible ECG information might be useful in risk stratification for such patients.
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31.
  • Ingvarsson, Annika, et al. (författare)
  • Impact of gender on echocardiographic characteristics in heart transplant recipients
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:4, s. 246-254
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims: Assessment following heart transplantation (HTx) is routinely performed using transthoracic echocardiography. Differences in long-term mortality following HTx related to donor-recipient matching have been reported, but effects of gender on cardiac size and function are not well studied. The aims of this study were to evaluate differences in echocardiographic characteristics of HTx recipients defined by gender. Methods and results: The study prospectively enrolled 123 (n = 34 female) HTx recipients of which 23 recipients was donor-recipient gender mismatched. Patients were examined with 2-dimensional echocardiography using Philips iE33 ultrasound system. Data were analysed across strata based on recipient gender and gender mismatch. Male recipients had larger left ventricular (LV) mass, thicker septal wall (P<0·001) and larger absolute LV volumes (P<0·001). Mean LV ejection fraction (EF) was higher in females (P<0·05), but no differences in conventional parameters of right ventricular (RV) function were found. Ventricular strain was higher in females than in males: LV global longitudinal strain (P<0·01), RV global longitudinal strain (P<0·05) and RV lateral free wall (P<0·05). The male group receiving a female donor heart had comparable EF and strain parameters to the female group receiving a gender-matched heart. Conclusion: We found that female recipient gender was associated with smaller chamber size, higher LV EF and better LV and RV longitudinal strain. Gender-mismatched male recipients appeared to exhibit function parameters similar to gender-matched female recipients. Our results indicate that the gender aspect, analogous to current reference guidelines in general population, should be taken into consideration when examining patients post-HTx.
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32.
  • Jogestrand, Tomas, et al. (författare)
  • Discrepancies in recommended criteria for grading of carotid stenosis with ultrasound
  • 2016
  • Ingår i: Clinical Physiology and Functional Imaging. - : WILEY-BLACKWELL. - 1475-0961 .- 1475-097X. ; 36:4, s. 326-329
  • Tidskriftsartikel (refereegranskat)abstract
    • The accuracy of duplex ultrasound for grading of internal carotid artery stenosis has been widely tested and shown to be high. However, different methods for measurement of the degree of carotid stenosis with the golden standard conventional angiography have been used in the different studies. This, together with other factors, has led to some confusion regarding the relation between the ultrasonographically measured flow velocity and the angiographically measured degree of stenosis. The ultrasound criteria that are used in Sweden (and in Germany) differ in an important way from the criteria recommended in North America and the United Kingdom for the same degree of angiographic stenoses. Possible reasons for the discrepancies are discussed in this article. The authors recommend absolute agreement locally whether ECST or NASCET criteria shall be used in the communication between radiologists, clinical physiologists, vascular surgeons, neurologists and other physicians involved in patient management decisions. Angle-dependent ultrasound criteria should be used and flow velocity measurements with ultrasound should be combined with assessment of plaque burden on 2D picture.
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33.
  • Jorstig, Stina Hellstrand, 1978-, et al. (författare)
  • A study to determine the contribution to right ventricle stroke volume from pulmonary and tricuspid valve displacement volumes
  • 2015
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 35:4, s. 283-290
  • 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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34.
  • Kumar, Sanjay, et al. (författare)
  • Diastolic function improves after resolution of takotsubo cardiomyopathy
  • 2016
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 6:1, s. 17-24
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Takotsubo cardiomyopathy (TTC) is a condition of reversible left ventricular (LV) systolic dysfunction. However, the diastolic function (DF) manifestations of TTC have not been widely investigated. We performed a bicentric study with retrospective analysis of DF in patients with TTC, during onset and at follow-up.METHODS: Twenty-eight patients with TTC (64 ± 10 years, F 24) were included. All underwent echocardiograms acutely and at the recovery phase (average three months later). Diastolic and systolic function parameters were recorded, including E-wave velocity (E), A-wave velocity, E/A ratio, relaxation (e') and contractility (S') based on tissue Doppler velocities of the mitral annuli, ejection fraction (EF), left atrial (LA) size and DF stages.RESULTS: Recovery, including the mean difference with 95% confidence interval, was associated with tending improvement (i.e. uncorrected significance) in E [13 cm s(-1) (-24, -2·3), P = 0·02] and in E/A ratio [0·2 (-0·41, -0·02), P = 0·04], as well as significant improvement (after multiple comparison correction) in mean e' [2·0 cm s(-1) (-3·3, -1·2), P<0·001] and in A-wave duration [29 ms (-46·7, -12·7), P = 0·002]. LA area tended to decrease during recovery [-2 cm² (0·33, 2·4), P = 0·01]. Improvement in DF stages was significant between the phases (21% versus 58% defined as normal DF, P = 0·016). Improvement in LVEF correlated with improvement in mean e' (r = 0·52, P = 0·02).CONCLUSIONS: TTC is associated with an acute impairment of conventional DF variables, which improves during recovery. DF recovery seems to occur in parallel with systolic recovery in patients with TTC.
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35.
  • Kölegård, Roger, et al. (författare)
  • Cardiac performance is influenced by rotational changes of position in the transversal plane, both in the horizontal and 60° head-up postures
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 38:6, s. 1021-1028
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Echocardiography is usually performed with the subject/patient lying in the left lateral position (LLP), because the acoustic window is better in this than in the supine position (SP). The aim was to investigate cardiac responses to rotational changes of position in the transversal plane, from SP to LLP while horizontal, and from leaning on the back (HUT-LB) to leaning on the left side (HUT-LL) while tilted 60° head-up from the horizontal. Methods: Healthy men (n = 12) underwent 10-min HUT provocations. Cardiac variables were measured using two-dimensional echocardiography, Doppler, tissue Doppler imaging and arterial pressures using a volume-clamp method. Results: In horizontal posture, cardiac volumes were smaller in SP than in LLP: end-diastolic volume (EDV) by 14%, end-systolic volume (ESV) by 13%, stroke volume (SV) by 14%, and cardiac output (CO) by 16% (P<0·03). In addition, the mitral annular plane systolic excursion (MAPSE) was 11% smaller (P = 0·001) and the left ventricle isovolumic relaxation time (IVRT) 27% longer in SP than in LLP. The ejection fraction, heart rate, arterial pressure and pulmonary ventilation were similar in SP and LLP. During HUT, EDV, SV, CO and MAPSE were smaller, and IVRT was longer, in HUT-LB than in HUT-LL, by −19%, −20%, −17%, −18% and +35%, respectively (P<0·04). Conclusions: Cardiac performance is enhanced in LLP versus SP and in HUT-LL versus HUT-LB, which can be attributed to improved venous return, conceivably, wholly or in part, due to increased hydrostatic pressure gradients between the caval veins and the heart in the LLP and HUT-LL positions.
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36.
  • Lind, Lars (författare)
  • A detailed lipoprotein profile in relation to intima-media thickness and echogenicity of three major arteries
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:6, s. 415-421
  • Tidskriftsartikel (refereegranskat)abstract
    • ObjectiveTo investigate differences in risk‐factor profile, with special emphasis on detailed characterization of the lipoprotein profile, for intima‐media thickness (IMT) and echogenicity of the intima‐media complex (IM‐GSM) in three major arteries: the carotid, femoral and brachial arteries.MethodsIMT and IM‐GSM were measured by ultrasound in the carotid, femoral and brachial arteries in 778 subjects, all aged 75 years (50% women), in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, in which a detailed lipoprotein profile was also determined by nuclear magnetic resonance spectroscopy.ResultsFirst, IMT was considerably lower, and IM‐GSM higher, in the brachial artery compared to the other two arteries. Second, IMT and IM‐GSM in the arteries were related to each other. Third, significant different traditional risk‐factor profiles were seen for both IMT and IM‐GSM, with generally weaker relationships for IMT in the femoral and brachial arteries compared with the carotid artery. Fourth, the strength of associations between an atherogenic lipoprotein profile and IMT in the carotid artery was attenuated in the femoral artery and virtually absent in the brachial artery. Fifth, slightly different lipoprotein profiles were seen for IM‐GSM in the three arteries.ConclusionDifferences between the carotid, femoral and brachial artery IMT and IM‐GSM were seen regarding the traditional risk factors, as well as the lipoprotein profile.
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37.
  • Lind, Lars, et al. (författare)
  • Endothelium-dependent vasodilation is related to the occurrence of cortical brain infarcts at MR imaging : The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study
  • 2017
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 37:2, s. 194-197
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Infarcts in the brain can be divided into larger cortical and smaller deep lacunar infarcts. The pathogenesis differs between these two types of infarctions.OBJECTIVE: This study aims to investigate the relationship between measures of endothelium-dependent vasodilation (EDV) and occurrence of cortical and lacunar infarcts in a population-based sample.METHODS: In the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study, 1016 subjects aged 70 were evaluated by the invasive forearm technique with acetylcholine (EDV) and brachial artery ultrasound to assess flow-mediated vasodilation (FMD). Six to seven years later MRI of the brain was performed, and the prevalence of cortical and lacunar infarcts was visually assessed in 407 randomly selected subjects.RESULTS: Lacunar infarcts were found in 22% and cortical infarcts in 5·9% of the subjects. EDV and FMD were both significantly related to the occurrence of cortical, but not lacunar infarcts. In a model adjusting for gender, waist circumference, body mass index, fasting blood glucose, systolic and diastolic blood pressure, HDL and LDL cholesterol, serum triglycerides, smoking, antihypertensive treatment and statin use, both EDV and FMD were independent predictors of cortical infarcts (P = 0·035 and P = 0·008, respectively).CONCLUSIONS: Endothelium-dependent vasodilation in both forearm resistance vessels and the brachial artery was related to the occurrence of cortical, but not lacunar, infarcts at MRI in a population-based sample independently of traditional risk factors.
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38.
  • Lind, Lars (författare)
  • Endothelium-dependent vasodilation predicts the development of the metabolic syndrome
  • 2015
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 35:6, s. 411-417
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Different techniques to evaluate endothelium-dependent vasodilation (EDV) in resistance and conduit arteries have been described and have been associated with the occurrence of the metabolic syndrome (MetS) in cross-sectional studies. This study aimed to evaluate whether EDV in resistance and conduit arteries could predict future development of the MetS in the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study. Methods: In the population-based PIVUS study (1016 subjects all aged 70 at baseline), the invasive forearm technique with acetylcholine given in the brachial artery (resistance arteries, EDV) and the brachial artery ultrasound technique with the measurement of flow-mediated dilatation (conduit artery, FMD) were evaluated. Six hundred and twenty-four subjects free of the MetS (NCEP/ATPIII criteria) at the age of 70 were reinvestigated at the age of 75. Results: During the 5-year follow-up, 109 new subjects developed the MetS. EDV, but not FMD, predicted the development of the MetS (OR 0.78 for a 1 SD increase in EDV, 95% CI 0.62-0.97, P = 0.033). Of the five components of the MetS, EDV could significantly predict the development of the glucose (P = 0.02), waist circumference (P = 0.01) and the triglyceride components (P = 0.002), but not significantly so the HDL (P = 0.09) and blood pressure components (P = 0.92). Conclusions: EDV in resistance arteries, but not in the brachial conduit artery (FMD), was a predictor of future development of the MetS, mainly by prediction of future impairments in fasting glucose, serum triglycerides and waist circumference in an elderly cohort.
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39.
  • Lind, Lars, et al. (författare)
  • Lifetime change in central and peripheral haemodynamics in relation to exercise capacity
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : WILEY. - 1475-0961 .- 1475-097X. ; 39:4, s. 261-275
  • Tidskriftsartikel (refereegranskat)abstract
    • Exercise capacity as well as many resting central and peripheral haemodynamic features declines by age. We aimed to investigate which haemodynamic features change the most during life and which change in parallel to exercise capacity. We performed a maximal bicycle exercise test with gas exchange in 103 healthy subjects (24 young, 55 middle-aged and 24 elderly). Endothelial function, arterial compliance/stiffness and heart rate variability (HRV) were evaluated, and the myocardium and carotid arteries were investigated by ultrasound. Exercise capacity declined by almost 50% over the lifespan. Several markers reflecting arterial compliance/stiffness and HRV, as well as carotid intima-media thickness (IMT), showed lifetime impairments by >100%, while markers of LV systolic function, diastolic blood pressure and carotid artery blood flow showed only minor changes with age. The decline in exercise capacity clusters closely with many other variables measured during the exercise test, but also to resting vital capacity, left ventricular end-diastolic diameter and resting gas exchange (VO2, VCO2) to a lesser degree. Resting vital capacity was closely related to exercise capacity in the middle-aged group. We conclude that many of the resting markers of central and peripheral haemodynamics declined during life, in parallel to the decline in exercise capacity. However, some haemodynamic features, such as LF/HF ratio at HRV, stiffness index beta of the carotid artery, and heart rate reserve at the exercise test, showed a more exaggerated decline, indicating that those are not closely linked to exercise capacity.
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40.
  • Lindholm, Anthony, et al. (författare)
  • Decreased biventricular longitudinal strain in patients with systemic sclerosis is mainly caused by pulmonary hypertension and not by systemic sclerosis per se
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:3, s. 215-225
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Patients with pulmonary arterial hypertension (PAH) due to systemic sclerosis (SSc) have high mortality. Left ventricular (LV) peak global longitudinal strain (GLS) is decreased in SSc. It is unknown whether low GLS is due to SSc or PAH. Therefore, our primary aim was to evaluate both LV and right ventricular free wall GLS (RVFW GLS) in SSc, with and without PAH, using cardiac magnetic resonance with feature tracking. Secondary aim was to relate GLS to invasive mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR). Methods: Thirty-eight patients with SSc, 19 patients with SSc-PAH and 19 healthy controls for comparison, were included. Endocardial and epicardial borders were delineated in cine images (short-axis stack and three long-axis views) for volumetric and strain calculations. Results: Systemic sclerosis-PAH had lower LV and RVFW GLS than SSc (LV: P = 0·01, RV: P<0·001) and controls (LV: P = 0·02; RV: P<0·001), with no difference between SSc and controls. LV strain correlated with mPAP (R = 0·42, P = 0·03) and PVR (R = 0·52, P = 0·006). RVFW GLS correlated with mPAP (R = 0·68, P<0·001) and PVR (R = 0·59, P = 0·001). ROC curves for predicting PAH had AUC 0·73 for LV strain (P = 0·003) and 0·86 for RVFW GLS (P<0·001). Conclusions: Lower GLS is mainly determined by increased pulmonary pressure and not by SSc per se. Low LV and RVFW GLS are indicative of increased mPAP and PVR, which opens for improved non-invasive methods to select patients eligible for right heart catheterization and to monitor the effects of PAH therapy.
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41.
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42.
  • Martinsen, S., et al. (författare)
  • The role of long-term physical exercise on performance and brain activation during the Stroop colour word task in fibromyalgia patients
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : WILEY. - 1475-0961 .- 1475-097X. ; 38:3, s. 508-516
  • Tidskriftsartikel (refereegranskat)abstract
    • The Stroop colour word test (SCWT) has been widely used to assess changes in cognitive performance such as processing speed, selective attention and the degree of automaticity. Moreover, the SCWT has proven to be a valuable tool to assess neuronal plasticity that is coupled to improvement in performance in clinical populations. In a previous study, we showed impaired cognitive processing during SCWT along with reduced task-related activations in patients with fibromyalgia. In this study, we used SCWT and functional magnetic resonance imagingFMRI to investigate the effects of a 15-week physical exercise intervention on cognitive performance, task-related cortical activation and distraction-induced analgesia (DIA) in patients with fibromyalgia and healthy controls. The exercise intervention yielded reduced fibromyalgia symptoms, improved cognitive processing and increased task-related activation of amygdala, but no effect on DIA. Our results suggest beneficial effects of physical exercise on cognitive functioning in FM.
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43.
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44.
  • Mortensen, Mike A., et al. (författare)
  • Artificial intelligence-based versus manual assessment of prostate cancer in the prostate gland: a method comparison study
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:6, s. 399-406
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim : To test the feasibility of a fully automated artificial intelligence-based method providing PET measures of prostate cancer (PCa). Methods : A convolutional neural network (CNN) was trained for automated measurements in 18F-choline (FCH) PET/CT scans obtained prior to radical prostatectomy (RP) in 45 patients with newly diagnosed PCa. Automated values were obtained for prostate volume, maximal standardized uptake value (SUVmax), mean standardized uptake value of voxels considered abnormal (SUVmean) and volume of abnormal voxels (Volabn). The product SUVmean × Volabn was calculated to reflect total lesion uptake (TLU). Corresponding manual measurements were performed. CNN-estimated data were compared with the weighted surgically removed tissue specimens and manually derived data and related to clinical parameters assuming that 1 g ≈ 1 ml of tissue. Results : The mean (range) weight of the prostate specimens was 44 g (20–109), while CNN-estimated volume was 62 ml (31–108) with a mean difference of 13·5 g or ml (95% CI: 9·78–17·32). The two measures were significantly correlated (r = 0·77, P<0·001). Mean differences (95% CI) between CNN-based and manually derived PET measures of SUVmax, SUVmean, Volabn (ml) and TLU were 0·37 (−0·01 to 0·75), −0·08 (−0·30 to 0·14), 1·40 (−2·26 to 5·06) and 9·61 (−3·95 to 23·17), respectively. PET findings Volabn and TLU correlated with PSA (P<0·05), but not with Gleason score or stage. Conclusion : Automated CNN segmentation provided in seconds volume and simple PET measures similar to manually derived ones. Further studies on automated CNN segmentation with newer tracers such as radiolabelled prostate-specific membrane antigen are warranted.
  •  
45.
  • Nilsson, Henric, et al. (författare)
  • Cardiopulmonary exercise testing for evaluation of a randomized exercise training intervention following aortic valve replacement
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : WILEY. - 1475-0961 .- 1475-097X. ; 39:1, s. 103-110
  • Tidskriftsartikel (refereegranskat)abstract
    • Aortic valve surgery is the definitive treatment for aortic stenosis (AS). No specific recommendation is available on how exercise training should be conducted and evaluated after aortic valve replacement (AVR). This study aimed to examine the effect of aerobic exercise training on exercise capacity following AVR. In addition to our primary outcome variable, peak oxygen uptake (peakVO(2)), the effect on submaximal cardiopulmonary variables including oxygen uptake kinetics (tau), oxygen uptake efficiency slope (OUES) and ventilatory efficiency (VE/VCO2 slope) was evaluated. Following AVR due to AS, 12 patients were randomized to either a group receiving 12 weeks of supervised aerobic exercise training (EX) or a control group (CON). Exercise capacity was assessed by a maximal cardiopulmonary exercise test (CPET). There was a significant increase in peak load (+28%, P = 0 center dot 031) and in peakVO(2) (+23%, P = 0 center dot 031) in EX, corresponding to an increase in achieved percentage of predicted peakVO(2) from 88 to 104% (P = 0 center dot 031). For submaximal variables, there were only non-statistically significant trends in improvement between CPETs in EX. In CON, there were no significant differences in any maximal or submaximal variable between CPETs. We conclude that 12 weeks of supervised aerobic exercise training induces significant adaptations in cardiopulmonary function following AVR, especially in regard to maximal variables including peakVO(2). In addition, we provide novel data on the effect on several submaximal variables following exercise training in this group of patients.
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46.
  • Petrini, J., et al. (författare)
  • Aortic versus carotid intima-media thickness and impact of aortic valve disease
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 38:5, s. 895-902
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND AND AIMS: Intima-media thickness is a marker for atherosclerosis but is also influenced by shear stress and flow. We evaluated the relation between intima-media thickness of the descending aorta (AoIMT) and the common carotid artery (CIMT) in patients with and without severe aortic valve disease (sAVD). METHODS: A total of 310 patients (233 with sAVD, 77 without) were examined with regard to AoIMT and CIMT using transesophageal echocardiography and carotid ultrasound, respectively, before valvular and/or aortic surgery. Digitally stored B-mode images were used for semiautomatic AoIMT and CIMT measurements. RESULTS: There were no significant differences in patients with or without sAVD with regard to AoIMT (1.35 +/- 0.31 vs. 1.35 +/- 0.33 mm) or CIMT (0.80 +/- 0.15 vs. 0.78 +/- 0.16 mm). The correlations between AoIMT and CIMT were r = 0.29 in patients with and r = 0.51 in patients without sAVD, and the difference between these correlations was significant (P<0.05). In multivariate regression, age was the main determinant for AoIMT and CIMT in both groups, further in sAVD, the aortic mean pressure gradient (Pmean ) was a determinant of AoIMT, but not of CIMT. CONCLUSIONS: The correlation between CIMT and AoIMT is weaker in patients with sAVD compared to those without sAVD. Pmean is also a significant predictor of AoIMT, but not of CIMT. This implies that, in addition to the atherosclerotic process, turbulent aortic flow or altered blood flow helicity created by large stroke volumes and diastolic flow reversal or high-velocity jets, affect the intima-media of the descending aorta and common carotid artery differently.
  •  
47.
  • Petrini, Johan, et al. (författare)
  • Circumferential strain by velocity vector imaging and speckle-tracking echocardiography : validation against sonomicrometry in an aortic phantom
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 38:2, s. 269-277
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Evaluation of arterial deformation and mechanics using strain analysis on ultrasound greyscale images has gained increasing scientific interest. The aim of this study was to validate in vitro measurements of circumferential strain by velocity vector imaging (VVI) and speckle-tracking echocardiography (STE) against sonomicrometry as a reference method. Method: Two polyvinyl alcohol phantoms sized to mimic the descending aorta were constructed and connected to a pulsatile flow pump to obtain high-resistance flow profiles. The ultrasound images of the phantom used for strain analyses were acquired with a transesophageal probe. Global and regional circumferential strains were estimated using VVI and STE and were compared with the strain acquired by sonomicrometry. Results: Global circumferential peak strain estimated by VVI and STE correlated well to sonomicrometry (r = 0·90, P≤0·001; and r = 0·97, P≤0·01) with a systematic bias of −0·78% and +0·63%, respectively. The reference strain levels were 1·07–2·54%. Circumferential strain values obtained by VVI were significantly lower than those obtained by STE (bias −1·41%, P≤0·001). Conclusion: Global circumferential strain measured by VVI and STE correlates well with sonomicrometry. However, strain values obtained by VVI and STE differ significantly, which should be taken into consideration when comparing results from studies using different software for aortic strain measurements.
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48.
  •  
49.
  • Rundqvist, Louise, et al. (författare)
  • Left ventricular diastolic function is enhanced after peak exercise in endurance-trained adolescents as well as in their non-trained controls
  • 2018
  • Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 38:6, s. 1054-1061
  • Tidskriftsartikel (refereegranskat)abstract
    • The aims of the study were to explore the temporal change of cardiac function after peak exercise in adolescents, and to investigate how these functional changes relate to maximal oxygen uptake (VO2max ). The cohort consisted of 27 endurance-trained adolescents aged 13-19 years, and 27 controls individually matched by age and gender. Standard echocardiography and colour tissue Doppler were performed at rest, and immediately after as well as 15 min after a maximal cardio pulmonary exercise test (CPET) on a treadmill. The changes in systolic and diastolic parameters after exercise compared to baseline were similar in both groups. The septal E/e'-ratio increased immediately after exercise in both the active and the control groups (from 9·2 to 11·0; P<0·001, and from 8·7 to 10·2; P = 0·008, respectively). In a comparison between the two groups after CPET, the septal E/e'-ratio was higher in the active group both immediately after exercise and 15 min later compared to the control group (P = 0·007 and P = 0·006, respectively). We demonstrated a positive correlation between VO2max and cardiac function including LVEF and E/e' immediately after CPET, but the strongest correlation was found between VO2max and LVEDV (r = 0·67, P<0·001) as well as septal E/e' (r = 0·34, P = 0·013). Enhanced diastolic function was found in both groups, but this was more pronounced in active adolescents. The cardiac functional response to exercise, in terms of LVEF and E/e', correlates with the increase in VO2 uptake. These findings in trained as well as un-trained teenagers have practical implications when assessing cardiac function.
  •  
50.
  • Sadik, May, 1970, et al. (författare)
  • Automated quantification of reference levels in liver and mediastinal blood pool for the Deauville therapy response classification using FDG-PET/CT in Hodgkin and non-Hodgkin lymphomas
  • 2019
  • Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:1, s. 78-84
  • Tidskriftsartikel (refereegranskat)abstract
    • Background 18F-FDG-PET/CT has become a standard for assessing treatment response in patients with lymphoma. A subjective interpretation of the scan based on the Deauville 5-point scale has been widely adopted. However, inter-observer variability due to the subjectivity of the interpretation is a limitation. Our main goal is to develop an objective and automated method for evaluating response. The first step is to develop and validate an artificial intelligence (AI)-based method, for the automated quantification of reference levels in the liver and mediastinal blood pool in patients with lymphoma. Methods Results The AI-based method was trained to segment the liver and the mediastinal blood pool in CT images from 80 lymphoma patients, who had undergone 18F-FDG-PET/CT, and apply this to a validation group of six lymphoma patients. CT segmentations were transferred to the PET images to obtain automatic standardized uptake values (SUV). The AI-based analysis was compared to corresponding manual segmentations performed by two radiologists. The mean difference for the comparison between the AI-based liver SUV quantifications and those of the two radiologists in the validation group was 0 center dot 02 and 0 center dot 02, respectively, and 0 center dot 02 and 0 center dot 02 for mediastinal blood pool respectively. Conclusions An AI-based method for the automated quantification of reference levels in the liver and mediastinal blood pool shows good agreement with results obtained by experienced radiologists who had manually segmented the CT images. This is a first, promising step towards objective treatment response evaluation in patients with lymphoma based on 18F-FDG-PET/CT.
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