Blog
About

49
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Whole-heart four-dimensional flow can be acquired with preserved quality without respiratory gating, facilitating clinical use: a head-to-head comparison

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background

          Respiratory gating is often used in 4D-flow acquisition to reduce motion artifacts. However, gating increases scan time. The aim of this study was to investigate if respiratory gating can be excluded from 4D flow acquisitions without affecting quantitative intracardiac parameters.

          Methods

          Eight volunteers underwent CMR at 1.5 T with a 5-channel coil (5ch). Imaging included 2D flow measurements and whole-heart 4D flow with and without respiratory gating (Resp(+), Resp(−)). Stroke volume (SV), particle-trace volumes, kinetic energy, and vortex-ring volume were obtained from 4D flow-data. These parameters were compared between 5ch Resp(+) and 5ch Resp(−). In addition, 20 patients with heart failure were scanned using a 32-channel coil (32ch), and particle-trace volumes were compared to planimetric SV. Paired comparisons were performed using Wilcoxon’s test and correlation analysis using Pearson r. Agreement was assessed as bias ± SD.

          Results

          Stroke volume from 4D flow was lower compared to 2D flow both with and without respiratory gating (5ch Resp(+) 88 ± 18 vs 97 ± 24.0, p = 0.001; 5ch Resp(−) 86 ± 16 vs 97.1 ± 22.7, p < 0.01). There was a good correlation between Resp(+) and Resp(−) for particle-trace derived volumes (R 2 = 0.82, 0.2 ± 9.4 ml), mean kinetic energy (R 2 = 0.86, 0.07 ± 0.21 mJ), peak kinetic energy (R 2 = 0.88, 0.14 ± 0.77 mJ), and vortex-ring volume (R 2 = 0.70, −2.5 ± 9.4 ml). Furthermore, good correlation was found between particle-trace volume and planimetric SV in patients for 32ch Resp(−) (R 2 = 0.62, −4.2 ± 17.6 ml) and in healthy volunteers for 5ch Resp(+) (R 2 = 0.89, −11 ± 7 ml), and 5ch Resp(−) (R 2 = 0.93, −7.5 ± 5.4 ml), Average scan duration for Resp(−) was shorter compared to Resp(+) (27 ± 9 min vs 61 ± 19 min, p < 0.05).

          Conclusions

          Whole-heart 4D flow can be acquired with preserved quantitative results without respiratory gating, facilitating clinical use.

          Electronic supplementary material

          The online version of this article (doi:10.1186/s12880-015-0061-4) contains supplementary material, which is available to authorized users.

          Related collections

          Most cited references 24

          • Record: found
          • Abstract: found
          • Article: not found

          Asymmetric redirection of flow through the heart.

          Through cardiac looping during embryonic development, paths of flow through the mature heart have direction changes and asymmetries whose topology and functional significance remain relatively unexplored. Here we show, using magnetic resonance velocity mapping, the asymmetric redirection of streaming blood in atrial and ventricular cavities of the adult human heart, with sinuous, chirally asymmetric paths of flow through the whole. On the basis of mapped flow fields and drawings that illustrate spatial relations between flow paths, we propose that asymmetries and curvatures of the looped heart have potential fluidic and dynamic advantages. Patterns of atrial filling seem to be asymmetric in a manner that allows the momentum of inflowing streams to be redirected towards atrio-ventricular valves, and the change in direction at ventricular level is such that recoil away from ejected blood is in a direction that can enhance rather than inhibit ventriculo-atrial coupling. Chiral asymmetry might help to minimize dissipative interaction between entering, recirculating and outflowing streams. These factors might combine to allow a reciprocating, sling-like, 'morphodynamic' mode of action to come into effect when heart rate and output increase during exercise.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Mitral regurgitation.

            Mitral regurgitation affects more than 2 million people in the USA. The main causes are classified as degenerative (with valve prolapse) and ischaemic (ie, due to consequences of coronary disease) in developed countries, or rheumatic (in developing countries). This disorder generally progresses insidiously, because the heart compensates for increasing regurgitant volume by left-atrial enlargement, causes left-ventricular overload and dysfunction, and yields poor outcome when it becomes severe. Doppler-echocardiographic methods can be used to quantify the severity of mitral regurgitation. Yearly mortality rates with medical treatment in patients aged 50 years or older are about 3% for moderate organic regurgitation and about 6% for severe organic regurgitation. Surgery is the only treatment proven to improve symptoms and prevent heart failure. Valve repair improves outcome compared with valve replacement and reduces mortality of patient with severe organic mitral regurgitation by about 70%. The best short-term and long-term results are obtained in asymptomatic patients operated on in advanced repair centres with low operative mortality ( /=80-90%). These results emphasise the importance of early detection and assessment of mitral regurgitation.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Navigator-echo-based real-time respiratory gating and triggering for reduction of respiration effects in three-dimensional coronary MR angiography.

              To test the hypothesis that respiration effects in three-dimensional (3D) coronary magnetic resonance (MR) imaging can be reduced with navigator-echo-based gating or triggering according to the superior-inferior position of the diaphragm. Real-time respiratory gating and respiratory triggering (breath hold with feedback) were implemented with navigator echoes in a magnetization-prepared, segmented, 3D coronary imaging sequence. The two techniques were first tested with a motion phantom. An imaging protocol that compared real-time respiratory-gated acquisition, real-time respiratory-triggered acquisition, and continuous acquisition was then evaluated in six healthy subjects. Real-time respiratory-gated and respiratory-triggered acquisition were superior to continuous acquisition with two signals averaged (P = .025). The performance of the gated acquisition was about the same as that of the triggered acquisition (P = .05). Navigator-echo-based, real-time respiratory-gating and respiratory-triggering techniques are practical methods for effective reduction of respiration effects in coronary MR imaging.
                Bookmark

                Author and article information

                Contributors
                mikael.kanski@med.lu.se
                johannes.toger@med.lu.se
                katarina.ehrenborg@med.lu.se
                cxanthis@gmail.com
                karin.markenroth@philips.se
                einar.heiberg@med.lu.se
                marcus.carlsson@med.lu.se
                hakan.arheden@med.lu.se
                Journal
                BMC Med Imaging
                BMC Med Imaging
                BMC Medical Imaging
                BioMed Central (London )
                1471-2342
                18 June 2015
                18 June 2015
                2015
                : 15
                Affiliations
                [ ]Department of Clinical Physiology, Lund University, Lund University Hospital, Lund, Sweden
                [ ]Department of Numerical Analysis, Center of Mathematical Sciences, Lund University, Lund, Sweden
                [ ]Department of Computer Science and Biomedical informatics, University of Thessaly, Lamia, Greece
                [ ]Philips Healthcare, Lund, Sweden
                [ ]Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden
                [ ]Center for Mathematics, Faculty of Engineering, Lund University, Lund, Sweden
                Article
                61
                10.1186/s12880-015-0061-4
                4470048
                26080805
                © Kanski et al. 2015

                This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

                Categories
                Research Article
                Custom metadata
                © The Author(s) 2015

                Comments

                Comment on this article