Scholarly article on topic 'Visualization and quantification of 4D blood flow distribution and energetics in the right ventricle'

Visualization and quantification of 4D blood flow distribution and energetics in the right ventricle Academic research paper on "Veterinary science"

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Academic research paper on topic "Visualization and quantification of 4D blood flow distribution and energetics in the right ventricle"

Carlhäll et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):O83 http://jcmr-online.com/content/13/S1/O83

Magnetic Resonance

ORAL PRESENTATION Open Access

Visualization and quantification of 4D blood flow distribution and energetics in the right ventricle

Carl Johan Carlhall1, Alexandru G Fredriksson1*, Jakub Zajac1, Jonatan Eriksson1, Petter Dyverfeldtl1, Jan Engvall1, Ann F Bolger2, Tino Ebbers1

From 2011 SCMR/Euro CMR Joint Scientific Sessions Nice, France. 3-6 February 2011

Background

Right ventricular (RV) function has important prognostic value in both right- and left-sided acquired and congenital heart diseases (1). Assessment of RV function is challenging because of its complex crescent shaped geometry and load conditions being significantly influenced by respiration. Incremental insights into RV blood flow patterns have the potential to add to our understanding of RV function (2), but remain incompletely characterized.

Results

The portion of RV inflow passing directly to outflow (Direct Flow), possessed a larger pre-systolic KE than the other three flow components (p<0.01)(Figure 3). The Direct Flow had a larger volume than the other flow components (p<0.001), and was located mainly in the basal half of the ventricle (Figures 1 and 2). The Residual Volume was larger than the Delayed Ejection

Hypothesis

We hypothesized that a specific portion of the RV end-diastolic (ED) blood volume is prepared for effective systolic ejection and that this sub-volume can be identified based on its pre-systolic kinetic energy (KE) and location.

Method

Three-directional, 3-dimensional cine phase-contrast CMR velocity-data and morphological bSSFP images were acquired on a 1.5T scanner (Philips Achieva) in ten healthy subjects (4 female, aged 46±17 years [mean ±SD]). A previously validated method was used for the flow analysis (3): The RV endocardium was segmented (http://segment.heiberg.se) from the morphological images at ED and end-systole (ES). Pathlines were emitted from the ED blood volume and traced forward and backward in time until ES. Accordingly, the ED blood volume could be automatically separated into four functional flow components (3,4)(Figures 1 and 2). By the volume occupied by each trace, its velocity and the density of blood, the kinetic KE was calculated throughout the cardiac cycle.

1Center for Medicallmage Science and Visualization (CMIV), Linkôping University, Linkôping, Sweden

Full list of author information is available at the end of the article

Bio Med Central

Figure 1 Visualization of right ventricular (RV) flow at end-diastole in a healthy subject. Direct Flow (green), blood that enters and leaves the RV within the analyzed cardiac cycle (CC), Retained Inflow (yellow), blood that enters but does not leave the RV within the analyzed CC; Delayed Ejection Flow (blue), blood that leaves but does not enter the RV within the analyzed CC. RA, right atrium; RV, right ventricle.

© 2011 Carlhäll et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Carlhäll et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):O83 Page 2 of 2

http://jcmr-online.com/content/13/S1/O83

Direct Flow 44 ± 6%

Residual Volume 23 ± 6%

Retained Inflow

17 ± 2%

elayed Ejection Flow

15 ± 3%

Figure 2 Illustration of the four right ventricular (RV) flow components as a percentage of RV end-diastolic volume (EDV) in healthy subjects.

Author details

1Center for MedicalImage Science and Visualization (CMIV), Linkoping University, Linkoping, Sweden. 2University of California San Francisco, San Francisco, CA, USA.

Published: 2 February 2011 References

1. Haddad R, et al: Circ 2008, 117:1717-31.

2. Kilner P, et al: Nature 2000, 404:759-61.

3. Eriksson J, et al: JCMR 2010, 12:9.

4. Bolger AF, et al: JCMR 2007, 9:741-47.

doi:10.1186/1532-429X-13-S1-O83

Cite this article as: Carlhall et al.: Visualization and quantification of 4D blood flow distribution and energetics in the right ventricle. Journal of Cardiovascular Magnetic Resonance 2011 13(Suppl 1):O83.

Flow (p<0.01) and the Retained Inflow (p<0.05), and was located mainly in the apical half of the ventricle (Figures 1 and 2).

Conclusions

Semi-automatic analysis of 4D CMR velocity data allows separation of RV flow into distinct functional components. The present findings suggest that diastolic flow in the normal RV creates favorable conditions for effective systolic ejection, defined by pre-systolic KE and location, for the Direct Flow component. These flow-specific aspects of RV diastolic-systolic coupling may provide new useful perspectives on RV- and interventricular function in health and disease.

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Figure 3 End-diastolic kinetic energy for the four right ventricular flow components in healthy subjects.

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