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P218 Assessment of mean pulmonary artery pressure with 4D flow MRI
Poster Walks Poster Walk 6: Basic Science/Pulmonary hypertension
P218 Assessment of mean pulmonary artery pressure with 4D flow MRI L. Crowe1, G. Guglielmi1, A.-L. Hachulla1, S. Noble2, P.M. Soccal3, M. Beghetti4, F. Lador3, J.-P. Vallée1 1 Department of Radiology, 2Department of Cadiology, 3Department of Pneumology, Hôpitaux Universitaires de Genève, 4 Pediatric Cardiology Unit, Children’s University Hospital, Geneva, Switzerland Introduction: A robust non-invasive method to estimate increased mean pulmonary artery pressure (mPAP) is needed. Recently, a 2D velocity encoding MRI study has shown that vortex duration in the pulmonary artery (PA) was related to mPAP (Reiter, Radiology,2015;275(1):71). This present study investigated the potential of 4D flow MRI to assess mPAP. Methods: Thirteen patients with suspected Chronic Thromboembolic Pulmonary Hypertension (CTEPH) were assessed by right heart catheterization (RHC) and cardiac MRI, including a 4D phase contrast sequence. Streamlines were reconstructed in the pulmonary artery and the duration of the vortical blood flow, defined as closed concentric ring-shaped curves parallel to the pulmonary artery (PA), was measured as a % of the cardiac cycle. The vortex duration was compared to the RHC mPAP, right ventricular volume (RVV), PA diameter and PA distensibility. Results: CTEPH was confirmed in 11 / 13 patients. The mPAP was 30.3 15.2 mmHg (11-66 mmHg). On the 4D flow data, vortex was difficult to assess on the first trial but after a learning curve, reproducibility was excellent with an ICC between vortex duration measurements of 0.93. Vortex duration correlated excellently with mPAP with R2 ¼ 0.75, p< 0.005 and outperformed all the other parameters (RVV: R2 ¼ 0.0026, p¼0.87; PA diameter: R2 ¼ 0.29, p¼0.087; PA distensibility: R2 ¼ 0.09, p¼0.32). Discussion and conclusion: Vortex duration derived from 4D flow MRI was the most promising MRI parameter to assess PA pressure. Further work should include the development of automated method to facilitate the vortex duration measurement.
POSTER WALKS
Figure 1 – Examples of 4D flow streamlines in a sagittal plane centred on the pulmonary trunk in 2 CTEPH patients with a mild pulmonary hypertension (left) or with a normal pulmonary pressure (right). In the patient on the left, the pulmonary trunk (between both arrows) was dilated with a flow showing a vortex by comparison with the laminar flow in the patient on the right. DOI:
Figure 2 – Vortex duration measured on the 4D flow images in the pulmonary trunk was significantly correlated with the mPAP.
http://dx.doi.org/10.1016/j.chest.2017.04.123
Copyright ª 2017 American College of Chest Physicians and Swiss Respiratory Society SGP. Published by Elsevier Inc and Karger. All rights reserved.
journal.publications.chestnet.org
117A
P218 Assessment of mean pulmonary artery pressure with 4D flow MRI L. Crowe1, G. Guglielmi1, A.-L. Hachulla1, S. Noble2, P.M. Soccal3, M. Beghetti4, F. Lador3, J.-P. Vallée1 1 Department of Radiology, 2Department of Cadiology, 3Department of Pneumology, Hôpitaux Universitaires de Genève, 4 Pediatric Cardiology Unit, Children’s University Hospital, Geneva, Switzerland Introduction: A robust non-invasive method to estimate increased mean pulmonary artery pressure (mPAP) is needed. Recently, a 2D velocity encoding MRI study has shown that vortex duration in the pulmonary artery (PA) was related to mPAP (Reiter, Radiology,2015;275(1):71). This present study investigated the potential of 4D flow MRI to assess mPAP. Methods: Thirteen patients with suspected Chronic Thromboembolic Pulmonary Hypertension (CTEPH) were assessed by right heart catheterization (RHC) and cardiac MRI, including a 4D phase contrast sequence. Streamlines were reconstructed in the pulmonary artery and the duration of the vortical blood flow, defined as closed concentric ring-shaped curves parallel to the pulmonary artery (PA), was measured as a % of the cardiac cycle. The vortex duration was compared to the RHC mPAP, right ventricular volume (RVV), PA diameter and PA distensibility. Results: CTEPH was confirmed in 11 / 13 patients. The mPAP was 30.3 15.2 mmHg (11-66 mmHg). On the 4D flow data, vortex was difficult to assess on the first trial but after a learning curve, reproducibility was excellent with an ICC between vortex duration measurements of 0.93. Vortex duration correlated excellently with mPAP with R2 ¼ 0.75, p< 0.005 and outperformed all the other parameters (RVV: R2 ¼ 0.0026, p¼0.87; PA diameter: R2 ¼ 0.29, p¼0.087; PA distensibility: R2 ¼ 0.09, p¼0.32). Discussion and conclusion: Vortex duration derived from 4D flow MRI was the most promising MRI parameter to assess PA pressure. Further work should include the development of automated method to facilitate the vortex duration measurement.
POSTER WALKS
Figure 1 – Examples of 4D flow streamlines in a sagittal plane centred on the pulmonary trunk in 2 CTEPH patients with a mild pulmonary hypertension (left) or with a normal pulmonary pressure (right). In the patient on the left, the pulmonary trunk (between both arrows) was dilated with a flow showing a vortex by comparison with the laminar flow in the patient on the right. DOI:
Figure 2 – Vortex duration measured on the 4D flow images in the pulmonary trunk was significantly correlated with the mPAP.
http://dx.doi.org/10.1016/j.chest.2017.04.123
Copyright ª 2017 American College of Chest Physicians and Swiss Respiratory Society SGP. Published by Elsevier Inc and Karger. All rights reserved.
journal.publications.chestnet.org
117A