Cardiovascular magnetic resonance myocardial feature tracking detects quantitative wall motion during dobutamine stress

Andreas Schuster, Kutty Shelby, Padiyath Asif, Parish Victoria, Gribben Paul, Danford, Makowski, Bigalke Boris, Beerbaum Philipp, Nagel, Nagel Eike

Description

Dobutamine stress cardiovascular magnetic resonance (DS-CMR) is an established tool to assess hibernating myocardium and ischemia. Analysis is typically based on visual assessment with considerable operator dependency. CMR myocardial feature tracking (CMR-FT) is a recently introduced technique for tissue voxel motion tracking on standard steady-state free precession (SSFP) images to derive circumferential and radial myocardial mechanics. We sought to determine the feasibility and reproducibility of CMR-FT for quantitative wall motion assessment during intermediate dose DS-CMR. Methods 10 healthy subjects were studied at 1.5 Tesla. Myocardial strain parameters were derived from SSFP cine images using dedicated CMR-FT software (Diogenes MRI prototype; Tomtec; Germany). Right ventricular (RV) and left ventricular (LV) longitudinal strain (Ell RV and Ell LV ) and LV long-axis radial strain (Err LAX ) were derived from a 4-chamber view at rest. LV short-axis circumferential strain (Ecc SAX ) and Err SAX ; LV ejection fraction (EF) and volumes were analyzed at rest and during dobutamine stress (10 and 20 μg · kg -1 · min -1 ). Results In all volunteers strain parameters could be derived from the SSFP images at rest and stress. Ecc SAX values showed significantly increased contraction with DSMR (rest: -24.1 ± 6.7; 10 μg: -32.7 ± 11.4; 20 μg: -39.2 ± 15.2; p < 0.05). Err SAX increased significantly with dobutamine (rest: 19.6 ± 14.6; 10 μg: 31.8 ± 20.9; 20 μg: 42.4 ± 25.5; p < 0.05). In parallel with these changes; EF increased significantly with dobutamine (rest: 56.9 ± 4.4%; 10 μg: 70.7 ± 8.1; 20 μg: 76.8 ± 4.6; p < 0.05). Observer variability was best for LV circumferential strain (Ecc SAX ) and worst for RV longitudinal strain (Ell RV ) as determined by 95% confidence intervals of the difference. Conclusions CMR-FT reliably detects quantitative wall motion and strain derived from SSFP cine imaging that corresponds to inotropic stimulation. The current implementation may need improvement to reduce observer-induced variance. Within a given CMR lab; this novel technique holds promise of easy and fast quantification of wall mechanics and strain.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2011
• Nombre de lectures: 5
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Schusteret al.Journal of Cardiovascular Magnetic Resonance2011,13:58 http://www.jcmronline.com/content/13/1/58

R E S E A R C H

Open Access

Cardiovascular magnetic resonance myocardial feature tracking detects quantitative wall motion during dobutamine stress 1*†2†2 22 3 Andreas Schuster , Shelby Kutty , Asif Padiyath , Victoria Parish , Paul Gribben , David A Danford , 1,4 1,5 1,3†1† Marcus R Makowski , Boris Bigalke , Philipp Beerbaum and Eike Nagel

Abstract Background:Dobutamine stress cardiovascular magnetic resonance (DSCMR) is an established tool to assess hibernating myocardium and ischemia. Analysis is typically based on visual assessment with considerable operator dependency. CMR myocardial feature tracking (CMRFT) is a recently introduced technique for tissue voxel motion tracking on standard steadystate free precession (SSFP) images to derive circumferential and radial myocardial mechanics. We sought to determine the feasibility and reproducibility of CMRFT for quantitative wall motion assessment during intermediate dose DSCMR. Methods:10 healthy subjects were studied at 1.5 Tesla. Myocardial strain parameters were derived from SSFP cine images using dedicated CMRFT software (Diogenes MRI prototype; Tomtec; Germany). Right ventricular (RV) and left ventricular (LV) longitudinal strain (Ell RV and Ell LV ) and LV longaxis radial strain (Err LAX ) were derived from a 4 chamber view at rest. LV shortaxis circumferential strain (Ecc SAX ) and Err SAX ; LV ejection fraction (EF) and volumes 1 1 were analyzed at rest and during dobutamine stress (10 and 20μg ∙ kg ).∙ min Results:In all volunteers strain parameters could be derived from the SSFP images at rest and stress. Ecc SAX values showed significantly increased contraction with DSMR (rest: 24.1 ± 6.7; 10μg: 32.7 ± 11.4; 20μg: 39.2 ± 15.2; p < 0.05). Err SAX increased significantly with dobutamine (rest: 19.6 ± 14.6; 10μg: 31.8 ± 20.9; 20μg: 42.4 ± 25.5; p < 0.05). In parallel with these changes; EF increased significantly with dobutamine (rest: 56.9 ± 4.4%; 10μg: 70.7 ± 8.1; 20μg: 76.8 ± 4.6; p < 0.05). Observer variability was best for LV circumferential strain (Ecc SAX ) and worst for RV longitudinal strain (Ell RV ) as determined by 95% confidence intervals of the difference. Conclusions:CMRFT reliably detects quantitative wall motion and strain derived from SSFP cine imaging that corresponds to inotropic stimulation. The current implementation may need improvement to reduce observer induced variance. Within a given CMR lab; this novel technique holds promise of easy and fast quantification of wall mechanics and strain.

* Correspondence: [e-mail] †Contributed equally 1 King’s College London British Heart Foundation (BHF) Centre of Excellence; National Institute of Health Research (NIHR) Biomedical Research Centre at Guy’s and St. Thomas’NHS Foundation Trust; Wellcome Trust and Engineering and Physical Sciences Research Council (EPSRC) Medical Engineering Centre; Division of Imaging Sciences and Biomedical Engineering; The Rayne Institute, St. Thomas’Hospital, London, UK Full list of author information is available at the end of the article

© 2011 Schuster 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.