A novel and practical cardiovascular magnetic resonance method to quantify mitral annular excursion and recoil applied to hypertrophic cardiomyopathy

Abstract

BackgroundWe have developed a novel and practical cardiovascular magnetic resonance (CMR) technique to evaluate left ventricular (LV) mitral annular motion by tracking the atrioventricular junction (AVJ). To test AVJ motion analysis as a metric for LV function, we compared AVJ motion variables between patients with hypertrophic cardiomyopathy (HCM), a group with recognized systolic and diastolic dysfunction, and healthy volunteers.MethodsWe retrospectively evaluated 24 HCM patients with normal ejection fractions (EF) and 14 healthy volunteers. Using the 4-chamber view cine images, we tracked the longitudinal motion of the lateral and septal AVJ at 25 time points during the cardiac cycle. Based on AVJ displacement versus time, we calculated maximum AVJ displacement (MD) and velocity in early diastole (MVED), velocity in diastasis (VDS) and the composite index VDS/MVED.ResultsPatients with HCM showed significantly slower median lateral and septal AVJ recoil velocities during early diastole, but faster velocities in diastasis. We observed a 16-fold difference in VDS/MVED at the lateral AVJ [median 0.141, interquartile range (IQR) 0.073, 0.166 versus 0.009 IQR -0.006, 0.037, P < 0.001]. Patients with HCM also demonstrated significantly less mitral annular excursion at both the septal and lateral AVJ. Performed offline, AVJ motion analysis took approximately 10 minutes per subject.ConclusionsAtrioventricular junction motion analysis provides a practical and novel CMR method to assess mitral annular motion. In this proof of concept study we found highly statistically significant differences in mitral annular excursion and recoil between HCM patients and healthy volunteers.

Evaluation of diastolic function by three-dimensional volume tracking of the mitral annulus with cardiovascular magnetic resonance: comparison with tissue Doppler imaging

“…This process produces a map of the correlation between the point (and its surroundings) in the initial image and the points within that corresponding neighborhood in the subsequent image; the location of the maximum correlation represents the likely location of the initial point (and its surrounding template) within the subsequent image. In this study, NCC enabled semi-automated AVJ tracking that reduced the long post-processing time previously required with manual AVJ tracking [19]. In addition, the use of reproducibility analyses here showed that the use of NCC limited variability in calculated MA sweep volume measurements between users.…”

“…The atrioventricular junction (AVJ), the septal and lateral junction between the left atrium and ventricle, was tracked in two-, three-, and four-chamber long-axis CMR views over the cardiac cycle [19]. This was performed semi-automatically in lab-written MATLAB (MathWorks Inc., MA, USA) using normalized cross-correlation (NCC), a well-known feature-tracking algorithm [23,24] that has been used in MA location tracking in CMR [18].…”

“…In a prior study, a 2D manual tracking technique in assessing CMR MA motion had been reported [19]. In this paper, we aimed to expand on this prior technique and identify patients with diastolic dysfunction by using 3D MA sweep volumes calculated from routinely acquired long-axis cine-CMR images, comparing the results to TTE.…”

Assessment of diastolic function and atrial remodeling by MRI - validation and correlation with echocardiography and filling pressure

“…In cardiovascular magnetic resonance imaging (MRI), methods exist that can measure those diastolic parameters (Paelinck et al 2005;Bollache et al 2010;Duarte and Fernandez 2010;Leng et al 2015;Saba et al 2014;Seemann et al 2017). For example, quantification of LA volumes is established (Wylie et al 2008;Maceira et al 2010), but there is a lack of standardized methods for MRI assessment of diastolic parameters linked to valvular flow and motion (i.e., E, A, and especially e 0 ).…”

Review of Journal of Cardiovascular Magnetic Resonance 2015

“…The phenotyping of cardiomyopathy is a primary clinical indication for CMR, and has become mainstream in hypertrophic cardiomyopathy, [57–59] including the development of hypertrophy atlases [60]. Recent attention has been focussed on T1 imaging for the assessment of diffuse fibrosis in cardiomyopathy, [61, 62] with T1 standardisation, [63] technical developments, and the assessment of diffuse fibrosis in cardiomyopathy.…”