Simplified post processing of cine DENSE cardiovascular magnetic resonance for quantification of cardiac mechanics

Abstract

BackgroundCardiovascular magnetic resonance using displacement encoding with stimulated echoes (DENSE) is capable of assessing advanced measures of cardiac mechanics such as strain and torsion. A potential hurdle to widespread clinical adoption of DENSE is the time required to manually segment the myocardium during post-processing of the images. To overcome this hurdle, we proposed a radical approach in which only three contours per image slice are required for post-processing (instead of the typical 30–40 contours per image slice). We hypothesized that peak left ventricular circumferential, longitudinal and radial strains and torsion could be accurately quantified using this simplified analysis.Methods and ResultsWe tested our hypothesis on a large multi-institutional dataset consisting of 541 DENSE image slices from 135 mice and 234 DENSE image slices from 62 humans. We compared measures of cardiac mechanics derived from the simplified post-processing to those derived from original post-processing utilizing the full set of 30–40 manually-defined contours per image slice. Accuracy was assessed with Bland-Altman limits of agreement and summarized with a modified coefficient of variation. The simplified technique showed high accuracy with all coefficients of variation less than 10% in humans and 6% in mice. The accuracy of the simplified technique was also superior to two previously published semi-automated analysis techniques for DENSE post-processing.ConclusionsAccurate measures of cardiac mechanics can be derived from DENSE cardiac magnetic resonance in both humans and mice using a simplified technique to reduce post-processing time by approximately 94%. These findings demonstrate that quantifying cardiac mechanics from DENSE data is simple enough to be integrated into the clinical workflow.

Right Ventricular Strain, Torsion, and Dyssynchrony in Healthy Subjects Using 3D Spiral Cine DENSE Magnetic Resonance Imaging

“…All metrics including global and regional torsion, strain and dyssynchrony were compared between the two observers using Bland-Altman analysis. Additionally, a modified coefficient of variation (CoV) was computed using Equation 9 where x 1 and x 2 are the observations of a given metric by the two observers and N is the number of datasets for which reproducibility was assessed [29], [30]. …”

High field magnetic resonance imaging of rodents in cardiovascular research

“…If its preclinical application has been more limited than tagging so far, technical adjustments allowing multiphase application [177], 3D acquisitions [178] and simplified post-processing [52,140], could allow wider use of DENSE MRI in mice in the future.…”

Longitudinal observations of progressive cardiac dysfunction in a cardiomyopathic animal model by self-gated cine imaging based on 11.7-T magnetic resonance imaging

“…Other advanced methods for the detection of myocardial changes need to be applied. Cardiovascular MRI, such as displacement encoding with stimulated echoes, tagged MRI sequences, and manganese-enhanced MRI, can assess advanced measures of cardiac mechanics and tissue alterations such as interstitial fibrosis, strain, and torsion 25 – 27 . We believe that advanced MRI techniques to identify early alterations in cardiac function in cardiac disease models, such as the J2N-k hamster, will prove useful for the assessment of disease development in the future.…”