User-initialized active contour segmentation and golden-angle real-time cardiovascular magnetic resonance enable accurate assessment of LV function in patients with sinus rhythm and arrhythmias.

Francisco Contijoch,Joseph Gorman,Hannah Rears,Robert C Gorman,Kelly Rogers,Michael Hansen,Yuchi Han,Walter R.T Witschey,Paul Yushkevich

doi:10.1186/s12968-015-0146-9

Abstract

BackgroundData obtained during arrhythmia is retained in real-time cardiovascular magnetic resonance (rt-CMR), but there is limited and inconsistent evidence to show that rt-CMR can accurately assess beat-to-beat variation in left ventricular (LV) function or during an arrhythmia.MethodsMulti-slice, short axis cine and real-time golden-angle radial CMR data was collected in 22 clinical patients (18 in sinus rhythm and 4 patients with arrhythmia). A user-initialized active contour segmentation (ACS) software was validated via comparison to manual segmentation on clinically accepted software. For each image in the 2D acquisitions, slice volume was calculated and global LV volumes were estimated via summation across the LV using multiple slices. Real-time imaging data was reconstructed using different image exposure times and frame rates to evaluate the effect of temporal resolution on measured function in each slice via ACS. Finally, global volumetric function of ectopic and non-ectopic beats was measured using ACS in patients with arrhythmias.ResultsACS provides global LV volume measurements that are not significantly different from manual quantification of retrospectively gated cine images in sinus rhythm patients. With an exposure time of 95.2 ms and a frame rate of > 89 frames per second, golden-angle real-time imaging accurately captures hemodynamic function over a range of patient heart rates. In four patients with frequent ectopic contractions, initial quantification of the impact of ectopic beats on hemodynamic function was demonstrated.ConclusionUser-initialized active contours and golden-angle real-time radial CMR can be used to determine time-varying LV function in patients. These methods will be very useful for the assessment of LV function in patients with frequent arrhythmias.

Highlights

Data obtained during arrhythmia is retained in real-time cardiovascular magnetic resonance, but there is limited and inconsistent evidence to show that rt-CMR can accurately assess beat-to-beat variation in left ventricular (LV) function or during an arrhythmia
There are a large number of potential reconstruction parameters that contribute to temporal resolution, we focused on the image exposure time Image exposure time (Tex) and frame rate FR
Validation of active contour segmentation (ACS) To validate the use of ACS, we processed cine-CMR images with ACS and compared measured LV values to those obtained by manual segmentation of the same cine-CMR images

Summary

Introduction

Data obtained during arrhythmia is retained in real-time cardiovascular magnetic resonance (rt-CMR), but there is limited and inconsistent evidence to show that rt-CMR can accurately assess beat-to-beat variation in left ventricular (LV) function or during an arrhythmia. Assessment of LV function in normal subjects and patients has been performed using several rt-CMR methods with varying degrees of accuracy, summarized in Table 1 [1,2,3,4,5,6]. These studies imaged patients in sinus rhythm and a single cardiac cycle from each 2D acquisition was selected for LV function assessment. The potential to measure beat-to-beat variation in LV function has not been described using rt-CMR methods

Methods

Results

Conclusion