Temporal compounding of cardiac ultrasound data: Improving image quality and clinical measurement repeatability

Abstract

Echocardiography provides a powerful and versatile tool for assessing cardiac morphology and function. However, cardiac ultrasound suffers from speckle as well as static and dynamic noise. Over the last three decades, a number of studies have attempted to address the challenging problem of speckle/noise suppression in cardiac ultrasound data. No single method has managed to provide a widely accepted solution. Temporal Compounding is a noise suppression method that utilises spatial averaging of temporally aligned cardiac B-Mode data. Reliable temporal alignment is vital for effective Temporal Compounding. In this study we introduce a novel, accurate and robust technique for the temporal alignment of cardiac cycles with variable temporal characteristics and examine the effect of Temporal Compounding in four clinical measurements performed on routine echocardiographic examinations. Results from 32 patients demonstrate speckle/noise suppression, shadowing reduction, anatomical structure enhancement and improvement in measurement repeatability with no significant or systematic bias introduced. Temporally compound data may be able to provide a good alternative to B-Mode data in clinical measurements as well as a first step to further post-processing of cardiac ultrasound data.

Postprocessing Approaches for the Improvement of Cardiac Ultrasound B-Mode Images: A Review

“…Original (left) and compound (right) parasternal long axis ED frames of low image quality and diagnostic value. The images are generated using the temporal compounding approach as described in [105] and [112]. Compounding suppresses tissue speckle and chamber noise substantially.…”

“…Figs. 4 and 5 [105] provide representative examples of the effect of temporal compounding on cardiac ultrasound images over a range of image qualities and diagnostic values.…”

“…The temporal alignment to a reference cardiac cycle was performed using a dynamic programming time-wrapping algorithm requiring no ECG information. The compounding method enhanced the M-mode cardiac ultrasound The images are generated using the temporal compounding approach as described in [105] and [112]. Compounding suppresses tissue speckle and chamber noise substantially.…”

“…This assumption is very restrictive and may result in severe blurring of the imaged cardiac structures in the processed images. Perperidis et al [105], [112] attempted to address this limitation by introducing a seven-stage nonlinear temporal alignment along with a robust rigid spatial alignment using exclusively intensity information from within the image sequences. Qualitative and quantitative results on the quality and diagnostic value of the processed images were very promising ( Figs.…”

Dynamic Enhancement of B-Mode Cardiac Ultrasound Image Sequences

“…Other studies have utilised the repeated rhythmic contractions of the heart to acquire and compound multiple partially decorrelated 2-D images of the same cardiac phase over consecutive cardiac cycles through a single acoustic window. The process has been referred to as temporal compounding (Abiko et al 1997;Amorim et al 2009;Klingler et al 1989;Olstad 2002;Perperidis et al 2009;Rigney and Wei 1988;Unser et al 1989;van Ocken et al 1981;Vitale et al 1993).…”