Frame rate required for speckle tracking echocardiography: A quantitative clinical study with open-source, vendor-independent software

Abstract

Objectives: To determine the optimal frame rate at which reliable heart walls velocities can be assessed by speckle tracking.Background: Assessing left ventricular function with speckle tracking is useful in patient diagnosis but requires a temporal resolution that can follow myocardial motion. In this study we investigated the effect of different frame rates on the accuracy of speckle tracking results, highlighting the temporal resolution where reliable results can be obtained. Material and methods:27 patients were scanned at two different frame rates at their resting heart rate. From all acquired loops, lower temporal resolution image sequences were generated by dropping frames, decreasing the frame rate by up to 10-fold.Results: Tissue velocities were estimated by automated speckle tracking. Above 40 frames/s the peak velocity was reliably measured. When frame rate was lower, the inter-frame interval containing the instant of highest velocity also contained lower velocities, and therefore the average velocity in that interval was an underestimate of the clinically desired instantaneous maximum velocity. Conclusions:The higher the frame rate, the more accurately maximum velocities are identified by speckle tracking, until the frame rate drops below 40 frames/s, beyond which there is little increase in peak velocity. We provide in an online supplement the vendor-independent software we used for automatic speckle-tracked velocity assessment to help others working in this field.

Automatic detection of end‐diastolic and end‐systolic frames in 2D echocardiography

“…All patients in our study were at rest with a heartbeat rate range of 31–115 beats/min. In a recent study, we have shown that a frame rate of >40 frames/s is sufficient for reliable speckle tracking . The automated algorithm also showed similar levels of disagreement for the two acquired frame rates.…”

“…In a recent study, we have shown that a frame rate of >40 frames/s is sufficient for reliable speckle tracking. 24 The automated algorithm also showed similar levels of disagreement for the two acquired frame rates. However, at higher heart rates, for example during stress tests when the heart rates are higher by twofold to threefold, the time intervals shorten.…”

A method for determining local pulse wave velocity in human ascending aorta from sequential ultrasound measurements of diameter and velocity

“…D was recorded in the parasternal long axis view (PLAX) to ensure the measurements were perpendicular to the vessel center-line. M-mode was chosen in preference to B-mode to maximize the frame rate (Negoita et al 2016 ) and the M-mode cursor was placed immediately downstream of the sino-tubular junction. U was measured in the apical five chamber view (A5CH) using pulse wave (PW) Doppler with a 5 mm sample volume placed in the center of the aorta as close as possible to the location of the D measurement.…”

Semiautomatic Vendor Independent Software for Assessment of Local Arterial Stiffness

“…Diameter was recorded in 2D M-mode to achieve tracking with a high temporal resolution (as opposed to Bmode (2D) which would make the tracking highly dependent on acquisition frame rate [5]) by placing the cursor downstream of the sino-tubular junction with the Mmode line as perpendicular as possible to the aortic wall. Blood velocity was measured with pulsed wave Doppler and the sample volume was placed in the ascending aorta, as close as possible to the measurement location for diameter.…”