Automated Analysis of Strain Rate and Strain: Feasibility and Clinical Implications

doi:10.1016/j.echo.2005.01.032

Journal of the American Society of Echocardiography

Volume 18, Issue 5, May 2005, Pages 411-418

https://doi.org/10.1016/j.echo.2005.01.032 Get rights and content

Background

This study evaluated 3 new automated methods, based on a combination of speckle tracking and tissue Doppler, for the analysis of strain rate (SR) and strain. Feasibility and values for peak systolic strain rate (SR_s) and end-systolic strain (S_es) were assessed.

Methods

Thirty patients with myocardial infarction and 30 normal subjects were examined. Customized software with automatic definition of segments was used for automated measurements. SR_s and SR_es were measured over each segment simultaneously and identified automatically. The study compared tissue Doppler-based SR and strain measurements without (method 1) and with segment tracking (method 2) to speckle tracking-based measurements (method 3). For tracking, speckle tracking and tissue Doppler were used in combination. Standard manual analysis was used as a reference.

Results

The automated analysis (16 segments, 3 apical views) required 2 minutes; manual analysis took 11 minutes. Accuracy was compared in 56 segments (28 mid-infarcted and 28 normal) from 28 patients and was 93.9% for method 1, 93.8% for method 2, 95.8% for method 3, and 96.2% for the manual method. In the normal group, mean SR_s (0.27 s⁻¹) was less with method 3 than with the other methods (P < .001).

Conclusions

Our findings indicate that automated analysis of SR and strain, with some manual adjustment, is feasible and quicker than manual analysis. Diagnostic accuracy was similar with all methods. SR_s was lower in the speckle tracking-based method than in the Doppler-based methods.

Section snippets

Study population

The main study examined 30 patients (mean age 65 ± 9 years; 11 women) with a first myocardial infarction (17 inferior/13 anterior, 23 Q-wave, mean creatine kinase MB 266 μg/L, mean troponin T 7.4 μg/L) and 30 subjects (mean age 57 ± 12 years; 15 women) with normal ventricles, coronary angiography, and dobutamine stress echocardiography. Finally, to evaluate the influence of B-mode frame rate on undersampling and precision in speckle tracking (method 3), further analysis was done in 10 healthy

Feasibility data

In all, 799 segments (665 normal and 134 infarcted) were analyzed by all 4 methods. Between 20% and 25% of all segments analyzed using automated methods had to be discarded, compared with only 8% of segements analyzed manually (Table 1). Method 3 yielded the greatest number of analyzable segments for both SR_s and S_es (81.5% and 80.3%, respectively) of the automated methods, but still fewer than manual analysis (92.3% and 90.3%, respectively) (Table 1). Feasibility was lowest in the lateral and

Discussion

The present study has demonstrated that automated analysis methods are feasible and faster than standard manual analysis, but they enable analysis of fewer segments. The automated methods still require some manual adjustments.

References (16)

A. Heimdal et al.
Real-time strain rate imaging of the left ventricle by ultrasound
J Am Soc Echocardiogr
(1998)
A. Stoylen
Strain rate imaging by ultrasonography in the diagnosis of coronary artery disease
J Am Soc Echocardiogr
(2000)
L. Bohs et al.
Speckle tracking for multi-dimensional flow estimation
Ultrasonics
(2000)
O. Bonnefous et al.
Time domain formulation of pulse-Doppler ultrasound and blood velocity estimation by cross-correlation
Ultrason Imaging
(1986)
G. Trahey et al.
Angle-independent ultrasonic blood flow detection by frame-to-frame correlation of B-mode images
Ultrasonics
(1988)
A. Stoylen et al.
Strain rate imaging by ultrasonography in the diagnosis of coronary artery disease
J Am Soc Echocardiogr
(2000)
K. Kaluzynski et al.
Strain rate imaging using two-dimensional speckle tracking
IEEE Trans Ultrasonogr Ferroelectr Freq Control
(2001)
J. Kirkhorn et al.
A new technique for improved spatial resolution in high-frame-rate color Doppler imaging
Proc IEEE Ultrason Symp
(2003)

There are more references available in the full text version of this article.

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Advancements enabling high frame rate 2D images allowed successful implementation of semi-automated strain measurements using speckle tracking methods. This approach achieved accuracy similar to manual measurements and reduced analysis time by up to 82%, positioning semi-automated 2D speckle strain for better clinical uptake (40). Given that 2D speckle tracking–based strain analysis was introduced clinically as a semi-automated technique and was validated by using sonomicrometry (41), there is limited published data comparing the accuracy and reproducibility of automated versus manual methods (Table 3) (40,42–44).
Echocardiography remains the predominant modality for cardiac imaging. Recent technological advances have led to the availability of new echocardiographic techniques for more accurate quantification of volumes, function, myocardial mechanics, and valvular heart disease. However, in our opinion, the real-world clinical uptake of these techniques has been poor due to limited awareness and familiarity, associated time burden, and issues of variability. Automation represents a potential solution to these issues and has already made routine myocardial strain measurements and 2- and 3-dimensional left ventricular ejection fraction measurements a clinical reality. Further enhancements in automation and data in understudied populations are likely to assist in the uptake of these new quantitative echocardiographic techniques in routine clinical practice. This review discusses current automated quantification techniques in echocardiography and their limitations and describes how these techniques can be incorporated into echocardiography laboratories.
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Strain rate imaging by tissue Doppler (TDI) is vulnerable to stationary reverberations and noise (clutter). Anatomic Doppler spectrum (ADS) presents retrospective spectral Doppler from ultra-high frame rate imaging (UFR-TDI) data for a region of interest, that is, ventricular wall or segment, at one time instance. This enables spectral assessment of strain rate (SR) without the influence of clutter. In this study, we assessed SR with ADS and conventional TDI in 20 patients with a recent myocardial infarction and 10 healthy volunteers. ADS-based SR correlated with fraction of scarred myocardium of the left ventricle (r = 0.68, p < 0.001), whereas SR by conventional TDI did not (r = 0.23, p = 0.30). ADS identified scarred myocardium and ADS Visual was the only method that differentiated transmural from non-transmural distribution of myocardial scar on a segmental level (p = 0.002). Finally, analysis of SR by ADS was feasible in a larger number of segments compared with SR by conventional TDI (p < 0.001).
Tissue Velocities and Myocardial Deformation in Asymptomatic and Symptomatic Aortic Stenosis
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Assessment of myocardial longitudinal function has proved to be a sensitive marker of deteriorating myocardial function in aortic stenosis, demonstrated by both color Doppler tissue imaging and recently by two-dimensional speckle-tracking echocardiography. The aim of this study was to compare velocity (color Doppler tissue imaging) and deformation (two-dimensional speckle-tracking echocardiography) in relation to global and regional longitudinal function in asymptomatic and severe symptomatic aortic stenosis.
In a cross-sectional design, 231 patients with aortic stenosis were divided into four groups: asymptomatic moderate aortic stenosis (aortic valve area, 1.0–1.5 cm²; n = 38), asymptomatic severe aortic stenosis (aortic valve area < 1.0 cm²; n = 66), and symptomatic severe aortic stenosis with preserved (n = 68) and reduced (<50%) left ventricular ejection fraction (n = 59).
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Intraobserver variability showed intraclass correlation coefficients of 0.87 (95% CI, 0.67–0.95; P < .001) with a CV of 2.6 ± 2.0% for GLS, 0.70 (95% CI, 0.21–0.87; P = .007) with a CV of 2.6 ± 3.7% for SRS, 0.89 (95% CI, 0.72–0.96; P < .001) with a CV of 3.8 ± 3.1% for SRE, and 0.85 (95% CI, 0.61–0.94; P < .001) with a CV of 7.7 ± 7.6% for SRA. Two-dimensional speckle-tracking echocardiography allows the assessment of myocardial deformation through the cardiac cycle by following the motion of natural acoustic markers on grayscale B-mode images, in an angle-independent manner.7-10 Most notably, GLS and derived strain rate parameters can be measured, which have been shown to provide additional and valuable information beyond EF in different clinical scenarios, such as in subjects with coronary artery disease, heart failure, and cardiomyopathies.9,10,21,22
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Two hundred consecutive Olympic athletes (grouped into skill, power, mixed, and endurance disciplines) and 50 untrained controls were evaluated by two-dimensional speckle-tracking echocardiography. Left ventricular global systolic longitudinal strain (GLS), systolic strain rate, early diastolic strain rate (SRE) and late diastolic strain rate (SRA) were calculated.
GLS was normal, although mildly lower, in athletes compared with controls (−18.1 ± 2.2% vs −19.4 ± 2.3%, P < .001), without differences related to type of sport. Systolic strain rate was also lower in athletes (−1.00 ± 0.15 vs −1.11 ± 0.15 sec⁻¹, P < .001), with the lowest value in endurance disciplines (−0.96 ± 0.13 sec⁻¹, P < .001). No difference existed for SRE (1.45 ± 0.32 vs 1.51 ± 0.35 sec⁻¹, P = .277), while SRA was lower in athletes (0.67 ± 0.25 vs 0.81 ± 0.20 sec⁻¹, P < .001). Both SRE (1.37 ± 0.30 sec⁻¹, P < .001) and SRA (0.62 ± 0.23 sec⁻¹, P < .001) showed the lowest values in endurance disciplines. The fifth and 95th percentiles calculated as reference values in athletes were as follows: for GLS, −15% and −22%; for systolic strain rate, −0.8 and −1.2 sec⁻¹; for SRE, 1.00 and 2.00 sec⁻¹; and for SRA, 0.30 and 1.20 sec⁻¹.
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However, as much of the clutter and cavity noise is removed by the second harmonic analysis, there is not a direct correspondence between quality of the B-mode image and quality of tissue Doppler analysis. It has been customary to evaluate the quality of the curves visually, discarding segments where curves are not representative of the B-mode evaluation (Ingul et al. 2005). The BBV method provides a more objective criterion for this.
The variation in longitudinal strain and strain rate (SR) between two consecutive heartbeats (beat-to-beat-variation, BBV) was used to evaluate the analyzability of longitudinal strain and SR in tissue Doppler images in term neonates. Strain and SR BBV analysis and visual evaluation of analyzability were performed in 2394 segments; 1739 segments (73%) were deemed to be analyzable by visual evaluation, with an intra-rater κ score of 0.87 and inter-rater κ score of 0.61 (p < 0.001). Compared against visual evaluation, the κ scores for identification of analyzable segments were 0.57 based on SR BBV and 0.58 based on strain BBV (p < 0.001). The areas under the receiver operating characteristic curves for identification of analyzable segments were 0.87 (0.85–0.88) for strain BBV and 0.87 (0.85–0.89) for SR BBV (p < 0.001). For both BBVs, the sensitivity for identification of analyzable segments was 77% at a specificity of 80%. Analysis of BBV can be used for automated, objective and expert-independent assessment of analyzability.

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: Supported by a grant from the Norwegian University of Science and Technology.

¹: Hans Torp and Asbjorn Stoylen have received honoraria from GE Vingmed for lecturing.

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Original articleAutomated Analysis of Strain Rate and Strain: Feasibility and Clinical Implications

Background

Methods

Results

Conclusions

Section snippets

Study population

Feasibility data

Discussion

J Am Soc Echocardiogr

J Am Soc Echocardiogr

Ultrasonics

Ultrason Imaging

Ultrasonics

J Am Soc Echocardiogr

Strain rate imaging using two-dimensional speckle tracking

IEEE Trans Ultrasonogr Ferroelectr Freq Control

A new technique for improved spatial resolution in high-frame-rate color Doppler imaging

Proc IEEE Ultrason Symp

Original article
Automated Analysis of Strain Rate and Strain: Feasibility and Clinical Implications