• Journal of Cardiovascular Imaging
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• v.30 no.2
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• pp.123-124
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• 2022

• Journal of Cardiovascular Imaging
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• v.30 no.3
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• pp.197-201
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• 2022

• Journal of Biomedical Engineering Research
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• v.24 no.3
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• pp.141-149
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• 2003

This paper proposes a method of measuring and imaging the stiffness of human soft tissue to diagnose cancers or tumors which have been difficult to detect in ultrasound B-mode imaging systems. To measure the soft tissue stiffness, sinusoidal vibrations are applied to it, and the magnitude of its mechanical vibration is determined by estimating the temporal variation of speckle pattern brightness in ultrasound B-mode images. It is verified by simulation and experiment that the proposed method can estimate the relative tissue stiffness from B-mode images with a relatively small amount of computation.

• Journal of Cardiovascular Imaging
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• v.30 no.4
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• pp.307-319
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• 2022

BACKGROUND: Current guidelines indicate electrical dyssynchrony as the major criteria for selecting patients for cardiac resynchronization therapy, and 25-35% of patients exhibit unfavorable responses to cardiac resynchronization therapy (CRT). We aimed to evaluate different cardiac mechanical dyssynchrony parameters in heart failure patients using current echo-Doppler modalities and we analyzed their association with electrical dyssynchrony. METHODS: The study included 120 heart failure with reduced ejection fraction (HFrEF) who underwent assessments for left ventricular mechanical dyssynchrony (LVMD) and interventricular mechanical dyssynchrony (IVMD). RESULTS: Patients were classified according to QRS duration: group I with QRS < 120 ms, group II with QRS 120-149 ms, and group III with QRS ≥ 150 ms. Group III had significantly higher IVMD, LVMD indices, TS-SD speckle-tracking echocardiography (STE) 12 segments (standard deviation of time to peak longitudinal strain speckle tracking echocardiography in 12 LV-segments), and LVMD score compared with group I and group II. Group II and group III were classified according to QRS morphology into left bundle branch block (LBBB) and non-LBBB subgroups. LVMD score, TS-SD 12 TDI, and TS-SD 12 STE had good correlations with QRS duration. CONCLUSIONS: HFrEF patients with wide QRS duration (> 150 ms) had more evident LVMD compared with patients with narrow or intermediate QRS. Those patients with intermediate QRS duration (120-150 ms) had substantial LVMD assessed by both TDI and 2D STE, regardless of QRS morphology. Subsequently, we suggest that LVMD indices might be employed as additive criteria to predict CRT response in that patient subgroup. Electrical and mechanical dyssynchrony were strongly correlated in HFrEF patients.

• Journal of radiological science and technology
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• v.47 no.4
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• pp.279-286
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• 2024

Echocardiography is a widely used test to evaluate the contractility of the heart. However, this exam is cannot be said to be objective because the test relies on the examiner's visual judgment. Therefore, although a lot of efforts are being made to quantify the strain through speckle tracking echocardiography (STE), there are some limitations, and studies of conditions to supplement are needed. Through this study, we determine whether the general characteristics of the subjects affect vessel-specific strain and whether changes in various imaging conditions (general, resolution, compression, gain, chroma) affect vessel-specific strain. According to the results of the study, the general conditions obtained during the examination were generally less significant compared to other conversion conditions, and Resolution, Compress, Gain, Chroma, and LAD showed significant correlations under the Compress conditions (p < .05). Therefore, Accurate strain assessment will be made if echocardiography is analyzed using significant conditions for each stenotic vessel

• The Journal of the Acoustical Society of Korea
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• v.29 no.1E
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• pp.11-27
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• 2010

Nowadays, ultrasound Doppler imaging is widely used in assessing cardiovascular functions in the human body. However, a major drawback of ultrasonic Doppler methods is that they can provide information on blood flow velocity along the ultrasound beam propagation direction only. Thus, the blood flow velocity is estimated differently depending on the angle between the ultrasound beam and the flow direction. In order to overcome this limitation, there have been many researches devoted to estimating both axial and lateral velocities. The purpose of this article is to survey various two-dimensional velocity estimation methods in the context of Doppler imaging. Some velocity vector estimation methods can also be applied to determine tissue motion as required in elastography. The discussion is mainly concerned with the case of estimating a two-dimensional in-plane velocity vector involving the axial and lateral directions.

• Journal of Cardiovascular Imaging
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• v.31 no.4
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• pp.191-199
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• 2023

BACKGROUND: Assessment of left ventricular (LV) function plays a pivotal role in the management of patients with valvular heart disease, including those caused by rheumatic heart disease. Noninvasive LV pressure-strain loop analysis is emerging as a new echocardiographic method to evaluate global LV systolic function, integrating longitudinal strain by speckle-tracking analysis and noninvasively measured blood pressure to estimate myocardial work. The aim of this study was to characterize global LV myocardial work efficiency in patients with severe rheumatic mitral stenosis (MS) with preserved ejection fraction (EF). METHODS: We retrospectively included adult patients with severe rheumatic MS with preserved EF (> 50%) and sinus rhythm. Healthy individuals without structural heart disease were included as a control group. Global LV myocardial work efficiency was estimated with a proprietary algorithm from speckle-tracking strain analyses, as well as noninvasive blood pressure measurements. RESULTS: A total of 45 individuals with isolated severe rheumatic MS with sinus rhythm and 45 healthy individuals were included. In healthy individuals without structural heart disease, the mean global LV myocardial work efficiency was 96% (standard deviation [SD], 2), Compared with healthy individuals, median global LV myocardial work efficiency was significantly worse in MS patients (89%; SD, 4; p < 0.001) although the LVEF was similar. CONCLUSIONS: Individuals with isolated severe rheumatic MS and preserved EF, had global LV myocardial work efficiencies lower than normal controls.

• Clinical and Experimental Pediatrics
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• v.59 no.4
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• pp.190-195
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• 2016

Purpose: Severe aplastic anemia (SAA), a fatal disease, requires multiple transfusion, immunosuppressive therapy, and finally, hematopoietic stem cell transplantation (HSCT) as the definitive treatment. We hypothesized that iron overloading associated with multiple transfusions and HSCT-related complications may adversely affect cardiac function. Left ventricular (LV) function was assessed in children after HSCT for SAA. Methods: Forty-six consecutive patients with a median age of 9.8 years (range, 1.5-18 years), who received HSCT for SAA and who underwent comprehensive echocardiography before and after HSCT, were included in this study. The data of LV functional parameters obtained using conventional echocardiography, tissue Doppler imaging (TDI), and speckle-tracking echocardiography (STE) were collected from pre- and post-HSCT echocardiography. These data were compared to those of 40 age-matched normal controls. Results: In patients, the LV ejection fraction, shortening fraction, end-diastolic dimension, mitral early diastolic E velocity, TDI mitral septal E' velocity, and STE LV longitudinal systolic strain rate (SSR) decreased significantly after HSCT. Compared to normal controls, patients had significantly lower post-HSCT early diastolic E velocity and E/A ratio. On STE, patients had significantly decreased LV deformational parameters including LV longitudinal systolic strain (SS), SSR, and diastolic SR (DSR), and circumferential SS and DSR. Serum ferritin levels showed weak but significant correlations (P<0.05) with LV longitudinal SS and SSR and circumferential SS and DSR. Conclusion: Subclinical LV dysfunction is evident in patients after HSCT for SAA, and was associated with increased iron load. Serial monitoring of cardiac function is mandatory in this population.

• Journal of Cardiovascular Imaging
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• v.31 no.3
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• pp.125-132
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• 2023

BACKGROUND: There is limited data on the residual echocardiographic findings including strain analysis among post-coronavirus disease (COVID) patients. The aim of our study is to prospectively phenotype post-COVID patients. METHODS: All patients discharged following acute COVID infection were systematically followed in the post-COVID-19 Recovery Clinic at Vancouver General Hospital and St. Paul's Hospital. At 4-18 weeks post diagnosis, patients underwent comprehensive echocardiographic assessment. Left ventricular ejection fraction (LVEF) was assessed by 3D, 2D Biplane Simpson's, or visual estimate. LV global longitudinal strain (GLS) was measured using a vendor-independent 2D speckle-tracking software (TomTec). RESULTS: A total of 127 patients (53% female, mean age 58 years) were included in our analyses. At baseline, cardiac conditions were present in 58% of the patients (15% coronary artery disease, 4% heart failure, 44% hypertension, 10% atrial fibrillation) while the remainder were free of cardiac conditions. COVID-19 serious complications were present in 79% of the patients (76% pneumonia, 37% intensive care unit admission, 21% intubation, 1% myocarditis). Normal LVEF was seen in 96% of the cohort and 97% had normal right ventricular systolic function. A high proportion (53%) had abnormal LV GLS defined as < 18%. Average LV GLS of septal and inferior segments were lower compared to that of other segments. Among patients without pre-existing cardiac conditions, LVEF was abnormal in only 1.9%, but LV GLS was abnormal in 46% of the patients. CONCLUSIONS: Most post-COVID patients had normal LVEF at 4-18 weeks post diagnosis, but over half had abnormal LV GLS.

• Journal of Cardiovascular Imaging
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• v.31 no.3
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• pp.145-149
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• 2023

BACKGROUND: ¹⁸F-sodium fluoride positron emission tomography/computed tomography (¹⁸F-NaF PET/CT) has been proven to be useful in identification of microcalcifications, which are stimulated by inflammation. Blood speckle imaging (BSI) is a new imaging technology used for tracking the flow of blood cells using transesophageal echocardiography (TEE). We evaluated the relationship between turbulent flow identified by BSI and inflammatory activity of the aortic valve (AV) as indicated by the ¹⁸F-NaF uptake index in moderate aortic stenosis (AS) patients. METHODS: This study enrolled 18 moderate AS patients diagnosed within the past 6 months. BSI within the aortic root was acquired using long-axis view TEE. The duration of laminar flow and the turbulent flow area ratio were calculated by BSI to demonstrate the degree of turbulence. The maximum and mean standardized uptake values (SUVmax, SUVmean) and the total microcalcification burden (TMB) as measured by ¹⁸F-NaF PET/CT were used to demonstrate the degree of inflammatory activity in the AV region. RESULTS: The mean SUVmean, SUVmax, and TMB were 1.90 ± 0.79, 2.60 ± 0.98, and 4.20 ± 2.18 mL, respectively. The mean laminar flow period and the turbulent area ratio were 116.1 ± 61.5 msec and 0.48 ± 0.32. The correlation between SUVmax and turbulent flow area ratio showed the most positive and statistically significant correlation, with a Pearson's correlation coefficient (R²) of 0.658 and a p-value of 0.014. CONCLUSIONS: The high degree of trans-aortic turbulence measured by BSI was correlated with severe AV inflammation.