Postprocessing Method for Enhanced Left Ventricular Thrombus Detection in Echocardiography

Figures

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  Figure 1. Patient Selection Flowchart. A total of 16,562 echocardiography examinations were performed in our echocardiography unit from 2023 to 2024. Among these, 636 examinations were conducted specifically to assess for thrombus in the left ventricle. In 29 of these cases, the echocardiography contrast agent SonoVue was injected due to insufficient video quality.

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  Figure 2. Diagram illustrating the results obtained by two independent observers using LVTDM, contrast-echo, and non-contrast transthoracic echocardiography. The figure depicts the number of cases in which thrombus was detected or not detected after postprocessing by observer 1, observer 2, injection of ultrasonic contrast SonoVue, and at baseline images. All baseline images were suspicious for thrombus. After postprocessing with LVTDM, thrombus was identified by observer 1 in 14 cases and by observer 2 in 15 cases. Thrombus was detected in 11 patients using SonoVue. Overdiagnosis of thrombus detection occurred in 3 cases for observer 1 and 4 cases for observer 2 after LVTDM analysis. Thrombus was not missed with LVTDM by either observer 1 or observer 2.

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  Figure 3. Diagnostic performance of the LVTDM compared to contrast echo results, assessed using Receiver Operating Characteristic (ROC) curves. The diagnostic performance of the Left Ventricular Thrombus Detection Method (LVTDM) compared to contrast echocardiography results, assessed using ROC curves. The area under the ROC curve (AUC) for Observer 1 was 0.917, while for Observer 2, it was 0.889. Observer 1 demonstrates a higher discriminatory power compared to Observer 2, as indicated by its higher AUC value of 0.917 versus Observer 2’s AUC of 0.889. Both observers achieved AUC values greater than 0.5, suggesting high diagnostic accuracy.

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  Figure 4. Echocardiography images depicting thrombus in the left ventricle obtained by conventional echocardiography, after postprocessing with LVTDM, and contrast echo. (A). Conventional echocardiography image showing suspicion of thrombus in the apex of the left ventricle [arrow], requiring confirmation by additional methods. (B). Image obtained after postprocessing with LVTDM, providing improved visualization of thrombus in the left ventricle [arrow]. (C). Contrast echocardiography image following injection of SonoVue. A filling defect in the apex of the left ventricle is consistent with thrombus [arrow]. Abbreviations: LV—left ventricle, LA—left atrium.

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  Figure 5. Proposed Diagnostic Algorithm for Left Ventricular Thrombus Detection. LVTDM is particularly valuable in routine echocardiographic exams where image quality or apex visualization is compromised, offering a sensitive method for detecting thrombi early. Contrast echocardiography should be employed if image quality is still inadequate or if LVTDM results are positive. Cardiac MRI should be reserved for confirmatory purposes, especially in cases where treatment decisions hinge on thrombus presence.