Detective Flow Imaging Endoscopic Ultrasonography in Subepithelial Lesions

Gastrointestinal stromal tumors (GIST) are the most common malignant subepithelial lesions (SELs) found in the gastrointestinal tract. The diagnosis and differentiation of these lesions from other subepithelial hypoechogenic tumors (i.e.as leiomyoma), is important as this may have an impact in the prognosis and treatment of either. Due to GIST's notable features (vascularity and deep location), endoscopic ultrasound (EUS) is the first-line diagnostic approach. Based on this, three models (color-doppler EUS, power-doppler EUS, and e-FLOW EUS), are useful for real-time vascularity detection; however, these modalities are not helpful for fine and slow flow vessel detection. For overcoming this limitation, contrast-enhanced EUS (CE-EUS) is proposed as a first-line approach. Nevertheless, the use of contrast may be harmful, thus limited to some patients. To avoid contrast-related adverse events, a novel diagnostic method known as detective flow imaging endoscopic ultrasonography (DFI-EUS) has emerged. This technique detects fine vessels and slow flow without contrast. Despite the advantages of the latter, few studies have compared it with other diagnostic approaches in the evaluation and differentiation of SELs. Hence, the investigators aim to evaluate the utility of DFI-EUS in the diagnosis of SELs (GIST and leiomyoma) by comparing it with CE-EUS.