Fluctuational Imaging for the Diagnosis of Hepatic Hemangioma: A Multicenter, Prospective Study

\[Background and Rationale\] Hepatic hemangioma is the most common benign tumor of the liver, with a reported prevalence of up to 20% in the general population. On B-mode ultrasonography, a typical hemangioma appears as a well-defined hyperechoic lesion compared with the surrounding liver parenchyma. However, hyperechogenicity is observed in only approximately 70% of cases, while the remaining lesions may appear hypoechoic or mixed echogenic. Additional sonographic features such as posterior acoustic enhancement or an echogenic rim may aid diagnosis, but none are specific to hemangioma. Consequently, contrast-enhanced CT or MRI is commonly required for definitive diagnosis, even when a hemangioma is strongly suspected on conventional ultrasound. In 2020, Kobayashi et al. (Ultrasound Med Biol 2021;47:941-946)reported a novel ultrasound finding termed the "fluttering sign," defined as con