What are the ultrasound characteristics of a hemangioma, specifically its echogenicity, such as isoechoic (having the same echogenicity as surrounding tissues)?

From the Guidelines

Hemangiomas on ultrasound typically appear as well-defined, mixed echogenicity solid masses with central and peripheral vessels on grayscale US, but they can occasionally present as isoechoic or hypoechoic lesions. When a hemangioma appears isoechoic on ultrasound, it can be more challenging to diagnose as it may blend with surrounding tissue. This presentation is less common and may require additional imaging techniques for confirmation. According to the most recent study 1, ultrasound is useful in distinguishing infantile hemangiomas from vascular malformations and for identifying infantile hemangiomas.

Key Characteristics

• Well-defined mixed echogenicity solid masses
• Central and peripheral vessels on grayscale US
• Can appear isoechoic or hypoechoic in some cases
• May require additional imaging techniques, such as color Doppler ultrasound or contrast-enhanced ultrasound (CEUS), for confirmation. The isoechoic appearance occurs because the internal structure of some hemangiomas contains a balance of fibrous tissue, blood vessels, and fat that creates an acoustic impedance similar to surrounding normal tissue, resulting in similar echogenicity on standard ultrasound, as described in previous studies 1. However, the most recent study 1 provides the most up-to-date information on the ultrasound characteristics of hemangiomas.

From the Research

Ultrasound Characteristics of Hemangioma

• The echogenicity of hemangiomas can vary, with studies showing that they can be hyperechoic, hypoechoic, isoechoic, or have a mixed echo pattern 2
• Isoechoic hemangiomas, which have the same echogenicity as surrounding tissues, can be recognized by the presence of a hyperechoic rim 2
• The internal echo level of hemangiomas can be homogeneous or heterogeneous, with some studies showing that homogeneous hyperechoic (35.0%) and homogeneous hypoechoic (22.9%) patterns are common 2
• Other ultrasound characteristics of hemangiomas include the absence of lateral shadow (100%) and no attenuation of posterior echoes (100%) 2
• Contrast-enhanced ultrasound can also be used to characterize hemangiomas, with typical findings including peripheral nodular arterial enhancement and homogenous centripetal filling within 180 seconds 3

Specific Findings

• A study of 271 hepatic hemangiomas found that 12 masses were isoechoic, and could be recognized by the hyperechoic rim 2
• Another study found that contrast-enhanced ultrasound demonstrated typical hemangioma imaging characteristics, including peripheral nodular contrast enhancement and iris-diaphragm sign, in a high percentage of patients with undetermined lesions 3
• Ultrasound findings can be useful in differentiating hemangiomas from malignant forms, especially in asymptomatic patients with hyperechoic, well-defined lesions 4