What are echogenic foci (hyperechoic areas)?

From the Guidelines

Echogenic foci in the fetus are generally considered to be benign findings, but their presence can indicate an increased risk of certain conditions, such as aneuploidy, cystic fibrosis, and congenital infections, and therefore, require careful evaluation and management. The clinical significance of echogenic foci varies widely based on their location, size, number, and the patient's clinical context 1. In the fetal heart, echogenic foci (called intracardiac echogenic foci) are commonly seen and typically represent mineralization of papillary muscles, which are usually benign findings.

Some key points to consider when evaluating echogenic foci include:

• The location of the echogenic foci, as this can help to determine the potential underlying cause
• The size and number of echogenic foci, as larger or multiple foci may be more likely to be associated with underlying pathology
• The patient's clinical context, including any relevant medical history or risk factors
• The results of any additional testing or evaluation, such as noninvasive aneuploidy screening or diagnostic testing via amniocentesis

For pregnant people with no previous aneuploidy screening and isolated echogenic intracardiac focus, echogenic bowel, urinary tract dilation, or shortened humerus, femur, or both, we recommend counseling to estimate the probability of trisomy 21 and a discussion of options for noninvasive aneuploidy screening with cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive 1. Additionally, for fetuses with isolated echogenic bowel, we recommend an evaluation for cystic fibrosis and fetal cytomegalovirus infection and a third-trimester ultrasound examination for reassessment and evaluation of growth 1.

It is also important to note that while isolated echogenic bowel is associated with an increased risk of stillbirth, most fetuses with an isolated echogenic bowel have normal outcomes 1. The utility of antenatal fetal testing in this scenario is of unproven benefit, and partial or complete resolution of isolated echogenic bowel is reassuring, and normal fetal outcomes are likely 1.

From the Research

Echogenic Foci Overview

• Echogenic foci are abnormal findings that can be identified during fetal ultrasound examinations 2, 3, 4, 5, 6
• These foci can be found in various locations, including the lungs and heart 2, 3, 4, 5, 6

Clinical Significance of Echogenic Foci in Fetal Lungs

• Isolated echogenic pulmonary foci are rare findings that carry a good prognosis 2
• However, when echogenic foci in the lungs are identified, careful evaluation for associated abnormalities is warranted 2
• In one study, 5 fetuses with isolated echogenic foci in the lungs had normal outcomes, while 2 fetuses with associated anomalies had terminated pregnancies 2

Echogenic Foci in the Fetal Heart

• Echogenic intracardiac foci are common findings during routine fetal ultrasound examination 3
• The left ventricle is the most frequent location of echogenic foci in the heart 3, 4, 5, 6
• Isolated left-sided echogenic foci are generally considered a benign condition, probably representing a normal variant of papillary muscle development 3, 4, 5
• However, multiple or diffuse echogenic foci in the fetal heart may signal a poor prognosis and deserve further search for associated pathologies 4

Association with Congenital Heart Disease

• The presence of echogenic foci in the heart may be associated with an increased risk of congenital heart disease 3, 4, 6
• Right-sided echogenic foci are more frequently associated with fetal cardiac anomalies than left-sided or bilateral foci 6
• In one study, the prevalence of congenital heart disease was significantly higher in fetuses with a right-sided echogenic focus than in those with left-sided or bilateral foci 6

Postnatal Significance

• As an isolated finding, an echogenic cardiac focus may be associated with a statistically significant but clinically insignificant decrease in birth weight 5
• In one study, postnatal echocardiography found no cases of intracardiac tumor or myocardial dysfunction, and only one neonate had minor structural malformations 5