Normal left atrium: appearance in children on frontal chest radiographs

Area of Science:

• Pediatric Radiology
• Cardiovascular Imaging
• Thoracic Anatomy

Background:

• The right lateral border of the left atrium is a recognizable feature on anteroposterior radiographs.
• Understanding its normal appearance is crucial for accurate pediatric chest imaging interpretation.

Purpose of the Study:

• To determine the frequency of visualization of the right lateral border of the left atrium in pediatric frontal radiographs.
• To differentiate normal left atrial borders from pathological findings that may mimic this shadow.

Main Methods:

• Review of 543 frontal chest radiographs, predominantly of children.
• Comparison of plain chest radiographs with frontal angiocardiograms to confirm the anatomical structure.

Main Results:

• The right lateral border of the left atrium was visualized in 30% of the reviewed radiographs.
• A prominent shadow was observed in only 2.5% of cases.
• Angiocardiography confirmed the shadow represents the lateral or inferior wall of the left atrium.

Conclusions:

• The right lateral border of the left atrium is a common finding in pediatric anteroposterior radiographs.
• Knowledge of this anatomical landmark aids in the differential diagnosis of cardiac abnormalities in children.