The variable appearance of the left superior intercostal vein

Area of Science:

• Radiology
• Anatomy
• Thoracic Imaging

Background:

• The left superior intercostal vein is a thoracic structure with variable visualization on chest radiographs.
• Accurate identification of thoracic anatomy is crucial for interpreting chest imaging findings.

Purpose of the Study:

• To document the prevalence, location, and appearance of the left superior intercostal vein on postero-anterior chest radiographs.
• To describe variations in the vein's presentation, specifically the aortic "nipple" and retroaortic portion.

Main Methods:

• Review of several hundred postero-anterior chest radiographs.
• Systematic documentation of the left superior intercostal vein's visibility, location, and morphology.

Main Results:

• The left superior intercostal vein was visualized in 9.5% of the reviewed radiographs.
• Variations in the vein's end-on appearance (aortic "nipple") and retroaortic portion were observed and described.
• The retroaortic portion can be visible through the aortic knob.

Conclusions:

• The left superior intercostal vein is an identifiable structure in a subset of patients on chest X-ray.
• Understanding its anatomical variations is important for accurate radiological interpretation and avoiding misdiagnosis.