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FETAL ESOPHAGUS |
- Can be visualized as early as 15 weeks gestation as two echogenic parallel lines (1) in the neck and posterior chest.
- After 26 weeks it appears as a tubular echogenic structure having one of two patterns:
- Two parallel echogenic lines.
- Several parallel echogenic lines (the "multilayered pattern"). This is seen in 49% of cases prior to 26 weeks gestation and in 87% of cases after 26 weeks gestation.
- The thoracic esophagus can be visualized in about 90% of cases, the cervical esophagus (between the pharynx and the upper limit of the chest) in 19% of cases and the abdominal segments (between diaphragm and stomach) in 30% of cases (1).
- Swallowing may be seen intermittently (1-2 movements of the pharynx or mandible per minute).
- Anatomy.
- Trachea is anterior and bifurcates into the main bronchi.
- Esophagus continues without division.
- Trachea does not show variation in size unlike the esophagus.
- Azygous vein courses parallel and to the right of the spine (2).
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Note fluid movement within the
esophagus on color flow imaging |
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REFERENCES |
- Avni WF, Rypens F, Milaire J. Fetal esophagus. Normal sonographic appearance. J Ultrasound Med 1994;13:175-180.