Korean J Radiol.  2003 Jun;4(2):136-139. 10.3348/kjr.2003.4.2.136.

Paratracheal Air Cysts: Sonographic Findings in Two Cases

• Kim YJ
• Kim EK
• Kim J
• Park CS

• KMID: 1118817
• DOI: http://doi.org/10.3348/kjr.2003.4.2.136

Abstract

We report two cases of paratracheal air cyst discovered incidentally at neck ultrasonography and confirmed at CT. The cysts were located at the inferoposterior aspect of the right lobe of the thyroid. Ultrasonography revealed an ill-defined hypoechoic mass containing hyperechoic foci which mimicked calcifications. Neck CT confirmed the presence of an ill-defined air pocket which communicated with the trachea through a slit.

Keyword

Trachea, cysts; Trachea, US; Trachea, CT

Figure

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  Fig. 1 A 43-year-old woman who underwent a routine medical checkup. A, B. Transverse (A) and longitudinal (B) sonograms of the neck depict a 2.9 × 1.4 - cm hypoechoic mass (thick arrows) with multiple hyperechoic foci (thin arrow) at the inferoposterior aspect of the right lobe of the thyroid gland. C. Neck CT shows an air-filled cyst (arrow) with an irregular wall to the right of the trachea. D. Reformatted coronal CT image depicts slit-like communication (arrowhead) between the trachea and the air cyst. (A=right common carotid artery, C=paratracheal air cyst, E=esophagus, T=trachea)

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  Fig. 2 A 65-year-old man who presented with anterior neck pain. A, B. Transverse (A) and longitudinal (B) sonograms of the neck reveal a 2.5×1.1-cm hypoechoic mass (thick arrows) with multiple hyperechoic foci (thin arrows) at the inferoposterior aspect of the right lobe of the thyroid gland. C. Neck CT shows an air cyst (arrow) to the right of the trachea, with slit-like communication between it and the trachea. D. Reformatted coronal CT image reveals the presence of an air pocket to the right of the trachea. (C=paratracheal air cyst, E=esophagus, T=trachea, Th=right lobe of the thyroid gland)

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  Fig. 3 A phantom model made with pork and a balloon. A, B. A small balloon connected to a syringe was placed between two slices of pork, and ultrasonography was performed. C. The balloon is depicted as a hypoechoic mass (arrows) with an echogenic wall. Within it, muliple hyperechoic foci are observed.

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