Ultrasound Case of the Month

42 y/o female with right anterior chest wall pain

Metallic markers placed over anterior chest wall at site of pain. No abnormality was detected on the initial radiographs.

Figures A and B. Long axis images of the costochondral junction of the right anterior second and thirdribs. (A) Red arrow depicts cortical discontinuity along the second rib at the costochondral junction (yellow arrows demonstrate the hyaline cartilage). (B) A normal costo-chondral junction is seen at the third rib (green arrow- rib cortex; yellow arrows- cartilage). The rib appears as a bright reflector with posterior shadowing. A wavy echogenic line below the cartilage represents the pleural surface (blue arrows). The rib and adjacent cartilage should appear as a continuous line.

A. B.

Figure C. Transverse view through the 2nd costochondral junction. A smallhypo-echoic gap ( red arrow) is present in the rib, corresponding to the non-displaced fracture. This should normally be smooth and continuous. There is dense shadowing deep to the rib. The linear white line deep to the rib relates to the pleural edge (blue arrows).

Diagnosis: Costochondral junction fracture, right second anterior rib

Ultrasound provides a sensitive method to detect radiographically occult rib and cartilage fractures.

References: 1. Griffith et al. Sonography compared with radiography in revealing acute rib

fractures. AJR 1999; 173: 1603-0. 2. Turk et al. Evaluation by ultrasound of traumatic rib fractures missed by

radiography. Emerg Radiol 2010; 17: 473-7.