Rib fractures are the most common (25%) injuries resulting from blunt chest trauma and are usually revealed on plain radiographs. However, plain radiograph sometimes may not show fractures, especially in nondisplaced fractures and costal cartilage fractures.

CT is the gold standard technique for showing rib fractures. However, cartilage fractures can be easily overlooked when focusing on bony fractures or pulmonary parenchymal tissue and also doesn't show up in the commonly used bone window 3D volume rendering.

In the literature, the usefulness of ultrasonography in detecting rib fractures varies widely from not significant to more sensitive than radiography.

The greatest advantage of ultrasonography is the ability to directly explore the tender point by asking the patient to pinpoint the most painful rib during the examination.

In patients presenting with blunt chest trauma, ultrasonography can provide a prompt means to confirm or rule out associated findings such as pleural effusion, pneumothorax and hemothorax.

On the other hand, the advantages of ultrasonography include non-invasiveness, portability, relative inexpensiveness, lack of radiation, and repeatability, making it a valuable diagnostic tool.

In the pediatric population and pregnant women, ultrasonography may be preferable. 

This case shows the importance of ultrasonography in the evaluation of rib fractures, especially in minor or mild blunt chest trauma.