Final answer:
Computed tomography (CT) scanning is the imaging modality commonly used to evaluate head trauma.
Step-by-step explanation:
The imaging modality commonly used to evaluate head trauma is computed tomography (CT) scanning. CT scanning uses a series of x-ray images taken from different angles to create detailed cross-sectional images of the head. This technique is particularly useful for detecting fractures, bleeding, and other types of injuries in the skull and brain.