Table 3.

Comparison of Advantages and Disadvantages of CT and MRI

Variable	Head CT	MRI
Technical	Head trauma/skull fracture	Better for most examinations
	Acute bleed	Parenchyma and
	Calcifications	white matter lesions
	Emergent mass effect/herniation process	Posterior fossa and brain stem
	Emergent hydrocephalus MRI contraindications (metallic foreign bodies, claustrophobia, size/weight)	CT contraindications (generally related to radiation risks: pregnancy, children < 3 y)
Practical	Quick imaging time (emergencies)	Longer imaging time
	Broad availability (emergencies)	Higher cost (although becoming less costly)
	Low cost	No radiation, safer for repeated studies

Abbreviations: CT = computed tomography, MRI = magnetic resonance image.