Table 2.

Strengths and weaknesses of HUS and MRN in evaluation of trauma to the peripheral nerves.

	Ultrasound	MRI
Strengths	•Higher spatial resolution for assessment of nerve morphology and fascicular pattern within the nerve (direct nerve changes)	•Enables objective assessment
	•Longer coverage (entire nerve) in short time	•Better detection of muscle denervation changes (indirect findings)
	•Comparison with contralateral side is easy	•Deeper structures can be optimally assessed
	•Real time dynamic evaluation, especially in entrapment syndromes	•Osseous edema and fractures can be accurately assessed
	•Guiding perineural intervention procedures	•The whole soft tissue envelope is better evaluated in a single imaging series
	•Faster and cheaper
	•No contraindications
	•Peri-implant imaging is better
	•Better assessment of very superficial nerves (digital nerves, superficial sensory branches of radial and median nerves)
	•Doppler assessment (intraneural/perineural congestion)
Limitations	•Operator dependent and requires time to learn	•Artefacts from metallic implants (even if MR compatible) may make the nerve evaluation difficult
	•Anisotropy in long axis may lead to interpretation errors	•Lower spatial resolution for nerve morphology (especially in case of smaller nerves)
	•Evaluation difficult for deeper nerves (thigh) and in obese patients	•Claustrophobia & cardiac pacemakers are a limitation
		•Magic angle artifact may lead to interpretation errors