Advanced imaging pathways
For complex lesions and surgery, CT, MRI and ultrasound answer different questions about bone, soft tissue and vascular or nodal structures.
Understand
CT depicts bone and acute structural detail, MRI characterises many soft tissues without ionising radiation, and ultrasound assesses accessible soft tissues and salivary glands. The question determines the modality.
Assess
State whether the concern is cortical destruction, soft tissue extent, nodal disease, duct obstruction or vascularity. Consider contrast, artefact and contraindications.
Apply
Interpret specialist imaging with the radiologist and clinical examination. Do not use a modality's normal result to dismiss a problem it is poorly suited to detect.
Key distinctions
MRI offers soft-tissue contrast and can help define tumour or salivary pathology, while CT depicts cortical bone and can be useful in acute complex infection or trauma. Ultrasound is accessible for superficial soft tissues and salivary glands and can guide sampling. Contrast use, implants, motion and patient tolerance influence choice. Ask the radiologist a specific question and correlate the report clinically.
Think through a case
MRI is requested for a deep soft tissue mass, while CT better defines suspected cortical destruction. The modality must fit the tissue question.
The distinction to remember
Do not interpret a negative study as excluding pathology outside that modality's strengths.
Test your recall
Which modality usually gives better soft tissue contrast: CT or MRI?
Show answer
MRI.