Hepatocellular carcinoma treatment response: Imaging findings and criteria

Table 1 Imaging technique

	CT	MRI	CEUS
Availability	Broadly available	Limited accessibility	Limited accessibility
Costs	Less expensive	High	Less expensive
Radiation exposure	Moderate	None	None
Time taken	Fast	Long	Fast
Advantages	Good soft tissue contrast	High soft tissue contrast; Problem-solving technique	High temporal resolution; No nephrotoxicity of contrast agents
Limits	Nephrotoxicity of contrast agents; Radiation exposure	Claustrophobia; Metal and medical implants (e.g., peace-makers) due to magnetic field pulses	High level of operator expertise; Deep lesion location Patient obesity

CT: Computed tomography; MRI: Magnetic resonance imaging; CEUS: Contrast enhanced ultrasound.

Table 2 Differences between Response Evaluation Criteria in Solid Tumors 1.1, Modified Response Evaluation Criteria in Solid Tumors, and LR-TRA

	RECIST 1.1	mRECIST	LR-TRA
Evaluation targets	Largest diameter of target lesions	Largest diameter of the viable portion of target lesions	Mass-like enhancement; Ancillary Li-RADS features
Advantages	-	Evaluation of post-treatment changes in lesion vascularity	Response to therapy is evaluated at a lesion-level; Pseudoprogression is not taken into account; Evaluation of response to radiotherapies
Limits	Post-treatment changes in lesion vascularity are not evaluated; Evaluation of response to immunotherapies	Evaluation of response to immunotherapies	Evaluation of response to systemic or immunotherapy; Hepatobiliary phase is not an ancillary feature

RECIST 1.1: Response Evaluation Criteria in Solid Tumors 1.1; mRECIST: Modified Response Evaluation Criteria in Solid Tumors; LR-TRA: LI-RADS Treatment Response.