Randomization and masking
Using SPSS software (Version 26, IBM, Armonk, NY), a statistician generated a randomization scheme that allocated the enrolled participants in a 1:1 ratio to two groups. The randomization scheme consisted of an enrollment order combined with treatment codes (A and B). Participants were assigned by a clinician who was aware of the order of the randomization scheme but unaware of the meaning behind each code. The assignment was made based on the enrollment order specified in the randomization scheme. Sonographers, statisticians, and outcome evaluators remained blinded to the allocation, while physicians and patients were informed.