This is A non-blinded trial. Oral radioiodine was given 24 hours after the second injection of rhTSH, and scanning was done 48 hours after the radioiodine administration. Each patient was scanned first following rhTSH and then scanned after thyroid hormone withdrawal.

Inclusion Criteria:

• Subjects voluntarily sign the informed consent form (ICF).
• Age 18-75 years old, either male or female.
• Patients with diagnosed differentiated papillary or follicular thyroid carcinoma, including papillary-follicular variant,.
• Patients with a total or near-total thyroidectomy within 6 weeks prior to administered.
• Low iodine diet for 4 weeks prior to randomized.

Exclusion Criteria:

• Pregnant or breast feeding women.
• Patients with other malignancies (exception for in situ cervix uterine cancer, baso cellular skin cancer or breast cancer in remission)
• Subjects who are unsuitable to the trial in combination with other serious diseases, as identified by the investigator.
• Subjects who have participated in another clinical trial of a new drug or medical instrument within 1 months before screening.