The Radionuclide Iodine 123 (I is identified by letter "F" and occupies the 5th position in the ICD10-PCS procedure code structure.
Below a selection of ICD 10 PCS codes related to CG42F
Nonimag Nucl Med Uptake Thyroid Gland w Technetium 99m
Nonimag Nucl Med Uptake Thyroid Gland w Oth Radionuclide
Nonimag Nucl Med Uptake of Thyroid Gland using Iodine 131
Nonimag Nucl Med Uptake of Thyroid Gland using Iodine 123