The Qualifier None is identified by letter "Z" and occupies the 6th position in the ICD10-PCS procedure code structure.
Below a selection of ICD 10 PCS codes related to CG421Z
Nonimag Nucl Med Uptake of Thyroid Gland using Iodine 123
Nonimag Nucl Med Uptake of Thyroid Gland using Iodine 131
Nonimag Nucl Med Uptake Thyroid Gland w Oth Radionuclide
Nonimag Nucl Med Uptake Thyroid Gland w Technetium 99m