The Radionuclide None is identified by letter "Z" and occupies the 5th position in the ICD10-PCS procedure code structure.
Below a selection of ICD 10 PCS codes related to C21GZ
Planar Nucl Med Imag of Myocardium using Thallium 201
Planar Nuclear Medicine Imaging of Myocardium
Planar Nucl Med Imag of Myocardium using Technetium 99m
Planar Nucl Med Imag of Myocardium using Indium 111
Planar Nucl Med Imag of Myocardium using Oth Radionuclide