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 C025YZ
Tomo Nucl Med Imag Cerebrospinal Fluid w Oth Radionuclide
Tomo Nucl Med Imag of Cerebrospinal Fluid using Indium 111