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 CP171Z
Planar Nucl Med Imag Spine & Pelvis w Oth Radionuclide
Planar Nucl Med Imag of Spine & Pelvis using Technetium 99m