The Contrast 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 BW3PZ
MRI of Brachial Plexus using Oth Contrast, Unenh, Enhance
MRI of Brachial Plexus using Oth Contrast
Magnetic Resonance Imaging (MRI) of Brachial Plexus