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 BW3HZ
Magnetic Resonance Imaging (MRI) of Retroperitoneum
MRI of Retroperitoneum using Oth Contrast, Unenh, Enhance
MRI of Retroperitoneum using Oth Contrast