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 BQ31Z
Magnetic Resonance Imaging (MRI) of L Hip using Oth Contrast
Magnetic Resonance Imaging (MRI) of Left Hip
MRI of L Hip using Oth Contrast, Unenh, Enhance