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 BY33Z
Magnetic Resonance Imaging (MRI) of Fetal Abdomen
MRI of Fetal Abd using Oth Contrast
MRI of Fetal Abd using Oth Contrast, Unenh, Enhance