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 B54CZZ
Ultrasonography of Left Lower Extremity Veins, Intravascular
Ultrasonography of Left Lower Extremity Veins
Ultrasonography of Left Lower Extremity Veins, Guidance