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 B300ZZ
Plain Radiography of Thoracic Aorta
Plain Radiography of Thoracic Aorta using L Osm Contrast
Plain Radiography of Thoracic Aorta using H Osm Contrast
Plain Radiography of Thoracic Aorta using Other Contrast