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 B24BZ
Ultrasonography of Heart with Aorta, Transesophageal
Ultrasonography of Heart with Aorta using Other Contrast
Ultrasonography of Heart with Aorta
Ultrasonography of Heart with Aorta, Intravascular