Venous Doppler ultrasound procedures are billed using either CPT code 93970 or 93971, according to Radiology Today magazine. The difference between these CPT codes is the extent of the study, with 93970 used for complete bilateral studies and 93971 reserved for unilateral or limited studies.
The CPT codes for Doppler ultrasound are used alone or in conjunction with other codes, depending on the extent of the testing performed, notes the American College of Radiology. The CPT codes 93970 and 93971 apply to either the upper or lower extremities.
Doppler ultrasound is categorized as a noninvasive vascular diagnostic study, according to the American College of Radiology. The imaging procedure reflects sound waves in order to assess the blood flow through a blood vessel.