Radiology Coding Alert

Answer: Determining the correct CPT Code for an ultrasonic procedure requires knowledge of the different types of US procedures and their components.

Diagnostic ultrasound is an imaging technique that uses high-frequency ultrasound waves to create images of body structures. These images are usually viewed in black and white, or shades of gray. Many of the ultrasound CPT Code descriptions refer to what is called a B-scan and/or real time. A B-scan is a two-dimensional ultrasonic scanning procedure with a two-dimensional display, while real time indicates two-dimensional scanning with a display of both two-dimensional images and motion with time.

Doppler ultrasonography is defined as the application of diagnostic ultrasound to detect moving blood cells or other moving structures and measure their direction and speed of movement. The Doppler effect is used to evaluate movement by measuring changes in frequency and of the echoes reflected from the moving structures.

Doppler US permits real-time viewing of blood flow that cannot be obtained by other sonographic methods. Doppler provides the ability to observe changes in blood flow, which are displayed in color and can be heard as a change in pitch.

The duplex scan earned its name because it combines two types of ultrasound, B-mode imaging (real time) and Doppler ultrasound. Duplex scans are ultrasonic scanning procedures with the display of both two-dimensional structure and motion with time and Doppler ultrasonic signal documentation with spectrum analysis and/or color flow velocity mapping or imaging.

As far as billing is concerned, duplex scans include both real-time scans and Doppler evaluation. But not all real-time scans include Doppler, nor do all Doppler studies include real-time imaging.

The report provided lacks important clinical detail. If the examination performed was a complete transab-dominal pelvic ultrasound, the code would be 76856, 76857 for a limited exam, and 76830 for a transvaginal exam. None of these examinations includes Doppler analysis of specific vessels. However, evaluation of blood flow in solid structures such as masses or organs is included in the routine examination. Based on the report as provided, it does not appear that in this case additional coding for Doppler evaluation is indicated.

If detailed Doppler evaluation of blood vessels necessary to answer the pertinent clinical question is performed (and for nonfacility patients specifically requested by the referring physician or necessitated by the emergent condition of the patient), the appropriate CPT code(s) for additional Doppler studies should be reported in addition to the real-time ultrasound codes (e.g., 93975, 93976, 93978, 93979). It must be understood that the nature of the Doppler services provided must be congruent with the CPT definitions of the particular codes.