The correct reporting of Doppler or duplex services provided depends on what was ordered, what was performed, and what was documented. Per Current Procedural Terminology (CPT) instructional notes, “…color Doppler alone, when performed for structure identification with a real-time ultrasound examination, is not reported separately.”1 Also noted, “The use of a simple hand-held or other Doppler device that does not produce hard copy output, or that produces a record that does not permit analysis if bidirectional vascular flow, is considered to be part of the physical examination of the vascular system and is not separately reported.”2 The American College of Radiology further states, “It is important to remember that the duplex study represented by codes 93975/93976 should not be coded when a quick look with color Doppler is done to check whether flow is present or for structure identification.”3 If these apply at the time of a diagnostic ultrasound exam, only the appropriate ultrasound code will be reported.
CPT defines a duplex scan as an “ultrasonic scanning procedure for characterizing the pattern and direction of blood flow in the arteries or veins with the production of real-time images integrating B-mode two-dimensional vascular structure, Doppler spectral analysis, and color flow Doppler imaging.”4 Best practice is to include this information in the technique portion of your report. At a minimum the technique part of the report should state “A duplex Doppler was performed”.5
Technique terms to support a duplex scan are:
- Imaging (Real-time, B mode, 2-D) with
- Doppler spectral analysis and
- Color flow Doppler
A duplex scan may only be reported when documentation of the assessment of flow with color, recording a spectral waveform is provided, and a report of the findings is present. “Documentation of color Doppler without documentation of spectral Doppler analysis is not sufficient to support the assignment of a duplex code.”6
Whether normal or abnormal, include findings related to both the color flow and the spectral analysis. Some examples might be:
- Normal flow, compressibility, augmentation demonstrated on spectral analysis
- If no flow is visualized then there should be a mention in the radiology report that the spectral Doppler evaluation showed no flow.
- If the waveform appears normal, this should also be mentioned in the report.
- Normal flow pattern is noted on color Doppler imaging
If a diagnostic ultrasound is performed at the same patient encounter as a duplex scan, a separate report for each individual exam is suggested as best practice. If one report is generated, then separate documentation of each exam (via separate paragraphs) should be provided, including technique and findings, in order to support performance and reporting of both services. This is especially important since many “procedure to procedure” National Correct Coding Initiative (NCCI) edits are in place for diagnostic ultrasound and duplex codes.
For example, when both exams are adequately supported by the documentation, a complete diagnostic non-obstetric ultrasound exam of the female pelvis (76856) may be reported in addition to a duplex Doppler imaging evaluation. Complete study (93975) includes bilateral arterial inflow and venous outflow evaluation. The limited study (93976) is reported if unilateral evaluation or only arterial or venous evaluation is performed. These code combinations are bundled per NCCI edits (one service is considered a component of the other service). A modifier must be reported if the documentation supports a complete, separate, non-overlapping exam was performed. If all the requirements for each exam are not supported by the dictated final report, only the most comprehensive CPT may be reported.
Include the medical indication or reason for each exam performed.
- If the diagnostic ultrasound resulted in a finding which requires evaluation by duplex imaging, include this information
Doppler doesn’t always mean Duplex
“Doppler” may also be part of a “physiologic” non-imaging, noninvasive vascular study. There are CPT codes specific to the extremities which describe the evaluation of non-imaging physiologic recordings of pressures with Doppler analysis of bi-directional flow, plethysmography, and/or oxygen tension measurements appropriate for the anatomic area studied.
If a duplex is being performed always say “duplex” or “duplex Doppler”
In summary, multiple exams performed at the same patient encounter presents the challenge of providing complete documentation for each of the separate exams performed. To help obtain appropriate reimbursement in a timely manner, it’s essential that complete documentation of the exams performed is provided.