93975

Duplex Scan, Abdominal Aorta and Inferior Vena Cava, or Unspecified Visceral Arteries and/or Veins; Unilateral or Bilateral

CPT code 93975 describes a non-invasive diagnostic ultrasound procedure known as a duplex scan. This procedure combines B-mode (grayscale) imaging with Doppler ultrasound to evaluate blood flow and structural integrity within specific abdominal vessels. The scan can target the abdominal aorta and inferior vena cava (IVC) to assess for conditions such as aneurysms, dissections, thrombosis, or stenoses. Alternatively, it can focus on unspecified visceral arteries and/or veins, which may include vessels supplying the kidneys, liver, spleen, or intestines, to detect various vascular pathologies. The "duplex" aspect refers to the simultaneous use of real-time imaging (B-mode) to visualize the vessel's anatomy and pulsatile Doppler to assess blood flow characteristics, including velocity, direction, and flow patterns. This comprehensive assessment allows for the identification of blockages, narrowing, or abnormal widening of vessels, as well as the presence of clots or other intraluminal abnormalities. The procedure is typically performed by a trained sonographer and interpreted by a physician, often a radiologist or vascular specialist. It is a valuable tool for diagnosing conditions that can lead to significant morbidity and mortality if left untreated, providing critical information for surgical planning or medical management. The term "unilateral or bilateral" in the code description signifies that the service covers the examination of one or both sides of the body where applicable, for example, in the case of renal arteries or veins. The selection of specific visceral vessels depends on the clinical indication provided by the referring physician. The study evaluates vessel lumen diameter, wall characteristics, presence of plaque, and hemodynamic changes.

Clinical Indications

  • Evaluation of suspected abdominal aortic aneurysm (AAA)
  • Monitoring known AAA
  • Assessment for abdominal aortic dissection
  • Evaluation of suspected inferior vena cava (IVC) thrombosis or obstruction
  • Diagnosis and surveillance of renal artery stenosis (e.g., in patients with refractory hypertension)
  • Evaluation of suspected mesenteric ischemia (e.g., celiac, superior mesenteric artery stenosis/occlusion)
  • Assessment of portal hypertension (e.g., portal vein thrombosis, splenorenal shunts)
  • Evaluation of suspected hepatic vein outflow obstruction (Budd-Chiari syndrome)
  • Pre-operative mapping for vascular surgery
  • Post-operative surveillance after abdominal vascular repair (e.g., stent placement, endarterectomy)
  • Evaluation of abdominal bruits or pulsatile masses
  • Assessment of unexplained abdominal pain or ascites
  • Follow-up of vascular anomalies or malformations
  • Evaluation of transplant renal artery/vein patency and flow

Procedure Steps

  1. Patient Preparation: Explain procedure, position patient supine, expose abdomen.
  2. Transducer Selection: Select appropriate low-frequency (2-5 MHz) curvilinear or phased array transducer.
  3. Gel Application: Apply acoustic coupling gel to the abdominal skin.
  4. B-mode Imaging: Obtain grayscale images of the target vessels (e.g., abdominal aorta, IVC, renal arteries/veins, mesenteric arteries/veins).
  5. Vessel Identification and Documentation: Identify and document the anatomy of the main abdominal aorta from the diaphragm to the bifurcation, the IVC, and specific visceral vessels as indicated. Measure diameters of the aorta if aneurysm is suspected.
  6. Pulsed Doppler Analysis: Apply pulsed Doppler to assess blood flow velocity, direction, and waveform characteristics within the identified vessels.
  7. Color Doppler Mapping: Utilize color Doppler to visualize blood flow patterns, identify areas of turbulent flow, and confirm vessel patency.
  8. Spectral Waveform Acquisition: Acquire spectral Doppler waveforms at multiple points along the vessel, including any areas of suspected stenosis or occlusion.
  9. Measurements and Calculations: Perform measurements such as peak systolic velocity (PSV), end-diastolic velocity (EDV), and calculate ratios (e.g., renal-aortic ratio) if indicated.
  10. Documentation: Capture and store relevant images and Doppler waveforms, ensuring comprehensive documentation of normal and abnormal findings.
  11. Interpretation: A physician reviews the acquired images and data to generate a diagnostic report.

Coding Guidelines

  • CPT code 93975 is used for duplex scans of the abdominal aorta and inferior vena cava OR unspecified visceral arteries and/or veins. It is inherently a bilateral or unilateral code; no separate bilateral modifier is typically used.
  • The code covers both the technical and professional components of the service. If performed in a facility setting, the facility bills for the technical component and the physician for the professional component.
  • If both the abdominal aorta/IVC and *specific* visceral arteries/veins are studied, use 93975 for the aorta/IVC and additional codes (e.g., 93976 for specific visceral duplex) if distinct studies are performed and separately documented for different indications. However, note that 93975 states "unspecified visceral arteries and/or veins", implying it can cover the screening of several abdominal vessels without specifying each one. If the study focuses on *specific* vessels for a *specific* indication beyond a general survey, 93976 might be more appropriate. Clarification is often needed from payer policies or the documentation itself.
  • Do not report 93975 in conjunction with 76770 (Ultrasound, retroperitoneal) if the duplex scan is the primary study and the retroperitoneal ultrasound is merely incidental to the vascular assessment.
  • When evaluating for renal artery stenosis, code 93975 is appropriate if the entire renal vascular system (including aorta/IVC) is surveyed or if the focus is on unspecified visceral vessels. Many payers consider 93975 to include evaluation of renal arteries/veins as "unspecified visceral vessels." If the study is specifically limited to renal arteries and veins (a "targeted" study), 93976 might be considered, but 93975 usually encompasses this.
  • Documentation must clearly state the vessels examined, the findings, and the medical necessity.

Associated ICD-10 Codes