74425

Urography, antegrade (pyelostogram, nephrostogram, ureterogram), radiological supervision and interpretation

CPT code 74425 describes the radiological supervision and interpretation (RS&I) component of antegrade urography. This procedure involves the visualization of the upper urinary tract—specifically the renal pelvis, calyces, and ureters—following the direct introduction of radiopaque contrast material. The term 'antegrade' refers to the direction of flow, which follows the natural physiological path of urine from the kidneys down toward the bladder, as opposed to 'retrograde' studies which are performed via the urethra. This imaging is typically performed in a fluoroscopy suite or an interventional radiology department. The process begins after access to the renal collecting system has been established, often through a previously placed percutaneous nephrostomy tube or via a newly inserted needle (the surgical access/injection component is coded separately). Once the contrast is injected, the radiologist uses fluoroscopy to monitor the filling of the renal pelvis and the transit of contrast through the ureter. This allows for the real-time assessment of the internal anatomy, the identification of filling defects such as calculi or tumors, the localization of obstructions or strictures, and the evaluation of the integrity of the collecting system in cases of suspected trauma or fistula. The RS&I component represented by 74425 specifically covers the professional work of directing the imaging, interpreting the findings in real-time, and producing a formal written report detailing the anatomical and functional observations of the urinary tract.

Clinical Indications

  • Evaluation of the site and cause of urinary tract obstruction
  • Assessment of the integrity of the ureter following trauma or surgery
  • Diagnosis of ureteral strictures or narrowings
  • Characterization of filling defects within the renal pelvis or ureter
  • Preoperative mapping of anatomy prior to stone removal or reconstructive surgery
  • Evaluation of a percutaneous nephrostomy tube position and function
  • Assessment of congenital anomalies of the upper urinary tract
  • Detection of urinary fistulas or leaks
  • Monitoring of healing following ureteral stenting or repair

Procedure Steps

  1. The patient is positioned on the fluoroscopy table, typically in a prone or semi-prone position.
  2. The existing percutaneous nephrostomy tube site is cleaned and prepped in a sterile manner.
  3. If no tube exists, percutaneous access is established by a surgeon or interventionalist (coded separately).
  4. A small amount of urine may be aspirated to confirm needle or catheter position within the collecting system.
  5. Radiopaque contrast media is slowly injected into the renal pelvis under fluoroscopic guidance.
  6. The radiologist observes the filling of the renal calyces and the renal pelvis for any abnormalities.
  7. The patient may be tilted (Trendelenburg or reverse Trendelenburg) to facilitate the flow of contrast into the ureter.
  8. Multiple spot films or digital images are captured at various stages of filling and drainage.
  9. The passage of contrast into the bladder is confirmed to assess for total or partial obstruction.
  10. The procedure concludes once the upper urinary tract is sufficiently opacified and visualized.
  11. The contrast is often drained back through the nephrostomy tube if necessary, and the tube is secured.

Coding Guidelines

  • Code 74425 represents only the radiological supervision and interpretation. The injection procedure or catheter placement must be reported separately (e.g., see 50433, 50435).
  • Do not report 74425 in conjunction with bundled codes that already include RS&I, such as 50430 or 50431.
  • If performed by a different physician than the one performing the injection, the radiologist reports 74425 for the interpretation component.
  • For retrograde urography, use code 74420 instead.
  • Ensure that the medical record contains a formal written report of the findings to satisfy the requirements for a supervision and interpretation code.
  • In cases of bilateral procedures, modifier 50 may be applicable depending on the surgical component, though 74425 is often used once if the interpretation covers both sides during the same session.

Associated ICD-10 Codes