Summary & Overview
CPT 50431: Nephrostogram or Ureterogram via Existing Access
CPT code 50431 denotes a diagnostic radiologic procedure in which contrast is injected through an existing access to produce a ureterogram or nephrostogram. Nationally, this code captures targeted imaging of the renal collecting system used to evaluate the function of nephrostomy or pyelostomy tubes, detect ureteropelvic junction obstruction, and identify contrast extravasation around tube sites. The code consolidates the diagnostic injection with radiological supervision and interpretation, making it relevant for hospitals, outpatient imaging centers, and interventional radiology practices.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical indications and typical sites of service, an explanation of the service bundled by the code, and a summary of payer coverage considerations. The publication highlights common billing modifiers and usage patterns, clarifies the clinical context for ordering the procedure, and points to areas where policy language commonly affects coverage and payment. Data not provided in the input—such as associated taxonomies, specific ICD-10 diagnoses, and related codes—are noted as unavailable.
Billing Code Overview
CPT code 50431 describes a diagnostic contrast injection study performed through an existing access route to visualize the internal structures of the kidneys, renal pelvis, and/or ureters. The procedure involves injecting contrast material into the ureters (ureterogram) or directly into the renal collecting system (nephrostogram) to evaluate anatomy and function.
Service Type: Diagnostic radiologic contrast study of the urinary collecting system via existing access
Typical Site of Service: Hospital outpatient department, ambulatory surgical center, or interventional radiology suite
This procedure includes the complete diagnostic service and all required radiological supervision and interpretation. It is commonly used to assess the function of nephrostomy or pyelostomy tubes, identify ureteropelvic junction obstruction, or detect leakage of urine around a tube insertion site.
Clinical & Coding Specifications
Clinical Context
A 68-year-old male with a long-standing left nephrostomy tube presents with decreased urine output from the tube and intermittent flank pain. Prior imaging suggested possible obstruction at the ureteropelvic junction. The interventional radiologist performs a nephrostogram by accessing the existing nephrostomy catheter, instilling radiopaque contrast through the catheter, and obtaining fluoroscopic images of the renal collecting system and ureter to assess catheter patency, detect obstruction, and evaluate for extravasation. The workflow includes review of prior imaging and labs, informed consent, sterile preparation of the access site, contrast injection through the existing nephrostomy or pyelostomy tube, fluoroscopic imaging and interpretation, and documentation of findings and any immediate management recommendations such as tube repositioning or exchange if indicated. Typical site of service is the hospital radiology suite, outpatient radiology or interventional suite, or ambulatory surgical center when clinically appropriate. The service is diagnostic and includes radiological supervision and interpretation.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing physician interpretation separately from technical component |
TC |