ACR Radiology Coding Source™ July-August 2005

The genitourinary system includes all organs involved in reproduction and in the formation and excretion of urine. The urinary system consists of the kidneys (with calyces and renal pelves – together often called the collecting system) and the ureters, urinary bladder, and urethra. Discussion of the various radiological studies of the urinary system will be addressed here since there is much confusion about when to use the radiologic, ultrasound and nuclear medicine urinary system codes. The male and female genital systems will not be discussed here.

Radiologic Diagnostic Studies of the Urinary Tract

Non-invasive diagnostic imaging studies of the urinary system include ultrasound of the kidneys, ureters, and bladder (76770, 76775, 76857), nuclear medicine kidney, bladder, and ureteral studies (CPT 787xx range), and urography (74400-74420).

Ultrasound

CPT® 2005 imposed requirements on coding for complete abdominal and retroperitoneal ultrasound studies relating to documentation of all the obligate elements that constitute complete studies of these anatomic regions. Guidelines provided in the CPT 2005 code book make it clear that a diagnostic ultrasound study of the kidneys and urinary bladder is coded with 76770, which is a complete retroperitoneal study. Although the kidneys are one of the required elements of both a complete abdominal and a complete retroperitoneal ultrasound study, coding for both an abdominal and retroperitoneal ultrasound study performed together is considered unusual, and should only be done when an ordering physician documents the circumstances of medical necessity1. If only the kidneys are imaged, code 76775 should be used. If only the bladder is imaged, CPT 2005 instructions state that code 76857 should be used.

Radiography

Intravenous urography (pyelography) is radiography of the urinary tract following the injection of contrast into a vein with resultant opacification of the urinary tract (ie, urethra, bladder, ureter, renal pelves, and kidneys). Code for intravenous urography (pyelography) with 74400-74415.

Retrograde urography (pyelography) is imaging performed after the injection of contrast through a catheter placed into the ureter via the urethra and bladder. The imaging may be interpreted by a radiologist, although the surgical portion of the procedure is most often performed by another physician (ie, urologist) in the OR Cysto Suite. Code for the interpretation of imaging for retrograde urography (pyelography) with 74420.

Nuclear Medicine

Nuclear medicine diagnostic studies (78700 through 78740) cover a range of methods for obtaining diagnostic information about the kidneys and collecting system. Anatomy, vascular flow, and renal function can be measured with or without pharmacological intervention, and the definitions of these CPT codes are fairly straightforward. A nuclear medicine study to measure urinary bladder residual is coded with 78730. This study is performed to assess how well the bladder empties, and to detect the presence of any obstruction or dysfunction. The detection of vesicoureteral reflux, utilizing imaging during radionuclide filling and emptying of the urinary bladder is reported by code 78740. When these nuclear medicine studies are performed, the catheterization of the urinary bladder by a physician performed prior to theses studies is coded separately with 51701, 51702, or 51703.

Diagnostic Studies With Surgical Components

As mentioned in the preceding paragraphs, many surgical codes figure into CPT coding for urinary tract diagnostic studies. Cystography, the study of the bladder with direct injection of a radiopaque agent, is coded with 51600/74430, and a dynamic study while voiding is coded with 51600/74455. The injection procedure for cystography includes the catheterization of the bladder; therefore, catheterization is not coded separately. For retrograde urethrocystography, codes 51610/ 74450 are reported.

Antegrade urography (pyelography) is performed commonly by a radiologist who performs both the surgical and supervision and interpretation portions of the study. In this diagnostic procedure, there is injection of contrast through a percutaneously placed needle or catheter into the renal collecting system to obtain imaging of the upper collecting system down through the ureter. The codes used to describe this study are 50390/74425 for needle placement and 50392/74425 for catheter placement. This procedure may be done prior to making a decision to perform a therapeutic interventional procedure that would allow drainage of urine from the kidney or collecting system.

A nephrostogram is a urogram (pyelogram) performed through an existing nephrostomy catheter. This diagnostic study is coded with 50394/74425 and is done to evaluate the collecting system and ureter through a previously placed nephrostomy tube. Care should be taken in coding for this study. It should not be coded for a patient who presents for a routine nephrostomy tube change even if contrast is injected, and when no formal diagnostic assessment is necessary.2

A loopogram (50690/74425) is a diagnostic study done to evaluate an ileal conduit and the ureters using an iodinated contrast injection into the ileal conduit. An ileal conduit is created for patients who have undergone cystectomy or have other loss of normal bladder function. A portion of the ileum is used to create a replacement for the urinary bladder, and into this, the ureters are implanted. The opening of the ileal conduit is through the skin of the abdomen, through which the urine drains. The

loopogram study is used to determine whether the ureters are implanted and functioning without obstruction or extravasation. This study is accomplished through a catheter inserted through the skin into the ileal conduit.

Therapeutic Interventional Urinary System Procedures

The last category of procedures included in this discussion are the urinary tract therapeutic interventional procedures, such as radiofrequency ablation of renal lesions, cyst aspiration, nephrostomy, ureteral stent placement, cystostomy, and the removal or replacement of these resulting catheters and/or stents.

Radiofrequency ablation of renal lesions is becoming more common. As of 2005, CPT does not include a surgical code for this procedure. It is correctly reported with the unlisted procedure code 53899 plus the appropriate RFA guidance code (76362, 76394, or 76940). Note that the RFA guidance codes include needle placement, as well as monitoring of ablation. Look for new CPT codes to be available in 2006 related to this procedure.

Other renal interventions for treatment of lesions or fluid collections include renal abscess drainage (50021/75989), and renal cyst aspiration (50390 and appropriate modality-specific needle placement guidance code).

Nephrostomy tube placement is the insertion of a percutaneous needle/catheter through the back and into the upper collecting system to drain urine from the collecting system to the outside of the body. Placement of a nephrostomy tube is coded 50392/74475, and 76360, or 76942. The radiological supervision and interpretation code (RS&I) 74475 includes fluoroscopic guidance, therefore, fluoroscopic guidance (76003) is not coded separately. However, if CT guidance (76360) or ultrasound guidance (76942) is utilized in addition to fluoroscopy, these may be additionally coded. Exchange of a nephrostomy tube is coded with 50398/75984. Both the nephrostomy tube placement and nephrostomy tube change code pairs should be coded. (Follow payer-specific instructions for use of modifiers or units for bilateral coding.) When contrast is injected in the course of a new nephrostomy placement or nephrostomy tube change only to guide that procedure and a true diagnostic study of the collecting system/ureter is not performed, this is included in the RS&I codes.

A closely related procedure is the antegrade placement through the renal pelvis of a ureteral catheter component, or ureteral stent. This is done to facilitate internal drainage of urine through the ureter into the bladder, and is coded with 50393/74480. When both nephrostomy tube placement and ureteral catheter/stent placement are performed at the same time through the same access, it is appropriate to code for both, using the -59 or -51 modifier on 50392. The choice of modifier is based on carrier and payer specific instructions.3 Often, the question is asked about coding for dilatation for the insertion of a nephrostomy catheter or ureteral stent. Dilatation of a normal tract

for insertion of the catheter or stent is part of the surgical code 50392. Dilatation involving creation of a larger tract, for subsequent endourologic procedures, is not part of 50392 or 50393. Such dilatation should be coded with 50395/74485. Using a balloon catheter to dilate a lesion or stricture in the ureter is not described in CPT and would be coded with the unlisted procedure code 53899.

Ureteral stents are occasionally removed and replaced. Such services can be coded separately, since the global period for the initial placement of the stent is zero days. CPT 2005 has no code to describe ureteral stent removal or replacement, through any access (nephrostomy, ileal conduit, or other percutaneous method). As with some of the other areas of urinary system procedure coding, look for new codes in CPT 2006 to describe some of these procedures. In 2005, these should be coded using the unlisted urinary system procedure code 53899. Note that any nephrostomy tube removal that does not require imaging is included in the Evaluation and Management (E&M) service performed on that day.

New to CPT in 2005, 50391 was introduced for the purpose of instillation of therapeutic agent(s) into the renal pelvis. The procedure is accomplished through an existing nephrostomy tube.4 The insertion of that tube is separately reportable, as described above.

Last, there is the direct aspiration of the urinary bladder by suprapubic needle access (51000), trochar or intracatheter (51005) or with the insertion of a suprapubic catheter (51010). Creation of a new suprapubic percutaneous cystostomy, sometimes done by the radiologist, would be coded with 51040. For cystostomy tube (suprapubic catheter) changes, code 51705 or 51710, and add 75984 if guidance is used. Code 75984 would include any contrast injection used for guidance.

References:

For additional information on coding of urinary studies, please reference the following coding guides:

Nuclear Medicine Coding User's Guide 2005 Ultrasound Coding User's Guide 2003 Interventional Radiology Coding User's Guide 2005

1 Clinical Examples in Radiology, Update Bulletin, Volume 1, Bulletin 1, 2005

2 Interventional Radiology Coding User's Guide, 2005

3 For all coding recommended in this article, consult CCI to determine if modifiers are necessary and appropriate.

4 CPT Changes, An Insider's View, 2005