Radiology Coding Alert

Understand when a PET CT is a necessary procedure.

Each year, the National Correct Coding Initiative (NCCI) edits foster proper coding methods and control improper coding for Part B claims. However, the wording in the NCCI manual can be tricky to navigate at times, especially for radiology techniques like positron emission tomography (PET) and PET computed tomography (CT) procedures.

Read on to understand NCCI edits as they pertain to PET and PET CT scans.

Bring Clarity to Fuzzy PET Scan NCCI Guidelines

When radiologists receive an order for tumor imaging via PET scans, you can use several codes in the CPT^® code set to document those procedures. Chapter IX of the NCCI Policy Manual provides guidelines to help ensure correct, accurate coding for your Medicare reimbursement claim (URL: www.cms.gov/files/document/chapter9cptcodes70000-79999final112021.pdf). 

If your radiologist is performing a single PET scan of a patient, you can select from the following CPT^® codes depending on the body area that’s imaged:

• 78811 (Positron emission tomography (PET) imaging; limited area (eg, chest, head/neck))
• 78812 (…; skull base to mid-thigh)
• 78813 (…; whole body)

A CT scan may be required at the same time as a PET scan to help with attenuation correction and anatomical localization. “[The radiologists] use a CT machine — they don’t do a full CT on the patient — but they perform it to help get some of the anatomical landmarks because a PET scan is just a bunch of fuzz on the screen,” says Ruby O’Brochta-Woodward, BSN, CPC, CPMA, CDEO, CPB, COSC, CSFAC, CPC-I, RCC, Coding Supervisor of Consulting Radiologists in Edina, Minnesota.

According to the NCCI manual, you’ll use CPT^® codes 78814-78816 (Positron emission tomography (PET) with concurrently acquired computed tomography (CT) for attenuation correction and anatomical localization imaging; …) if the radiologist performs a CT scan for attenuation correction and anatomical localization at the same time as a PET scan. However, if the radiologist performs a CT scan only for localization, then you shouldn’t report it separately with 78811-78816 (Positron emission tomography (PET) imaging …).

If your facility can perform PET and PET CT scans on the same machine, the guidelines state a “medically reasonable and necessary diagnostic CT scan may be separately reportable with an NCCI PTP-associated modifier.” “If I did [a diagnostic CT and a PET CT scan] on the same machine, then I would report my PET code as the PET without CT, and then report my CT with my normal CT code,” O’Brochta-Woodward says.

The important part is to know whether the radiologist is using the same equipment or separate machines to perform the diagnostic CT scan.

Handling PET Scan HCPCS Guidelines

If a radiologist is performing a PET scan, the NCCI guidelines require the use of a radiopharmaceutical diagnostic imaging agent. You can only report HCPCS codes A9555 (Rubidium Rb-82, diagnostic, per study dose, up to 60 millicuries) and A9526 (Nitrogen N-13 ammonia, diagnostic, per study dose, up to 40 millicuries) with the following PET codes:

• 78491 (Myocardial imaging, positron emission tomography (PET), perfusion study (including ventricular wall motion[s] and/or ejection fraction[s], when performed); single study, at rest or stress (exercise or pharmacologic))
• 78492 (…; multiple studies at rest and stress (exercise or pharmacologic))

If your report includes CPT^® codes 78459 (…, metabolic evaluation study (including ventricular wall motion[s] and/ or ejection fraction[s], when performed), single study), 78608 (Brain imaging, positron emission tomography (PET); metabolic evaluation), or 78811-78816, then the documentation should list HCPCS code A9552 (Fluorodeoxyglucose F-18 FDG, diagnostic, per study dose, up to 45 millicuries).