Whole-Body FDG PET/CT for Tumor Localization — Without Contrast
A whole-body imaging test that uses an FDG radiotracer and CT to locate areas of increased metabolic activity, often for cancer evaluation.
["This scan can help identify the location and extent of tumors or other areas of increased metabolic activity."]
Key facts at a glance
- LOINC
- 82805-3
- Short code
- PT+CT Whole body Tum loc W FDG+WO contr
- Synonyms
- PT+CT Whole body Tum loc W FDG+WO contr
- Category
- liver
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- pt-ct
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This is a positron emission tomography combined with computed tomography (PET/CT). A radioactive tracer called fluorodeoxyglucose (FDG) is given through a vein, and the PET scanner measures where the tracer accumulates in the body. The CT provides detailed anatomical images, and this version is performed without iodinated IV contrast.
Why might I need this test?
It may be used to locate a suspected tumor, assess how widely cancer has spread, evaluate treatment response, or look for metabolically active tissue when other imaging is inconclusive. It may also help evaluate certain inflammatory or infectious conditions.
How is the test performed?
You receive an IV injection containing the FDG tracer and then rest quietly for a period determined by the imaging center. You lie on a table that moves through the PET/CT scanner, which takes whole-body images. The procedure generally takes about 30 to 60 minutes, although the total visit may take longer.
How do I prepare for the test?
Follow the center's instructions, which may include avoiding strenuous exercise for about 24 hours and fasting for several hours beforehand. Tell the imaging team about diabetes, pregnancy or breastfeeding, medications, recent surgery, and any prior reaction to PET tracers. Because no iodinated contrast is used, contrast-specific precautions may not apply.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Increased FDG uptake can occur with many kinds of cancer, but it can also reflect inflammation, infection, or normal physiologic activity. Uptake does not by itself establish a cancer diagnosis and must be interpreted with the scan findings, symptoms, and other tests. Areas without increased uptake are less likely to be metabolically active, but a normal scan cannot completely exclude disease.
Short name
Whole-Body FDG PET/CT
Frequently asked questions
Is this the same as a routine CT scan?
Does this test use IV contrast?
Will I be radioactive after the test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy