Skip to content

CT Contrast Agent Level, Whole Blood — Concentration, Intravenous Administration

Published: August 9, 2026Updated: August 16, 2026

Measures the concentration of CT contrast material in whole blood after intravenous administration, usually in connection with CT angiography.

Quick summary

["This blood test measures how much CT contrast material is present after it is given through a vein."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
86965-1
Short code
CTA LE ves-Bl W contr IV
Synonyms
CTA LE ves-Bl W contr IV
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct-angio
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This test measures the amount of radiologic contrast material in a blood sample. It is generally associated with contrast-enhanced CT imaging, including CT angiography, and reflects recent intravenous contrast exposure.

Why might I need this test?

A contrast level may be checked to confirm that contrast material was delivered or to help assess its presence in the blood. In some circumstances, it may support evaluation of contrast exposure and kidney function, although it is not a routine stand-alone kidney test.

How is the test performed?

A blood sample is collected and analyzed in the laboratory to determine the concentration of the contrast agent. The result is interpreted in relation to the dose received, the time the blood was drawn, and the imaging procedure performed.

How do I prepare for the test?

Follow the instructions provided for your CT procedure. Tell the care team about kidney disease, prior contrast reactions, and current medications. Fasting is not usually required specifically for this measurement, but hydration may be recommended when contrast is used.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CT contrast agent level

Frequently asked questions

Is this the same as a kidney function test?
No. This test measures CT contrast material in the blood, while kidney function tests directly evaluate how well the kidneys filter substances from the body.
Why does the timing of the blood draw matter?
Contrast material is cleared from the blood over time, so the concentration can change quickly. A sample drawn shortly after the injection may be much higher than one collected later.
Do I need to stop any medications before this test?
Do not stop medicines on your own. The care team should review metformin, kidney medications, and other relevant drugs with you and follow the instructions for the CT procedure.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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