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: Calculated Global Noise Index

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

: This is a calculated value that summarizes the overall amount of signal noise or variability across a measurement, rather than measuring a specific substance in your body.

Quick summary

[": A \"global noise\" result reflects how much background variability was present across a set of readings during testing, not a disease marker."]

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

Key facts at a glance

LOINC
96912-1
Short code
CTNOISE
Synonyms
Calc CT global noise
Category
chemistry
Sample
serum
Container
Not applicable; calculated from imaging data
Units
N/A
Ref low
30
Ref high
40
Critical range
— – 65 N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 18 years
Method
calculated
Specimen volume
Not applicable
Stability
Not applicable
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

: What This Test Represents

: The term "global noise" refers to an overall measure of unwanted fluctuation or background signal collected across a whole set of measurements. A "calculated" result means the value was derived mathematically from other data rather than measured directly from a sample.

: Why It Is Calculated Rather Than Measured

: Because this is a calculated index, no single physical substance is being tested. Instead, the laboratory or system combines multiple raw readings into one summary number to describe overall signal quality or variability.

: What the Number Describes

: Higher or lower values generally reflect how consistent or noisy the underlying readings were. This kind of index is used to characterize measurement behavior and is not, by itself, a direct measure of your health.

: How to Interpret Your Result

: Your result should be interpreted in the context of the specific system or method that produced it. Because the exact meaning depends on the underlying method, ask your care team what this calculated index represents in your particular testing situation.

Reference range

Reference range varies by CT scanner type, reconstruction algorithm, and institution; generally target noise level should be ≤30-40 HU for diagnostic quality coronary CTAN/A

Specimen: serum

No specific preparation required; ensure heart rate is controlled (typically <65 bpm) per institutional CCTA protocol for optimal image quality assessment

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

: NONE

Frequently asked questions

: Does a high or low global noise value mean I am sick?
: No. This is a calculated measure of signal variability across readings, not a disease marker. Your care team can explain what the value means in the specific context of your test.
: Why is there no specific reference range given here?
: Because this value depends on the particular system or method that produced it, a single universal range would be misleading. The appropriate interpretation is best provided by the laboratory or clinician involved in your testing.
: Should I be worried about this result?
: This index describes measurement consistency rather than a health condition, so it is not a reason for alarm on its own. Discuss any concerns with your healthcare provider, who can explain how it relates to your overall testing.
  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