Tau PET SUVR Calculator

Actual Tau PET SUVR Calculator ROI mean target/reference concentration ratio, matched acquisition/timing/tracer, pool/reference selection external; not amyloidcentiloid or biological diagnosis. Actual independently matched observations/units and protocol, not diagnosis, causal mechanism, clinical decision or validated individual prediction.

Description

PET standardized uptake value ratio compares a target-region mean with a matched reference-region mean.

PET standardized uptake value ratio compares a target-region mean with a matched reference-region mean.^[1]

This tool computes a tau-tracer concentration ratio from already qualified samples without choosing the reference region or diagnosing pathology.

When to use Tau PET SUVR Calculator

This tool computes a tau-tracer concentration ratio from already qualified samples without choosing the reference region or diagnosing pathology.

How to use Tau PET SUVR Calculator and how it works

Prepare qualified target roi tracer concentrations, qualified reference roi tracer concentrations, using the input definitions and matching units below.
Enter the required fields and run Tau PET SUVR Calculator.
Read result.value using the units, signs and ordering explained below.
Correct any rejected inputs and rerun; interpret the result within the stated model and its assumptions.

Input field	Meaning	Value type	Requirement
actualQualifiedTargetRoiTracerConcentrations	Actual Qualified Target Roi Tracer Concentrations. Use the units and matching context stated in the calculation below.	array of number	Required; other constraints below
actualQualifiedReferenceRoiTracerConcentrations	Actual Qualified Reference Roi Tracer Concentrations. Use the units and matching context stated in the calculation below.	array of number	Required; other constraints below

Require nonempty nonnegative target and reference ROI concentration lists. Compute each arithmetic mean independently; list lengths need not match. Require the reference mean to be positive, then return target mean divided by reference mean as a dimensionless SUVR. Tracer, acquisition time, ROI eligibility and reference selection are supplied context rather than checked model inputs.

suvr=mean(targetRoiConcentrations)/mean(referenceRoiConcentrations)

Apply the input ordering, units and branch conditions stated above.

Output field	Meaning	Value type
result	Object containing the calculated or selected fields below.	object
result.value	Numeric model result on the ratio, score, constant or density basis explained above.	number

json

{
  "input": {
    "actualQualifiedTargetRoiTracerConcentrations": [
      2,
      4
    ],
    "actualQualifiedReferenceRoiTracerConcentrations": [
      1,
      2
    ]
  },
  "output": {
    "result": {
      "value": 2
    }
  }
}

Limitations and assumptions

The calculation uses the supplied observations and model inputs. It does not collect measurements, select a reference population or coefficient, or establish that the model applies to the actual case. The stated branch conditions and output units remain part of the result.

All fields require explicit values. Unexpected fields, wrong types, nonfinite numbers and sparse arrays are rejected. Alignment, bounds and supported-token rules are explained above; extremely large inputs or nonfinite results can also fail. Input errors differ from successful false comparisons, unavailable-domain flags and empty match lists.

Alternative or Complementary methods

Use FDG PET SUVR Calculator for a complementary operation: An FDG PET uptake ratio depends on matched tracer timing and a separately chosen reference region.

Use CSF Plasma Ratio Calculator for a complementary operation: A CSF-to-plasma ratio requires concentration measurements on the same analytical basis and matched context.

References

Tau PET SUVR Calculator — tool.io

Similar or alternative tools

FDG PET SUVR Calculator
An FDG PET uptake ratio depends on matched tracer timing and a separately chosen reference region.
CSF Plasma Ratio Calculator
A CSF-to-plasma ratio requires concentration measurements on the same analytical basis and matched context.