Standardized Uptake Value
Encyclopedia
The Standardized Uptake Value (SUV) is often used in PET
imaging for (semi-)quantitative analysis of PET. It is useful for a simple analysis of fluorodeoxyglucose
(FDG) images, e.g. to monitor the progress of disease during cancer therapy. It can also be used with other PET agents when no arterial input function is available for kinetic modeling. If the arterial input function is available, commonly via blood sampling, other measures like the Fractional Uptake Rate should be used or more advanced pharmacokinetic
modeling undertaken.
The SUV is calculated either pixel-wise or over a region of interest
(ROI) for each image of a dynamic series at time points t as the ratio of tissue radioactivity concentration (e.g. in MBq/kg=kBq/g) at time t, c(t), and injected dose (e.g. in MBq) at the time of injection (t=0) divided by body weight (e.g. in kg).
Some authors prefer to use the lean body weight or the body surface area instead of the body weight. Also for c(t) either the maximum or mean value of a ROI is taken.
SUVs can be affected by image noise, low image resolution and user biased ROI selection. Several corrections, e.g. for glucose in case of FDG, have been recommended, see and references therein. For other tracers like FLT, it may be that a semiquantitative analysis and a threshold used to e.g. classify lesions in benign and malign is no better than a qualitative analysis. More robust data seem to be necessary to decide which approach is the better, see. e.g. comments in .
In summary, SUVs are a convenient measure for the evaluation of FDG-PET images, but care has to be taken with respect to its pitfalls and interpretation of the results.
Positron emission tomography
Positron emission tomography is nuclear medicine imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide , which is introduced into the body on a...
imaging for (semi-)quantitative analysis of PET. It is useful for a simple analysis of fluorodeoxyglucose
Fluorodeoxyglucose
Fludeoxyglucose or fluorodeoxyglucose , commonly abbreviated 18F-FDG or FDG, is a radiopharmaceutical used in the medical imaging modality positron emission tomography...
(FDG) images, e.g. to monitor the progress of disease during cancer therapy. It can also be used with other PET agents when no arterial input function is available for kinetic modeling. If the arterial input function is available, commonly via blood sampling, other measures like the Fractional Uptake Rate should be used or more advanced pharmacokinetic
Pharmacokinetics
Pharmacokinetics, sometimes abbreviated as PK, is a branch of pharmacology dedicated to the determination of the fate of substances administered externally to a living organism...
modeling undertaken.
The SUV is calculated either pixel-wise or over a region of interest
Region of interest
A Region of Interest, often abbreviated ROI, is a selected subset of samples within a dataset identified for a particular purpose.For example:* on a waveform , a time or frequency interval...
(ROI) for each image of a dynamic series at time points t as the ratio of tissue radioactivity concentration (e.g. in MBq/kg=kBq/g) at time t, c(t), and injected dose (e.g. in MBq) at the time of injection (t=0) divided by body weight (e.g. in kg).
Some authors prefer to use the lean body weight or the body surface area instead of the body weight. Also for c(t) either the maximum or mean value of a ROI is taken.
SUVs can be affected by image noise, low image resolution and user biased ROI selection. Several corrections, e.g. for glucose in case of FDG, have been recommended, see and references therein. For other tracers like FLT, it may be that a semiquantitative analysis and a threshold used to e.g. classify lesions in benign and malign is no better than a qualitative analysis. More robust data seem to be necessary to decide which approach is the better, see. e.g. comments in .
In summary, SUVs are a convenient measure for the evaluation of FDG-PET images, but care has to be taken with respect to its pitfalls and interpretation of the results.
See also
- Functional imagingFunctional imagingFunctional imaging , is a method of detecting or measuring changes in metabolism, blood flow, regional chemical composition, and absorption....
- Medical imagingMedical imagingMedical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...
- Multi-compartment modelMulti-compartment modelA multi-compartment model is a type of mathematical model used for describing the way materials or energies are transmitted among the compartments of a system. Each compartment is assumed to be a homogenous entity within which the entities being modelled are equivalent...
- Patlak plotPatlak plotA Patlak plot is a graphical analysis technique based on the compartment model that uses linear regression to identify and analyze pharmacokinetics problems involving irreversible uptake, such as in the case of deoxyglucose...
- PharmacokineticsPharmacokineticsPharmacokinetics, sometimes abbreviated as PK, is a branch of pharmacology dedicated to the determination of the fate of substances administered externally to a living organism...
- Physiologically-based pharmacokinetic modellingPhysiologically-based pharmacokinetic modelling-What is a PBPK model?:Physiologically based pharmacokinetic modeling is a mathematical modeling technique for predicting the absorption, distribution, metabolism and excretion of synthetic or natural chemical substances in humans and other animal species...