| Method | Outcome | Requirements for | Applicable to parametric imaging | Vulnerabilities | |
|---|---|---|---|---|---|
| PET scan | Input | ||||
| Fit to compartment
model (gold standard) or reference region model |
Transport and binding/metabolism rate constants, vascular volume, VT, Ki | Dynamic study | arterial plasma | no, except K1, Ki, or VT images | None, if comprehensive model. All plasma input methods are vulnerable to systematic errors in plasma metabolite analysis. Possibly non-specific binding in plasma (fP) |
| BPND, R1 | Dynamic study | reference tissue | yes/no (depending on model) | non-specific binding in tissue (free fraction fND) | |
| Transport and binding/metabolism rate constants, vascular volume, volumes of distribution (VT), BPF, BPP, BPND, R1 | Dynamic study | arterial plasma and reference tissue | yes/no (depending on model) | possibly non-specific binding in plasma and/or tissue (fP and fND) | |
| Spectral analysis | Ki or VT, number of identifiable compartments | Dynamic study | plasma | yes | non-specific binding in plasma and/or tissue (fP and fND) |
| Ratio | BPND | Dynamic study | reference | yes | non-specific binding in tissue (fND), vascular volume, bias dependent on BP |
| Ratio, approaches BPND | Single scan | reference | yes | time from injection, non-specific binding in tissue (fND), vascular volume | |
| Multiple-time graphical analysis (MTGA): Gjedde-Patlak and Logan plots | Ki | Dynamic study | plasma | yes | non-specific binding to plasma proteins (fP) |
| Ki | Dynamic study | reference | yes | non-specific binding in tissue (fND) | |
| VT | Dynamic study | plasma | yes | non-specific binding in plasma and tissue (fP and fND) | |
| DVR (VT/VND) | Dynamic study | reference | yes | non-specific binding in tissue (fND), reference k2 | |
| Fractional uptake rate, sometimes referred to as Retention index | FUR, approaches Ki | Single scan | plasma | yes | Distribution volumes of free and non-specifically bound tracer, vascular volume |
| Standardized uptake value | SUV | Single scan | i.d. | yes | Perfusion, peripheral clearance, non-specific binding in plasma and tissue (fP and fND), vascular volume |
The outcome of many of the methods is the (equilibrium)
volume of distribution VT (or DV). If valid reference region exists,
the regional distribution volume ratio can be calculated as
DVR = DVROI/DVREFERENCE. This, in turn,
relates to the
binding potential BPND:
BPND = DVR - 1.
However, this measure is vulnerable to change of non-specific binding
in tissue.
| Method | Outcome | Requirements for | Applicable to parametric imaging | Vulnerabilities | |
|---|---|---|---|---|---|
| PET scan | Input | ||||
| Ratio | BPND | Single scan | reference | yes | non-specific binding in tissue (fND), vascular volume |
| VT | Single scan | venous plasma | yes | non-specific binding in tissue (fND), vascular volume | |
Innis RB, Cunningham VJ, Delforge J, Fujita M, Gjedde A, Gunn RN, Holden J, Houle S, Huang SC, Ichise M, Iida H, Ito H, Kimura Y, Koeppe RA, Knudsen GM, Knuuti J, Lammertsma AA, Laruelle M, Logan J, Maguire RP, Mintun MA, Morris ED, Parsey R, Price JC, Slifstein M, Sossi V, Suhara T, Votaw JR, Wong DF, Carson RE. Consensus nomenclature for in vivo imaging of reversibly binding radioligands. J Cereb Blood Flow Metab. 2007; 27(9): 1533-1539.
Logan J, Alexoff D, Kriplani A. Simplifications in analyzing positron emission tomography data: effects on outcome measures. Nucl Med Biol. 2007; 34: 743-756.
Slifstein M, Laruelle M. Models and methods for derivation of in vivo neuroreceptor parameters with PET and SPECT reversible radiotracers. Nucl. Med. Biol. 2001; 28: 595-608.
Last updated: 2008-11-28