Description Usage Arguments Details Value Author(s) References See Also

The multilinear reference tissue model (MRTM) estimates the binding potential from an observed time activity curve without the need for arterial sampling. Instead, a second time activity curve must be provided from a suitable reference region where there is negligible binding.

1 | ```
multilinearReferenceTissueModel(tac, ref, time, tstar, MRTM2 = TRUE, k2prime = NULL)
``` |

`tac` |
a vector corresponding to the time activity curve from the tissue (in Bq/mL). |

`ref` |
a vector corresponding to the time activity curve from the reference region (in Bq/mL). |

`time` |
a vector of average frame times (in minutes). |

`tstar` |
the time (in minutes) where the linear relationship between the response and covariates may be assumed to be true. |

`MRTM2` |
a logical value that selects the three-parameter model (MRTM) or the two-parameter model (MRTM2), where k2prime is fixed. |

`k2prime` |
the value of k2prime that has been fixed. |

See the references.

The numeric integration required to construct the design matrix is
performed by interpolating the time activity curves, both for the
tissue and reference region, to one-second resolution and then
performing the `cumsum`

operation on them.

Given the nonlinear relationship between binding potential and the
regression parameters, the `deltamethod`

is used to approximate
its standard error.

`BP` |
Binding potential |

`BP.error` |
Approximate standard error of the binding potential |

`R1` |
Ratio of the volumes of distrubution for the tissue and reference region (assumes a one-tissue model is valid) |

`R1.error` |
Approximate standard error for the ratio |

`k2` |
Clearance rate constant from the tissue to plasma (assumes a one-tissue model is valid) |

`k2.error` |
Approximate standard error for k2 |

`X` |
Design matrix used in the linear regression |

`beta` |
Regression coefficients |

Brandon Whitcher bwhitcher@gmail.com

Ichise, M., Ballinger, J.R., Golan, H., Vines, D., Luong, A., Tsai,
S. and Kung, H.F. (1996) Noninvasive quantification of dopamine D2
receptors with iodine-123-IBF SPECT, *Journal of Nuclear
Medicine*, **37**, 513-520.

Ichise, M., Liow, J.-S., Lu, J.-Q., Takano, A., Model, K., Toyama, H.,
Suhara, T., Suzuki, K., Innis, R.B., Carson, R.E. (2003) Linearized
reference tissue parametric imaging methods: Application to [11C]DASB
positron emission tomography studies of the serotonin transporter in
human brain, *Journal of Cerebral Blood Flow \& Metabolism*,
**23**, 1096-1112.

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