AIF

Class: NodeParkerStandardAIF

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A population based standard AIF. The bolus arrival of the AIF is adjusted to the data labeled as ‘Dynamic Series’. The adjustment is made based on an average curve from the "Dynamic Series''. The region in which the curve is averaged is:

- The supplied mask or
- The entire image if no mask is supplied.

To find the best bolus arrival time (BAT) an extensive search is performed with a time step given in the UI of the node. The merit function on which the best arrival time is based on is a fit to the Kety/Extended Kety model. The fit is performed for a maximum duration after the bolus arrival as indicated in the settings.

The node produces an AIF [mM] that is matched to the bolus arrival of the dynamic data. In addition, bolus arrival time and frame number are also accessible as outputs. These are useful when defining the baseline signal of a DCE-MRI scan.

Inputs

Dynamic Series

Input dynamic series.

Type: Image4DFloat, Required, Single

Mask

Input mask. This mask defines the region which is averaged to create the AIF.

Type: Image4DBool, Optional, Single

Outputs

AIF

Resulting AIF.

Type: CurveCollection

Start Time

The bolus arrival time.

Type: Double

Start Frame

The bolus arrival frame.

Type: Double

Settings

AIF parameters

Peak amplitude, A1, [mM] Number

The amplitude of the main peak

Peak width, Sigma1, [min] Number

The width (standard deviation) of the main peak

Peak time, T1, [min] Number

The time at the center of the main peak

Recirculation peak amplitude, A2, [mM] Number

The amplitude of the recirculation peak

Recirculation peak width, Sigma2, [mM] Number

The width (standard deviation) of the recirculation peak

Reciruclation peak time, T2, [min] Number

The time at the center of the recirculation peak

Tail amplitude, Alpha, [mM] Number

The amplitude of the concentration in the tail.

Tail drop-off, Beta, [min⁻¹] Number

The rate with which the tail concentration drops of.

Tail raise, s, [min⁻¹] Number

The speed with which the tails raises at the arrival of the bolus.

Tail delay time, tau, [min] Number

The tail raise delay.

Large vessel Hematocrit, Hct Number

The Hematocrit.

BAT parameters

Search timestep [s] Number

The BAT search time step.

Duration of fit [min] Number

The duration (after bolus arrival) during which the fit should be performed.

Fitting model Selection

The model used in the fitting.

Values: Normal, Extended

References

Parker GJ, Roberts C, Macdonald A, et al. Experimentally-derived functional form for a population-averaged high-temporal-resolution arterial input function for dynamic contrast-enhanced MRI. Magn Reson Med 2006;56:993–1000.
Murase K. Efficient method for calculating kinetic parameters using T1-weighted dynamic contrast-enhanced magnetic resonance imaging. Magn Reson Med 2004;51:858–862

Keywords: AIF, Kety, DCE, Parker, BAT, bolus, arrival