Flow, Relaxation, and Resonance Offset (aka Sample Effects)
I group these all into the concept of Sample effects (we can change the name!).
- Note: These three items only affect the profile.* So, while we could add this as a transformation, in reality, it only affects the profile and not the pulse.
The purpose of this panel is to inject models for real systems and see how that affects the profile: e.g. does the amplitude of an inversion pulse reach to the expected maximum, do the imaginary amplitudes get mangled, does the quality of the slice profile get diminished?
NOTE: There are no new values generated by the sample effects "panel" that need to be saved to the database or exported for use in a machine.
Flow
Currently this is not optional - when this page is selected in Matpulse. We should plan on changing this to be optional in RFPulse, by adding the "Use Flow" field listed below.
Use Flow: Check box, On or Off.
Flow Value: A real number with an optional spinner of slider to change.
The next three (five really) fields are to choose the inputs to this routine, and how they should be interpreted. We may not need these radio buttons (i.e. these choices) as we are working in a pipelined environment - so our inputs should be clear, i.e. just the previous pulse results.
The Radio choices are mutually exclusive…
Use B1,G1: radio selection. for constant gradients.
- In Matpulse, this selection is used to indicate that we just need to read in a "B1" value. Then we specify what the G1 value is, i.e. the slice thickness for the sake of this calculation.
- G1 Value: The gradient. For SLR pulses this implies the slice thickness.
Use B2,G2: radio selection
- No additional value to specify
Use B2,G2,F2: radio selection
- @@@ Jerry indicated that the F2 is calculated from the G2 based on a scaling factor (i.e the slice thickness mentioned below). He also said that we do not need this radio selection, as F2 does not affect the profile. We only need to specify the scaling factor and calculate the F2 when we output the B2 and G2 for a particular machine (MR machine). Only at that time do we need to specify the offset.
- Slice Position (offset) - real number (a float).
Relaxation Time(s)
This has basically the same information as on the "Relaxation Effects" page, in a slightly more compact form.
Use Relaxation: Check Box. If checked the two input fields become available for edit and are initially populated with the values of "Inf" or infinity.
T1: The T1 relaxation time. A float. Initially set to "Inf" or Infinite.
T2: The T2 relaxation time. A float. Initially set to "Inf" or Infinite.
Resonance Offset
Add Resonance Offset: Check Box, On or Off.
Offset: In Hz. A float.
mm vs Hz: If G2 use mm, if no gradient use Hz, if G1 give users a choice.
Expansion Factor: Should not be needed as we have a choice of normal or extended range.
See, in Mapulse …
- Jflow/MJLJM.M
- Jflow/MJLCALCC.M