Just run the main .m file in Matlab. Tested mostly on R2018-R2019.
TrueT2-DIR is based on Madhuranthakam et al, Mag Res Med 2012 67(1):81-88.
For more info, see comments in the IR_Calculator.m file.
With this spreadsheet tool you can calculate TrueT2-DIR TI sequence parameters based on measured T1 values, for a predetermined set of other parameters.
The T1-vs-TI IR-Calc tool could be deployed in clinical settings without MatLab access. Simulations and regressions therein have to be redone for each clinical setting.
- Miho Kita's online tool for calculating TI for various sequence types
- XRayPhysics' explanation of simple inversion mathematics
- On T1 times in tissues: Lalande et al, MRI 2016
Have fun inverting! Øystein
The user T1/T2 times can be set to any tissues you like, as long as you figure out what acts as "WM/GM/MS/CSF" for your purposes.
These are default T1/T2 times for the "1.5 T" set of user relaxation times, taken from GE's values and literature:
- ?? : T1 T2 (ms)
- WM : 660 80
- GM : 1200 95
- MS : 1200 100
- CSF: 4308 3500
Here are some experimental values used for imaging synovitis in the knee in one of our studies:
- WM : 1000 50 for healthy synovium
- GM : (not used)
- MS : 1100 80 for synovitis
- CSF: 3600 1200 for synovial fluid
These values are mostly guesswork for now, in part based on attempted measurement of said values. But the point is, IR-Calc can be used this way. Of course, it can be a challenge to procure good value estimates.