Normally a TI in the range of 400~700 ms. is used for „normal‟ T1 weighted studies (good anatomy visualisation). but you should consider STIR and FLAIR sequences based on your study.

*TI of 160 ms(1.5 Tesla system)->effective way of suppressing signal from fat tissue.

The TI varies per field strength B0.

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Range of TE (to calculate T2): 80~250

I will say it depends the T1 and T2 you are expecting. For T1 you should use a range of Tis with the last one being 5 times the expected T1.

For T2 the TE's will be a range from minimum TE up to 2-3 times the expected T2.

This way you should have a nice fit

I agree with Willy Gsell as for T2, but I'd not waste time to acquire IR's with so long TI.

The most significant part of the curve is around the nulling point, that happens at TI = ln(2)*T1 (around 0.7*T1), so I'd start with a short TI and stop earlier then at 5*T1.

The signal equation is too steep at very low TI and too flat at very long TI.

1. For measuring T1, when using MRI (rather than spectroscopy), a spoiled gradient echo sequence (ie FLASH) done with different flip angles (eg 20 and 40 degrees)  is more accurate than either inversion recovery with different  inversion times or a saturation recovery spin echo with different TR's.

2. For measuring T2, use a multi echo conventional spin echo with 4 to to 8 echoes (preferably with non slice selective 180 refocusing pulses)

In both cases use a single slice to avoid cross talk or off resonance effects.

Remember that the slice profile of an MRI slice varies somewhat with flip angle (particularly at higher flip angles), which affects measurement accuracy.

Dear Avruch

for T1 if I want to use FLASH what equation I have to use to fit the data, because i try to use  inversion recovery with different inversion times but it didn't give a good results and what are the range of  flip angles do yo suggest,

Thanks

You can find an online T1 value calculator using variable flip angle (VFA) FLASH at mritoolbox.com (in the parameter fitting section - use drop down menu).

10 to 50 degree flip angles are good.  At higher flip angles the slice profile deteriorates (ie, the flip angle is not uniform across the slice thickness)