Hi All!

I consistently see <= 10 ms TRs in ADNI dataset, but I also have some MP-RAGE MRIs (that are not from ADNI) that report 2300ms TR.
They are both from Siemens' 3T MRI scanners.

From what I understand it's because TR for MP-RAGE sequence can refer to either:

• the time from a 180 degree inversion pulse to another, as is depicted in a schematic diagram at https://mriquestions.com/ir-prepped-sequ... , or
• the time between two consecutive pulses in the acquisition phase, as is depicted in the fig. 1 of http://www.ajnr.org/content/ajnr/19/2/23...

My question is: why are some MRIs reporting 1 and others reporting 2?
Is it presumably because the scanners were configured differently?
Or is it dependent on which model the sequence ran on?
Or am I totally misunderstanding it?

Could some of you more knowledgeable than me chime in?

Best,
Horsng Junn