Ballpark from human brain data collected today on a Philips 3T: gray matter T1=620; T2*=1145

Thank you ellimore

But T1 value of CSF seems to quite lower. shouldn't T1 of CSF be higher?

Ellimore i am sorry for last reply.

I thought that the values of CSF. I think gray matter values are different.

Thank you agata.

I agree with T1 value but could you suggest any literature for T2 star value of Gray matter. For my simulation i need the T2 star value also.

Hi,

Kruger et al 2001 and Wanasapura 1999 both suggest T2* of gray matter is ~49ms at 3T.

T1 of gray matter at 3T was also reported by Wanasapura 1999 as ~1300ms matching well with Jezzard et al.

Thank you An Vu

Could you also suggest some literature for T1 and T2star of CSF.

Hmmm, sorry that I'm not an expert on, but it's possible the literature I cited also studies CSF.

I have found this old paper for T1 estimation on the brain.... It may help:

Wansapura et al. JMRI 9: 531-538 (1999).

Well, relaxation times are not easily measureable as you usually have multiple compartiments in the brain that can have different relaxation times. Therefore relaxation properties are usually multi-exponential. To make thinks worse you can also have frequency and phase shifts between these signal components and the signal formation can be dependent on tissue orientation within the scanner. Especially T2* is effected, and therefore you will usually get different values if you measure T2* depending on the signal model you use and the echo times you choose to measure.

Properties for CSF are easily obtainable, just measure a water phantom. CSF relaxation times are approximately equal to water.

The definitive study on relaxation values at 3T was performed by Greg Stanisz et al. 1. Stanisz, G. J. et al. T1, T2 relaxation and magnetization transfer in tissue at 3T. Magn Reson Med 54, 507–512 (2005). A copy of Table 1 is attached for your use.

Hi Harshan, without knowing what structures you're interested in, it's not really possible to answer definitively. Have a look at our paper in NeuroImage for reference to cortical R1 and R2* (reciprocal of each will give you T1 and T2*). These were mapped using various versions of the MPM protocol developed at the WTCN by Weiskopf, Lutti, Callaghan, Helms, Dick and colleagues. Note that the raw data are available from the Birkbeck repository as FreeSurfer-readable ascii files, should you wish to import those and base your simulations on real data.

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