Total readout time is the echo spacing (dwell time) times the number of phase encoding steps.  If you use grappa, divide the number of phase encoding steps by the grappa factor.  

Peace,

Matt.

From: Dianne Patterson <[log in to unmask]>
Reply-To: FSL - FMRIB's Software Library <[log in to unmask]>
Date: Wednesday, April 3, 2013 10:30 PM
To: <[log in to unmask]>
Subject: [FSL] topup, 4th column of acqparams.txt?

The fsl website says the 4th column in the acqparams.txt file

0 -1 0 0.062
0 -1 0 0.062
0 1 0 0.062
0 1 0 0.062

is the total readout time (defined as the time from the centre of the first echo to the centre of the last) in seconds.

Our MR tech is not entirely clear about what you mean here.  We thought you might mean the TR from the description, else perhaps the dwell time.  Could you provide any additional information about this parameter?  We are on a Siemens Skyra with VD13.

Thankyou,

Dianne

--
Dianne Patterson, Ph.D.

Research Scientist
[log in to unmask]
University of Arizona
Speech and Hearing Science 314

1131 E 2nd Street, Building #71
(Just East of Harvill)

621-9877

==============

If you write me (expecting an answer) and I don't respond within a

day, then the email may have been lost.
You can always write me at [log in to unmask]
==============