Hi,
I think per default Siemens tries to avoid recording the most outer slice last. Thus, for even slice numbers (N=6, for example) the excitation reads:
2 4 6 1 3 5
For odd (N = 5), you get:
1 3 5 2 4
Furthermore, transversal slices are usually recorded feet->head, sagittal slices right->left.
However, the image numbering may be set to non-default values. You would see that in the protocol entry
sSliceArray.ucImageNumb... = 0x1
And you must then check how this all translates into your converted data;)!
Cheers-
Andreas
-----Ursprüngliche Nachricht-----
Von: FSL - FMRIB's Software Library [mailto:[log in to unmask]] Im Auftrag von Peter Fried
Gesendet: Dienstag, 26. Juni 2007 22:00
An: [log in to unmask]
Betreff: Re: [FSL] Slice Order
To the best of my knowledge, yes.
> Hi Peter,
> Thank you! Does that mean that I was wrong about the Siemens scanner
> collecting odd slices first, when the total number of slices is even?
> Dan
>
> On 6/26/07, Peter Fried <[log in to unmask]> wrote:
>> Hi Dan,
>>
>> I ran into the same problem when I started. You'll want to create a
>> text file that reads {1, 3, 5, ..., 0, 2, 4, ...} (each number on a
>> new line).
>>
>> This is fsl-speak for {2, 4, 6, ..., 1, 3, 5, ...}, which is the
>> interleaved order for an even number of Siemens' slices.
>>
>> I'll attach the version I use for a 34-slice acquisition on a Siemens.
>> Note that it is a slice-order file, not a slice-timing file as the
>> name suggests.
>>
>> -Pete
>>
>> > Hello,
>> > I am not sure which slice order option to use. We use a Siemens
>> > 3T,
>> and
>> > collect an even number of
>> > slices; my understanding is that in this situation the odd slices
>> > are collected first.
>> > The interleaved option "0 2 4... 1 3 5" looks like it is even
>> > numbers first, but in the instructions for making a slice order
>> > file, it says the first slice should be 1, not zero...so perhaps
>> > the interleaved option is really doing odd slices first (ie, '0 2
>> > 4' refers to the
>> first,
>> > third and fifth slice)? Is using a slice order text file that says
>> > "1 3 5 ... 2 4 6..." the same as using
>> the
>> > interleaved option?
>> > Thanks,
>> > Dan
>> >
>>
>>
>
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