Hi Andreas,<div><br></div><div>There are basically two types of files; those with and without header information. Raw and Rec files are raw formats without header. So, every time you open them, you have to tell DtiStudio about their image dimensions. If you find anything wrong about image dimensions, it is either you specified the wrong parameters or you didn't specify and DtiStudio simply used parameters of the previous data (DtiStudio assumes the parameter of the new data are the same as the previous ones if you don't specify).</div>
<div><br></div><div>Because RAW and Rec files do not contain image dimension information, the dimension information you had in Analyze (i.e. 0.86mm) is lost. If you find the image resolution is 1mm later when you load Rec, that means you specified so when you load the Rec (e.g. matrix size is 256x256 and FOV is 256x256 in the data loading window). In this case, you simply had to type in correct FOV (e.g. 240x240).</div>
<div><br></div><div>DtiStudio doesn't have functions to change dimensions. So before and after data processing, the dimensions should remain the same. If your image looks blurrier, the only reason I can think of is due to image co-registration.</div>
<div><br></div><div>The same goes for the number slices. Analyze format contains this information but Rec/RAW don't. There is a field to specify the number of the slices in the initial data loading window. If you don't specify this field, it keeps the information from the previous session. If the number of the slices are 55, then you have to explicitly type "55" or choose "All slices".<br>
<br><div class="gmail_quote">On Fri, Jul 15, 2011 at 7:35 PM, Andreas Buchmann <span dir="ltr"><<a href="mailto:buchmann2@wisc.edu">buchmann2@wisc.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
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<p class="MsoNormal"><font size="2" face="Arial"><span lang="DE-CH" style="font-size:10.0pt;font-family:Arial">Dear MRI-Studio experts,<u></u><u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="DE-CH" style="font-size:10.0pt;font-family:Arial"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">I'm using DTI Studio version 3.0.2.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">When I open images with a certain voxel size and later swap
to images with a different voxel size, DTI Studio still uses the old voxel
size.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">For example, analyze images correctly shown in 0.86mm
in-plane resolution were saved as 1x1mm voxels in rec format (but with correct
slice thickness, which changed too), so the images were blurred in xy-plane.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">Earlier, I observed a similar problem with defining image
parameters in the 'DTI mapping' tab: for example, the program switched some
parameters automatically to the new image type, leaving others according to the
old images, which lead to inconsistencies (for example, 39 slices, but the
slice number went from 0 to 54).<u></u><u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">I solved the problem by reading in the new image type
several times. Is there a less cumbersome procedure?<u></u><u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">Many thanks<u></u><u></u></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">Andreas<u></u><u></u></span></font></p>
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