Assuming you import each slice as an image, you can bring them each in as a
field (ReadImage), group them (CollectSeries) and Stack them into a volume.
You could isolate this operation in a macro to simplify the networks you
write.  In that case you could create a ForEach loop to do each Import and
then the CollectSeries->Stack at the end.  That macro could also handle the
appropriate number of slices/images as well as the pixel size of each at
Import.  What would be returned in each case would be a single field as a
3d volume.

BTW, I think someone has written a DICOM filter (e.g., perhaps Ed Farrell,
who retired from IBM Research a few years ago).  I recall references to it
in the past.

1.  Rectilinear regions could be specified by Slab. the results of which
could be passed to Statistics to get mean values.  Alternatively,
coordinates could be specified interactively on a rendered image by
ProbeList or Pick and the points could be used to define a polygon to then
create a more abitrarily-shaped ROI.
2.  If you keep the slices as a series rather than stack them as a volume,
when you apply whatever operation it will be done on the individual images
separately, putting the results into a similar series.  You could then
animate, for example, through the slices to see the changes per time.
3.  The Filter module supports a number of different kernels, and you can
add your own.  Reduce uses weighted average interpolation to smooth data to
a lower-resolution grid, maintaining the same bounding box.


Alexander Kluge <[EMAIL PROTECTED]>
@opendx.watson.ibm.com on 07/14/2001 09:22:25 AM

Please respond to [email protected]

Sent by:  [EMAIL PROTECTED]


To:   [email protected]
cc:
Subject:  [opendx-users] First advice please



First, I apologize for a question one could probably answer by
r<ing>tfm thoroughly. But this takes really a lot of time and I would
like to have a little success first as a motivation for the start.

Could you be so kind to draft in very short terms possible ways to
achieve the results desired. Maybe some of the sample files has a
similar structure?

Given are 1 to 3 stacks of 40 to 60 time slices/repetitions of an
image of 196 to 256 x 256 pixel with 16bith depth. For a given Data
set, all images have the same pixel size. Time axis is known,
intervals are constant. Data are stored in one dicom series, but can
be converted to tiff.
1. I want to specify one/several ROI in one image of the series and
get the mean value of the pixel values of all images as y, the time
beeing the x axis.
2.1 I want to perform a similar computation on every single pixel for
the whole series, e.g. computing the slope of intensity changes over
time, transit times and so on and get the result e.g. as a color coded
parameter map as an overlay over the original grid.
2.2 I want to filter all images with the same algorithm (smoothing,
grouping e.g. 3x3 pixel into one) to be able to perform the
calculation of 2.1. in a realistic amount of time (maybe due to the
web- and x-server running on my W98 machine, opendx is really slow).

Thank you for any help

Alexander


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