[Insight-users] Dicom slice position

[Jolinda Smith]

Hi Mathieu,

The answer to the first question is yes, it does. As for the second,
your ascii picture is misleading. What you've drawn is a skewed volume,
where the slice normal is along the y-axis only, but the origin of each
slice shifts in both y and z. Presumably, you actually have a rotated
volume. You can check this with the image orientation patient field: it
should look something like almost 1/zero/very small/very small/0/almost
1. This field gives the direction cosines for the rows and columns.
There probably are no "missing" areas, as you can see if you just flip
through your images. They don't "drift" over to the left.

Jolinda

> Jolinda,
>
> I have a question about your program MRI convert. I used it to convert
> my set of DICOM images. And as you said it takes into account the
Image
> Position Patient. Here is the value I extracted from my files:
>
> Patient [ -199.506987\-34.042491\255.448394]
> Patient [ -199.510827\-32.554461\255.259324]
> Patient [ -199.514667\-31.066431\255.070254]
> Patient [ -199.518497\-29.578401\254.881184]
> Patient [ -199.522337\-28.090371\254.692124]
> Patient [ -199.530017\-25.114311\254.313984]
> Patient [ -199.533847\-23.626281\254.124914]
> Patient [ -199.526177\-26.602341\254.503054]
> Patient [ -199.537687\-22.138251\253.935844]
> Patient [ -199.541527\-20.650221\253.746784]
> Patient [ -199.545367\-19.162191\253.557714]
> Patient [ -199.549197\-17.674161\253.368644]
> Patient [ -199.553037\-16.186131\253.179574]
> Patient [ -199.556877\-14.698111\252.990514]
> Patient [ -199.560717\-13.210081\252.801444]
> Patient [ -199.564557\-11.722051\252.612374]
> Patient [ -199.568387\-10.234021\252.423304]
> Patient [-199.572227\-8.745991\252.234234]
> Patient [-199.576067\-7.257961\252.045174]
> Patient [-199.579907\-5.769931\251.856104]
> Patient [-199.583737\-4.281901\251.667034]
> Patient [-199.587577\-2.793871\251.477964]
> Patient [-199.591417\-1.305841\251.288904]
> Patient [ -199.595257\0.182189\251.099834]
> Patient [ -199.599087\1.670219\250.910764]
> Patient [ -199.602927\3.158249\250.721694]
> Patient [ -199.606767\4.646279\250.532624]
> Patient [ -199.610607\6.134309\250.343564]
> Patient [ -199.614437\7.622339\250.154494]
> Patient [ -199.618277\9.110369\249.965424]
> Patient [-199.622117\10.598399\249.776354]
> Patient [-199.625957\12.086429\249.587284]
> Patient [-199.629787\13.574459\249.398224]
> Patient [-199.637467\16.550519\249.020084]
> Patient [-199.633627\15.062489\249.209154]
> Patient [-199.641307\18.038549\248.831014]
> Patient [-199.645137\19.526574\248.641954]
> Patient [-199.648977\21.014603\248.452884]
> Patient [-199.652817\22.502633\248.263814]
> Patient [-199.656657\23.990662\248.074744]
> Patient [-199.660487\25.478692\247.885674]
> Patient [-199.664327\26.966721\247.696614]
> Patient [-199.668167\28.454751\247.507544]
> Patient [-199.672007\29.942780\247.318474]
> Patient [-199.679677\32.918839\246.940334]
> Patient [-199.675847\31.430810\247.129404]
> Patient [-199.683517\34.406869\246.751274]
> Patient [-199.687357\35.894898\246.562204]
> Patient [-199.691197\37.382928\246.373134]
> Patient [-199.695027\38.870959\246.184064]
>
>
> So acquisition axe is Y (Y spacing is 1.5), but there is also a Z
variation.
>
> So my questions is:
> - Does MRIConvert takes this Z variation also into account ?
> - If yes how come the result is still 512*512 ? There should be some
> black/white area
>
>           512
>      -------------
>     -------------
>    -------------
>   -------------
> -------------
>      512
> <-->         <-->
> In those two areas you don't know the value of the pixel, right ?
>
> Thanks for putting some light on it.
>
> mathieu
> Ps: When will the linux version be available ?
>