how can I refer to the image in opened by image tool from matlab command line?

hi,

I have to small questions:

1. I opened the image from command line:

h_imtool=imtool('test.dcm')

then I wanted to draw a ROI with

BW=roipoly(h_imtool),

but it does not work, I just can draw a ROI if I open image in a figure window. I can not do it in image tool. But it should be possible.. Is there also any method to refer from command line to image that I opened directly in image tool instead of opening it from commanlinde?

2.The images I have is a multiple DICOM CT set (more than 100 slices). I wanted to make a roi for one of those ( to mark the table), do the invert mask (so I can hide the table) and copy that to other slices.Then make one histogram for all slices. The latter works fine, although here I am surprised it works only if I change the int16 (DICOM output) to double, otherwise I got the message while building histogram that either the eps has to be single or double. According to the help histogram can be defined for int16, so I do not know what is wrong? Does the histogram not work with int16??

thank you in advance, wishing a nice day/night to all,

Aga