I’ve been using 3D slicer for a while. I have got the cross-sectional area of a muscle after I used the “segment editor” module AND the " Segment Cross-Section Area" module. But I don’t know how to measure the HU values of the ROI. How can I get the average, median, max，min HU value of it. I used CT image datas.
You can use Segment Statistics module to get these statistics for each segment.
If you need the values separately for each slice then you may use @jmhuie’s SegmentGeometry extension. Currently it provides only average, but would not be hard to add other statistics as well if there is a good reason. Note that min/max are extremely fragile metrics (a single voxel could throw off your results), probably you would want to use percentiles (1st and 99th or 5th and 95th) instead.
Yep, wouldn’t be difficult at all to add extra calculations if you decide there are certain ones you’d like