Can erase segment but not draw

Support
1

Slicer 4.11.0
Windows 10 Pro

Hello, hopefully this question has not been answered before. If so, please point me in the right direction.
I have a patient I am trying to create segmentation for, in order to 3d print the results. I am working off two different MRI scans of the patient, one of these volumes is Axial, one coronal. I created the segmentation off of the Coronal scan, like so:
image
But sometimes I’ll jump over to the axial view (by loading that volume) to cross reference what I’m doing. When I’ve loaded that axial volume I have two questions:
1- It seems to get all blocky (like the below picture), anything I can do to fix that?
2- I can use the “erase” segment editor tool to erase things that are clearly in the wrong spot, but if I try to “paint” a segment, it seems to only work if my paint diameter is 3% or over, if its 2% or smaller I’ll paint and nothing shows up. When I do get something to show up using the right diameter brush it seems off center of where I painted. Any ideas?

image
image1731×868 289 KB

2

Have you tried draw a circle and then right-click mouse to accept it.

image

Or try to update the slicer to see how it goes.

3

That helps workaround the “not working” problem, but it still comes out blocky, see below:
image image

4

could you check the two scans volume-info firstly to see if they are matched? When you do cross-reference, is there any resampling ?

5

You selected the DWI volume as master but you’re segmenting the anatomical MRI.

Either create a new segment and choose the proper master, or change the geometry of the existing one (click the box icon next to the master selector and choose the MRI as reference - you can make it isotropic etc too there).