What units does the reformat module use?

Support
#1

Hi all,

Our goal is to rotate the coronal plane to a specific angle X in relation to the axial plane. We would like to use the Reformat Module.

Our question is: what are the units used in the Rotation Segment? If we want to rotate the coronal plane in 40º what should be put in the LR bar?

Thanks in advance,
Mariana Masteling

Slicer_reformat_units

#2

Those entries are in degrees - typing in 40 appears to work for me. Does it not give what you expect?

#3

We thought it was in degrees too. But after rotating it to 57º, using AnglePlanes Plugin and rotating to the same angle using Reformat, the results aren’t similar.

57º rotation using AnglePlanes Plugin
28_3d_57_angleplanes_2

57º rotation using reformat (this angle is 32º not 57º)
28_3d_57_reformat_2

The same DICOMs were used to create the previous plots, they are just not shown.

#4

Did you try the negative rotation?

Here’s what I did that worked:

  • download MRHead Sample Data
  • use the Reformat module to rotate the Green plane by 40 degrees
  • go to the Transforms module and create a Linear Transform applied to the MRHead
  • set the rotation around LR to be -40

The resulting coronal view of the rotated data looks right.

image

#5

I confirm that it is rotation in degrees. Note that rotations are incremental: if you rotate around multiple axes, the previous rotation slider is always reset to 0.

These angles may refer to the same rotation - they are just different angles of the same triangle: 57deg = 90deg - 32deg (-1deg probably measurement error).

#6

Thank you all for your clarifications :slight_smile: