Dear SCT experts,
I have question about definiton of morphometric metrics/measures for diagnosis of SC compression:
In the paper Martin et al., 2018 (full ref below) are described 3 morphometric metrics/measures:
- Flattening - measured with compression ratio (CR)=AP/transverse diameter
- Indentation - measured using solidity=the percentage of area representing spinal cord within the convex hull that subtends the spinal cord
- Torsion - measured with relative rotation, which was calculated as the angle between the transverse axis and horizontal, relative to adjacent slices (difference from the average rotation of above and below slices)
I would like to ask how are these metrics related with metrics extracted by sct_process_segmentation function (respectively by process_seg.py function which is called by it) (I use SCT v4.0.0). I can get following morphometric measures from this function:
- Angle_AP, angle_RL
- Diameter_AP, diameter_RL
It is clear that from diameter_AP and diameter_RL I can compute CR which represents Flattening how is it defined in Martin et al., 2018 paper.
But I am not sure which outputs from sct_process_segmentation function (If any) are analogical to Indentation and Torsion from Martin et al.,2018 paper. Could you please clarify to me if there is relationship between metrics from the paper and from sct_process_segmentation function?
Maybe, second question. I know that SCT is under continuous development and I can see in CHANGES.md file at github that sct_process_segmentation function has been little bit modified between v4.0.0 and current v4.1.0. Should I recompute morphometric metrics again with this newest SCT version?
Thanks a lot!
Martin, A. R., De Leener, B., Cohen-Adad, J., Cadotte, D. W., Nouri, A., Wilson, J. R., … Fehlings, M. G. (2018). Can microstructural MRI detect subclinical tissue injury in subjects with asymptomatic cervical spinal cord compression? A prospective cohort study. BMJ Open, 8(4), e019809. https://doi.org/10.1136/bmjopen-2017-019809