Online Supplement

Online Table 2. Results from point-by-point review of radiological criteria and parameter based on a 5-point scoring system. C = core set of parameters for structured report; R = parameter for research purposes; E = excluded

Criterion/Parameter / Measure / Decision
Reproducibility/Reliability / Correlation with symptoms/ outcome / Takes individual (anatomical) diversity into account / Quantitative: Universal threshold discriminating between stenosis and non-stenosis feasible
Qualitative: Presence in majority of patients (sensitivity) / Quantitative: Ease of measurement
Qualitative: Ease of understanding by physicians reading the report
Central Stenosis
Quantitative
No.3 Anterior-posterior diameter of dural/thecal sac / High / Unknown / No / Yes / Easy / R
No.4 Compression of thecal sac area in % of normal mid-sagittal diameter / High / Unknown / Yes / Yes / Not so easy / R
No.5 Cross-sectional area of dural tube/sac / High / Unknown / No / Yes / Intermediate / R
Qualitative
No.15 Compromise of the central zone / Good to high / Unknown / Yes / Yes / Easy / C
No.17 Redundant nerve roots of the cauda equina / Unknown / Unknown / Unknown / No / Not easy / E
No.18 Relation from fluid to cauda equina / Moderate / Unknown / Yes / Yes / Easy / C
No.16 Reduction of posterior epidural fat [1] / E
No.19 Sedimentation sign[2] / E
No.20 Visual assessment of the central spinal stenosis[3] / E
Lateral Stenosis
Quantitative
No.8 Lateral recess height / Moderate / Unknown / No / Maybe / Not easy / R
No.9 Depth of lateral recess / Moderate / Unknown / No / Maybe / Easy / R
Qualitative
No.21 Compression of the sub-articular area / Moderate / Unknown / Yes / Yes / Not easy / E
No.22 Nerve root compression in the lateral recess / Moderate / Unknown / Yes / Yes / Easier than no. 21 / C
Foraminal
Quantitative
No.11 Foraminal diameter[4] / E
Qualitative
No.23 Foraminal nerve root impingement / Moderate – high / Unknown / Yes / Yes / Easy / C
No.24 Size and shape of the foramen / Low / Unknown / Unknown / Yes / Unknown / E
No.26 Compromise of the foraminal zone / Moderate – high / Unknown / Yes / Yes / Easy / C
No.27 Perineural
intraforaminal fat[5] / E

[1] This criterion was reported in only one study and there was overall consensus that there is too little data. All agreed that it should not be included in standard reports.

[2] Experts were uncertain about the importance since it is a new parameter, published in 2010. Consensus was reached that it currently cannot be recommended for standard report. It can also be captured in other parameters.

[3] During discussion, experts agreed to exclude this criterion because of the overlap with no. 15.

[4] This parameter originates from a CT study from1985, which is rather old and does not imply any relation to the size of the nerve root. There was consensus to exclude it.

[5] One of the experts, a surgeon, considered this an important criterion. But he would not need this information in addition to the other parameters in the core set; i.e., it has no additional value as it is covered by a single item, no. 26. Compression of the nerve is more important than the fat around the nerve.