Article Figures & Data
Figures
- FIG 1.
Sample T2-weighted axial section at L2/L3 graded normal with the following: A, Free-form annotation around the DSCA of 166 mm2. B, Line annotation with a DSDIA of 14 mm. C, Line annotations with a DDRDIA of 0.4. D, Free-form annotations with DDRCA of 0.41. The square root is used as a normalization step to account for the quadraticity of area measures.
- FIG 2.
Sample T2-weighted axial MR imaging slices of the lumbar spine for each stenosis grade, determined qualitatively by a neuroradiologist, with the metrics annotated. A, Grade: normal; level, L1/L2; DSCA, 167 mm2; DSDIA, 15 mm; DDRDIA, 0.42; DDRCA, 0.40. B, Grade: mild; level, L3/L4; DSCA, 104 mm2; DSDIA, 10 mm; DDRDIA, 0.24; DDRCA, 0.27. C, Grade: moderate; level L4/L5; DSCA, 115 mm2; DSDIA, 10 mm; DDRDIA, 0.22; DDRCA, 0.24. D, Grade: severe; level, L2/L3; DSCA, 64 mm2; DSDIA, 7 mm; DDRDIA, 0.14; DDRCA, 0.16.
- FIG 3.
Decision rules and cutoff thresholds generated by a decision the tree classifier (maximum depth = 3, maximum leaves = 4, criterion = Gini impurity) for each quantitative metric.
- FIG 4.
Receiver operator characteristic curve using each quantitative metric as a score for binary classification of stenosis. AUROC values are reported in the legend.
Tables
- Table 1:
Classification of each spinal level as normal versus stenosed on the evaluation cohort (n = 130) using each quantitative metrica
Metrics Compared AUROC: Group 1 AUROC: Group 2 Z-Statistic Significance DSCA vs DSDIA 96.5 (95.0–97.7) 96.6 (95.1–97.8) 0.19 P = .85 DSCA vs DDRDIA 96.5 (95.0–97.7) 98.0 (96.7–98.9)b 2.24b P = .02b DSCA vs DDRCA 96.5 (95.0–97.7) 98.6 (97.4–99.3)b 3.54b P = .004b DSDIA vs DDRDIA 96.6 (95.1–97.8) 98.0 (96.7–98.9)b 2.56b P = .01b DSDIA vs DDRCA 96.6 (95.1–97.8) 98.6 (97.4–99.3)b 2.89b P = .004b DDRDIA vs DDRCA 98.0 (96.7–98.9) 98.6 (97.4–99.3) 1.57 P = .12 - Table 2:
Classification of each spinal level as normal, mild, moderate, and severe stenosis on the evaluation cohort (n = 130) using decision trees trained on the development cohort (n = 130)
Metric Accuracy AUROC Cohen κ Accuracy 95% CI AUROC 95% CI κ 95% CI DSCA 64.9 (60.9–69.0) 76.6 (73.9–79.3) 0.62 (0.57–0.66) DSDIA 71.4 (67.1–75.7) 80.9 (78.0–83.8) 0.69 (0.64–0.75) DDRDIA 76.5 (72.6–80.4)a 84.3a (81.7–86.9)a 0.75a (0.71–0.79)a DDRCA 78.9 (75.0–82.9)a 86.0a (83.3–88.5)a 0.80a (0.75–0.83)a ↵a Ratio-based metrics with higher κ scores (P < .001).
- Table 3:
AUROC for binary classification based on each metric across symptomatic splits (VAS <7 versus VAS ≥7) of low back pain and radicular paina
Metric Symptomatology Analysis of Low Back Pain VAS < 7 VAS ≥ 7 Significancea AUROC 95% CI AUROC 95% CI P Value Low Back Pain DSCA 97.7 (96.7–98.6) 95.1 (92.9–97.3) P < .001 DSDIA 96.6 (95.4–97.8) 96.5 (94.9–98.1) P = .43 DDRDIA 96.8 (95.6–97.9) 97.5 (96.1–98.8) P < .001 DDRCA 98.5 (97.8–99.2) 96.3 (94.8–97.9) P < .001 Radicular back pain DSCA 98.4 (97.4–99.4) 96.3 (94.5–98.1) P < .001 DSDIA 98.2 (96.8–99.6) 96.9 (95.5–98.2) P < .001 DDRDIA 98.7 (97.9–99.5) 97.1 (95.6–98.5) P < .001 DDRCA 99.0 (98.4–99.6) 97.1 (95.5–98.7) P < .001 ↵a The P values represent a comparison of AUROCs among the symptomatic splits.
- Table 5:
Classification of each spinal level as normal, mild, moderate, and severe stenosis on the prognostic cohort (n = 58) using decision trees trained on the development cohort (n = 130)
κ Scores for Grading Stenosis across Surgical vs Nonsurgical Levels Metric Nonsurgical Levels Surgical Levels Significancea κ 95% CI κ 95% CI P Value DSCA 0.65 (0.57–0.75) 0.74 (0.63–0.85) P < .001 DSDIA 0.67 (0.58–0.77) 0.68 (0.51–0.85) P = .23 DDRDIA 0.69 (0.61–0.76)b 0.77b (0.65–0.90)b P < .001b DDRCA 0.71 (0.62–0.79) 0.73 (0.58–0.87) P < .001
