Table 2.

Agreement between scoring modalities relative to MRI Pfirrmann grade cut-off

Compared modalities	Pfirrmann grade ≥ 1	Pfirrmann grade ≥ 2	Pfirrmann grade ≥ 3	Pfirrmann grade ≥ 4	Pfirrmann grade = 5
Radiography vs. CT	64.2% (58.5–69.4)	64.4% (58.5–69.9)	65.6% (58.0–72.5)	67.0% (59.0–74.2)	67.1% (58.9–74.3)
Radiography vs. MRI	20.1% (16.2–24.6)	46.4% (40.1–52.8)	80.8% (75.1–85.4)	85.4% (80.3–89.3)	83.9% (78.4–88.2)
CT vs. MRI	45.9% (39.9–52.0)	51.1% (44.6–57.5)	62.8% (54.8–70.0)	64.9% (56.5–72.4)	62.8% (54.2–70.7)

Model estimates (95% CI) of pairwise agreement between scoring modalities for each MRI Pfirrmann grade cut-off used to binarize data into a ‘positive’ or ‘negative’ score for intervertebral disc (IVD) calcification

CT computed tomography, MRI magnetic resonance imaging