Incremental Diagnostic Value of Zero-Echo-Time Magnetic Resonance Imaging for Osseous Cervical Neural Foraminal Stenosis: A Retrospective Multireader Study

Background/Objectives: Conventional cervical magnetic resonance imaging (MRI) depicts cortical bone poorly, whereas computed tomography (CT) adds radiation exposure. We evaluated whether adding zero-echo-time (ZTE) imaging improves detection of CT-defined grade ≥2 foraminal stenosis. Methods: This single-centre retrospective diagnostic accuracy study included 81 consecutive eligible patients evaluated between October 2024 and June 2025 who underwent cervical MRI and CT within 14 days. Two blinded musculoskeletal radiologists graded 810 foramina from C2-C3 through C6-C7 using conventional MRI and MRI + ZTE. A study-specific scale incorporated narrowing, nerve-root morphology, and surrounding fat appearances. Consensus CT grading was the reference standard; grade ≥2 defined a positive foramen. Paired differences were assessed with patient-clustered bootstrap resampling. Results: Mean age was 48.9 ± 13.6 years; 55 patients were women. CT identified grade ≥2 stenosis in 150/810 foramina (18.5%). Adding ZTE increased sensitivity from 68.7% to 87.3% for Reader 1 and from 17.3% to 35.3% for Reader 2. Sensitivity differences were 18.7 percentage points (95% confidence interval [CI], 10.6–27.1) and 18.0 percentage points (95% CI, 6.6–30.3), respectively. Specificity increased from 90.5% to 96.8% and from 96.7% to 97.6%, respectively. Areas under the receiver operating characteristic curve increased by 0.115 (95% CI, 0.076–0.164) and 0.121 (95% CI, 0.061–0.184). Binary interreader agreement increased numerically from κ = 0.25 to κ = 0.41. Conclusions: Adding ZTE improved detection of CT-defined grade ≥2 foraminal stenosis, although sensitivity remained low for one reader. Effects on CT use, management decisions, and clinical outcomes require prospective evaluation.