Evaluation of cervical ossification of the posterior longitudinal ligament with 3D broadband IR-prepared ultrashort echo-time imaging: a pilot study

Purpose We aimed to evaluate the feasibility of 3D broadband inversion-recovery-prepared ultrashort echo-time (3D IRP UTE) imaging for assessing ossification of the posterior longitudinal ligament (OPLL). Materials and methods The study consisted of 25 consecutive patients with cervical OPLL [13 women, 12 men; mean age 66.3 (47–84) years] who underwent CT, 3T conventional MR, and 3D IRP UTE imaging studies. Two readers independently assessed the 3D IRP UTE images for the type (mixed, continuous, circumscribed, segmental) and distribution of OPLL. All readers consensually assessed the diagnostic certainty of OPLL on conventional MR and 3D IRP UTE images by using a 3-point scale system. Interobserver and intermodality agreement was assessed by κ statistics. A Wilcoxon signed-rank test was used to evaluate the difference of diagnostic certainty between conventional MR and 3D IRP UTE imaging. Results Interobserver and intermodality agreements were good ( κ = 0.73) and excellent ( κ = 0.81) for the OPLL type, and excellent ( κ = 0.85) and good ( κ = 0.76) for the assessment of the distribution of OPLL, respectively. The mean level of the diagnostic certainty of OPLL was significantly higher for 3D IRP UTE than conventional MR imaging ( p = 0.002). Conclusion 3D IRP UTE imaging may be useful for assessing OPLL.