Analysis and interrater reliability of pB-C2 using MRI and CT: Data from the Park-Reeves Syringomyelia Research Consortium on behalf of the Pediatric Craniocervical Society

Todd C. Hankinson, Gerald F. Tuite, Dagmara I. Moscoso, Leslie C. Robinson, James C. Torner, David D. Limbrick Jr., Tae Sung Park, and Richard C. E. Anderson for the Park-Reeves Syringomyelia Research Consortium Investigators: 2017 Journal of Neurosurgery: Pediatrics Vol. 20 / No. 2 / Pages 170-175 Read More


Objective: The distance to the ventral dura, perpendicular to the basion to C2 line (pB-C2), is commonly employed as a measure describing the anatomy of the craniovertebral junction. However, both the reliability among observers and the clinical utility of this measurement in the context of Chiari malformation Type I (CM-I) have been incompletely determined. Methods: Data were reviewed from the first 600 patients enrolled in the Park-Reeves Syringomyelia Research Consortium with CM-I and syringomyelia. Thirty-one cases were identified in which both CT and MRI studies were available for review. Three pediatric neurosurgeons independently determined pB-C2 values using common imaging sequences: MRI (T1-weighted and T2-weighted with and without the inclusion of retro-odontoid soft tissue) and CT. Values were compared and intraclass correlations were calculated among imaging modalities and observers. Results: Intraclass correlation of pB-C2 demonstrated strong agreement between observers (intraclass correlation coefficient [ICC] range 0.72-0.76). Measurement using T2-weighted MRI with the inclusion of retro-odontoid soft tissue showed no significant difference with measurement using T1-weighted MRI. Measurements using CT or T2-weighted MRI without retro-odontoid soft tissue differed by 1.6 mm (4.69 and 3.09 mm, respectively, p < 0.05) and were significantly shorter than those using the other 2 sequences. Conclusions: pB-C2 can be measured reliably by multiple observers in the context of pediatric CM-I with syringomeyelia. Measurement using T2-weighted MRI excluding retro-odontoid soft tissue closely approximates the value obtained using CT, which may allow for the less frequent use of CT in this patient population. Measurement using T2-weighted MRI including retro-odontoid soft tissue or using T1-weighted MRI yields a more complete assessment of the extent of ventral brainstem compression, but its association with clinical outcomes requires further study. © AANS, 2017.

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Posted on August 25, 2017
Posted in: HPAN, Neurodegeneration, Publications Authors: