Introduction : There is little research on the reliability, reproducibility and usefulness of assessing sagittal deformity from MRI studies
Objectives: To establish a normal range of kyphosis as measured by MRI and to compare sagittal measurements obtained by MRI and standard radiographs in children with kyphosis and in normal children.
Materials and Methods: Retrospective review identified 46 patients with no spinal deformity and 24 patients with increased kyphosis without significant frontal plane deformity who had spinal MRI. Sagittal measurements made via MRI were compared to measurements made from matched radiographs.
Results: Normal range for kyphosis as measured by MRI was (T1-T12=13°-43°). In patients without frontal plane deformity, there were no significant differences in mean Cobb angle measured by x-rays and MRI in all locations (see table). In the kyphosis group there was a significant difference in T1-T12(p=.043) and T5-T12(p=.007) measurements(see table), however there was no significant difference in the T1–T5 measurements(p=.985, see table).
Conclusion: In this cohort without frontal plane deformity, sagittal measurements on MRI did not differ significantly from plane x-ray measurements. In deformity patients there was no significant difference between measurements of the T1 to T5 kyphosis in plane x-ray and the MRI group indicating that the MRI can be used to assess the cephalad kyphosis when planning treatment.
Significance: This study established a normal range of kyphosis measured by MRI and suggests that MRI can be used as a reliable measure to assess the proximal spine in cases where radiographs do not provide adequate visualization.