Introduction: The concerns over the oncologic potential of cumulative doses of ionizing radiation in children and adolescents being monitored in AIS has led to the search for radiation‐free diagnostic imaging modalities, including MRI. We hypothesize that a novel, upright positional MRI protocol can produce reliable spinal curvature images compared with traditional Xray, and may serve as a radiation‐free alternative to traditional diagnostic monitoring for curve progression in AIS.
Methods: Twenty consecutive patients (13F, 7M, average age 13.7yrs, range: 11–17yrs) with a diagnosis of AIS seen by a single surgeon were enrolled. Average major curve magnitude was 30.6°(range: 10–69°). Subjects underwent traditional plain radiographic scoliosis imaging (36″ cassettes), followed within 1 week by upright MRI using a standardized protocol. Complete MRI data acquisition was performed in <7minutes using a steady‐state gradient echo 3D pulse sequence (TE=5.608, TR=14.720, Flip angle=30 deg). The two volumes were stitched together to facilitate multi‐planar reconstruction analysis. Two independent observers measured the major and minor Cobb angle magnitudes on each set of plain film and MRI images.
Results: There was excellent inter‐rater reliability between plain film radiography and upright MRI measurements for major Cobb angle (R=0.91) and very strong reliability for minor Cobb angles (R=0.81). Intra‐rater reliability for both Xray and MRI measurements of major Cobb angles was excellent (R=0.96, 0.95, respectively). Intra‐rater reliability for both Xray and MRI measurements of the minor Cobb angles was also excellent (R=0.96, 0.92, respectively).
Conclusion: Our results show that upright positional MRI is capable of producing major and minor Cobb angle measurements that highly correlate with traditional plain film radiographic measurements, and may therefore be a radiation‐free alternative/substitute for diagnostic screening in AIS.
Significance: Radiation‐free diagnostic screening for AIS can be performed safely, quickly (total data acquisition time: <7min), and with costs comparable to Xray imaging. We submit that upright, positional MRI may serve as an alternative/replacement for traditional ionizing imaging techniques.