Estudo da reprodutibilidade de uma técnica de ressonância magnética dinâmica para mielopatia cervical espondilótica

Abstract

Pratali RR. Study of the reliability of a dynamic magnetic resonance imaging technique for cervical spondylotic myelopathy [Thesis]. Ribeirão Preto: University of São Paulo, Faculty of Medicine of Ribeirão Preto; 2019.Since dynamic factors may contribute to the etiology and severity of cervical spondylotic myelopathy (CSM), dynamic (flexion-extension) magnetic resonance imaging (MRI) may be useful to better evaluate for spinal stenosis and cord compromise. The objectives of the present study were to evaluate morphometric variations of the cervical spine in patients with CSM using a standard technique of dynamic MRI, to assess the inter-and intra-observer reliability of measurements of morphometric parameters based on this imaging, and to compare the resulting measurements with those previously published. Dynamic cervical MRI was obtained using a standard protocol with the neck in neutral, flexion, and extension positions. The morphometric parameters considered were anterior length of the spinal cord (ALSC), posterior length of the spinal cord (PLSC), spinal canal diameter (SCD) and spinal cord width (SCW). Two observers analyzed the parameters independently, and the inter-and intra-observer reliabilities were assessed by the intraclass correlation coefficient (ICC). 18 patients were included in the study and all completed the dynamic MRI acquisition protocol. The inter-and intra-observer reliabilities demonstrated "almost perfect agreement" (ICC > 0.9; p < 0.001) for ALSC and PLSC in all positions. The SCD had inter-and intra-observer reliability classified as "almost perfect agreement" (ICC: 0.83-0.98; p < 0.001 and ICC: 0.90-0.99; p < 0.001, respectively) in all positions. The SCW had inter-and intra-observer reliability classified as "substantial agreement" (ICC: 0.73-0.94; p < 0.001 and ICC: 0.79-0.96; p < 0.001, respectively) in all positions. ALSC and PLSC in neutral, flexion and extension positions from the present study were significantly different compared to the measurements previously published (p < 0.001).As conclusion, the dynamic MRI protocol presented was safe and may allow a more complete evaluation of variations in the cervical spine in patients with CSM than traditional MRI protocols. The morphometric parameters based on this protocol demonstrated excellent interand intra-observer reliabilities.