Diffusion-weighted magnetic resonance imaging for the healthy cervical multifidus: A potential method for studying neck muscle physiology following spinal trauma

STUDY DESIGN: Cross-sectional. oBJectiVe: To develop a new magnetic resonance imaging (MRI) measure for the diffusive properties of the healthy cervical multifidus and to determine the interrater and intrarater reliability of the measurement. BACKGROUND: Diffusion-weighted MRI, via calculation of the apparent diffusion coefficient (ADC), provides a representation of microscopic movements of water molecules in human tissues and may be useful to assess structural changes in neck muscle, as has been observed following whiplash. The optimal imaging parameters, however, have not been established. METHODS: A diffusion-weighted MRI measure was developed, and, for the basic examination, the right cervical multiffidus muscle at the C5 level was studied. A total of 6 asymptomatic volunteer individuals (3 females and 3 males) underwent a single diffusion-weighted MRI scan. Interrater and intrarater agreement was evaluated using Bland-Altman plots and intraclass correlation coefcients. results: Mean ADCb0-b50 and ADCb50-250 were significantly different from one another (P =.03). The plots confirmed the agreement of raters for ADC of the right cervical multifidus at C5. conclusions: A quantitative and reliable diffusion-weighted MRI measure of cervical multifidus ADC has been described. There appears to be a fast and slow component ADC for the healthy multifidus, suggesting changes in extracellular and intracellular volume. Further comparative study is needed to quantify ADCs in the neck muscles in patients with traumatic whiplash.