MRI is an imaging modality that uses non-ionising radiation to construct useful diagnostic images. MRI with superior soft tissue resolution gives critical information on ligamentous, soft tissue and cord injury and is currently the gold standard for soft tissue assessment. Here in this chapter, we discuss MRI for assessment of traumatic SCI. MRI is the imaging modality of choice to diagnose acute cord compression and its effects in SCI.
Table 1 Diagnosis and Prognostication with MRI
MRI is the imaging modality of choice in SCI due to its high psychometric and prognostic value.
Yasin et al., show that MRI is a highly sensitive (97%) and accurate technique (95%). MRI demonstrated high psychometrics in SCI with or without edema and hemorrhage, except when trying to asses for combination of edema and hemorrhage without contrast as Ghasemi et al., (2015) demonstrate. Karpova et al., (2013) demonstrate high intraobserver correlation for quantitative MRI measurements related to the spine.
MRI also showed strong prognostic value in predicting the initial injury and course of injury based on signal intensity. Selden et al., (1999) showed that hemorrhage on MRI scans were correlated with motor-complete injury at admission and associated with poor long-term Frankel Grade scores. Initial MRI pattern was associated with recovery. MRI signal characteristics consistent with spinal cord edema or hemorrhage predicted worse functional outcome as Wilson et al., demonstrate. The study conducted by Flanders et al., (1996) found that individuals with spinal cord hemorrhage had significantly worse upper and lower motor scores at the time of injury and at 12 months. Miyanji et al., (2007) demonstrate that the frequency of intramedullary hemorrhage, edema, and cord swelling were more common in American Spinal Injury Association A versus American Spinal Injury Association B-D. Moreover, they were directly correlated with SCI severity. Only one study by Wang et al., (2016) showed no significant correlation between MRI findings and motor, sensory or American Spinal Injury Association score.
There is level 4 evidence (from one case series study; (Karpova et al., 2013), and two observational studies; (Ghasemi et al., 2015, Yasin et al., 2017) that MRI has strong inter-observer correlation, sensitivity, specificity, predictive value, and diagnostic accuracy in detecting and evaluating SCI in individuals.
There is level 5 evidence (from one case series study; (Schroeder et al., 2016) that the incidence of surgical treatment and spinal decompression is not significantly different between individuals based on the presence of signal intensity on an MRI.
There is conflicting level 3 evidence (from one cohort study; (Mabray et al., 2016), one case control study; (Seif et al., 2018), two case series; (Flanders et al., 1996), (Wilson et al., 2012), and six observational studies; (Aarabi et al., 2017, Schaefer et al., 1992, Selden et al., 1999, Song et al., 2016, Takahashi et al., 1993, Zohrabian et al., 2016) and level 5 evidence (from one observational study (Wang et al., 2016) that MRI is effective in determining microstructural measurements and can reliably predict AIS classification, motor score and status and progression of injury in individuals with SCI and controls.
There is level 5 evidence (from one cohort study; (Martinez-Perez et al., 2017) that early MRI has prognostic value in its ability to evaluate ligamentous injury and edema which are predictors of poor neurologic outcome.
There is level 5 evidence (from one observational study; (Miyanji et al., 2007) that MRI can be used to detect hemorrhage, edema, and cord swelling in individuals with SCI. A greater number of positive detections were significantly associated with increased SCI severity and American Spinal Injury Association classification.
There is level 5 evidence (from two observational studies; (Boldin et al., 2006; Shepard & Bracken 1999) that MRI may be used to predict complete SCI given the detection of hemorrhage and edema in individuals with SCI.
There is level 5 evidence (from one observational study; (Dalkilic et al., 2018) that MRI could be used to assess hematoma length and predict AIS classification at baseline.
There is level 5 evidence (from one observational study; (Matsushita et al., 2017) that MRI is effective in detecting spinal microstructures which can be used to effectively predict American Spinal Injury Association motor scores, and Frankel D scores in individuals with SCI.
MRI is an effective diagnostic tool to assess damage to microstructures within the spinal cord as well as detecting other indications of damage such as hemorrhage and edemas.
MRI may be reliably used to predict an individual’s injury severity, American Spinal Injury Association score, motor score, AIS, and neurologic outcome given an SCI.