Multishot diffusion-weighted MR imaging features in acute trauma of spinal cord.

OBJECTIVES: To analyse diffusion-weighted MRI of acute spinal cord trauma and evaluate its diagnostic value.

METHODS: Conventional MRI and multishot, navigator-corrected DWI were performed in 20 patients with acute spinal cord trauma using 1.5-T MR within 72 h after the onset of trauma.

RESULTS: Twenty cases were classified into four categories according to the characteristics of DWI: (1) Oedema type: ten cases presented with variable hyperintense areas within the spinal cord. There were significant differences in the apparent diffusion coefficients (ADCs) between lesions and unaffected regions (t = -7.621, P < 0.01). ADC values of lesions were markedly lower than those of normal areas. (2) Mixed type: six cases showed heterogeneously hyperintense areas due to a mixture of haemorrhage and oedema. (3) Haemorrhage type: two cases showed lesions as marked hypointensity due to intramedullary haemorrhage. (4) Compressed type (by epidural haemorrhage): one of the two cases showed an area of mild hyperintensity in the markedly compressed cord due to epidural haematoma.

CONCLUSIONS: Muti-shot DWI of the spinal cord can help visualise and evaluate the injured spinal cord in the early stage, especially in distinguishing the cytotoxic oedema from vasogenic oedema. It can assist in detecting intramedullary haemorrhage and may have a potential role in the evaluation of compressed spinal cord.

KEY POINTS: • Multishot, navigator-corrected diffusion-weighted MRI is helpful when evaluating spinal cord injury (SCI). • Four types of SCI may be classified according to the DWI characteristics. • DWI differentiates cytotoxic from vasogenic oedema, thereby determining the centre of SCI. • DWI can assist in detecting intramedullary haemorrhage. • DWI can help evaluate the degree of compressed spinal cord.