The diagnosis value of apparent diffusion coefficient and fractional anisotropy of MR-diffusion tensor imaging for different courses of cervical cord compression

English Keywords:Cervical cord compression  MRI  MR-diffusion tensor imaging  Apparent diffusion coefficient  Fractional anisotropy

English Abstract:

  【Abstract】 Objectives: To study the diagnosis value of apparent diffusion coefficient(ADC) and fractional anisotropy(FA) of MR-diffusion tensor imaging(MR-DTI) for different courses of cervical cord compression.Methods: 50 patients with cervical cord compression were involved in this study from January 2010 to June 2011. These patients were divided into 3 groups, group A: acute cervical cord compression group(n=15) underwent the cervical cord MRI within 72h after the injury; group B: chronic cervical cord compression group(n=23) had more than 6 months cervical myelopathy history; group C: chronic history with acute cervical cord compression group(n=12) had more than 6 months cervical myelopathy history and suffered from an acute cervical cord injury, and underwent the MR scan within 72h after the injury; group D included 15 healthy volunteers with normal MRI. All cases in 4 groups underwent MR-DTI.The values of ADC and FA in the compressed cervical cord in group A, B and C, and those at C5/6 in group D were meassured and compared.Results: The values of ADC in group A, B, C and D were (0.712±0.241)×10-3mm2/s, (1.012±0.256)×10-3mm2/s, (0.812±0.125)×10-3mm2/s and (0.823±0.106)×10-3mm2/s respectively, and the values of FA in group A, B, C and D were 0.401±0.098, 0.472±0.095, 0.496±0.172 and 0.541±0.158 respectively. Group A had significantly lower values of ADC and FA than group D(P<0.05); the FA decreased and ADC increased in group B compared with group D(P<0.05). The value of ADC had no change(P>0.05), but the value of FA decreased(P<0.05) in group C compared with group D. Group A had lower values of ADC and FA than group B and C（P<0.05）, and group B had higher value of ADC and lower value of FA than group C, which showed significant difference（P<0.05）. Conclusions: The ADC and FA under MR-DTI can determine different courses of cervical cord compression.