摘要The present study examined 24 children with acute Guillain-Barré syndrome using magnetic resonance imaging (MRI) plain scans and fat-suppressed enhanced T1-weighted imaging (T1WI)scans. Axial MRI plain scans centering on the medullary conus were positive in nine patients (38%).These displayed variable thickening involving the cauda equina with isointensity on T1WI and isointensity or slight hyperintensity on T2WI. False negatives were obtained in patients with cervical and cranial nerve symptoms. Contrast enhancement of T1WI with fat suppression w as positive in all patients in the cauda equina with varied thickening and enhancement centering on the medullary conus. Five patients (36%) were positive in the cervical nerves and 3 patients (50%) were positive in the cranial nerves. These patients had corresponding cervical and cranial nerve symptoms,respectively. Patients with serious clinical symptoms in the lower limbs exhibited obvious involvement of the cauda equina by MRI. Statistical analysis revealed a positive correlation between the extent of enlargement of the cauda equina, centering on the medullary conus, and cerebrospinal fluid protein concentration.