Authors: Chao Hou Hongbin Han Xiaohong Yang Xiaojuan Xu Hui Gao Dongsheng Fan Yu Fu Yu Sun Bo Liu
Publish Date: 2012/01/03
Volume: 33, Issue: 5, Pages: 1101-1105
Abstract
Although flexion cervical MRI has been recommended for the diagnosis of Hirayama disease HD no study focused on the MR features at different neck flexion angles Moreover no uniform flexion angle has been confirmed in clinical practice The purpose of this study is to quantitatively investigate the MRI typical signs of HD patients in different neck flexion degree and gives a suggestion to the MR scanning Cervical MRI in neutral and different flexion positions cervical flexion angle 20° 25° 30° 35° and 40° were performed in 45 HD patients Three MRI features including anterior shifting of the posterior wall of the cervical dural canal ASD widening of cervical epidural space and epidural flow voids EFV at each flexed position were summarized To evaluate ASD quantitatively the widest cervical epidural space with the maximum sagittal diameters d and cervical canal sagittal diameter D at the same level were measured The d/D values at different angles were calculated and compared ASD was demonstrated in 34 out of 45 cases 756 at 20° and in all cases 100 at other 4 angles χ 2 = 25728 P 005 Significant difference was demonstrated for the appearance rate of EFV mean 728 among different angles χ 2 = 11373 P = 0021 The peak mean d/D value was found at 35° Neck flexion angles have effects on ASD widening of cervical epidural space and EFV 25° is recommended as the least effective diagnostic flexion angle for MRI diagnosis of HD and 35° may be the best one
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