Spinal sonography and magnetic resonance imaging in patients with repairedmyelomeningocele: Comparison of modalities

The goals of this study were to evaluate the feasibility of using ultrasono graphy of the spine in the follow-up evaluation of patients with repaired m yelomeningocele at birth and to compare sonography with the accepted modali ty of magnetic resonance imaging. Over a period of 4 years we performed 165 sonographic studies in 101 patients; 107 sonographic studies had MR imagin g results for comparison We collected our data prospectively. The quality o f the sonograms was good in 110 of 129 studies, acceptable in 17 of 129, an d poor in two of 129. The sonographic examinations failed in 33 of 165 stud ies (200;%). Concordant information was obtained between ultrasonography an d magnetic resonance imaging in the following percentage of studies: level of the distal end of the cord in 82%;, position of the cord in the canal in 59%, presence of hydromyelia in 63%, cord duplication in 96%, adhesions in 16%, intradural mass in 37%, cord measurements in 85%, and dural sac measu rements in 83%:. At the lumbosacral level, we saw no cord pulsation in 57% of the studies in patients with cord adhesions and in 20% of those without adhesions. At the lower thoracic level, we saw no pulsation in 35% of the s tudies in patients with cord adhesions and in 7% of those without adhesions . Postoperative studies of cord release surgery in eight patients showed va ried findings. We conclude that in those patients who have a spinal defect or interlaminar space allowing proper visualization of the lumbosacral spin al canal, ultrasound can provide fairly similar information to that obtaine d with magnetic resonance imaging of that area with no need for sedation an d at a reduced cost. Ultrasonography seems more sensitive than magnetic res onance imaging in the detection of cord adhesions, which is particularly re levant in the diagnosis of tethering.