Transducer frequency considerations in intraoperative US of the spine.

To determine the effect of transducer frequency, we used intraoperative spinal ultrasound to study 15 patients. All patients but one had spinal stenosis and/or disk disease affecting the cervical cord (n = 5), the thoracic cord (n = 1), or the lumbosacral area (n = 8). One patient had an arteriovenous malformation of the cervical cord. Both 5-MHz and 10-MHz transducers were used in one patient; a transducer with the option of 3.5, 5, or 7.5 MHz was used in ten; and a 10-MHz transducer was used in four. We found that, intraoperatively, 10-MHz transducers currently produce the most detailed images of the spine.