MRI-guided treatment of degenerative spinal diseases

In the treatment of degenerative spinal diseases, CT-guided local injections, RF or ethanol denervation of facet joints and laser decompression of herniated intervertebral disks offer a precisely aimed and effective option in cases of back pain and sciatica. As CT involves significant exposure of the patient to ionising radiation, we evaluated the feasibility of MR-guided therapy. MRI offers a variety of advantages, such as excellent soft-tissue contrast, high flow and temperature sensitivity, and arbitrary slice orientation within a 3D data set. The recently-introduced low-field open magnets, though of compromising imaging capabilities, have considerably facilitated access to the patient. The use of instruments and ancillary equipment, however, is made difficult by the high magnetic field and sensitive RF system of the MRI scanner. The techniques of MR-guided injection and using MR-compatible cannulae were developed and tested with ex vivo specimens of the spine and animal phantoms. 184 patients were treated with periradicular corticoid injections, six patients with laser decompression, 21 patients with neurolysis of facet joints and 16 patients underwent chemical lumbar sympathectomy. MR-guidance is feasible and the early clinical results are promising and comparable to those of CT-guided pain therapy. Further technical improvement of MR technology are required to facilitate the procedures.