Axial Loading During CT, MRI Improves Diagnosis

buy microsoft office enterprise 2007

buy Microsoft Office 2003 Professional sp3buy autodesk autocad 2009

Axial Loading During CT, MRI Improves Diagnosis

Myelographic examinations are regularly performed on patients with possible encroachment into the spinal canal. Computed tomography (CT) and magnetic resonance imaging (MRI) scans are in some ways superior to myelography when examining the spinal canal because of their capability for analyzing the content of the canal.

Narrowing of the spinal canal occurs during axial loading and extension, yet CT and MRI scans are still commonly performed with patients in a supine, relaxed position, which causes enlargement of the canal.
To assess the significance of axial loading when diagnosing patients with lumbar spine degeneration, 172 patients with symptoms of sciatica, low back pain (LBP), or neurogenic claudication were analyzed with CT or MRI in a relaxed-psoas position and in a supine position during axial compression. Compression was achieved with a loading device consisting of a harness and elastic straps, subjecting supine patients to a load of approximately 40% of their body weight. The authors sought "additional valuable information" that could be obtained from axial loading, including decrease in the dural sac cross-section; disc herniation; narrow intervertebral foramen or lateral recess; or synovial cyst.
Additional valuable information was discovered in 29% of the subjects during axial loading. Considering each condition separately, additional data were obtained in 69% of neural claudication patients and 14% of sciatica patients, but in none of the LBP patients. Additional valuable information increased to 50% of sciatica cases when recommended inclusion criteria for axial examinations were utilized.
Conclusion: Axial loading during CT and MRI imaging may add additional valuable information to a clinician, especially in neurogenic claudication patients and selected sciatica patients. The authors suggest that an axial-loading examination should only be performed after a conventional, unloaded supine CT or MRI examination in these patients to avoid loading of an osteoporotic or fractured spine and to optimize diagnosis.
Willén J, Danielson B. The diagnostic effect from axial loading of the lumbar spine during computed tomography and magnetic resonance imaging in patients with degenerative disorders. Spine 2001:26(23), pp. 2607-2614.