Imaging Studies to define Anatomy of Potentially Correctable Lesion
(See also Neck Imaging
In addition to x-rays, the imaging studies most generally used to define a possible anatomic cause for evidence of physiologic abnormalities include plain myelography, MRI
, CT-myelography, discography, and CT-discography.
Abnormal findings on anatomic studies such as MRI, CT, myelography, and discography may be misleading, however, if they are not corroborated with evidence of physiologic abnormality from the medical history, physical examination, or physiologic tests. One problem with imaging studies is that in many patients, there is an inability to find any defects. Another problem is the lack of a "gold standard" in determining if an anatomic defect seen on imaging tests is actually the cause of symptoms. Anatomic abnormalities of the lumbar spine, such as degenerative changes and bulging or herniated discs, are found to increase with aging on x-rays and other imaging tests in subjects asymptomatic for low back problems.273
et al.,`06 prospective cohort found neither back pain severity nor disability were predicted by structural findings or minor trauma. Carragee's group also found symptoms serious or not, with or without non-major trauma (without fracture or dislocation) did not increase MRI changes over their prospective 5 year study. Also, having advanced structural changes did not make subjects more likely to become symptomatic with minor trauma and not so minor events, than without a traumatic event.
Award winning studies find development of MRI lumbar spine degenerative changes in identical twins to be extremely similar despite wide variations in exposures to work, load and vibration (6 fold differences).Battie,Videman 274e-g
Imaging use suggested for:
1. Strong Neurologic Signs
- High impact trauma
-Cauda Equinae symptoms
-Risk Factors for cancer, infection, or occult fractures
3. Persistent symptoms >4-8 weeks
Caveat for Over-use of imaging studies risks:
1.reinforcing the suspicion of serious disease,
2.magnifying the importance of nonspecific findings,
3.labeling patients with spurious diagnoses.
"Patients should understand that imaging is to rule out serious conditions, and to expect degenerative findings." Carragee EJ, Persistent Low Back Pain, NEJM 352;18 May 5, 2005
Several studies stress the importance of not relying too heavily on imaging studies alone for assessment when nerve root compromise is suspected.30
The anatomic level of imaging study findings must correspond to the side and the level of concern physiologically detected through the history, physical examination, or other physiologic methods.
Diagnostic logic should flow easily from strong evidence of a correctable lesion on imaging studies to obviously explain strong evidence of physiologic compromise (Neurological PE findings, electrodiagnostic findings or Bone scan) which in turn should strongly suggest the reason for symptoms. Strong concordant findings are required in the controlled trials that support surgical or other risk related interventions. The logic should flow like water down a Cascade of Concordance. The easier justification, the easier it is to both act promptly and justify your reasoning should the decision be questioned later.
SRC Spinemate - only used or reproduced with written permission from SResourceC@aol.com