Mehran Midia - The Canadian Pain Society

Anatomy of Imaging Painful Spine
In order to utilize appropriate imaging tools in order to diagnose and treat patients with
acute or chronic spinal pain it is essential to:
A. Be familiar with spinal anatomy and pain generators in the spine
B. Have a clear understanding of indication of imaging
C. Order appropriate imaging tool depend on anatomy and etiology in question
D. Understand the limitation of the individual test and interpretation
E. Be systematic and methodical in approaching the clinical question and the
evidence
A- Cause of spinal pain can be divided based on:
Location: Disc, nerve, facet, ligamentum flavum
Etiology: Degenerative, infectious, inflammatory, neoplastic, iatrogenic, etc
And further more could be:
a. Discogenic Due to
a. Expression of inflammatory degenerative disc by-products
b. Direct annular innervations by nociceptive fibers
b. Encroachment of the nerve roots
a. Radiculopathy (disc, facet, lig, muscle)
b. Lateral recess stenosis
c. Neural foraminal stenosis
d. Extra-foraminal (piriformis synd)
e. Spinal canal narrowing (pseudoclaudication)
c. Pain from the affected spinal element
a. Facet arthropathy, spinous process
d. Sacroiliac Joint
e. Motion and instability

B- "The wise man doesn't give the right answers, he poses the right questions." Claude
Levi-Strauss
“You can tell whether a man is clever by his answers. You can tell whether a man is wise
by his questions." Naguib Mahfouz
In order to get the best out of imaging consultation it is prudent for the refereeing
physician to have taken a full history and examined his or her patient thoroughly and to
communicate their findings to the radiologist.
Imaging yield increases if ordering physician is able to generate and communicate a
specific question or concern rather than working on shut gun approach (GIGO). Also
having more information is helpful for the radiologist to use proper protocol for imaging
and make suggestion for additional imaging if needed.
Question that often arise can be divided into:
1- Confirmation of clinical judgment and establish cause
2- Exclusion of sinister or treatable disease
3- Guide treatment
4- Assess for complications
Social indication of imaging often results in imaging reports with little benefit in overall
patient care and may cause delay in diagnosis if it is not appropriately used.
1- Reassure patient
2- Defensive medicine and medicolegal concerns
3- Buy time
C- Spine can be imaged using conventional x-ray, CT, MRI, Bone Scan, Myelogrpahy,
Discography and Bone Densitometry. These tests could be used stand-alone or in
combination depend on the specific question that is needed to be answered, structure in
question and potential etiology that is being entertained. Conventional x-ray and CT are
useful to assess osseous structures. MRI is essential for assessment of soft tissues and is
the workhorse of spinal imaging for variety of conditions. Intravenous contrast is helpful
when assessing for post surgical scar, infection, tumor or arachnoiditis. CT myelography
is only indicated in assessing patient with spinal hard ware in place when conventional
CT or MR is inconclusive.
D- The physician ordering the test should have an understanding of indication and
contraindication of each test, limitations due to inherent techniques, sensitivity,
specificity, accuracy positive and negative predictive value, intra and inter observer
variability of the test they order.
Not knowing these limitations and omitting to investigate the correct piece of anatomy
with the correct investigation could result in sense of false security and significant delay
in proper treatment of their patients. It also this could result in many incidental finding
that could trigger a battery of unnecessary and related investigation.

Always do remember that spine is a window to the spinal cord and is a part of nervous
system. It is wise to look up and down!
E- Following a systematic checklist could be helpful for physicians when reviewing
imaging of their patient presenting with spinal pain.
Using ABCDEFs Spine imaging makes interpreting imaging easy.
Alignment
Bone Density, Bone Marrow
Canal, Cord, Conus Medullaris, Cauda Equina
Disc
Epidural, Extraforaminal, Enhancement
Foramina, Facet, Lig Flavum, Fracture
IJ, Sacrum
Patient with prior back surgery often seek medical attention with persistent or recurrent
symptoms. The causes of failed back surgery are as follows:
Early: Hematoma, infection, insufficient decompression, nerve root trauma,
unrecognized disc fragment, Sx at wrong level
Late: Arachnoiditis, Epidural fibrosis, Facet Degeneration, instability, new or
recurrent disc herniation, pseudomenigocele, spinal stenosis, osteomyelitis
In Conclusion:
“The radiologist who takes a superficial history and allows it to influence his diagnosis is
a menace. Certain x-ray appearance makes operation desirable, regardless of the
diagnosis suggested by classical clinical medicine. On the other hand, the clinician cannot
shift his/her responsibility to the radiologist. It is his/her duty to ask himself weather the
symptoms can be explained based on the x-ray findings or weather an alternative
explanation is essential. The x-ray department can be as good as the clinician it allows it
to be, without the fullest collaboration mistakes and mutual recriminations are
inevitable,”
Book Summary from British Medical Journal page 914 Oct. 22 nd 1949. “Radiologist and
Clinicians” By De M, Chiray et al. Paris 1949.
D. A Jennings