Greetings! To address the first part of your question on the
viability of an MRI, I located a report from the Medical Multimedia
Group (http://www.medicalmultimediagroup.com/pated/back/back.html)
which addresses the use of MRI in diagnosing back pain. The
information suggests first a thorough physical examination then a
compilation of patient history and the use of X-rays: "X-rays of your
lower back may also be ordered at the initial office visit if your
back pain has been going on for more than 4-6 weeks. X-rays are
sometimes ordered if there are specific reasons to suspect a fracture,
infection, or possibly a malignant tumor of the spine. X-rays show the
bones of the lumbar spine. Most of the soft tissue structures of the
spine do not show up. Still, much can be learned from the X-rays in
certain instances."
The report then gives alternate methods of imaging the spine, and the
first mentioned is the MRI:
"The MRI (Magnetic Resonance Imaging) scan is the most common test
used to look at the spine. The MRI scanner uses magnetic waves instead
of radiation. Imagine if you could slice through the spine layer by
layer and take pictures of each slice. That's exactly what the MRI
scanner allows us to do. Multiple pictures of the spine are taken by
the MRI scanner. This allows us to view not only the bones of the
spine, but also the nerves and disks. Slices can also be taken across
the spine, giving a cross sectional view. The MRI scanner allows us to
see the nerves and disk quite clearly."
However, the text then indicates that an MRI scan "is, perhaps, too
good at showing the anatomic details of the spine. There is a growing
body of evidence that suggests that not all abnormalities that show up
on the MRI scan are really the cause of the individual patient's
problem. Abnormalities, such as bulging disks, show up frequently in
normal volunteers undergoing MRI scans - folks who have never had any
problem with their back. The bottom line is this - an MRI scan is a
great test to show the lumbar spine anatomy, but it must be correlated
carefully with your symptoms so that the findings aren't blown out of
proportion."
This latter information was also supported on a site called Spine
Health (http://www.spine-health.com/topics/cd/myths/myth02.html ) :
"Myth: An MRI scan or other diagnostic test is needed to diagnose my
condition - Fact: Most health professionals can develop a successful
treatment approach based on a thorough medical history and physical
examination. Only specific symptom patterns in a minority of cases
indicate the need for MRI scans or other sophisticated tests.
Typically, MRI scans are used when patients are not responding to
appropriate treatment."
Both of the sources suggest MRI as a viable tool in discovering the
cause of back pain but both also suggest it as an additional tool in
diagnosis, not the first tool to use.
The Spine Health site also echoes the statement at Medical Multimedia
Group concerning people who have abnormalities of the spine but have
not complained of back problems: "Myth: The abnormality on my MRI scan
needs to be cured - Fact: An abnormality that is seen on an imaging
test (MRI, CT scan) does not necessarily cause pain. In fact, the vast
majority of people who never have had an episode of low back pain will
have abnormalities (herniated disc, degenerative disc) on an imaging
test. For patients experiencing low back pain, 92% - 96% can be
treated successfully without surgery."
In a study titled "Occult and secondary injuries missed by plain
radiography of the cervical spine in blunt trauma patients" (Published
in Emergency Radiology 2001;8:200-6. by Mower WR et al.) the
conclusion was "Plain radiographs frequently fail to reveal injuries
to the cervical spine, particularly those involving the lamina and
lateral mass. The majority of the missed injuries represent secondary
injuries in patients with a sentinel injury identified on these films.
However, plain films fail to detect any injury in a minority of
injured patients."
This information was found at
http://www.ahcpr.gov/about/coer/grntpubs/grntpub1.htm which listed
"some of the publications resulting from research grants overseen by
Center for Outcomes and Effectiveness Research."
The results of the above study were listed as "Plain radiographs were
completed in 570 of 818 victims of acute cervical spine injury and
revealed 702 of 1,056 injuries. Plain films failed to detect 98 occult
injuries present in 60 patients (10.5 percent), and failed to detect
256 secondary injuries in 510 patients (89.5 percent) who had a
sentinel injury identified. Plain radiographs failed to reveal 79 of
136 (58.1 percent) lateral mass injuries and 67 of 105 (63.8 percent)
lamina injuries, making these the most frequent sites of missed
injury."
I could discover no basis in which the MRI was the first image
suggested in diagnosis. In the various other reports I found, it was
always used after a physical examination and X rays. I also found
information from the Radiology Channel
(http://www.radiologychannel.net/backpain/index.shtml) that stated "CT
has the advantage of accessibility, especially in comparison to MRI in
many institutions. In the vast majority of cases, CT imaging is as
good as it gets or, at least, as good as it needs to be. In more
complicated cases, an MRI may be called for." This statement seems to
show that a CT scan would be used before an MRI.
The entire article deals with back pain and I suggest you read the
full text. Also stated is "MRI has the advantage of picking up
information about an entire section and rendering images of that area
in any plane. The radiologist can rotate the images and look at them
from the side, obliquely, or as cross-sections. The other advantage of
MRI is that it is simply a much better modality to study soft
tissues." I believe the text here will assist you in drawing your own
comparison of the methods.
I also discovered an interesting MRI device for better capturing
images in back pain cases. At the site
http://spacephysiology.arc.nasa.gov/projects/mri.html, NASA Ames
Research Center, was a diagram of an MRI-Compatible Spinal
Compression Harness. This harness is described as "a new research and
diagnostic tool to study the physiology/biomechanics of intervertebral
discs and pathophysiology of back pain in patients on Earth and
astronauts in space. The spinal compression apparatus consists of a
non-metallic footplate connected to shoulder pads by adjustable
elastic cords. Amount of spinal compression is measured by
non-metallic force transducers. Alternative features of the spinal
compression harness include helmet-like headgear with adjustable
elastic straps to provide cervical compression, a saddle to distribute
compression to the seat, or attachments which isolate compression to
particular limb segments."
Since standing and reclining are two different positions, it made
sense to me that this harness should be used with MRI scans for the
image to be able to see what occurs when pressure is applied to the
spine because most people do not recline 24 hours a day. There is a
diagram there which shows how the device works and there is more
commentary concerning it that you may find of interest.
Regarding studies, there is one located at
http://www.ahcpr.gov/research/apr01/401RA10.htm on outcomes and
effectiveness of research titled "Researchers study the causes of low
back pain, use of imaging to identify herniated disks, and cancer in
back pain patients." There are two studies on the page and the first
deals with your query.
Another source for this is a commentary from David F. Winfield, M.D.,
which deals with "Imaging of Low Back Pain"
and it is located at http://www.msit.com/ra_back.htm. He comments on
five imaging options beginning with X rays.
The American Academy of Family Physicians offers a report on low back
pain titled "Diagnosis and Management of Acute Low Back Pain" and
located at http://www.aafp.org/afp/20000315/1779.html. There they
offer tables for study, including one on "Differential Diagnosis of
Acute Low Back Pain
" and another on "Laboratory and Radiographic Findings in Selected
Causes of Low Back Pain"
I hope my research is of assistance in your quest and should you need
any clarification before rating my answer, please request it and I
will be happy to conduct further research in this area.
SEARCH PHRASES:
MRI low back pain
MRI diagnoses back pain
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study MRI merit
MRI vs radiograph back pain study
MRI vs X ray back pain
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effectiveness of MRI back pain
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back pain diagnosis study |
Clarification of Answer by
journalist-ga
on
06 Nov 2002 10:05 PST
I found a few studies regarding the additional conditions you
specified:
The Natural History of Spondylolysis and Spondylolisthesis: 45-Year
Follow-Up
http://www.spineuniverse.com/displayarticle.php/article970.html
Spinal Stenosis (MRI/radiograph info about halfway down the page)
http://www.emedicine.com/med/topic2889.htm
Radiology Cases in Pediatric Emergency Medicine Volume 7, Case 12
Muhammad Waseem, MD (about three-quarters of the way down the page)
http://www.hawaii.edu/medicine/pediatrics/pemxray/v7c12.html
"After identification of a mediastinal lesion on a
conventional radiograph, CT or MRI is the preferred
modality for further evaluation of the middle and
anterior mediastinum, whereas MRI is definitely the
preferred modality for posterior mediastinal lesions,
since most are neurogenic lesions which delineate
better with MRI because of its multiplanar capabilities
(2)."
Neoplastic Epidural Spinal Cord Compression (ESCC) (about halfway down
the page)
http://www.hawaii.edu/medicine/pediatrics/pemxray/v7c12.html
"MRI vs. CT-Myelogram - Pro-MR - MRI has been shown to be more cost
effective"
Surgical Management of Malignant Tumors of the Adult Bony Spine* DAVID
W. CAHILL, MD, Tampa, FL (see sub-heading "Diagnostic Imaging")
http://www.sma.org/smj/96jul2.htm
Tuesday, January 06, 1998: (Day 1)
http://216.239.51.100/search?q=cache:5M9hWusOSiIC:www.inspirationcenter.net/Logan2000/tri7/xraydx2/XrayDxExam1Notes.doc+spinal+stenosis+MRI+vs+radiograph&hl=en&ie=UTF-8
"Cannot really see stenosis unless you use MRI or CT."
"Lumbar Spondylolysis: Determination of an Optimum Radiological
Screening Examination for Lumbar Spine"
http://www.mjm.mcgill.ca/issues/v01n01/spondyl.html
ACR Appropriateness Criteria™ for myelopathy - SOURCE(S): Radiology
2000 Jun;215(Suppl):495-505
http://www.guideline.gov/VIEWS/summary.asp?guideline=1669&summary_type=brief_summary&view=brief_summary&sSearch_string=
"The ability of magnetic resonance imaging to depict the spinal cord
directly, and to assess its contour and internal signal
characteristics reliably and noninvasively, has resulted in general
acceptance of MRI as the study of choice in the evaluation of cervical
myelopathy when spondylosis or disc herniation is the most likely
cause. When magnetic resonance imaging is not available, or to answer
specific questions before surgical intervention, myelography and
computed tomography myelography may be useful."
I hope this additional information is of assistance. Should you need
further clarification, please request it.
SEARCH PHRASES:
spondylolysis disc degeneration MRI
spondylolysis disc degeneration MRI vs radiograph
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spinal stenosis MRI vs radiograph
spinal tumors MRI vs radiograph
disc degeneration MRI vs radiograph
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