Radiology
After taking a thorough history, and performing a detailed physical examination, radiological confirmation is important. After all, this is a picture which tells the physician whether or not there is something mechanically present which may explain the symptoms.
 X-Ray
The X-Ray is a type of radiographic image that evaluates bones, joints and degenerative lesions in the spine. The x-ray is a minimally invasive procedure done in the office and requires only passive involvement on the part of the patient. With new equipment and advanced technology today, patients are exposed to minimal amounts of radiation during routine x-ray evaluation of the spine. The x-ray is a simple test, and can be very helpful in its ability to demonstrate bony abnormalities. Most often, an x-ray of the spine will be the first diagnostic tool used in evaluating back and neck pain, and it is usually done before consideration of an MRI or a CT scan.
The common spine X-Ray involves taking a picture of the spine by shooting an X-Ray beam through the body and recording the amount of radiation. Bones of the spine (vertebrae) which are in the middle of the body absorb the X-Rays while soft tissues such as the lungs, abdomen and even muscle tissue permit X-Rays to pass through easily. An X-Ray picture shows a clear image of dense tissues such as the bones and not much of the soft tissues. This image can offer essential information on the structure of the bones, the relationship of one bone to the next one and the overall alignment of the spine.
It is important to realize that the spine is a complex three dimensional structure and that X-Rays only offer a two dimensional analysis of the spine. Therefore, to maximize the understanding of spinal shape and alignment it is important to obtain two X-Rays of the spine, one seen from the front and the other seen from the side.
Good quality X-Rays will permit not only an analysis of the individual bones of the spine but also the overall contour of the spinal column. This is very important in such conditions such as scoliosis or kyphosis where complete analysis of spinal contour is essential.
In addition to standing and recumbent X-Rays, a physician may request a series of dynamic X-Rays to diagnose a spinal problem. These involve obtaining a set of pictures with the patient maximally bending forward and backward. This will permit an analysis of any possible instability (abnormal amounts of movement between vertebrae in the spine. Side bending X-Rays can offer significant information on the flexibility of a spinal deformity such as scoliosis. These bending films can help a surgeon in the decision-making process regarding levels of spinal fusion and overall spinal balance
X-rays provide detail of the bone structures in the spine, and are used to rule out instability (such as spondylolisthesis), tumors, and fractures. Images of bones are made by directing an x-ray beam through the body. The calcium in bone blocks penetration of the x-ray beam and the image of the bones is picked up as a shadow on a film positioned on the other side of the patient. X-rays do not capture the images of discs and nerve roots, since they don't contain any calcium. X-rays should not be performed in women who may be pregnant.
An AP (anterior to posterior) film of the lumbar spine is looking through the body, from front to back. This type of view can spot fractures, and is often useful for early detection of tumors involving the bone.
A lateral x ray of the lumbar spine is excellent for determining alignment of the spine. Compression fractures can be detected easily. In addition, collapse of the disk spaces may indicate degenerative disk disease.
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CT scans (Computerized Tomography).
This specialized x-ray shows the bony vertebrae in detail. Like an x-ray, a CT scan works by directing an x-ray beam through the body. Then a computer is used to reformat the image into cross sections of the spine. This process is repeated at different intervals. As a result, the spinal canal can be imaged and assessed for specific conditions. With its excellent bony detail, CT scans are very useful for assessing fractures. Through multiple views, CT scans will image specific conditions such as lumbar disc herniation and lumbar spinal stenosis. CT scans should not be performed on pregnant women.
A CT (computed axial tomography) scan shows "slices" through the lumbar spine. This type of image uses x rays, delivered in a circular manner circumferentially around the body. A sophisticated computer then adds the various rays, calculates densities of bones and soft tissue within the center of the rays, and produces a picture. The first CT scanner was made by EMI (which also produced Beatles records), and was extremely slow, and the pictures were relatively poor, by today's standards. Present day CT scans are fast, and quite sharp. CT is best for looking at bone, while soft tissue within the lumbar spine (such as nerves and herniated discs) are less optimally seen.
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Myelogram
Myelogram (injection of a dye or contrast material into the spinal canal) is utilized to diagnose disorders of the spinal canal and cord, such as nerve compression causing pain and weakness. The test is usually performed on an outpatient basis at a hospital or other medical facility by a neuroradiologist. Neuroradiology is a sub-specialty of radiology that conducts studies of the central nervous system. A Myelogram requires introduction of radiographic contrast media (dye) into the sac (dura) surrounding the spinal cord and nerves. The patient lies on his/her stomach during the test. After the skin area has been numbed, the dye is injected into the spinal sac followed by x-rays, CT, or MRI scans. After the images are processed, a neuroradiologist interprets the results and sends a report to the referring physician. Following the Myelogram, the patient is taken to a recovery area where he/she rests lying down with the head elevated for several hours. Once at home, quiet non-strenuous activities are recommended for 24 hours to allow the puncture site to heal. Plenty of fluids (e.g. water, juice) should be consumed to clear the dye from the body.
A Myelogram is a study in which a spinal tap is performed within the lumbar spine, and radio opaque (shows up on x-ray) dye is placed within the spinal fluid. X-rays are then taken, and CT scans are taken as well. The dye provides an outline of the nerves, and any abnormality, such as a herniated disk, can be seen as an indentation or defect in the normal filling of dye. In the Myelogram on the left, the normal column of white dye is significantly narrowed by compression upon the nerves.
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MRI (Magnetic Resonance Imaging).
This non x-ray study allows an evaluation of the spinal cord and nerve roots. It produces detailed images of discs and the spinal cord. An MRI images the spine by using a magnet that goes around the body to excite hydrogen atoms. After the atoms return to their normal level of excitation, they emit energy that is picked up on a scanner. There is no radiation with the magnet, so the scans may be performed on pregnant women. However, patients with a pacemaker implanted in their heart should not have a scan because the magnetic field will cause the pacemaker to malfunction. Also, anyone who works around metal should first have an x-ray of their eye sockets to ensure there are no metal filings in their eyes, which the magnetic field may cause to migrate and damage the eye. The scan is performed while the patient is lying in a fairly tight tunnel for 45-60 minutes. Some patients may not be able to tolerate this confined space, however newer generation scanners are designed with more open space.
(magnetic resonance imaging) provides exquisite views of the nerves and other soft tissues around the lumber spine. While they don't provide as much detail about the bone as a CT scan does, they do offer the advantage of showing images in many different planes (axial, coronal, sagittal). Sometimes herniated disks, which are subtle and difficult to see in one plane, are easily seen in another. These scans rely on magnetization of hydrogen atoms, and so far have not been found to have any long lasting adverse risks. Some patients have difficulty because the "bore" into which they must lie is relatively narrow, and "open" MRI scanners suit these patients better. Unfortunately there is some compromise of image quality in the open MRI scanners, and the closed machines of comparable technology still provide the best pictures.
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Discogram
Discography, or Discogram, is a diagnostic tool used to determine the structural integrity of an intervertebral disc (or discs) and to find out if a particular disc is responsible for the patient's back pain. Provocative Discography is a form of discography that replicates the patient's 'discogenic' pain. The term discogenic is defined as a pain syndrome characterized by local or radicular pain cause by nerve root compression. The test is performed on an outpatient basis in a hospital or medical facility, by either a radiologist or surgeon.
A Discogram is a study in which radio opaque dye is injected into the disk space. This is both an anatomical study as well as a functional study. It looks at the anatomy of the disk space, and can show when dye leaks through rents in the annulus fibrosis. But just as or even more important, it is a functional test. When the physician injects dye into the disk space, the patient reports, on a scale from 1 to 10, how much pain has been produced. If the pressure injection of dye into the disk space reproduces the patient’s usual low back pain, then surgical fusion of the disk space may have some benefit in improving the pain. As far as the low back team knows, it is the only test in which we hope a patient has significant pain, because that means the disk is likely a cause of the pain, and surgical fusion may help. This is usually a method of last resort, after all else has failed.
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Bone Scan - A test procedure that involves intravenously injecting a small quantity of a radiographic marker into the patient, and then running a scanner over the area of concern. The scanner detects the marker, which concentrates in any region exhibiting high bone turnover. A bone scan is utilized when there is suspicion of tumor, infection, or small fractures, i.e., conditions that all result in high bone turnover. A Bone Scan does not replace the above tests, but may provide additional information by eliminating other serious problems.
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CT scans (computerized tomography) with Myelogram. When combined with a Myelogram, a CT scan provides for excellent nerve detail. The Myelogram adds some additional risk and expense to the CT scan, but provides substantial information about the nerve roots. A Myelogram consists of injecting a radiographically opaque dye (dye that is picked up by x-ray) into the sac around the nerve roots, which in turn lights up the nerve roots. The CT scan follows and shows how the bone is affecting the nerve roots. This is a very sensitive test for nerve impingement and can pick up even very subtle lesions (injuries). The main risk with CT scans is that they use x-ray beams and should not be performed on pregnant women. The main risk with a Myelogram is the potential for a spinal headache. The spinal headache usually resolves in one to two days with rest and fluids, and seems to be more common for patients with a history of migraine headaches.
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