Intermountain
Spine Institute
Spine Institute
Magnetic Resonance Imaging (MRI) is a high quality method of imaging the interior of the body using the effect of magnetic waves on hydrogen protons. During varying periods and intensities of magnetization of hydrogen, the molecules align. Observing the relaxation time of the molecules after the magnet is turned off (the time it takes for the molecules to return to their normal orientation), a radio frequency wave is used to gather information and translated by a computer to produce a detailed visual image.
MRI is an excellent modality for the evaluation of soft tissue, since these tissues contain the most hydrogen. MRI is good at imaging bone as well.
Contrast agents, such as gadolinium can be used with MRI to detect tumors and their composition, inflammation, and to evaluate changes due to surgery and infection.
Computed tomography (CT) is a high quality method of imaging the interior of the body using X-rays (ionizing radiation). A tomogram is a slice or section image produced using a wave, in this case generated by gamma radiation. The resulting data is translated by a computer into visual images based upon the amount of radiation blocked by each type of structure in the body.
CT is an excellent modality for imaging bone. It is adequate for soft tissue evaluation, but is surpassed in most areas by MRI. Contrast, usually ionic radiopaque contrast, can be used to highlight tumors, infection, and inflammation or to delineate findings on a non-contrast scan.
CT is a common scan performed when a patient is unable to undergo MRI exam (i.e. pacemaker, surgical clips, cochlear implants).
Myelography, with or without CT, is a technique of visualizing the spinal canal by injection of radiopaque contrast into the canal. In spine applications, CT scan almost always follows myelography in order to obtain the most detailed information. MRI has largely replaced CT myelogram, however in post op patients whose hardware obscures visualization under MRI, or who cannot undergo an MRI, CT myelogram remains a useful modality.
Nuclear bone scan (or scintigraphy) is an imaging technique that utilizes bony uptake of a nuclear isotope to produce images of the skeleton. An isotope (i.e. Technicium99) is introduced via an intravenous line, and the patient waits for 2-3 hours for the isotope to be taken up by bone cells. A scintigraph or a computed tomogram is then obtained to create visual images of the skeleton. Because isotope uptake is based on osteoblastic (growth) activity, areas of increased bone activity results in increased isotope uptake. Areas of decreased bone activity or destruction result in decreased uptake. Both types of uptake can indicate disease states.
Nuclear bone scans are useful in detecting subtle bone damage or fracture. Bone scan is also useful as a screening tool for determining metastatic activity of some types of cancer.
Labeled white cell scans are useful in detecting infection in bone, joints and soft tissue. Blood is obtained from the patient via venipuncture. This blood is separated, and the white blood cells are mixed with the isotope of choice, and returned to the patient. Scintigraphy or bone scan is then performed in two phases. The first phase scan is performed soon after the labeling procedure. A second scan is performed 4 to 6 hours later.
This type of scan is very effective for detecting infections in the limbs (Tc99), and the spine (gallium67).
Plain X-ray or radiography is an imaging technique that utilizes ionizing radiation caught on a wave sensitive plate to image the human body, especially the skeleton.
Plain X-ray is analogous to standard photography in that a wave source is used to create an image on a sensitive plate. The body part to be evaluated is exposed to a directional beam of low-level ionizing radiation, positioned over an exposure plate. The plate is then developed chemically or electronically to produce an image.
X-ray is useful for imaging the skeleton, but is also used for imaging some soft tissues with the addition of contrast. X-ray is commonly used to evaluate for bony fractures, alignment problems, abnormal motion, and degenerative disease. It is also used for post-op evaluation of surgical hardware and fusion mass.
Selective nerve root block (SNRB) is a procedure designed to provide both diagnostic and therapeutic information about pain emanating from a radicular nerve. Some practitioners also call this procedure a selective epidural.
Under live and intermittent fluoroscopy a needle is placed adjacent to the target nerve as it exits the spine through the corresponding foramen. After placement verification using radiopaque contrast, a small amount of medication is then placed along the course of the nerve. For diagnostic purposes the medication used is a short acting local anesthetic. If therapeutic effect is also desired, a small amount of steroid may be injected concurrently to decrease inflammation and provide long-term pain relief.
An initial report is obtained from the patient concerning the change in their pain post-injection compared to pre-injection. A second report is obtained 1 – 2 weeks later.
SNRB is useful diagnostically when there is uncertainty about the involvement of a specific nerve root in the cause of spine and extremity pain.
Facet joint block is a procedure designed to provide diagnostic and therapeutic information about pain emanating from a facet or zygoapophyseal joint.
Under live and intermittent fluoroscopy a needle is advanced into the facet joint(s). After verification of placement using radiopaque contrast, a small amount of medication is injected into the joint. For diagnostic purposes the medication used is a local anesthetic. For therapeutic effect, steroid medication may be administered concurrently.
An initial report is obtained from the patient concerning the change in their pain post-injection compared to pre-injection. A second report is obtained 1 – 2 weeks later.
Facet joint blocks are useful in determining the role facet joints play in the causation of mechanical spine pain.
Facet medial branch block is a diagnostic injection used to evaluate patient suitability for ablation therapy, such as radiofrequency neurotomy/rhizotomy.
Under intermittent fluoroscopy, the sites of the medial branch nerves that serve the facets are identified. A needle is passed to the sites identified, and a small amount of local anesthetic is delivered.
An initial report is obtained from the patient concerning the change in their pain post-injection compared to pre-injection.
If the post injection improvement is adequate, the patient may be referred for neurotomy/rhizotomy.
Lumbar puncture is a diagnostic procedure used to collect cerebrospinal fluid. This procedure is mainly diagnostic, however it can be used therapeutically in a few cases, notably increased intracranial pressure.
Discography is a diagnostic procedure used to gather information about pain generation of spinal discs.
Under fluoroscopy, intervertebral discs are injected with a combination of saline and contrast medium. The procedure is performed with the patient awake but sedated so that immediate pain reports may be obtained as each disc is injected. In addition to injecting suspected painful discs, one normal appearing disc is selected as a control. Painless injection of the control disc is necessary to obtain a diagnostically valid discogram.
Following the discogram, a CT is often obtained to evaluate the morphology of the suspect discs.
Patients with a valid discogram that verifies a painful disc may be candidates for lumbar fusion.
Sacroiliac (SI) joint injections provide both diagnostic and therapeutic information.
Under fluoroscopy, a needle is introduced into the SI joint. Following demonstration of needle placement using radiopaque contrast material, a combination of steroid and local anesthetic is injected into the joint. If purely diagnostic information is desired, injection of anesthetic alone may be performed.
An initial report is obtained from the patient concerning the change in their pain post-injection compared to pre-injection. A second report is obtained 1 – 2 weeks later.
SI joint injections are useful in determining the role SI joints play in pain generation. This injection is the only clinically validated tool for diagnosis of SI pain.
Coccygeal (tailbone) joint injections provide both diagnostic and therapeutic information.
Under fluoroscopy, a needle is introduced into the target sacrococcygeal or coccygeal joint segment. Following demonstration of needle placement using radiopaque contrast material, a combination of steroid and local anesthetic is injected into the joint. If purely diagnostic information is desired, injection of anesthetic alone may be performed.
An initial report is obtained from the patient concerning the change in their pain post-injection compared to pre-injection. A second report is obtained 1 – 2 weeks later.
Coccygeal joint injections are useful in the treatment of coccygeal pain.
Injection of the hip joint provides both diagnostic and therapeutic information.
Under live and intermittent fluoroscopy, a needle is inserted into the joint capsule. Following verification of needle placement using radiopaque contrast, a combination of steroid and local anesthetic is injected into the joint. If purely diagnostic information is desired, injection of anesthetic alone may be performed.
Hip joint injection is useful in the non-surgical management of hip pain due to cartilage tears and degenerative disease. It is also useful to differentiate primary hip pain from back or nerve pain.
EMG is a test that evaluates electrical activity within skeletal muscle. Muscles emit signals that vary depending upon the state of the muscle fibers (e.g. relaxation and contraction). Various disease states can cause changes in these patterns that are detectable via EMG. EMG can also localize the cause of muscle weakness due to nerve impingement or damage.
EMG is performed by inserting a fine needle into a specific muscle and observing the response as the needle is inserted. Then the muscle is observed while at rest. Finally the patient is asked to contract the muscle, and the activity is again observed. The needle is relocated and the procedure repeated until a sufficient number of motor units have been observed.
EMG is useful in the diagnosis of many musculoskeletal and neurologic diseases, such as herniated disc, peripheral neuropathy.
NCS is a test that evaluates the function of the peripheral nerves, measuring the speed of impulses as they travel along nerve pathways. NCS is a non-invasive test, using surface electrodes to provide electrical stimulation to the tested nerves.
NCS measures the speed, amplitude, and latency of nerve impulse transmission. Both motor and sensory nerves are evaluated. F-wave and H-reflex studies are also commonly performed. These are observations of the effects of nerve transmission on muscle.
NCS is useful in diagnosing both localized nerve dysfunction (e.g. carpal tunnel syndrome) and generalized dysfunction (e.g. peripheral neuropathy).
EMG and NCS are commonly performed together.
CBC is a test that catalogs all the components of human blood. A count of each type of blood cell is reported, along with calculations of cell qualities and quantities that have been shown to be clinically useful. A specialized machine most often performs this count.
An additional study often requested with CBC is a differential. The differential further reports the percentage of each type of white blood cell.
CBC is useful in diagnosis of a wide variety of diseases, as well as an indicator of general health. CBC is most often used in spine care to screen for infection, indication of occult bleeding, or bleeding diatheses.
ESR is a simple non-specific blood test that indicates inflammation. A sample of blood is collected and placed in a graduated container. After one hour, the separation of blood cells from plasma is measured, and reported in mm/hour.
The sedimentation rate is affected by the amount of fibrinogen in blood. Elevated levels of fibrinogen cause red blood cells to adhere to each other, and thus increase the rate at which they sink.
ESR is used to evaluate the presence of inflammatory states, but does not reveal the cause.
CRP is a non-specific blood test that indicates inflammation. A sample of blood is collected and the level of the target protein is measured. This protein is manufactured by the liver in response to infectious or inflammatory disease states.
Two common types of CRP testing are performed, cardiac and non-cardiac. The former is used almost exclusively for diagnosis of cardiologic events. The latter is used in evaluating a wide variety of inflammatory diseases.
CRP is felt to be more sensitive than ESR, as well as more useful in evaluating the severity of inflammatory diseases over time.
RF is a blood test that assists in the diagnosis of rheumatoid arthritis. This test is designed to detect a specific autoantibody of immunoglobulin G.
High levels of RF indicate a high probability of rheumatoid arthritis, however elevated RF can occur as a result of other diseases. A negative RF does not rule out rheumatoid arthritis.
ANA is a blood test designed to detect a range of antibodies to human proteins, known as autoantibodies.
The basic ANA detects the presence of autoantibodies without specific typing. In the presence of a positive screening ANA, subtyping is performed to quantify and identify the specific type(s) of autoantibodies present.
High titers of autoantibodies are indicative of an autoimmune disorder (e.g. RA, SLE, Sjorgren’s Syndrome), however approximately 20% of the normal population carries an elevated ANA titer.
HLA B27 is a surface antigen strongly associated with spondyloarthropathy (joint disease in the spine). HLA B27 is most often associated with ankylosing spondylitis (AS), but is also associated with several other problems.
Up to 90% of patients with clinical findings of AS have a positive HLA B27, however less than 20% of HLA B27 positive patients develop AS. This reinforces the importance of clinical diagnosis rather than dependence on the test as diagnostic criteria.
CMP is a panel of blood tests that evaluates metabolic bodily function. The panel consists of tests for the following organs/systems:
Vitamin D – Test for levels of the calciferol group, which is important in promoting bone strength.
Vitamin B12 – Test for levels of cobalamin, important in formation of blood cells and nervous system function.
Serum Protein – Test for levels of several types of protein and albumin. This test screens for multiple disease states, including kidney problems, immune disorders, liver disease and multiple myeloma.
Thyroid hormone levels (T3, T4, TSH) – Test for levels of thyroid hormones and the thyroid stimulating agent. These tests evaluate the function of the thyroid gland.