Diagnostic Tools in Pain Management
In pain management, as well as in any other medical specialty, obtaining an accurate diagnosis is critical. Success in treatment will depend on this, because different diagnoses will most likely require very different treatment approaches. An accurate clinical diagnosis is typically based on correlating the physician's findings during the patient interview and examination with the results of the diagnostic tests. What makes this diagnosis more challenging, is that the originating pain structure can not always be easily identified, and many times diagnostic procedures may need to be performed to assist in this.
Please click on any term below for a detailed description of each diagnostic tool.
Patient Interview and Physical Examination
This is one of the key diagnostic tools used by the physician to evaluate the pain condition and determine the need for other tests. A working diagnosis will be made, and differential diagnoses will need to be ruled out. Finally, a treatment plan will be formulated, and alternatives will be discussed. Possible risks and benefits of the procedure will also be explained.
X-Rays
They provide details of bony structures. They are used to diagnose fractures, abnormal motion, bone changes due to arthritis and misalignment. However, an X-ray cannot be used to diagnose soft tissue problems (disc herniation, nerve pinching, etc.).
Computerized Tomography (CT scan)
A CT scan takes cross sectional images of the body and provides excellent bony detail as well as providing the capability of imaging soft tissue structures (discs, spinal cord, nerve roots, etc.). A computer is used to reformat the images, or "slices", of the body tissues, bones and organs. If needed, three dimensional images can be created. CT imaging is particularly useful because it can show soft tissues in addition to bones.
Magnetic Resonance Imaging (MRI)
It provides a clear diagnostic picture without using radiation. They can be closed or open units, at this point the former provides a better image. MRI uses radio waves in conjunction with a very powerful magnet and computer processing to generate realistic pictures of various parts of the body. However, because of the strong magnetic field used, patients with metallic foreign bodies (inner ear implants, pacemakers, spinal cord stimulators) cannot undergo an MRI. The MRI provides detailed images of soft tissues (particularly the brain, spinal cord, muscles, ligaments and cartilage), and is used for evaluating these structures. It provides excellent bony detail and can look at the shape and hydration of intervertebral discs to rule out bulging, herniation, tears, degenerative changes, etc. Peripheral nerves cannot be seen well on a standard MRI.
Computerized Tomography Myelogram
A CT Myelogram involves all the same procedures of a CT scan except that a contrast dye is injected into the spinal canal before the scan is taken. Common complications of this procedure include headache and a sore back. In rare cases, a seizure or meningitis can occur. Allergic reactions to the contrast dye include hives, nausea or vomiting, and/or anaphylactic shock. This test has, in most instances, been replaced by an MRI and is used primarily when there is a contraindication to an MRI, such us a pacemaker or other metal implants.
Bone Scan
This study involves the injection of a radioactive substance into the bloodstream. The substance, also called a tracer, is taken up by the bone and detected with a special type of camera. This is performed to rule out an inflammatory process, such as a tumor or infection, or an occult fracture. Bone scans, however, cannot distinguish what a lesion represents, and therefore cannot differentiate between a tumor, an infection, or a fracture.
Electromyography (EMG)
An electromyogram tests the functions of the nerve roots and the way that the nerves affect muscle function. The test involves placing small needles into the muscle. The electrical activity of the muscles is examined during both contraction and rest.
Nerve Conduction Velocity (NCV)
This study is used to diagnose diseases and evaluate the integrity of the peripheral nervous system.
