How is Low Back Pain diagnosed?

How is Low Back Pain diagnosed?

A thorough medical history and physical exam can usually identify any dangerous
conditions or family history that may be associated with the pain. The patient describes
the onset, site, and severity of the pain; duration of symptoms and any limitations in
movement; and history of previous episodes or any health conditions that might be
related to the pain. The physician will examine the back and conduct neurologic tests to
determine the cause of pain and appropriate treatment. Blood tests may also be ordered.
Imaging tests may be necessary to diagnose tumors or other possible sources of the pain.
A variety of diagnostic methods are available to confirm the cause of low Back Pain:

• X-ray imaging includes conventional and enhanced methods that can help
diagnose the cause and site of Back Pain. A conventional x-ray, often the first
imaging technique used, looks for broken bones or an injured vertebra. A
technician passes a concentrated beam of low-dose ionized radiation through the
back and takes pictures that, within minutes, clearly show the bony structure and
any vertebral misalignment or fractures. Tissue masses such as injured muscles
and ligaments or painful conditions such as a bulging disc are not visible on

conventional x-rays. This fast, noninvasive, painless procedure is usually
performed in a doctor’s office or at a clinic.

• Discography involves the injection of a special contrast dye into a spinal disc
thought to be causing low Back Pain. The dye outlines the damaged areas on xrays
taken following the injection. This procedure is often suggested for patients
who are considering lumbar surgery or whose pain has not responded to
conventional treatments. Myelograms also enhance the diagnostic imaging of an
x-ray. In this procedure, the contrast dye is injected into the spinal canal, allowing
spinal cord and nerve compression caused by herniated discs or fractures to be
seen on an x-ray.

• Computerized tomography (CT) is a quick and painless process used when disc
rupture, spinal stenosis, or damage to vertebrae is suspected as a cause of Low
Back Pain. X-rays are passed through the body at various angles and are detected
by a computerized scanner to produce two-dimensional slices (1 mm each) of
internal structures of the back. This diagnostic exam is generally conducted at an
imaging center or hospital.

• Magnetic resonance imaging (MRI) is used to evaluate the lumbar region for bone
degeneration or injury or disease in tissues and nerves, muscles, ligaments, and
blood vessels. MRI scanning equipment creates a magnetic field around the body
strong enough to temporarily realign water molecules in the tissues. Radio waves
are then passed through the body to detect the “relaxation” of the molecules back
to a random alignment and trigger a resonance signal at different angles within the
body. A computer processes this resonance into either a three-dimensional picture
or a two-dimensional “slice” of the tissue being scanned, and differentiates
between bone, soft tissues and fluid-filled spaces by their water content and
structural properties. This noninvasive procedure is often used to identify a
condition requiring prompt surgical treatment.

• Electrodiagnostic procedures include electromyography (EMG), nerve
conduction studies, and evoked potential (EP) studies. EMG assesses the
electrical activity in a nerve and can detect if muscle weakness results from injury
or a problem with the nerves that control the muscles. Very fine needles are
inserted in muscles to measure electrical activity transmitted from the brain or
spinal cord to a particular area of the body. With nerve conduction studies the
doctor uses two sets of electrodes (similar to those used during an
electrocardiogram) that are placed on the skin over the muscles. The first set gives
the patient a mild shock to stimulate the nerve that runs to a particular muscle.
The second set of electrodes is used to make a recording of the nerve’s electrical
signals, and from this information the doctor can determine if there is nerve
damage. EP tests also involve two sets of electrodes — one set to stimulate a
sensory nerve and the other set on the scalp to record the speed of nerve signal
transmissions to the brain.

• Bone scans are used to diagnose and monitor infection, fracture, or disorders in
the bone. A small amount of radioactive material is injected into the bloodstream
and will collect in the bones, particularly in areas with some abnormality.
Scanner-generated images are sent to a computer to identify specific areas of
irregular bone metabolism or abnormal blood flow, as well as to measure levels of
joint disease.

• Thermography involves the use of infrared sensing devices to measure small
temperature changes between the two sides of the body or the temperature of a
specific organ. Thermography may be used to detect the presence or absence of
nerve root compression.

• Ultrasound imaging, also called ultrasound scanning or sonography, uses high frequency
sound waves to obtain images inside the body. The sound wave echoes
are recorded and displayed as a real-time visual image. Ultrasound imaging can
show tears in ligaments, muscles, tendons, and other soft tissue masses in the
back.