MRI or magnetic resonance imaging is used to produce two-dimensional pictures of the inside of the human body, including detailed images of a bulging disc. When a spongy disc-like cushion between the vertebrae in the spine protrudes out from its normal position, doctors describe the condition as a bulging disc.
Diagnosis by MRI
A patient who believes she has a bulging disc should visit a health care professional who may be able to diagnose the problem through physical examination. Often a doctor will also request medical imaging. When viewing an MRI of the affected area, doctors will look for a disc that is bulging out of place and possibly touching a nerve root or the spinal cord. To the untrained eye, the side view MRI of spinal anatomy with a bulging disc may look like a soft cushion between two bones that is partially protruding from its pocket . From this view a bulging disc may also reveal a smaller, more compressed space compared to other vertebrae spacing. Through top-view MRI, a disc may appear slightly bulged around the border of the vertebrae, remaining symmetrical. According to the National Institute of Neurological Disorders and Stroke, most bulging discs occur in the lower lumbar portion of the spinal column.
Bulging Disc Characteristics
The spine has more than 30 bones called vertebrae that protect the spinal cord. In between vertebrae are discs that resemble soft cushions with a strong covering called the annulus and a jelly-like filling called the nucleus. A disc bulge happens when the cushion slips out of place. When viewing a disc bulge through MRI the liquid nucleus will appear intact inside the annulus. Depending on location, bulging discs can go unnoticed or patients may experience pain and discomfort in the back and/or other parts of the body such as the legs, feet and arms.
Spinal Cord Images
The spinal cord is a like a column with different sections. Vertebrae form the spine. Vertebrae are held together by ligaments, tendons and muscles and divided into regions along the spinal cord: cervical, thoracic, lumbar, sacral and coccygeal. MRI can show disc bulging between vertebrae from a front view, posterior view, top view and side view.
The Bigger Picture
There are many possible causes for a disc to bulge. These include disc degeneration due to age of patient, chronic poor posture, repetitive back strain such as heavy lifting and family history. Often a patient will undergo an MRI for an unrelated condition and discover one or more bulging discs that never caused any pain or discomfort. For many patients a bulging disc may be secondary to a more serious medical problem. For instance, pain can arise where the lumbar spine and sacral region connect because this section of the spine undergoes a lot of pressure and twisting.
Doctors cannot always feel a bulging disc upon physical examination. Often patients with back pain assume they have a bulging disc when in fact their pain is myofascial or dull aching muscle pain. Pain caused by hardening or sticking of the fascia and muscles may mimic the symptoms of a bulging disc. Other inflammatory conditions such as arthritis may also cause pain in parts of the body similar to those affected by a bulging disc. An MRI is a medical tool that can aid in identifying a bulging disc, but further tests and examination are necessary to conclude the disc bulge is the cause of a painful condition.