What are Diagnostic Tests for Spinal Disorders?
Diagnostic tests for spinal disorders are defined as studies or procedures performed to confirm or rule out a spinal disorder. Before making a treatment plan, your physician needs crucial information for a precise diagnosis, which a diagnostic test provides.
Spinal disorders are defined as diseases or conditions that affect the normal functioning of the spine.
The spine is made up of a column of small bones called vertebrae that surround and protect the spinal cord and nerves that branch out from the spinal cord. Each bone or vertebra is separated from the other by a spongy tissue called an intervertebral disc, which acts as a cushion and prevents the bones from rubbing against each other during movement. Based on their position, the vertebral column is categorized into 7 cervical vertebrae in the neck, 12 thoracic vertebrae in the chest region, 5 lumbar vertebrae in the lower back, and 5 fused bones of the sacrum and 3 fused bones that form the coccyx in the pelvic region. Some of the common spinal disorders include:
- Degenerative disc disease (DDD)
- Spinal stenosis
- Herniated disc
Diagnostic Tests for Spinal Disorders
Diagnosis of spinal conditions or disorders starts with a complete review of your medical history and a physical examination. Your physician will ask questions to understand the nature of your symptoms and when they began. Your physician will also assess the level of pain, muscle strength, range of motion, reflexes, and response to sensory stimulus. Diagnostic tests may include the following:
- Laboratory tests: During laboratory tests, your physician may order certain blood tests to detect metabolic abnormalities and inflammatory conditions. Different types of inflammatory conditions impact the spine including sacroiliitis (lower back and pelvis) and ankylosing spondylitis. Blood tests are also recommended to diagnose infections, such as discitis, which is an infection in one or more of the intervertebral discs.
- X-rays: An X-ray study is a fairly quick and painless diagnostic procedure that uses low-dose ionizing radiation to produce images of the internal structures of the body, including the spine. It is commonly used to detect bone fractures. Dense areas of the body such as the bone, through which X-rays do not pass, appear white on the image. When a fracture is present, the fracture line will appear black.
- Myelogram: Also known as myelography is a diagnostic imaging technique that uses a combination of injected contrast substance with X-rays or computed tomography (CT) to look for problems in the spinal cord, nerve roots, spinal canal, and other surrounding tissues.
- Magnetic resonance imaging (MRI): This diagnostic procedure utilizes a combination of powerful magnets, radiofrequency, and a computer interface to furnish clear and detailed images of soft tissue structures and organs in the body, including the spine. During the test, you will lie on a bed that moves into the cylindrical MRI machine and a series of images of the inside of your body is captured using a magnetic field and radio waves. These images are then enhanced by a computer for detailed review. MRI can reveal anatomical images of the spinal cord and is used to detect disorders such as spinal cord tumors.
- Computed tomography scan (CT or CAT scan): This is a diagnostic test that provides more detailed images of the spine than a traditional X-ray. CAT scans utilize a combination of computer technology and X-rays to produce cross-sectional images, both vertically and horizontally, of the spinal column and surrounding structures that provide detailed pictures of the bones and soft tissues.
- Nerve Conduction Studies (NCS): The main objective of a nerve conduction study is to assist with the diagnosis of nerve disorders in the spine and determine the site of abnormal sensations, such as tingling, numbness, or pain. This test is performed to assess disorders of the peripheral nervous system which includes the nerves that lead away from the brain and spinal cord and the smaller nerves that branch off from those nerves. Nerve conduction studies are often used to help diagnose nerve disorders such as pinched nerves.
- Discogram/discography: A discogram is a diagnostic procedure used to precisely locate which spinal discs are injured and causing back pain. Discograms are also used by some surgeons before spinal fusion surgery to help determine which discs need to be removed. The test involves injection of a contrast dye using a fine needle into the center of the disc to be examined under X-ray guidance. Then, an X-ray or CT scan is taken to visualize the spread of the contrast dye. If the disc is normal, the dye will remain in the center. If the dye spreads outside the disc, it may indicate tears in the outer ring of the disc.
- Bone scan: Your physician may recommend a bone scan for various reasons, such as to know more about a spinal tumor or fracture. This diagnostic test involves injection of a radioactive chemical called a tracer intravenously. This is followed by utilizing a special camera to capture images of the spine to spot changes in the bone.
- Selective nerve root block (SNRB): A selective nerve root block is the injection of an anesthetic and steroid medication around the spinal nerve root to diagnose if a specific spinal nerve is the source of pain. An SNRB test is done to detect spinal disorders such as cervical or lumbar radiculopathy (inflammation and irritation of a nerve root).
- Sacroiliac (SI) joint injection: Sacroiliac joints are joints in the lower back region, where the sacrum and ilium bones join. Any inflammation or irritation in the SI joints may cause pain in the lower back, abdomen, groin, buttocks, or legs. Sacroiliac joint injections can be used both for diagnostic as well as therapeutic purposes for pain. As a diagnostic tool, it helps your doctor locate the origin of pain. During an SI joint diagnostic test, steroid medication and local anesthetic are injected into the SI joint under fluoroscopic guidance. If pain is alleviated, it means the joint is the pain generator.