A CT scan of the spine uses X-rays to capture images of the spinal column. These horizontal and vertical cross-sectional images are processed by a computer to create a 3-D representation of the spine. Our radiologists use these representations to examine the vertebrae, intervertebral disks, spinal cord, and connective tissue from multiple viewing angles.
Reasons for a Spinal CT Scan
The mostly likely reason your doctor may refer you for a spinal CT is to examine your spinal column for damage. The common indications include:
- Disk herniation
- Congenital anomalies of the spine, such as spina bifida
CT scan of the spine is also used to evaluate the spine before and after surgery, diagnose pain, guide diagnostic procedures such as biopsy, and assess the effects of treatment on the spine after therapy.
Cervical Spine CT
A CT scan of the cervical spine examines the seven vertebrae at the top portion of the spine that connects to the base of the skull. Scanning this portion of the spine provides your doctor with valuable information about how the structures in your neck are functioning. Sometimes this exam is referred to as a C-Spine CT or neck CT.
Thoracic Spine CT
A CT scan of the thoracic spine images the 12 vertebrae in the middle portion of the spine. Your thoracic spine spans from the base of the neck to the middle of your back, running the length of your chest. This exam is also called a T-spine CT.
Lumbar Spine CT
A CT scan of the lumbar spine screens five vertebrae at the lower portion of the spine, in your lower back. Patients experiencing low back pain typically have their lumbar spine examined during a diagnostic imaging exam. Doctors and medical professionals often refer to this exam as an L-spine CT.
Just below the lumbar spine, there are five fused vertebrae known as the sacrum. The bottom of the sacrum connects to the coccyx (tailbone). The coccyx consists of three to five coccygeal vertebrae that are fused to form the tailbone.
Sacroiliac Joint CT Scan
Also known as an SI joint CT scan, this test examines the joints and ligaments that connect the sacrum and pelvis. The SI joint is incredibly strong, supporting the entire spine and weight of the upper body. Two symmetrical sacroiliac joints mirror each other at birth but can vary in strength over time based on an individual’s posture and lifestyle.
Your doctor might request an SI joint CT scan if you are experiencing low back or hip pain but are having difficulty identifying the source. SI joint problems can be hard to diagnose with physical exams, as the joint is buried deep inside your pelvis, surrounded by muscular tissue that connects rigid, fused bones. Computed tomography can be very useful when imaging complex anatomical structures like the joints in the pelvis.
During a CT of the spine, you will be moved into the scanner feet-first, on your back. If you are having a cervical spine CT, you will be moved deep into the scanner. If you are having a thoracic spine CT, just over half of your body will pass through the CT scanner. Lastly, a lumbar spine CT will require less of your body in the scanner, since they only need to scan your lower back.
A CT scan of the spine lasts roughly 5 minutes per section. Scanning the entire spine usually takes approximately 10 minutes to complete.
Being prepared for your spinal CT scan helps us take the best possible images for diagnosis. Please visit our exam prep page for more instructions specific to spine CT scan preparation.