CT guided injections are a modern procedure that uses imaging to precisely inject anti-inflammatory cortisone into different parts of the spine for pain relief.
CT guided injections are considered when the patient still experiences intolerable pain after oral-medication and physiotherapy have been tried. They work by treating the inflammation of nerve roots or facet joints of the spine and any inflammation in joints, throughout the body.
A CT guided injection may deliver cortisone at the site of pain. Cortisone belongs to a group of drugs commonly known as a corticosteroid. It can treat pain in any part of the body caused due to inflammation. When CT imaging is used to guide the injection into the area of pain, it allows to accurately deliver a high dose of cortisone without the potential side-effects of a cortisone tablet.
The procedure is relatively safe. It is performed at most scans centres by radiologists or in operating theatres by surgeons and pain physicians. The procedure is done under a local anaesthetic, at times a mild sedation may be administered.
An antiseptic wash is used to clean the skin over the area and a local anaesthetic is provided using a fine needle. The patient may experience a slight sting for a short time before the area numbs. Then, using a CT for guidance, a fine needle will be inserted at the injection site. Patients may experience some mild discomfort because of the needle placement and during injecting cortisone. Upon completion of the injection, the proceduralist will remove the needle and place an adhesive dressing at the injection site.
There are various types of CT guided injections as outlined below:
An epidural is a type of injection used to provide relief from some specific types of back and neck pain that are caused by a narrow spinal canal. The area around the spinal sac, inside the spinal canal is known as the epidural space. This space runs through the entire length of the spine and injections are used to treat multiple levels of the spinal cord.
A perineural injection delivers the medication close to the affected nerve. The nerves are sometimes prone to being compressed, “pinched” or impinged in the spinal pathway, from where the spinal nerves exit the spinal cord. This could be caused either by a bone spur or a bulging disc. This type of pressure on the spinal nerves may cause inflammation and pain. This pain may sometimes affect just the back or even radiate to the legs at times, which is commonly known as sciatica.
These injections are preferred to localise and treat any lower back pain which is being caused by problems of the facet joints. These joints are located on each side of our vertebrae. They allow back and forth movement of the spine. Facet joints may cause pain from inflammation of the joints caused by joint degeneration or arthritis.
The type of injectable intervention preferred for any patient is usually decided by the doctor based on the diagnosis. The diagnosis may be established by him or a referring doctor, through a CT scan or MRI scan.
Adverse reactions or any serious complications are very rare. A life-threatening reaction is extremely rare too (observed only for 1 in 170,000 patients) making this injection considerably safe. Side effects are thus believed to be minimal. The most common side effect is mild tenderness around the site of injection. This usually disappears within two days post the procedure.
However, some patients may experience some or none of the following side effects:
Some rare but serious side effects include:
Rarely, the injection may cause an allergic reaction if an x-ray contrast has been administered. This may include flushing, difficulty in breathing, or hives.
CT guided injections are mostly successful in providing pain relief to most patients. The effect of each injection tends to be temporary, ranging from one month to one year. Despite this, they are still considered beneficial in providing pain relief to patients especially during a severe episode of back pain.
A spinal injection for a patient with a local skin or a systemic infection puts them at a greater risk for spreading their infection into the spine.
For patients who do not have any life-threatening conditions, injections are offered to them as an elective procedure. However, if a patient has an accompanying medical condition, their doctor would carefully review the risks versus the benefits of receiving CT guided spinal injections and advise accordingly.
The frequency and number of injections vary for each patient based on their condition. Generally, however, doctors consider it reasonable to limit the injections to not more than three times per year. This helps to avoid systemic side effects.