CT-guided injections are medical procedures utilizing computed tomography (CT) scans to precisely guide a needle to a specific area in the body. This allows for the targeted delivery of medication, typically a steroid and local anesthetic, to treat various conditions. Spinal CT-guided injections can help identify the source of nerve compression or irritation causing pain in the neck, back, legs, or arms, aiming to provide relief.
Why Opt for CT Guided Injections?
CT-guided injections are particularly advantageous for individuals who:
- Have a history of spinal surgery involving instrumentation (screws, rods) or bone grafts that may obscure or distort spinal anatomy.
- Present with a localized issue, such as an inflamed joint or muscle/tendon, necessitating imaging guidance for accurate medication delivery.
Advantages of CT Guided Injections
The anti-inflammatory effects of the injected medication can last up to three months, although the pain relief may not be immediate, typically starting within 2-7 days post-injection.
CT-guided injections offer notable benefits compared to X-ray fluoroscopy, a more common image guidance technique. Some injections are administered without any imaging guidance, increasing the chance of inaccurate medication delivery.
With CT guidance, radiologists can:
- Achieve superior visualization of anatomical structures, including bones, nerves, joints, discs, soft tissues, and surgical instrumentation, often with millimeter-level accuracy, which is not possible with X-ray fluoroscopy.
- Administer smaller medication doses into the targeted area with exceptional precision and safety.
Preparing for a CT Guided Injection
Before undergoing a CT-guided injection, it’s crucial to inform your healthcare provider if you:
- Have existing X-ray, CT, or MRI scans. Bring these with you if available.
- Are currently taking any medications, especially if you have diabetes and are on insulin. Continue your usual medication and dietary regimen unless otherwise instructed.
- Use blood-thinning medications like Warfarin, Aspirin, or Clopidogrel.
- Have an iodine allergy or are pregnant or breastfeeding.
In certain cases, your physician may request the procedure to be performed under sedation. If so, you will need to fast (abstain from eating or drinking) before the procedure and a short hospital stay may be necessary.
What to Expect on the Day of Your CT Guided Injection
Arrange for someone to drive you home after the procedure. You can eat and drink as usual unless instructed otherwise.
Before the procedure, you may be asked to change into a gown for comfort and to avoid clothing interference with the images. You may also need to remove jewelry, eyeglasses, and any metal objects that could interfere with the imaging.
The CT Guided Injection Procedure: A Step-by-Step Overview
How Long Does A Ct Guided Injection Take? A typical CT-guided injection procedure takes approximately 15 minutes.
- You will lie on the CT table.
- The skin in the injection area will be cleaned with an antiseptic solution.
- A local anesthetic will be injected to numb the area.
- Using strict aseptic techniques to prevent infection, the radiologist will insert a fine needle into the targeted location, guided by the CT scanner.
- The CT machine provides real-time guidance, ensuring the needle is placed accurately and safely.
- A small amount of X-ray contrast or air may be injected to confirm correct needle placement.
During the injection, the high-resolution CT scans can reveal other potential pain sources or diseases in adjacent discs or facets that were not identified on routine scans. Typically, a long-lasting anesthetic and a long-acting steroid are injected together.
Post-Injection Recovery
The recovery period after a CT-guided injection typically lasts a few hours. Patients undergoing nerve root injections may experience temporary numbness in their legs or arms, which resolves as the local anesthetic wears off.
The local anesthetic provides initial pain relief, but the pain may return after a few hours as the anesthetic wears off. The steroid’s effect can last from a week to several months, or even years. In some cases, the injection may not provide pain relief. The steroid’s effects typically begin within a few days and reach their maximum effectiveness within two weeks.
Avoid strenuous activities for at least 48 hours post-injection. If necessary, a simple analgesic like paracetamol (Panadol) or an anti-inflammatory can provide relief. Applying an ice pack to the injection site may also help.
Potential Risks Associated with CT Guided Injections
Infection is a potential, though serious, side effect. Contact your doctor or the clinic immediately if you experience fever, redness, swelling, or increased pain at the injection site after the first two days.
Other potential side effects include:
- Temporary worsening of symptoms and weakness for 24-48 hours.
- Elevated blood sugar levels in diabetic patients.
- Insomnia, flushing, and palpitations.
- Local bruising and soreness.
Extremely rare, but serious side effects causing permanent neurological damage can occur.
If X-ray contrast is used, there is a small risk of an allergic reaction, which may involve flushing, hives, or difficulty breathing. Severe and life-threatening reactions are very rare.
