The following information is provided for the patients of Northridge Medical Center who will be or are planning to undergo a test known as a CT scan (Computed Tomography). This test is formerly known as a CAT scan. This test has been ordered by your referring doctor. More often than not a CT scan will require the injection of a contrast agent (dye) known as intravenous (IV) contrast.
IV contrast has an Iodine base. The contrast is injected into the body through an IV site in your arm usually in the bend of your elbow or forearm, which will be established by the Radiologic Technologist or a nurse. Both of who are proficient in IV therapy. The amount of IV contrast will vary per exam and patient size typically in the range of 30mls-150mls.
The use of administering the IV contrast greatly improves the accuracy and diagnostic value of the exam, assisting the Radiologist to exclude multiple conditions. The purpose of the IV contrast is to distinguish soft tissues from one another which would otherwise look very similar or the same.
Likewise with all medical procedures, there are risks involved when administering any substance, even IV contrast, however the benefit of an accurate diagnosis greatly outweighs the risk involved and any side effects (discussed below). The decision to use IV contrast is not taken lightly and has carefully been made by your referring doctor. Your doctor made this decision based on your individual signs, symptoms, past and current medical history and what your suspected diagnosis is. If, after reading all the information, you are not willing to undergo this exam with the use of IV contrast the exam may be preformed without it. Please be aware that that is your right as a patient; also know that doing so may result in an exam that is not as diagnostic. It may also be possible for another similar exam to be preformed; this should be discussed with your doctor or our Radiologist.
Most of the injections of IV contrast occur without incident. Most all patients do however experience some side effect. These include: a warm sensation, metallic taste, and a sensation of wetting themselves (you don’t actually wet yourself). The warm sensation can be quite intense for some. Many would describe it as a hot feeling all over, similar to a hot flash. These side effects fade away within seconds after the injection is complete and require no special treatment.
The most common reactions are minor contrast reactions, which occur in 1% of cases. Symptoms of these reactions include but are not limited to headache, sneezing, nausea, vomiting, mild hives, and mild local swelling and usually settle rapidly. Occasionally medications may be required to help alleviate minor contrast reactions. This would include Benadryl (antihistamine) and if needed Solu-Cortef (steroid). The Benadryl will cause drowsiness. If these steps are necessary you will need a responsible person to drive you home.
Less likely, in approximately 6.6 to 1 million (0.00066%) of cases a severe contrast reaction may occur known as anaphylaxis. These reactions are severe and most often life threatening and require immediate emergency treatment. Symptoms include rapid or slow heart rate, low blood pressure, severe asthma attack, complete circulatory collapse/ shock. The risk of a severe allergic reaction is increased in asthmatic patients approximately 1 in 2,000 (0.05%). Though the risk is extremely rare a person may die from a severe anaphylactic reaction, despite the best medical attempts and rapid treatment, occurring in 1 in 100,000 to 1 in 1,000,000 (0.0001%-0.00001%) of cases. At BJC Medical Center we possess the means and highly trained medical staff to treat and provide immediate life saving treatment should this be required.
There is no way to predict who will be allergic to IV contrast, unfortunately until the dye is given. Patients who are allergic to the IV contrast will typically experience symptoms within 10 minutes. Please find assurance and note that more than 10,000,000 injections are given in the United States each year. Apart from patients who have a known allergy to Iodine or those who have experienced a contrast reaction previously, the following are patients who are at a higher risk of reaction due to IV contrast:
- Patients with a history of diabetes
- Patients with a history of severe asthma
- Patients with a history of renal failure, disease, or have insufficient renal function
- Patient who have a history of an allergy to the IV contrast (dye), or Iodine
If you have any questions regarding your CT exam, please do not hesitate to call us at Northridge Medical Center Radiology (706-335-1420). We are more than willing to help you make an informed decision and to answer any questions you have regarding your procedure.
We are here to make you feel comfortable!