CT Scan: Frequently Asked Questions

CT scans allow doctors to see images of your internal organs and structures, including your heart and cardiovascular system, in great detail from a variety of angles. This gives your physicians critical information more quickly and, in many cases, more economically than they could achieve with other tests or invasive techniques. In those cases where doctors are trying to assess the risk of heart disease, the information from the CT scan can help them uncover disease at its earliest stages, and recommend changes in lifestyle or more aggressive treatment if needed.

Before your exam, a registered CT technologist or an RN will review your medical history ask you some questions and answer any questions you may have. They will describe what will happen and will remain in contact with you at all times during the procedure. If you are having “intravenous contrast” you will be required to sign a consent form at this point. CT examinations are not painful, however, if you have concerns about your ability to lie still and or hold special positions you should discuss this with the technologist prior to starting the exam. You may be asked to change into a gown before your examination to avoid possible interference from snaps, metal fasteners, belts etc. You will lie on the CT table and be given simple breathing instructions. As part of your test either a doctor or an RN may give you an injection either before or during the procedure. As the procedure begins you will be asked to hold your breath and you will feel the table move slightly. If at any point in the exam you experience discomfort you may tell the

Yes. CT uses X-rays in conjunction with advanced computer technology to generate very accurate and detailed images of your internal organs and structures. Your technologist will step into a control room to conduct the actual exam.You may notice a mechanical noise coming from the scanner. That is just the X-ray tube being activated and rotating around your body.

No. CT is a safe and non-invasive test that will not hurt at all.Your exam may require that a contrast agent be given intravenously that will make your blood vessels and tissues more visible. For some cardiac studies, two ECG leads may be placed on your chest to precisely time the image acquisition to the specific interval in the heartbeat when there is the least motion. This provides more accurate, reproducible data for follow-up studies. You will then be asked to lie perfectly still once the technologist has positioned you on the table.You will also be asked to hold your breath for a few seconds during the exam. Any movement may require the exam to be repeated.

Each exam is tailored to each patient’s symptoms and area of interest. Some exams take 5 minutes and others 15 minutes. For the majority of patients who are having their abdomen and/or pelvis scanned we require them to drink a special drink up to 2 hours prior to the scan time. Although we do not consider this scan time, you must allow for this drinking time when scheduling a procedure.

You may resume normal activity when your exam has been completed. Your results will be sent to your referring Physician within 48 hours of your exam time.

 This a term used to describe the latest generation of CT scanners. It offers an exciting new technology enabling unparalleled imaging of complex data sets and anatomic information.

CTA stands for Computed Tomography Angiography. CTA is one of several CT scan options that doctors can use to evaluate your cardiovascular health. With the help of a contrast agent, doctors can examine in very fine detail how well blood is flowing through your arteries, and identify any potential blockages or irregularities.

Calcium Scoring is one of several CT scan options that doctors can use to evaluate your cardiovascular health. CT Calcium Scoring is a noninvasive test for quantifying coronary artery calcium content. The information acquired during your CT exam is processed with a specific cardiac scoring software package that evaluates and quantifies the amount of calcium in your coronary arteries. The calcium content correlates to the degree of blockage in your arteries and consequently provides clinicians with a good indication of what risks you face from heart disease.

Intravenous contrast is used in CT to help highlight blood vessels and to enhance the tissue structure of various organs such as the brain, spine, liver and kidneys. "Intravenous" means that the contrast is injected into a vein using a small needle. Typically the contrast is loaded into a power injector, which injects the CT contrast using tubing through the needle into the body during a specific period in the CT exam. The injection is completely under the control of the technologist or radiologist. Once the contrast has been injected into the blood stream, it circulates through the heart and passes into the arteries, through the body's capillaries and then into the veins and back to the heart. As CT images are being acquired, the CT's x-ray beam is attenuated (weakened) as they pass through the blood vessels and organs flush with the contrast. This causes the blood vessels and organs filled with the contrast to "enhance" and show up as white areas on the x-ray or CT images.

Lenox Hill radiology only uses the newest and safest “non ionic” contrast available on the market. This is shown to have a much lower incidence of allergic reaction than the older “ionic” contrast. The most common side effect of the contrast includes a warm or hot "flushed" sensation during the actual injection and a "metallic" taste in the mouth, which usually lasts less than a minute or so. There is no treatment necessary for this as it is only a passing sensation. Another mild reaction that can take place following the administration of contrast is itching over various parts of the body with hives (bumps on the skin). This reaction can last from several minutes to several hours after the injection. This type of reaction is usually treated with medication administered by the radiologist, nurse, technologist or referring physician. More serious reactions, although much less likely, may include breathing difficulty, swelling of the throat, or swelling of other parts of the body. These reactions can be more serious if not treated immediately. Patients should inform the radiologist or technologist if they have a history of allergies, diabetes, asthma, a heart condition, kidney problems, or thyroid conditions. (See CT questionnaire). These conditions may predispose the patient to a higher risk of reactions or complications following the IV and may require premedication or preclude the patient from intravenous contrast.

Patients having a CT scan of either their abdomen or pelvis are usually required to drink a special drink for up to 2 hours prior to their scan time. The drink, which is Barium based travels from the stomach into the remainder of the gastrointestinal tract. The CT x-ray beam is attenuated (weakened) as it passes through the organs containing the contrast, for example, the large intestine. The organs filled with the contrast are then "enhanced" and appear as highlighted white areas on the CT images. Prior to the patients exam they are required to drink 3 12oz glasses of the flavored barium at specified time intervals. The last remaining cup will be drunk immediately prior to the procedure beginning to ensure the stomach is enhanced adequately.

You will be in contact with a technologist. Even when he or she is not in the CT room you will be able to communicate via intercom. The technologist will inform you when an exam is about to start, and when it is finished. Family members and/or friends are not permitted to stay with you in the CT room.