Computed tomography (otherwise known as CT or "CAT" scanning) combines advanced computers and rotating x-rays to create highly detailed cross-sectional computer-generated images of body parts and internal organs to detect different disease processes. The exam is fast, patient friendly, and has the unique ability to detect and diagnose a wide variety of medical conditions and abnormalities. It is frequently used as the primary diagnostic tool for early detection of tumors, infection, inflammatory conditions, stroke, obstructions, trauma, and kidney stones. At Norwalk Radiology & Mammography Center, CT scans are performed by certified technologists and every exam is interpreted by board-certified specialists in diagnostic radiology.
Why is CT performed?
CT can provide detailed cross sectional images and diagnostic information for nearly every part of the body that cannot be provided by conventional x-ray studies:
Head: including the brain, eyes, inner ear, and sinuses
Neck: including the throat, larynx, lymph nodes, salivary glands and thyroid gland
Chest: including the lungs, aorta, heart and mediastinum
Abdomen: including the liver, kidneys, pancreas, spleen, bile ducts, gallbladder, aorta, and bowel
Pelvis: including the prostate, female reproductive organs, bladder and bowel
Skeletal system: including the hand, feet, hips, and facial bones
Spine: including the lumbar and cervical spine
What can I expect during a CT exam?
If your examination is of the abdomen or pelvis you will have to drink oral contrast 1 hour prior to your scheduled appointment. Patients have to option to pick-up the oral contrast & instructions before their appointment and begin drinking at home/work and must arrive 15 minutes prior to their scheduled exam. Pick-up is available Monday-Friday until 4:30pm. Patients who do not pick-up the oral contrast in advance must arrive at our office 1 hour prior to their scheduled exam to drink the oral contrast as required to complete the procedure.
Although many examinations do not require intravenous injection of contrast, in some cases it may be required to optimize your study. This will be discussed with you in detail by one of our staff members at the time of your visit.
When it is time for the exam, the patient is positioned on the CT table by a technologist. Once situated, the table moves through a doughnut-shaped ring called a gantry. This allows the body part to be "scouted" by electronic sensors and then viewed on a monitor. For many types of examinations you will be asked to hold your breath and remain still for a few moments. With our high-speed spiral ("helical") scanner, image acquisition is so rapid, that breath holding is usually 20 seconds or less. Most examinations are completed in 10 to 15 minutes.
There is continuous intercom communication between the patient and the technologist who is stationed adjacent to the machine through a clear glass partition.
Why are oral and intravenous contrast used in CT?
Oral contrast is used to image the stomach and intestines. It is a very dilute, flavored, barium solution that you drink approximately 1 hour prior to an exam.
Intravenous contrast is sometimes referred to as "dye." Although colorless, it contains iodine, which makes specific organs, blood vessels, and tissues visible on x-rays for better detection of disease or injury. It is not radioactive. We only use "nonionic" contrast, which is formulated to minimize any risk of an allergic reaction. The risks and benefits of contrast will be explained to you when you arrive for your exam. Occasionally, mild allergic reactions may occur such as hives, rash, or itching. In rare instances a patient may have a more severe allergic reaction, which might include difficulty breathing, swelling in the throat, or loss of consciousness. Our staff is fully trained and experienced to manage any potential adverse reactions.
Patients will be asked, and should notify our staff, if they have a history of allergy to IV contrast or iodine injections, diabetes, asthma, kidney disease, severe heart disease, multiple myeloma, or sickle cell disease or are if they are taking glucophage.
Is there anything diabetic patients should know about
intravenous contrast?
Please contact our office if you are diabetic.
The following oral medications for diabetes may be taken prior to the exam, but must be discontinued for 48 hours AFTER the contrast injection. Please consult your physician and contact our office if you are diabetic.
Metformin alone:
Glucophage (metformin)
Glucophage XR (metformin extended release)
Fortamet (metformin extended release)
Riomet (glucophage oral solution)
Metformin generic (various manufacturers)
Metformin Combinations:
Glucovance (glyburide/metformin)
Metaglip (glipizide/metfromin)
Avandamet (rosiglitazone/metformin)
Actos Plus
Jamunet (Sitaglipin/Metformin)
Glumeta (contains Metformin)
Pioglitazone (contains Metformin)
Patients taking these medicines may take their medicine prior to the exam and need only stop for 48 hours after their exams. Please consult you physician.
Patients who are taking Glyburide, Glipizide, or Rosiglitazone only, need not stop their dosage.
How long will my CT exam take?
The CT scan itself takes 10-15 minutes; however, please allow 45 minutes for your visit. To ensure optimum results and patient safety, you will be asked to fill out a medical questionnaire and you will be interviewed by one of our staff before your exam. If applicable, contrast administration will be discussed and administered. If oral contrast is required (instead of an injection), please arrive 1 hour prior to your scheduled exam. If patients prefer to pick up the oral contrast and instructions in advance they must arrive at our offices by 4:30pm Monday-Friday to receive instructions from our registered technologists.
Do I need a referral (prescription) to have my CT exam?
Yes, your doctor must provide a referral (prescription) for you to receive an examination. In addition, some insurance carriers or HMOs require a precertification. Please discuss this with your doctor and your insurance company or HMO prior to your test.
What if I am claustrophobic?
Because the CT is open at both ends (like a doughnut), most claustrophobic patients have little difficulty with the procedure. If you are severely claustrophobic, you might ask your doctor to consider a mild sedative.
Is a CT exam safe?
Our spiral CT equipment produces a very low dose of x-ray exposure with negligible adverse effects. It is not much different than the exposure from "background environmental radiation" from the sun, air travel, television or computer screens.
When will I know the results of my exam?
A detailed written report of the procedure will be sent to the referring physician within 24 hours. Your physician will contact you to discuss the results. Urgent results are telephoned immediately to your doctor who will discuss the results with you.
What should I do to prepare for a
CT exam?
It is preferable that you wear comfortable, loose-fitting clothing (especially shirt or blouse). You may be asked to remove any clothing or jewelry that might degrade the CT images, such as belt buckles, earrings, bras, glasses, dentures, and hairpins.
If your examination is of the abdomen or pelvis you will have to drink oral contrast 1 hour prior to your scheduled appointment. Patients have to option to pick-up the oral contrast & instructions before their appointment and begin drinking at home/work and must arrive 15 minutes prior to their scheduled exam. Pick-up is available Monday-Friday until 4:30 pm. Patients who do not pick-up the oral contrast in advance must arrive at our office 1 hour prior to their scheduled exam to drink the oral contrast at required to complete the procedure.
For the following examinations, do not eat 4 hours before test. However, please take your prescription medication, as you normally would, with clear liquids only:
Chest
Neck/Salivary Glands/Face
Cervical Spine
Head
Abdomen and/or Pelvis
(Arrive 1 Hour Prior to Exam to Drink Oral Contrast, or pick-up prior to scheduled appointment to begin drink at home/work. Pick-up is available Monday-Friday until 4:30pm.)
CT can provide detailed cross sectional images and diagnostic information for nearly every part of the body that cannot be provided by conventional x-ray studies:
If your examination is of the abdomen or pelvis you will have to drink oral contrast 1 hour prior to your scheduled appointment. Patients have to option to pick-up the oral contrast & instructions before their appointment and begin drinking at home/work and must arrive 15 minutes prior to their scheduled exam. Pick-up is available Monday-Friday until 4:30pm. Patients who do not pick-up the oral contrast in advance must arrive at our office 1 hour prior to their scheduled exam to drink the oral contrast as required to complete the procedure. 
A detailed written report of the procedure will be sent to the referring physician within 24 hours. Your physician will contact you to discuss the results. Urgent results are telephoned immediately to your doctor who will discuss the results with you.