CAT Scan

Computerized Tomography (CT) scans are special x-ray tests that produce cross-sectional images of the body using x-rays and a computer. These images allow the radiologist to look at the inside of the body just as one would look at the inside of a loaf of bread by slicing it. In most exams, two-dimensional or three-dimensional reconstructions are created for a comprehensive evaluation of the area. CT scans are frequently used to evaluate the brain, neck, spine, chest, abdomen, pelvis and sinuses. Sometimes, physicians will order special thin section CT scans to upload onto the interactive computers in the operating room during complex neurosurgery or ENT procedures or as a map to plan radiation therapy.

Head or brain CT evaluates the various structures of the brain to look for a mass, stroke, bleed or blood vessel abnormality. It is also sometimes used to evaluate the skull.

Neck CT evaluates the soft tissues of the neck and is frequently used to study a lump or mass in the neck or to look for enlarged lymph nodes or glands.

CT of the chest is frequently used to further evaluate an abnormality on a plain chest x-ray. It is also often used to evaluate the lungs or look for pulmonary embolism (blood clot) in the lungs or enlarged lymph nodes.

Abdominal and pelvic CT evaluates the abdominal and pelvic organs and the gastrointestinal tract. These studies are often ordered to evaluate for a cause of pain and sometimes to follow-up on an abnormality seen on another test such as an ultrasound.

Extremity CT exams are usually reconstructed into two-dimensional or three-dimensional images to allow the radiologist and orthopedist to fully understand the extent of a fracture or bone lesion and plan surgery.

Sinus CT exam is used to both diagnose sinus disease and to look for a narrowing or obstruction in the sinus drainage pathway.

Maxillofacial CT exam is used to understand complex fractures of the face.

Spine CT test is most commonly used to look for a herniated disc or narrowing of the spinal canal (spinal stenosis) in patients with neck, arm back and/or leg pain.

What to Expect:
The CT scanner looks like a large donut with a narrow table. The patient lies on the table, which then slides into the center of the machine. The technologist is in the next room and can observe the patient through a large window. The x-ray tube moves rapidly around the area of anatomic interest. The sensor then sends the information to the computer. The computer reconstructs this data with special algorithms that are most sensitive to "see" findings in the bone, lung, brain, and soft tissues. Some scans (abdomen and pelvis) require the patient to drink a dilute barium liquid prior to the scan. Also, for certain exams contrast or dye must be injected into a vein during the scan. The entire procedure takes 15 to 45 minutes depending on what part of the body is being scanned. After the scan is finished, a board certified radiologist will interpret the study and send a report to the referring physician.

Preparation:
If you have ever had a prior allergic reaction to a contrast agent, we will need to know the type of contrast and the details of the reaction. We also need to know if you have a history of multiple allergies or asthma. Please let us know this information before your visit so that we can avoid the need to reschedule your appointment. We will be able to tell you if you will need premedication prior to your exam. If you are over age 60 or have diabetes, high blood pressure or any history of kidney or severe liver disease or transplant we will need the results of blood tests for kidney function before we give intravenous contrast. If you are a diabetic on metformin, you will be asked to stop taking your medication for 48 hours after your exam. A special instruction sheet will be given to you at the time of the exam.

Abdomen/Pelvis (renal stone protocol)
• No preparation necessary

Abdomen/ Pelvis
• Pick up one bottle of CT barium (Readi-Cat) the day before your exam or arrive 1 hour prior to your exam
• Do not eat or drink anything except water for 4 hours before your exam.
• One hour before your exam drink the whole bottle of barium (Readi-Cat).

Instructions for oral barium:
• Readi-Cat is pre-mixed and ready to use.
• It may taste better when refrigerated.
• Please SHAKE WELL before using.
• DO NOT mix with any other substance.
• DO NOT pour over ice.
• DO NOT have any liquid or solid food for FOUR HOURS prior to your scheduled appointment time.
• NOTE: During this preparation time, be sure to take all medications as prescribed by your physician.

Head/Neck/Chest/Extremities
• DO NOT eat or drink anything except water for 4 hours before your exam.

Sinus CT
• No preparation necessary