Computed Tomography (CT or CAT scan) is a diagnostic test used to create detailed images of internal organs, bones, soft tissues and blood vessels. It generates cross-sectional images which can then be viewed by a radiologist for interpretation. CT is one of the best methods for detecting many types of cancers since the images allow your healthcare provider to confirm the presence of a tumor and to determine its size and location. CT is often used in emergency situations since it can reveal internal injuries and bleeding quickly. It is fast, painless, and noninvasive. During a CT scan, different body parts absorb x-rays in varying degrees which makes it possible to distinguish them on an electronic image. Sometimes contrast material, also known as dye, may be necessary.
If the study requires contrast material, you cannot drink or eat anything 4 hours prior to your appointment. Depending upon the type of study, the CT technologist may inject the dye directly into a vein prior to the start of the exam. The study may also require oral contrast (by mouth). The oral contrast (smoothie) is used when examining the digestive tract. You will be instructed on how and when to drink the smoothie. This is usually done at home before your appointment. If you have a known allergy to contrast material, such as iodine which is in shellfish, your healthcare provider may prescribe medications to reduce the risk of an allergic reaction. Such medications usually need to be taken 12 hours prior to the study being performed.
If you are diabetic, have high blood pressure, are over 60 years of age, or only have 1 kidney, labs will need to be drawn. Your healthcare provider will advise you to have your blood drawn for a BUN and Creatinine (no more than 30 days prior to your appointment). Once you arrive for your appointment, you will be asked to change into a gown. The technologist will then take you to the scanning room. You will lie flat on your back upon a narrow examination table that slides in and out of the scanner which is located in the center of the CT unit. The technologist will be in a room with a computer workstation right next to the scanning room where he/she will operate the scanner and monitor your study. You will be able to communicate via a speaker.
You may be asked to suspend breathing during the scan and you will be reminded throughout the study to lie as still as possible so the images do not appear blurry. A CT examination is usually completed in 30 minutes. After the study is done, a board certified radiologist will review and interpret the results. These results will be then be faxed to your healthcare provider who will then review them with you.