# What to expect at your CT scan *A CT scan is a few minutes on an open table. What the exam shows, what contrast is, how to prepare, which centers do it and what happens after.* September 23, 2026 ยท Desert Imaging A CT scan sounds bigger than it is. The machine is a short, open ring, not a tunnel. The scanning itself takes a few minutes. Most of the time you spend with us is checking in, answering a few questions and, for some exams, drinking contrast. Here is the whole day, in order. ## What a CT scan shows CT, also called a CAT scan, is an X-ray machine joined to a computer. The X-ray tube circles you while the computer turns hundreds of thin views into cross-section pictures, like slices of a loaf of bread. Those slices can also be stacked into a 3D view. Doctors order CT because it shows bone, organs, blood vessels and soft tissue in one exam. It is common for the head and sinuses, the chest, the abdomen and pelvis, the spine, the kidneys and the joints, and for planning surgery. A CT angiogram, or CTA, adds contrast to show the arteries and veins. ## With contrast, without, or both Your doctor writes on the order whether your exam is with contrast, without contrast, or both. Contrast for CT is an iodine dye. For some exams you drink it. For others it goes through a small IV in your arm. Some exams need both. The contrast makes certain tissues and blood vessels stand out so the radiologist can see them clearly. You do not choose. The order decides, and we confirm which kind you are having when you book. ## How to prepare If your exam has no contrast, there is nothing to prepare. Eat normally, take your medications, and come in. If your exam uses contrast: - Do not eat for 4 to 6 hours before your appointment. Water is fine. - Skip your diabetic medication that day. Bring it with you to take afterward. - If your exam includes oral contrast, plan for an extra hour. You can arrive an hour early and drink it at the center, or pick it up the day before at West, Central or East and drink it at home on the schedule we give you. Wear comfortable clothes without metal zippers or snaps over the area being scanned. Leave jewelry at home if you can. ## What to tell us before the scan The technologist asks a short list of questions before every exam. It helps to have the answers ready: - Whether you could be pregnant. - Whether you are allergic to iodine or to any medication. - Whether you have diabetes or kidney disease. - Any surgery you have had, and any metal in your body. None of these answers stops the exam on their own. They tell the technologist and the radiologist how to run it safely. ## The scan itself You lie on a table that slides into the ring. The scanner hums as it turns, and the table moves in small steps or in one smooth pass. For chest and abdomen scans the technologist will ask you to hold your breath for a few seconds at a time. That is the whole job: lie still and breathe when you are told. The scanning takes 3 to 5 minutes. If you have IV contrast, you may feel a warm flush as it goes in, or a metallic taste. Both are normal and pass quickly. Our scanners meet the XR-29 dose standard. They set the X-ray dose to your size automatically, use separate protocols for children and adults, and record the dose in your report. ## After the exam You can drive, eat and go back to work right away. If you had contrast, drink water through the rest of the day to help your body clear it. One of our board-certified radiologists reads the exam. The report goes to the doctor who ordered it and appears in your patient portal. Your doctor goes over the result with you and decides what, if anything, comes next. ## About insurance Many plans require preauthorization for a CT scan. Your doctor's office usually requests it when they send us the order. If you are not sure whether yours has been approved, call your plan or ask us when you book. ## Where to get a CT scan in El Paso Desert Imaging does CT at three centers: West, at 122 W. Castellano Dr., East, at 1727 Lee Trevino Dr., and Central, at 7812 Gateway Blvd. East, Suite 120, where we also do CT angiography. West and East are open Saturdays. Request an appointment online, or call us and we will find the center and the time that work for you.