Erosive lesions were detected also at the beginning of the respiratory disease.
You should wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure.
Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and should be left at home or removed prior to your exam.
You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras containing metal underwire. You may be asked to remove any piercings, if possible. You will be asked not to eat or drink anything for a few hours beforehand, if contrast material will be used in your exam.
You should inform your physician of all medications you are taking and if you have any allergies. If you have a known allergy to contrast material, your doctor may prescribe medications usually a steroid to reduce the risk of an allergic reaction.
To avoid unnecessary delays, contact your doctor before the exact time of your exam. Also inform your doctor of any recent illnesses or other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems.
Any of these conditions may increase the risk of an unusual adverse effect. Women should always inform their physician and the CT technologist if there is any possibility that they may be pregnant. See the Safety page for more information about pregnancy and x-rays.
The CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the center. You will lie on a narrow examination table that slides into and out of this tunnel.
Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other in a ring, called a gantry. The computer workstation that processes the imaging information is located in a separate control room, where the technologist operates the scanner and monitors your examination in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone.
In many ways CT scanning works very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. It is this crucial difference in absorption that allows the body parts to be distinguished from one another on an x-ray film or CT electronic image. In a conventional x-ray exam, a small amount of radiation is aimed at and passes through the part of the body being examined, recording an image on a special electronic image recording plate.
Bones appear white on the x-ray; soft tissue, such as organs like the heart or liver, shows up in shades of gray, and air appears black. With CT scanning, numerous x-ray beams and a set of electronic x-ray detectors rotate around you, measuring the amount of radiation being absorbed throughout your body.
Sometimes, the examination table will move during the scan, so that the x-ray beam follows a spiral path. A special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT imaging is sometimes compared to looking into a loaf of bread by cutting the loaf into thin slices.
When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation.
These scanners, called multislice CT or multidetector CT, allow thinner slices to be obtained in a shorter period of time, resulting in more detail and additional view capabilities.
Modern CT scanners are so fast that they can scan through large sections of the body in just a few seconds, and even faster in small children. Such speed is beneficial for all patients but especially children, the elderly and critically ill, all of whom may have difficulty in remaining still, even for the brief time necessary to obtain images.
For children, the CT scanner technique will be adjusted to their size and the area of interest to reduce the radiation dose.
For some CT exams, a contrast material is used to enhance visibility in the area of the body being studied. The technologist begins by positioning you on the CT examination table, usually lying flat on your back.
Straps and pillows may be used to help you maintain the correct position and to help you remain still during the exam. Many scanners are fast enough that children can be scanned without sedation. In special cases, sedation may be needed for children who cannot hold still.
Motion will cause blurring of the images and degrade the quality of the examination the same way that it affects photographs.Build the foundation necessary for the practice of CT scanning with Computed Tomography: Physical Principles, Clinical Applications, and Quality Control, 4th plombier-nemours.comn to meet the varied requirements of radiography students and practitioners, this two-color text provides comprehensive coverage of the physical principles of CT .
Mar 07, · Computed tomography (CT), sometimes called "computerized tomography" or "computed axial tomography" (CAT), is a noninvasive medical examination or procedure that uses specialized X-ray equipment.
The advent of computed tomography (CT) has revolutionized diagnostic radiology. Since the inception of CT in the s, its use has increased rapidly. It is estimated that more than 62 million CT. J Radiol Sci December Vol No.4 Dedicated sinus computed tomography (CT) has been a useful tool in assessing patients with sinus disease.
What is a computed tomography (CT) scan? A CT scan is a non-invasive medical procedure used to help diagnose and treat medical conditions.
It combines the use of high-tech computer systems and X-rays to obtain specialized images of your brain, organs and/or bones. Number: Policy. Cardiac Indications. Aetna considers positron emission tomography (PET) medically necessary for the following cardiac indications.