CT (computarized tomography)
Computed tomography is a radiological diagnostic method for creating a cross-sectional image of the examined part of the body using X-rays (X-rays). During the examination, the patient lies on the table of the computed tomography device without moving. The table on which the patient is lying is taken to the open area of the device called “gantry” by manual or remote control. The device is connected to a computer. While the x-ray source performs a 360-degree rotation around the patient to be examined, the detectors arranged along the “gantry” detect the part of the x-ray beam passing through the body according to its passing characteristics and the data obtained are processed by a computer. As a result, cross-sectional images of the tissues are created one after the other. The images can be viewed on the computer screen. Images can be transferred to film or stored on optical disc, CD, DVD or PACS to be brought back to the computer screen when necessary. In addition, the images can be processed by the computer to obtain reconstructed images on axes perpendicular to each other. With the help of these images, 3D images can be created. CT especially shows the shape and placement of organs, soft tissues and bones very clearly. In addition, CT examinations change treatment methods by making differential diagnosis of diseases.
The examination itself is completely painless. During the examination, the patient is asked to lie on the table of the CT device without moving. Depending on the type of examination to be performed, the patient may be injected with contrast material through the arm veins or may be asked to drink contrast material. This part of the examination may be a little uncomfortable for the patient. Since contrast agents contain iodine, they may cause allergic reactions in some people. Before the examination, the patient should inform the technician or radiologist whether he/she has ever had an allergic reaction to such substances and, if so, whether he/she is allergic to other substances.
The patient may have received contrast material during a previous CT scan, a kidney scan called IVP or angiography. CT machines use X-rays. They are optimised for the safety of the patient and are designed to minimise radiation exposure during the examination. Since X-rays can harm the developing foetus in the womb, the patient should inform the doctor who wants the examination if there is a suspicion of pregnancy. There is no obstacle during breastfeeding. However, if a contrast agent is used in CT scan, the baby should be breastfed after the excretion of this substance from the body. (24 hours) On the day of the examination, solid food should not be eaten starting 4 hours before the appointment time, unless otherwise stated.
Restriction of solid food intake is a precaution taken for the safety of the patient before many medical procedures. If the examination is to be performed on the abdomen and especially the gastrointestinal system, the patient should fast for 12 hours. For this examination, liquid foods should be taken 3 days in advance. If necessary, a laxative is taken on the last night and an enema is performed on the morning of the examination. In oral contrast-enhanced examinations, water containing contrast material should be drunk 4 hours before the examination in accordance with the given recipe. The patient is taken to the CT room for the examination at the appointment time. Depending on the region to be examined, it may be requested to remove metal objects from the body, and the patient is positioned on the table according to the location of the region to be examined. It is important that the patient is comfortable because the patient should not move during the examination. CT examinations vary according to the medical problems of the patients and the body part to be examined. The radiologist decides how the examination requested by the clinician for the diagnosis of the disease should be performed. For example, if the abdominal region is to be examined, the area from the lower chest to the upper part of the pelvis will be scanned. During such an examination, you will be asked to hold your breath at certain intervals to avoid blurred images. The machine makes some sounds during the procedure. The table on which the patient lies will move slightly after each image is formed. In addition, the radiology technician or the machine will make audible warnings to the patient about holding and exhaling breath. In some examinations, contrast material may be injected by the doctor or radiology technician before or during the procedure. This will enable the radiologist to better evaluate the images. If the patient feels any discomfort during the procedure or after the injection of contrast material, he/she should report this to the radiologist or technician.
The examinations are planned individually for each patient, taking into account the clinical findings of the patients. If the CT examination performed on the patient is different from a previous CT examination or if additional images are required at the end of the examination, the patient should not worry. The shooting time from the beginning to the end is approximately 15 minutes.
After the radiologist has obtained enough information to make a conclusion about the disease of the person being examined, the examination is terminated and the patient can go home. After the examination, the patient can continue normal daily activities without any restrictions.
The examinations are evaluated by specialised radiologists and then converted into a written report and delivered to the patient. If you have any further questions, you can get the necessary information from the doctors and radiology technicians who will perform your examination.
In which areas is computed tomography (CT) used?
CT imaging method is preferred for detailed radiological imaging. Thus, it is easier to diagnose diseases, and the location of the patient’s problem can be easily determined. While the chest area, brain, heart and its surroundings can be easily examined using CT, the uterus and ovaries, abdominal cavity, excretory and digestive system can also be visualised. In addition, computerised tomography can be preferred in case of any fracture or crack in the skeletal system. Whichever part of the body is to be imaged, that part is examined in the device and the position of the patient is determined by the specialist accordingly.
Computerised tomography can also make successful diagnoses in bone density measurement.