CT scan: 6 popular apps to know

The article was professionally consulted by Specialist Doctor I Nguyen Truong Duc - Radiologist - Department of Diagnostic Imaging and Nuclear Medicine - Vinmec Times City International General Hospital.

Computerized tomography (English name is Computed tomography and abbreviated as CT) uses the technique of tomography x-ray, the collected data will be processed by a computer system to create images. With the development of algorithms and computer speed, the computer system will generate images in different directions (MPR), 3D volumetric imaging, MIP or virtual endoscopic imaging.
Combined with intravenous contrast agents, arteries, gastrointestinal tract... allows the doctor to evaluate in more detail the structure of the organs, the perfusion kinetics of the organs.
This process is repeated to create several slices of the body. The computer stacks these scans on top of each other to create a background eraser image used in computed tomographic angiography (CTA), detailing a patient's tumors or blood vessels.
With the technique of dual-energy computed tomography (Dual Source CT - DSCT) allows the doctor to evaluate the chemical structure of some lesions in the body such as evaluating urate crystals in the joint capsule or components. urolithiasis... Currently, CT has many applications in diagnosis and treatment. For example, a surgeon may use a CT scan to look at all sides of a tumor in preparation for surgery.

There are many reasons for doctors to order CT scans, here are the 6 most common uses of CT scans:
● In trauma: CT scans can detect problems with whole muscle injuries. such as: traumatic brain injury, head and neck trauma. In trauma to the musculoskeletal system as well as trauma to the thoracic, abdominal, and pelvic cavity.
● In cancer diseases: CT scan is very valuable in screening, diagnosing tumor pathologies as well as classifying, orienting treatment and monitoring after treatment such as cranial and head tumors. neck, lung, mediastinal, liver, pancreas, stomach, colon, kidney, bladder...
● In cardiovascular disease, CT scan is very valuable in diagnosing vascular disease coronary heart disease, cerebrovascular disease, renal artery disease, limb vascular disease... thanks to the non-invasive technique, it causes less harm to the patient than other interventional diagnostic techniques.
● CT scan can help determine the exact location, number, size of urinary stones as well as the structure of the stones, dual-energy CT can orient to the chemical nature of stones to help doctors urology diagnosis and treatment orientation of urolithiasis.
● In abdominal emergency, CT scan plays a very important role in diagnosing a number of common diseases in surgical abdominal emergencies that are limited by ultrasound assessment such as acute pancreatitis, appendicitis, necrotizing enterocolitis, bowel obstruction, peritonitis, intra-abdominal and pelvic abscess...
● Doctors use CT scans to plan and process treatments, such as directing biopsies, surgery, and radiation therapy. .

Patients should be examined by a specialist or general practitioner to assess their medical condition and order a safe and reasonable CT scan.
Patients may be asked not to eat or drink for several hours before the scan, or not to use contrast agents for 1-3 days before the scan.
The patient may also need to wear a hospital gown and remove any metal objects carried, such as jewelry.
An imaging technician will guide the patient through the CT scan. During the scan, the patient will lie on a table inside a large circular CT machine. As the table slowly moves through the scanner, the X-rays rotate around the patient's body.

Often patients will hear noise or buzzing during the scan. If the patient moves, the image can be blurred, so the patient will be asked to lie still and sometimes even need to hold their breath. Unconscious patients or young children may require sedation to keep the patient still.
Shooting time will depend on the technique to be tested, from a few minutes to half an hour. In most cases, the patient goes home the same day.

In CT, the combination of contrast agents will provide clearer images as well as evaluate the kinetics of enhancement, the circulation of contrast agents in the viscera in real time. These substances have a high density and appear white on images, highlighting blood vessels, organs, or other structures.
Contrast is usually made with preparations containing iodine or barium sulfate. Contrast is introduced into the body through many routes depending on the diagnostic purpose:
● Injection: Contrast is injected directly into a vein or artery, causing blood vessels, kidneys and urinary tract, liver or The patient's gallbladder stands out in the image.
● Contrast can be introduced into the body through drains or natural fistulas to help accurately diagnose some conditions.
● Oral: Drinking liquids with contrast can enhance the patient's ability to capture gastrointestinal tract more clearly.
● Enema: Contrast can be inserted into the rectum.
After the CT scan, the patient will need to drink plenty of water to help the kidneys remove the contrast material from the body.

CT scans use X-rays, which produce ionizing radiation. Research shows that this type of radiation can damage a patient's DNA and lead to gene mutations and cancer. But the risk is still very small, the chance that a patient will have a fatal cancer from a CT scan is about 1 in 2,000.
But the radiation effect is cumulative and lasts throughout your life. So the patient's risk increases with each CT scan. Therefore, before the scan, the patient may need to talk to the doctor about the potential risks and benefits, and ask why the patient needs a CT scan.
Ionizing radiation may be more harmful to children, as they are still developing. If the total time of radiation exposure is taken into account, the younger the child who was exposed to radiation early, the more years that child was exposed to radiation than those who started to be exposed to radiation when they were older. Therefore, to reduce the risk of cumulative complications from multiple radiation exposures, parents should ask if the doctor or technician can set the CT scanner to pediatric mode.
Patients should inform their doctor if they are pregnant or suspect that they are pregnant. If a patient needs imaging of the abdomen, the doctor may prescribe other imaging techniques that do not use radiation, such as ultrasound.

Some people are allergic to the contrast, but most have a mild reaction such as itching or a rash. In very rare cases, contrast can cause severe and life-threatening reactions. Therefore, the patient needs to stay in the hospital for a short time after the CT scan for monitoring. Patients should inform their doctor or healthcare provider of any allergies such as drug, seafood, or iodine allergies.
Intravenous contrast media use may worsen renal failure in patients with pre-existing renal impairment, so patients should inform their physician of their medical condition as well as seek medical advice. Renal function testing prior to intravenous contrast administration.
In addition, the patient also needs to provide information to the doctor about the current medical condition such as: diabetes and taking metformin; or heart disease, kidney disease.
Vinmec International General Hospital is equipped with many modern CT scanners such as 512 ranges, 640 ranges, two-energy CT... modern, providing clear images of the body with high accuracy. They have the potential to help doctors eliminate the need for follow-up tests, while also helping patients shorten hospital stays. In addition, this technology also integrates a shield to regulate radiation exposure. At the same time, it also prevents unnecessary radiation doses before and after the procedure. With 640-sequence CT scanning technology, the time to record images of the coronary system is only in one beat, significantly reducing image noise caused by movement, so patients can save a lot of time for the examination process. mine.
Doctor Duc has nearly 17 years of experience in diagnostic imaging at Hanoi E hospital. Currently, the doctor is working at the Department of Diagnostic Imaging - Vinmec Times City International Hospital.
To register for examination and treatment at Vinmec International General Hospital, you can contact the nationwide Vinmec Health System Hotline, or register online HERE.
Reference source: webmd.com