Purpose, Procedure, Risks, Side-Effects, Results

Written by WebMD Editorial Contributors

• How Do CT Scans Work?
• How Are CT Scans Done?
• What Is It Used For?
• What Is a CT Scan with Contrast?
• Are There Any Risks?
• What Are the Side Effects?
• More

A computed tomography (CT or CAT) scan allows doctors to see inside your body. It uses a combination of X-rays and a computer to create pictures of your organs, bones, and other tissues. It shows more detail than a regular X-ray.

You can get a CT scan on any part of your body. The procedure doesn’t take very long, and it’s painless.

They use a narrow X-ray beam that circles around one part of your body. This provides a series of images from many different angles. A computer uses this information to create a cross-sectional picture. Like one piece in a loaf of bread, this two-dimensional (2D) scan shows a “slice” of the inside of your body.

This process is repeated to produce a number of slices. The computer stacks these scans one on top of the other to create a detailed image of your organs, bones, or blood vessels. For example, a surgeon may use this type of scan to look at all sides of a tumor to prepare for an operation.

You’d probably get a scan at a hospital or radiology clinic. Your doctor might tell you not to eat or drink for a few hours before the procedure. You may also need to wear a hospital gown and remove any metal objects, such as jewelry.

A radiology technologist will perform the CT scan. During the test, you’ll lie on a table inside a large, doughnut-shaped CT machine. As the table slowly moves through the scanner, the X-rays rotate around your body. It’s normal to hear a whirring or buzzing noise. Movement can blur the image, so you’ll be asked to stay very still. You may need to hold your breath at times.

How long the scan takes will depend on what parts of your body are being scanned. It can take anywhere from a few minutes to a half-hour. In most cases, you’ll go home the same day.

Doctors order CT scans for a long list of reasons:

• CT scans can detect bone and joint problems, like complex bone fractures and tumors.
• If you have a condition like cancer, heart disease, emphysema, or liver masses, CT scans can spot it or help doctors see any changes.
• They show internal injuries and bleeding, such as those caused by a car accident.
• They can help locate a tumor, blood clot, excess fluid, or infection.
• Doctors use them to guide treatment plans and procedures, such as biopsies, surgeries, and radiation therapy.
• Doctors can compare CT scans to find out if certain treatments are working. For example, scans of a tumor over time can show whether it’s responding to chemotherapy or radiation.

In a CT scan, dense substances like bones are easy to see. But soft tissues don’t show up as well. They may look faint in the image. To help them appear clearly, you may need a special dye called a contrast material. They block the X-rays and appear white on the scan, highlighting blood vessels, organs, or other structures.

Contrast materials are usually made of iodine or barium sulfate. You might receive these drugs in one or more of three ways:

• Injection: The drugs are injected directly into a vein. This is done to help your blood vessels, urinary tract, liver, or gallbladder stand out in the image.
• Orally: Drinking a liquid with the contrast material can enhance scans of your digestive tract, the pathway of food through your body.
• Enema: If your intestines are being scanned, the contrast material can be inserted in your rectum.

After the CT scan, you’ll need to drink plenty of fluids to help your kidneys remove the contrast material from your body.

CT scans use X-rays, which produce ionizing radiation. Research shows that this kind of radiation may damage your DNA and lead to cancer. But the risk is still very small — your chances of developing a fatal cancer because of a CT scan are about 1 in 2,000.

But radiation’s effect adds up over your lifetime. So your risk increases with every CT scan you get. Talk to your doctor about the procedure’s potential dangers and benefits, and ask why the CT scan is necessary.

Ionizing radiation may be more harmful in children. That’s because they’re still growing. They also have more years to get exposed to radiation. Before the procedure, you may want to ask the doctor or technician if the CT machine’s settings have been adjusted for a child.

Tell your physician if you’re pregnant. If you need imaging for your stomach area, your doctor may recommend an exam that doesn’t use radiation, such as an ultrasound.

Some people are allergic to the contrast materials. Most of the time, the reaction is mild. It can lead to itchiness or a rash. In very few cases, the dye may trigger a life-threatening reaction. For this reason, your health care provider may want to monitor you for a short period after your CT scan. Tell your doctor about any allergies you have to medications, seafood, or iodine.

Your doctor should know, too, if you have diabetes and are taking the drug metformin. They’ll let you know if you should stop taking your medication before or after your procedure.

Although it’s rare, contrast materials can lead to kidney problems. Let your doctor know if you have any kidney issues before the CT scan.

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CT scan – Better Health Channel

Summary

Read the full fact sheet

• The computed tomography (CT) scan is a medical imaging procedure that uses x-rays and digital computer technology to create detailed pictures of the body.  
• It can image every type of body structure at once, including bone, blood vessels and soft tissue. 
• The CT scan is a non-invasive, painless and relatively safe procedure that doesn’t require any recovery time.

The computed tomography (CT) scan is a medical imaging procedure that uses x-rays and digital computer technology to create detailed two- or three-dimensional images of the body. Unlike other forms of medical imaging, the CT scan can make an image of every type of body structure at once, including bone, blood vessels and soft tissue.

CT scanning equipment consists of a large gantry (a supporting structure) with a circular hole. Inside the gantry is a rotating ring that carries the x-ray source and electronic x-ray detectors. An attached table slides the fully reclined (lying down) person into the hole.

Multiple x-ray projections are taken in thin cross-sections along the person’s body (imagine a loaf of sliced bread). The detectors collect the x-ray information from each cross-section and send them to a special computer that combines them into an image.

The CT scan may also be referred to by its older name of computed axial tomography or ‘CAT’ scan.

When a CT scan is used

Some of the common uses of the CT scan include:

• assessment of a body part’s structure or shape
• diagnosis of disease, particularly cancer
• diagnosis of trauma or injury
• diagnosis of vascular disease
• aid to planning particular surgeries
• aid to planning radiotherapy
• visual aid to radiotherapy administration
• visual aid to certain interventional procedures (going inside the body) such as biopsy or needle aspiration
• measurement of bone strength
• alternative to some types of exploratory or diagnostic surgery.

Medical issues to consider before a CT scan

Before you have a CT scan:

• Tell the doctor if you are pregnant or think you may be pregnant. Another type of test may be recommended.
• Tell the doctor if you have allergies, diabetes, thyroid condition or renal (kidney) impairment.
• Tell the doctor if you experience claustrophobia (fear of small spaces). The doctor may give you a mild sedative to help you relax during the procedure.
• Tell the doctor about any implanted device you may have such as a pacemaker or medication pump, as metal objects may distort the images.
• Follow all the instructions you are given. Some CT scans require the use of contrast material to improve the image quality. The contrast material may be taken orally or by an intravenous injection (or both).
• You may have to go without food and drink for a certain length of time before the procedure. Your doctor will give you detailed instructions on how to prepare for the test and what to expect.
• A very obese person may be too big for the circular hole of the CT machine. The doctor may advise another type of medical imaging or diagnostic test.

CT scan procedure

Generally, the procedure includes the following:

• You may be given a large drink to consume before the procedure. This drink is an oral contrast agent that helps to enhance pictures of the stomach, small intestines and bowel. In some cases, the contrast agent is administered as an enema.
• You will be asked to undress and wear a hospital gown. You must remove all metal objects including jewellery.
• You lie down on the scanner table. The radiographer may use straps and foam pillows to position your body and help keep you still.
• You may be given an intravenous injection of an iodinated contrast medium (a type of dye) to help produce better images. This substance may cause a strange warm feeling that lasts for a few seconds, a funny metallic taste in the mouth or the sensation that you have ‘wet’ yourself.
• The table slides into the circular hole in the machine.
• Depending on the body part and the condition being investigated, a number of images may be taken as the table moves in and out of the circular hole.
• The ring inside the gantry moves in a circle around you as it takes the x-ray images. Each revolution (turning) of the ring takes less than a second and there may be a number of revolutions depending on the examination.
• Lie very still. This is very important, as movement will blur the images. You may be asked to hold your breath for a few seconds while the CT machine takes the images.
• The equipment makes clicks and buzzes while taking the images. Don’t be alarmed – this is normal.
• Depending on the type of medical investigation, the CT scan may take anywhere from a few minutes to half an hour or more.

Immediately after the CT scan

You may be asked to wait while the radiographer reviews the images. In some cases, more images must be taken. Once the radiographer has enough good images, you can dress and leave when the radiographer says you can.

You may need to remain in the department for a short period after the procedure if you have received the iodinated contrast material. The medically qualified radiologist assesses the scans. The results are usually sent to your referring doctor, so you will need to make a follow-up appointment.

Complications of a CT scan

The CT scan is a very safe procedure. Some people who have an injection of iodinated contrast material may feel nauseous for a short time afterwards. On rare occasions, a person may have an allergic reaction to this substance.

Taking care of yourself at home after a CT scan

The CT scan is a non-invasive, painless and relatively safe procedure. Most people do not need any recovery time. Be guided by your doctor but, generally speaking, you can resume normal activities as soon as you leave.

Breastfeeding after a CT scan

Nursing mothers do not need to avoid breastfeeding after a CT scan, even if the iodinated intravenous dye was used.

Long-term outlook after a CT scan

There are no known long-term side effects from having a CT scan. However, the procedure is thought to very slightly increase a person’s chance of developing cancer. To keep this small risk in perspective, a typical CT scan will expose you to the same amount of radiation that you would receive from the general environment over about three years.

Alternatives to a CT scan

Alternatives to a CT scan depend on the medical condition under investigation but could include:

• MRI scan
• ultrasound
• blood test
• biopsy
• exploratory surgery.

Where to get help

• Your GP (doctor)
• Radiographer or radiologist

• CT scanExternal Link, 2018, Royal Children’s Hospital.
• Computed tomography (CT) – bodyExternal Link, 2018, RadiologyInfo.org, American College of Radiology and The Radiological Society of North America.
• Iodinated Contrast Media Guideline V2.3External Link, 2018, Faculty of Clinical Radiology, Royal Australian and New Zealand College of Radiologists.

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Intermediate results of CT for admission to the master’s program published — News — Forbes Kazakhstan

August 03, 2022

4210

To date, about 35 thousand applicants for admission to the magistracy have passed a comprehensive test. The threshold score was scored by about 45% of applicants. The average score is 72 points. The maximum score is 140 points out of 150 possible, the press service of the Ministry of Science and Higher Education of the Republic of Kazakhstan reports.

Since the beginning of testing, the results of 265 participants have been canceled for violation of the rules. In particular, 144 applicants were not allowed to take the exam for trying to carry smartphones, cheat sheets and other prohibited items. For violation of the rules during testing, 117 people were removed from the audience, their results were also canceled. Also, according to the results of post-proctoring, the results of 4 participants who took pictures and tried to take the exam materials out of the classroom were canceled.

As well as at the UNT, admission to exams is carried out according to a three-level proctoring system: through identification of the person Face ID, according to the identity card, identification of the person at the seat is also carried out. Thanks to the measures taken at the entrance to testing, 4 cases of face swapping were recorded in the first week of testing. That is, the participants tried to take the test by sending an outsider instead. Appropriate measures have been taken. No such violations were recorded in the second week.

“This week, registration for admission to non-civilian universities, such as the Academy of Justice under the Supreme Court of the Republic of Kazakhstan, the Academy of Law Enforcement Agencies under the General Prosecutor’s Office of the Republic of Kazakhstan, the Academy of the Ministry of Internal Affairs of the Republic of Kazakhstan, the Academy of Civil Protection named after. M. Gabdullina of the Ministry of Emergency Situations of the Republic of Kazakhstan. The entrance exam in a foreign language for this category of applicants will be held on August 6, ”said Ruslan Emelbaev, director of the National Testing Center of the Ministry of Education and Science of the Republic of Kazakhstan.

It should be reminded that more than 46 thousand applications were submitted for comprehensive testing, which is 6 thousand more than last year. Meanwhile, more than 13,000 grants have been allocated for graduate studies this year. This year, comprehensive testing for admission to the master’s program began on July 20 and will last until August 10, 2022.

The rules for admission to the magistracy this year remained unchanged. Comprehensive testing consists of three blocks: a test in a foreign language, to determine readiness for learning, and also according to the profile of a group of educational programs. At the same time, the presence of an international certificate confirming knowledge of a foreign language exempts from the language test.

There is a possibility of an online appeal, according to which, within 30 minutes after the completion of the test, the applicant must file a statement of disagreement with the results obtained. The appeal is considered within five days. A certificate of successful testing is placed in the applicant’s personal account.

It should be noted that this year the passing score remained the same: for admission to the master’s program in the scientific and pedagogical direction – 75 points, for the profile direction – 50 points.

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Test with answers on the topic “Positron emission tomography – computed tomography (PET-CT) in the diagnosis of prostate cancer (PCa)”

Your attention is presented to the Test with answers on the topic “Positron emission tomography – computed tomography (PET-CT) in the diagnosis of prostate cancer (PCa)” in the framework of the CME program: continuing medical education for medical professionals (doctors, nurses and pharmacists).
Test with answers on the topic “Positron emission tomography – computed tomography (PET-CT) in the diagnosis of prostate cancer (PCa)” within the framework of the CME program: continuing medical education for medical personnel of the highest and middle level (doctors, nurses and pharmaceutical workers ) allows you to better prepare for the final assessment and / or understand this topic.

• free of charge
• at
• diagnostics
• gland
• Computer
• CT
• medical
• at

90 032 NMO

• to
• Positron
• Positron Emission
• Prostate
• PET
• PET-CT
• cancer
• PCa
• s
• topic
• Test
• tomography
• emission

Radioisotope techniques in oncology (radionuclide diagnostics) are one of the most popular methods of radioisotope research in relation to cancer patients. PET/CT is a highly sensitive method for diagnosing prostate cancer and assessing the prevalence of the tumor process. The method will allow you to get a very clear image of both the skeletal system and the whole organism and to identify those pathological changes that have occurred as a result of the disease. Knowledge of the possibilities and features of conducting radioisotope studies is necessary in the daily practice of an oncologist and doctors of other specialties.

1. Absolute contraindication for radionuclide diagnostic methods

1) pregnancy;+
2) claustrophobia;
3) lactation;
4) the inability to stay in a prone position for a long time.

2. Depending on the ability to penetrate tissue and histohematic barriers, radiopharmaceuticals are divided into

1) diffusing and non-diffusing; +
2) organotropic and tropic to the pathological focus, compounds without pronounced selectivity;
3) reactor, cyclotron and generator.

3. Depending on the method of preparation, radiopharmaceuticals are divided into

1) diffusible and non-diffusible;
2) organotropic and tropic to the pathological focus, compounds without pronounced selectivity;
3) reactor, cyclotron and generator. +

4. In what device is the investigated object with radioactivity placed?

1) gamma camera;+
2) CT scanner;
3) magnetic resonance tomograph;
4) X-ray machine with fluoroscopy capability.

5. The most important advantages of generator nuclides

1) the possibility of transportation over long distances with subsequent separation of the daughter nuclide extempore; are short-lived, formed from isotopes with a long half-life; +
2) obtained by separating decay products from fuel rods or uranium targets;
3) are optimal in terms of minimizing radiation exposure.

6. Why is it necessary to increase the hydration of the patient’s body 1-2 hours before the PET-CT examination?

1) to increase the radiation dose;
2) to increase the rate of excretion of the radiopharmaceutical from the body;+
3) to improve the excretion of the radiopharmaceutical through the biliary tract;
4) to speed up image acquisition.

7. Changes of which nuclides represent the transformation of neutrons into protons with the release of electrons?

1) generator;
2) reactor; +
3) cyclotron.

8. Radiopharmaceuticals for PET based on the mechanism of penetration into the cell based on the use of specific membrane transporters include

1) 11C-methionine;
2) 18F-sodium fluoride;
3) 18F-choline; +
4) 68Ga-PSMA.

9. Requirements for radiopharmaceuticals include the following

1) High resolution imaging capability;
2) high radiation load;
3) minimum image acquisition time;
4) suitability of a radiopharmaceutical for certain clinical diagnostic tasks.+

10. What radioisotopes are used in PET-CT for prostate cancer?

1) 11C-methionine;
2) 131I;
3) 18F-FDG;
4) 18F-fluorocholine+

11. Which radiopharmaceuticals for PET-CT are tumorotropic in the diagnosis of prostate cancer?

1) 18F-FDG;
2) 18F-sodium fluoride;
3) 18F-fluoro choline;
4) 68Ga-PSMA.+

12. Which of the radiopharmaceuticals has a long half-life?

1) 11C-carboncholine;
2) 18F-fluorocholine; +
3) 68Ga-PSMA.

13. What is the most common method of administering radiopharmaceuticals?

1) intra-arterial;
2) intravenous;+
3) intramuscular;
4) oral.

14. Which PET-CT radiopharmaceutical for prostate cancer is most effective when PSA levels are below 2 ng/mL?

1) 11C-carbon choline;
2) 18F-FDG;
3) 18F-sodium fluoride;
4) 68Ga-PSMA.+

15. The most optimal in terms of minimizing the radiation load are nuclides

1) generator;
2) reactor;
3) cyclotron.+

16. The most sensitive and clinically used method of PET-CT of local recurrence and distant metastases of prostate cancer is currently

1) PET-CT with 18F-PSMA;+
2) PET-CT with 18F-FDG;
3) 18F-sodium fluoride PET-CT;
4) PET-CT with 18C-choline.

17. Field of application of radiopharmaceutical preparation 18F-PSMA for PET-CT in prostate cancer

1) identification of the degree of activity of the process;
2) determination of local recurrence and distant metastases; +
3) determination of local prevalence;
4) assessment of the state of the gastrointestinal tract.

18. Field of application of radiopharmaceutical 18F-sodium fluoride for PET-CT in prostate cancer

1) detection of metastases in the bone; +
2) detection of metastases in the lymph nodes;
3) determination of local recurrence;
4) assessment of local distribution.

19. The main advantage of 18F-PSMA over 68Ga-PSMA is

1) greater excretion of 68Ga-PSMA through the biliary tract;
2) greater excretion through the intestines;
3) lower excretion of 18F-PSMA in the urinary tract.+

0083

1) fasting for 6 hours before the test;
2) cancellation of all used drugs;
3) no special training.+

21. The advantage of nuclear medicine is

1) the ability to reflect the physiological and pathophysiological changes in the body with high spatial resolution;
2) the ability to reflect the physiological and pathophysiological changes in the body with low spatial resolution;+
3) high spatial resolution;
4) low spatial resolution.

22. On the second scan of 2-stage PET-CT with 18F-fluorocholine in prostate cancer, the level of accumulation in malignant changes

1) remains at the same level;
2) increases; +
3) decreases.

23. On the second scan of 2-stage PET-CT with 18F-fluorocholine in prostate cancer, the level of accumulation in the nodes of prostatic hyperplasia

1) remains the same;
2) increases;
3) decreases.+

24. At what level of prostate specific antigen does the sensitivity of the radiopharmaceutical 11C-carboncholine significantly decrease?

1) below 10 ng/ml;
2) below 2 ng/ml;+
3) below 20 ng/ml;
4) below 30 ng/ml.

25. The progression of the pathological process according to PET-CT in assessing the effectiveness of therapy for prostate cancer is characterized by

1) increase in the number of foci of increased accumulation of the radiopharmaceutical; +
2) decrease in the length of foci of increased accumulation of the radiopharmaceutical;
3) a decrease in the degree of accumulation of the radiopharmaceutical in existing lesions.

26. Radiopharmaceuticals for PET-CT 18F-sodium fluoride in prostate cancer by the nature of accumulation in organs and tissues belongs to

1) non-selective;
2) organotropic; +
3) tumoritropic.

27. Radiopharmaceutical product reflects physiological and biochemical changes in the body due to

1) accumulation by body structures; +
2) reflection by body structures;
3) damage to body structures;
4) dispersion by body structures.

28. Choline is a substrate for the synthesis

1) calcium hydroxyapatite;
2) glucose;
3) folic acid;
4) Phosphatidcholine.+

29. Broad practical significance for radioisotope diagnostics retained

1) 195pt, 200tl, 129te;
2) 55fe, 64cu, 197hg;
3) 7Be, 14C, 18F;
4) 99m-technetium, 123-iodine, indium radioisotopes and thallium nuclide (201-TI and 199-TI).+

ev;

2) 127 keV;
3) 511 keV;+
4) 68 keV.