Medical research and diagnostics

Computed tomography (CT) scan of the hip joint

The hip joint is the joint that is responsible for flexion / extension, abduction / adduction, pronation / supination of the hip. Also thanks to him, a person can perform a circular rotation of the thigh. The joint can be affected by a variety of diseases - starting with a standard injury, ending with rare bone cancer. For informative and rapid diagnosis used computed tomography. How does the method differ from x-rays, in what cases is tomography shown and what should we expect from the study?

The principle of operation of the computer tomograph

Computed tomography, like X-rays, uses X-rays for diagnostic purposes. Modern tomography is a whole software and hardware complex. It consists of mechanical assemblies, supersensitive detectors, X-ray emitters, various parts and software that deals with image analysis and visualization. The principle itself is based on the non-uniform absorption of X-rays by the tissues of a living organism. It depends on the location of the fabric, its specificity, density and other characteristics.

The device records the degree of absorption of the rays, transmits information to the computer, which analyzes it and forms an image of the area being diagnosed. From the set of step-by-step cuts, the equipment creates a three-dimensional image of the internal cavity / bones / vessels. The doctor examines them, highlights the norms and pathologies, develops an individual therapeutic course.

CT equipment receives sections of objects whose thickness is 0.05 millimeters. This indicates a high speed and diagnostic accuracy of scanning. Like any other diagnostic method based on X-rays, tomography distinguishes skin, fat, air, water, and soft tissue. The greatest difficulties arise with the study of soft tissues - the picture may not be sufficiently clear, and therefore not informative. To remedy the situation used radiopaque substances. If the use of contrast is not possible, the patient may be assigned an additional diagnosis (for example, an ultrasound examination).

What you need to know about applying contrast when conducting computed tomography?

The radiopaque substance helps to “separate” the organs and tissues from each other, to visualize them more clearly, to remove additional interference that may interfere with the evaluation of results. The main component of the contrast - iodine. The drug enters the body orally, spreading through the gastrointestinal tract or intracutaneously through the blood flow. The areas on which the iodine-containing drug falls are literally "highlighted" and become more noticeable. With the help of contrast, the attending physician can easily determine the pathological changes in the organ, examine the blood flow of cancerous growths, or evaluate the functions of the vessels.

Contrast is absolutely safe for the human body and is excreted naturally through the kidneys. Contrast use has contraindications - idiosyncrasy of the drug and severe kidney disease. In the first case, the risk of allergic reactions is high, in the second, there is a difficulty in removing the drug from the body.

Indications / contraindications for
Infectious / inflammatory processes in articular tissuesPregnancy (due to the harmful effects of radiation exposure to the fetus)
Diagnosis of congenital anomalies of development or damage after mechanical injuryClaustrophobia, various mental disorders (the patient will not be able to remain stationary, and stress can cause a number of complications of the existing disease)
Osteoarthritis with thinning cartilage tissueOverweight, which exceeds the maximum allowable weight for CT equipment (most devices are designed for patients up to 200 kilograms)
Arthritis (inflammation of the joint)Age up to 14 years
Air cavities in bones, cystsIndividual intolerance to iodine-containing drugs, thyroid pathology, diabetes, renal failure (with the passage of contrast tomography)
Cancer neoplasms regardless of the nature
Aseptic necrosis of the femoral head
Osteomyelitis in combination with purulent formations
General diagnosis of the hip joint before or after surgery
Assessment of the dynamics of various pathologies, determination of effectiveness or the formation of treatment tactics

Preparation for the study

Specific training is needed only when conducting contrast diagnostics. The patient must refrain from eating food for 6 hours before CT. This is necessary to minimize side effects. Moreover, the contrast agent spreads more quickly and efficiently through the “clean” gastrointestinal tract. In addition to refusing to eat, the patient must choose comfortable and safe clothing. It should be simple pants / t-shirt from natural or synthetic fabric without metallized decorative elements. Metal particles can distort the image, leaving empty white spots on the final three-dimensional image.

CT Method

The laboratory assistant helps the patient to climb onto a movable table and sit comfortably on it. Then the laboratory technician places the scanning ring just above the hip joint, conducts a short briefing and leaves for the adjoining room. A medical officer records the scan results and remotely monitors the patient's condition. The scanning ring directs X-rays to the hip joint, and the hypersensitive sensors record their absorbability by the tissues. Then the information enters the computer, which, using special algorithms, converts it into a three-dimensional picture of the scanned area.

During scanning it is important to observe complete immobility. Even defects of one or two scans will affect the final result and reduce the accuracy of the study. If the patient wishes, the laboratory technician can fix the limbs with special soft straps. The rest of the body (in addition to the scanned hip joint) is covered with a special apron, which reflects the X-rays. The duration of the procedure is about 5 minutes. When conducting contrast tomography, the time frame is extended to 20 minutes.

Contrast is used in cases where it is necessary to more clearly visualize the soft tissues and vessels surrounding the hip joint. Iodine-containing drug is administered immediately before scanning intravenously. Contrast quickly penetrates the blood vessels through the bloodstream and spreads throughout the body. Possible side effects from using contrast - nausea, vomiting, dizziness. If the patient feels a rapid deterioration, then the study is interrupted until the nature of the reaction is ascertained.

It is the contrast that represents the main danger during tomography. The substance can cause adverse symptoms even in people who are not allergic to its constituents. The risk of side effects is 3-4%.

Alternative research methods

The hip joint is the largest joint of the human body. Large size opens up a lot of methods for diagnosis. If for some reason computed tomography is undesirable or unavailable, you can use an ordinary X-ray. He remarkably visualizes bone tissue, identifies arthritis / arthrosis / various foreign bodies. Doctors recommend an ultrasound scan to diagnose fractures, injuries and cracks.

To assess the condition of soft tissues and diseases that may be associated with them, magnetic resonance imaging is prescribed. The method is considered the safest for the body, since it is based on the influence of a magnetic field. MRI shows the anatomical features of the muscular system, cartilage, ligaments, blood vessels and the articular capsule. Alternatively, arthroscopy can be used. This is an invasive technique that involves the introduction of microcamera inside the joint. The method is particularly relevant for the collection of biological material or surgical procedures.

Selection of the diagnostic method is always left to the doctor. He will evaluate the general condition of the body, select the most effective and safe research. Follow medical instructions and stay healthy.

Article author:
Furmanova Elena Alexandrovna

Specialty: pediatrician, infectious diseases specialist, allergist-immunologist.

Total experience: 7 years.

Education: 2010, SSMU, pediatric, pediatrics.

Experience infectious diseases more than 3 years.

He has a patent on the topic “A method for predicting a high risk of the formation of a chronic pathology of the adeno-tonsillar system in frequently ill children”. As well as the author of publications in the journals of the Higher Attestation Commission.

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Watch the video: CT Computed Tomography Scan: What to expect (November 2019).