Contents
The foot is the distal limb of a plantigrade living organism. The organ is a vault that is in contact with the surface of the earth and serves as a support when moving or fixing at one point. Foot pathologies can significantly impair the quality of movement and life of a person. Computed tomography is used for quick and informative diagnosis. What you need to know about the method, how exactly is the study carried out and what diseases are the human foot susceptible to?
How does computed tomography work?
The principle of operation of a CT scanner is based on x-rays. After a person is placed inside the CT machine, X-rays pass through their body. The degree of absorption of rays depends on the location, density, specifics of tissues, so it is not uniform. The device records the degree of absorption of rays by certain tissues, transfers this information to a special computer, processes it, taking into account the location of the tissues, and, based on the information received, creates an image of the scanned area in a three-dimensional format. For comparison, with a standard X-ray, we get a two-dimensional image of the shadows of organs. Computed tomography allows you to improve visualization and view each slice from a different angle in order to get as much information about the organ as possible.
Modern equipment receives an image of even the most insignificant elements. The cut thickness can reach 0,5 millimeters in various planes. Computed tomography, like any other method based on x-rays, separates 5 structural components: bones, fat, air, soft tissues and water. The greatest difficulties arise in the diagnosis of soft tissue structures. To do this, doctors advise the patient to undergo several types of diagnostics that work on the opposite principle. For example, computed tomography is often combined with ultrasound. To increase the information content of the method, radiopaque substances are used. After entering the body, they literally “color” the organs and blood vessels, which has a positive effect on visualization.
What you need to know about contrast tomography?
Radiopaque agents are used to improve the visualization of a particular organ/vessel. What does it give? The substance is administered to the human body orally or intravenously. In the first case, it spreads through the gastrointestinal tract, in the second – through the bloodstream. The liquid literally stains the vessels or organs through which it “travels”. The CT machine captures the dark areas of the body much better, so the tinted organs will be seen as clearly as possible in the final image. This greatly facilitates the work of the radiologist and other specialized specialists, and also increases the information content of the procedure.
Most radiopaque preparations contain iodine. Coloring liquids are absolutely safe and are independently excreted from the human body with the help of the kidneys. The only caveat: the contrast is contraindicated in case of individual intolerance to the drug and serious violations of kidney function. In the first case, the patient may develop a severe allergic reaction, in the second case, the removal of the substance from the body becomes more difficult.
Is CT diagnosis safe?
Tomography, like x-rays, is based on the study of x-rays. In this case, X-rays are allowed to be done only a few times a year due to the high radiation exposure. How is the CT scan going?
Absolutely all CT equipment operates at reduced radiation exposure. Scientists managed to reduce the degree of exposure as much as possible, but it is impossible to remove it completely. The time frame between CT scans is much shorter than between X-ray procedures. But using CT for multiple diagnostics, during pregnancy or in childhood, is not recommended. For this, ultrasound diagnostics or magnetic resonance imaging are more suitable, which are absolutely safe for the human body.
CT is used in almost all areas of medicine, from neurosurgery to urology. The informativeness of the method is much more valuable than the possible minimal risks. Moreover, modern equipment is constantly being improved. Scientists reduce the time of diagnosis, during which it is possible to obtain a full range of information, and therefore reduce radiation exposure.
Important: CT scans are performed only as directed by a doctor. In order to prevent, it is better to use non-radiation methods of research (ultrasound or MRI).
Indications/contraindications for
| Показания | Противопоказания |
|---|---|
| Mechanical damage to the foot – dislocations, subluxations, fractures | Pregnancy (due to the pathogenic effect of X-rays on the baby) |
| Infectious and inflammatory diseases | Age restriction (tomography is allowed from the age of 14, in especially severe cases it is possible to prescribe diagnostics at the age of seven) |
| Congenital or acquired developmental defects | Overweight (modern equipment is designed for patients weighing up to 200 kilograms) |
| Arthrosis (chronic pathology of the joints, which is associated with their deformation and limitations in mobility) | The general serious condition of the patient (notify the doctor of even a slight deterioration in the condition. The diagnosis may have to be postponed or canceled altogether) |
| Gout (pathology of the joints / tissues, which occurs due to the failure of metabolic processes in the body) | Liver failure, diabetes mellitus, thyroid pathology, renal failure (when conducting a contrast study) |
| Myositis (inflammation of skeletal muscles) | Mental deviations, fear of closed space (the patient will not be able to adequately respond to the requests of the radiologist, which will affect the effectiveness of the method) |
| Arthritis (inflammatory process in the joint) | |
| Defects in bone structure | |
| Damage to vessels of various etiologies | |
| Cancer neoplasms, regardless of the nature of the tumor | |
| General diagnosis of the foot before or after surgery |
Method of conducting
When performing tomography of the feet, no specific preparation is required. Immediately before the procedure, the laboratory assistant will ask you to remove all metal jewelry and clothing with metallic elements. The only caveat is that before diagnosis with contrast enhancement, the patient should refrain from eating 6 hours before the study.
Computed tomography of the foot is no different from the study of any other zone. Before the scan, the patient must provide medical documentation. It includes the direction of the attending physician for diagnostics with a preliminary diagnosis, specific instructions to the laboratory assistant if they take place, as well as a biochemical blood test for urea and creatinine, if a study with contrast enhancement is to be performed. The laboratory assistant studies the medical documentation, determines the type and features of the procedure (the area under study, with or without contrast). If it is necessary to improve the visualization of the soft tissues and vessels of the foot, then the contrast is administered intravenously immediately before the procedure. Contrast CT is performed on an empty stomach (the patient must refuse food 6 hours before contrast injection).
The radiologist helps the patient to sit on a sliding table. If desired, he can fix the body with soft straps. The patient must remain still during the scan. Even a slight reflex movement can spoil the scan, and hence the final XNUMXD image. The X-ray laboratory assistant selects the optimal location of the scanning ring, and covers the rest of the body with a special apron that protects tissues from X-rays. Once the patient is in a comfortable position, the technologist places the scanning ring over the foot, reports a possible communication device, and retires to the next room. From there, the medical officer monitors the scan and the patient’s condition.
Important: If you feel pain, discomfort, or want to stop the diagnostics for any other reason, immediately inform the laboratory assistant about it. It will help to fix the problem, identify the root cause and conduct a re-examination.
As soon as the device is started, the ring begins to rotate rapidly around the area under study, fixing the intensity of X-ray radiation and sections of the foot. The diagnostic takes about five minutes. When using contrast, the time frame increases to 10 minutes. Once all the information has been collected, the CT ring stops and the technologist returns to the office and helps the patient stand up/disengage from the straps.
No adaptation or recovery procedures after tomography are required. The patient can immediately return to the usual rhythm of life. The results of tomography are issued 30-60 minutes after the end of the diagnosis (the time frame may vary depending on the workload of the medical staff).
The result of CT is evaluated by at least 2 specialists – the laboratory assistant who performed the diagnostics and the attending physician. The laboratory assistant gives a general assessment of the condition of the foot, and the attending physician compares the information received with the clinic, anamnesis and data from other studies, if any. Taking into account all these data, a therapeutic course and specific recommendations for foot care are drawn up. Follow your doctor’s instructions and stay healthy!