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Many changes are diagnosed by X-ray examination. The technique has found its true purpose in many branches of medicine. Sometimes, due to the relatively low sensitivity, radiography is not able to detect signs of the disease, often there are plenty of them.
Therefore, patients are often referred for computed tomography. We are talking about the same X-ray method. But it is carried out on more advanced equipment. The complex structure of the device includes several ordinary ray tubes, special sensitive sensors and a computer monitor, where direct data processing is carried out, ready-made images of the structures of the study area are created. In addition, according to the images of the affected area, it is possible to study the structures of the lower leg as carefully as possible.
Brief information
This is a highly accurate diagnostic technique. It allows you to see in layers any area of the body in the pictures. The procedure is ideal for diagnosing inflammatory, tumor, destructive processes, injuries, foreign bodies. In particular, the technique perfectly visualizes the bones of the lower leg. This determines the popularity of the method for examining this part of the body.
CT is more suitable for examining bone elements. If you need to examine additional soft tissues, the technique is supplemented with contrast enhancement. This solution allows you to get more clear, high-quality images of various tissues in addition to bone.
Often, CT is the only method of examination that allows you to make an accurate diagnosis. A conventional x-ray allows you to see only the superficial part of the bone, CT makes it possible to consider pathological changes throughout the thickness of the bones. The procedure eliminates any kind of error due to an incorrectly chosen projection.
Work principles
Today, the technique is the leader in the accuracy of detecting pathological changes in the bones. The principle of operation is based on the same x-rays. They pass through tissues, translucent them. The intensity of the image depends on the density of the structures. So, the denser the elements under study, the longer the rays linger in them, and the brighter they are in the pictures. That is why bone structures, salt deposits are whitish in color, and empty areas, liquid structures are black. The physical capabilities of CT are in demand in cases with fractures and bone diseases. If the lower limb is injured with muscle damage or ligament rupture, then it is more appropriate to use MRI in the diagnosis.
Indications for CT
Mostly diagnostics are prescribed for:
- soreness;
- severe arthritis of the articular elements;
- to control the degree of bone fusion after a fracture;
- for planning further implantation of implants;
- abnormal development of bones;
- myeloma is suspected.
Despite the harmlessness of the procedure, a survey of such a plan is carried out in children only after 14 years. It is better to avoid the adverse effects of radiation on the physical health of children.
Features of the procedure
The technique is absolutely painless, not accompanied by discomfort. At the appearance of the slightest signs of discomfort, there is a constant two-way communication with the radiologist. According to the rules, the patient is left alone in the office. Control over the process is carried out through the glass from the adjacent room.
Scanning takes place in the supine position of the patient in the annular part of the apparatus. During the procedure, the table on which the patient is located moves somewhat. In this case, the patient must be motionless. This is a guarantee of image clarity.
Contrast enhancement technique
Contrast is a special substance based on iodine. It is necessary for maximum clarity of visualization of the examined elements. It is administered parenterally a few minutes before the diagnosis. Possesses neutrality, low toxicity on an organism. Therefore, it has practically no effect on the patient’s condition.
Neoplasms are much more common in the lower leg than other elements. Therefore, due to contrasting, it is possible to more clearly and accurately visualize any kind of structural changes.
When it enters the bloodstream, the contrast element stains the vessels, gradually accumulating in them. This allows a closer look at the area under study. So, it is precisely those zones that have increased blood flow and a dense network of vessels that are best visualized. We are talking about inflammatory elements, malignant neoplasms. The dosage of the contrast element is always selected individually. It all depends on the age and weight of the patient. The substance is excreted over several days.
Contraindications for examination
The technique is based on X-ray irradiation, so you should not repeat it many times. The load on the body from radiation is minimal, so there will be no harm from a single procedure, if necessary, repeated examinations are also acceptable. CT is completely safe if there are no contraindications to its conduct. The main ones include severe pain, which is accompanied by failures of motor reflexes. In this case, there may be an obstacle to maintaining immobility. It is strictly forbidden to perform CT at all stages of pregnancy. The rays can have an unpredictable effect on the intrauterine development of the baby.
According to the technical characteristics, the device is unable to diagnose patients weighing more than 180-200 kg.
In the case of contrast, contraindications increase. The procedure is not performed in the presence of renal failure. After all, problems with excretion delay the contrast element in the body. This provokes severe poisoning. Contrasting should not be used in the presence of any kind of non-reception of the iodine element. For allergy sufferers, as a precaution, it is better to refuse such a procedure. The study is not intended for patients with severe thyroid disease.
Lactation is a serious contraindication to contrast CT. The fact is that the iodine element easily penetrates into breast milk and can harm the baby. In extreme cases, if necessary, the procedure is performed, but the woman refuses to breastfeed for the next 48 hours.
Preparing for diagnostics
The study is carried out in the direction of a doctor. Therefore, it is desirable for each patient to have a medical referral, an extract from the outpatient card, and the results of previous studies. No preparation is required for conventional CT.
If a contrast examination is necessary, it is important not to eat for 3-4 hours before the procedure.
Tomography interpretation
All received images are evaluated by a radiologist. Such processing often takes no more than an hour. The patient receives several different pictures and their detailed interpretation.
The results must be shown to the doctor who sent for diagnosis, or to a specialist whose work is related to the identified pathology. Only by bringing together all the studies and evaluating the clinical picture, the doctor makes the final diagnosis.