Medical devices for diagnostics are constantly being improved. Most modern instruments, including tomographs, are entire software and hardware systems. All parts and mechanical components for them are manufactured with the highest precision, and for processing data, highly specialized computer applications are responsible.
What is CT?
The basis of the device under consideration is a tube emitting X-rays. It quickly rotates inside a large ring (gentry), in the center of which there is a movable couch (on which the patient lies). The movements of this table and tube are synchronized. A simplified explanation of what a CT scan is is a series of X-ray images of the desired part of the body from different angles. As a result, many images of the organ or biological structure are obtained in sections with a thickness of 1 mm, which are fixed by ultrasensitive sensors.
After the pictures are taken, the computer tomography is "collected" using specialized software. All available slices recorded by detectors in the gantry are processed by the operating system. Of these, the program "adds" a detailed three-dimensional image of the investigated area, it is displayed on the computer monitor. In such pictures, tiny organic structures are visible, and even dynamic changes in their functions.
What kinds of CT are there?
Medical technologies are progressing all the time, and therefore diagnostic devices are being improved. The following types of CT are available:
- spiral;
- multilayered;
- contrast;
- angiography;
- perfusion.
Spiral computed tomography
This form of apparatus has been used in diagnostic practice for 30 years. The spiral computer tomograph consists of 3 main parts:
- rotating X-ray tube;
- one series of ultrasensitive sensors along the circumference of the ring;
- the couch moving across the gantry.
Multilayer computed tomography
This type of device provides the most informative and most accurate research. Multispiral computed tomography (MSCT) differs from standard diagnostics with an increased number of detectors and tubes. In the described devices, the sensors are installed in 2-4 rows. On the circumference of the gantry, not one but two X-ray tubes can rotate, which greatly accelerates the investigation and reduces the radiation load.
Other advantages of MSCT:
- the newest software;
- high resolution images;
- optimal contrast pictures;
- the ability to register dynamic processes in real time;
- maximum detail of the cut;
- large area of anatomical coverage;
- the construction of 3D models of all systems and organs.
Computed tomography with contrast
To enhance the differentiation of organs located side by side and to make more precise small physiological structures, for example blood vessels, special types of CT studies are used. They suggest the introduction of drugs that increase the contrast of tissues when absorbing X-rays. Such computed tomography is carried out in 2 ways:
- Orally. The patient drinks a solution with a contrast agent. The volume of fluid, the sequence and frequency of its administration is calculated by the doctor.
- Intravenously. The contrast solution is administered by injection or by means of an automatic dropper.
CT angiography
This type of research was developed specifically for the study of the circulatory system. CT angiography of the vessels of the neck and head helps to detect any circulatory disturbances in these zones, including ischemic or hemorrhagic stroke, to assess the severity of their consequences, to detect neoplasms of any quality. To increase the informative value of the procedure, a contrast drug with iodine content is preliminarily injected into the ulnar vein.
One of the most modern and impressive achievements of medicine is multislice computer tomography of the head, neck, limbs and other parts of the body. Thanks to progressive software this manipulation allows creating a three-dimensional model of the whole circulatory system of a person with the possibility of its detailed mapping in any angles.
CT perfusion
The presented version of the study is considered the most perfect and accurate way to diagnose dangerous circulatory disorders. Perfusion computer tomography differs from the standard procedure with a minimum thickness of cut, which provides a more detailed 3D-model of organs as a result. Such manipulation is carried out with intravenous administration of a contrast medium under the control of an automatic dropper.
In medicine, only CT perfusion of the brain and liver is used. It helps not only to create a highly accurate three-dimensional image of these organic structures, but also to assess the intensity and efficiency of the passage of blood through their tissues, large and small vessels. On modern devices these processes can be observed in real time.
CT - indications and contraindications
This technology is widely used in medicine for several purposes. Computed tomography can be assigned as:
- screening;
- emergency diagnostics;
- planned inspection;
- evaluation of treatment effectiveness;
- control the implementation of therapeutic and diagnostic manipulations.
CT - indications for:
- fainting ;
- headache;
- dry prolonged cough;
- fever;
- convulsive syndrome;
- changes in mental status;
- head trauma;
- bleeding disorders;
- focal neurological deficit;
- paralysis;
- cognitive disorders ;
- high blood pressure;
- hypoventilation of the lungs;
- meningism;
- pain in any part of the body of unknown origin;
- stable change in the consistency and quality of the stool;
- digestive disorders;
- impaired mobility of the spine and joints;
- myalgia ;
- pathology of the respiratory system;
- internal bleeding ;
- Diseases of the teeth and oral cavity;
- suspicion of the presence of neoplasms of any quality;
- severe paresis and other conditions.
Contraindications to manipulation without using a contrast agent:
- pregnancy;
- Body weight exceeding the maximum allowed for the existing device.
CT with iodine-containing drugs has similar contraindications, and it can not be done in such cases:
- myeloma;
- an allergy to a contrast agent;
- diabetes mellitus in a serious stage;
- kidney failure ;
- unsatisfactory general condition of a person;
- pathology of the thyroid gland.
What does computed tomography show?
With the help of the described diagnostic technique, it is possible to examine all organic structures. What CT shows depends on the purpose of its purpose, the area under investigation and the type of procedure. Computer spiral tomography is used to diagnose internal organs, soft tissues, bones and joints. Angiography and perfusion is used for diseases of large and small blood vessels.
Computed tomography of the abdominal cavity
In this zone, the examination helps to identify pathologies of any organs of the digestive tract. Computed tomography of the kidneys, spleen, intestines, liver, pancreas is prescribed in case of suspicion of the following problems:
- abscess;
- cysts;
- infectious lesions;
- aneurysms;
- tumors;
- increased or inflamed lymph nodes;
- presence of foreign objects;
- diverticula;
- internal bleeding;
- appendicitis;
- congenital anomalies.
Computer tomography of the intestine involves the use of contrast medium. Before the manipulation, the patient will have to drink a special iodine-containing solution. Thanks to the application of the method of contrasting, the three-dimensional model of the intestine will clearly show not only the walls of the organ, but also the network of blood vessels, physiological curves and the state of the mucous membranes.
Computed tomography of the chest
This area of research provides informative diagnostics of the respiratory system, heart, esophagus, aorta, mammary glands and soft tissues. Computer tomography of the lungs and bronchi is recommended for the detection of such diseases:
- bacterial or viral infection;
- oncological tumor;
- aneurysm;
- embolism;
- tuberculosis;
- pneumonia ;
- developmental anomalies;
- post-traumatic changes;
- metastases;
- atelectasis;
- pleurisy;
- sarcoidosis;
- parasitic cysts;
- abscess.
Other pathologies that help diagnose thorax tomography:
- heart disease and large blood vessels;
- neoplasm in the mammary glands;
- mediastinitis;
- hiatal hernia;
- paralysis of the diaphragm;
- gastroesophageal reflux;
- anomalies in the development of the mediastinum;
- lymphogranulomatosis and others.
Computed tomography of the brain
The examination of the central organ of the central nervous system is applied against the background of any changes in its functioning. Before the procedure, the doctor should explain what a CT scan of the brain is - a series of X-ray images from different angles, allowing you to obtain high-quality images (slices) for building a detailed 3D model.
Manipulation helps to diagnose diseases and injuries of the body, to assess the intensity of circulation in the vasculature, to monitor the treatment process. Computer tomography of the brain shows the following violations:
- strokes;
- benign and malignant tumors;
- hematomas;
- injuries;
- abscess;
- acute pathology of blood circulation;
- encephalitis;
- meningitis;
- foreign bodies in soft tissue;
- cysts;
- congenital or acquired developmental anomalies;
- edema;
- fractures in the base of the skull;
- an increase in the cavity of the brain;
- hydrocephalus;
- venous thrombi;
- complications of ischemic attacks or strokes;
- disorders of the hemispheres and others.
Computer tomography of teeth
This study is required for severe dental diseases or for the need for surgical intervention under X-ray control. Computer tomography of the jaw helps to detect:
- neoplasms;
- cysts;
- inflammation of the surrounding root tissues;
- changes in the structure of periodontal and periodontium;
- the presence of abnormally located wisdom teeth;
- birth defects;
- injuries of the jaw;
- changes in mucous membranes;
- pathology of pulp;
- diseases of the root canals;
- circulatory disorders in the network of small vessels;
- anomalies of frontal and nasal sinuses.
Computed tomography of the spine
Presented manipulation is assigned to clarify the diagnosis with severe pain in the back and limit its mobility. What shows the CT of the spine:
- fractures;
- osteoporosis;
- deformation;
- osteochondrosis;
- hernia;
- change in the lumen of the spinal canal;
- destruction of vertebrae;
- abscesses;
- compression of the nerve roots of the spinal cord;
- arthritis of intervertebral joints;
- tumors;
- metastases from neighboring areas;
- hemorrhage;
- spondylosis;
- cracks in the vertebrae;
- scoliosis;
- rheumatic diseases;
- stenosis;
- inflammation;
- instability of vertebrae;
- myelopathy;
- squeezing of blood vessels.
Computer tomography of the sinuses of the nose
The procedure under consideration provides a thorough examination of all components of the upper respiratory tract:
- maxillary sinuses;
- frontal sinuses;
- latticed labyrinth;
- wedge-shaped cavities.
Computer tomography of the nose shows:
- etmoiditis;
- sinusitis;
- sinusitis;
- frontitis;
- sphenoiditis;
- tumors of mucous membranes of any quality;
- inflammatory processes;
- polyps;
- adenoids;
- deformities, fractures and other bone injuries;
- foreign objects;
- congenital anomalies of the structure.