A huge number of diseases and injuries can not be diagnosed only by the manifesting symptoms. Very often, patients who seek medical help are prescribed computed tomography (CT) and magnetic resonance imaging (MRI) scans. What are the named studies? Computed tomography or MRI - which is better? These issues are worth sorting out.
The essence of computed tomography
CT is a diagnostic method proposed in 1972. Scientists developed it due to the fact that conventional radiography had drawbacks. It allowed specialists in examining a particular patient to receive only one picture. Computed tomography has a lot of advantages. Firstly, thanks to this diagnostic method, you can get a number of pictures. Secondly, there are no shadow overlays on the images. Thirdly, CT has a higher sensitivity compared to conventional radiography.
Computed tomography is based on the use of x-rays. When using this diagnostic method, a special tomograph is used. This is a difficult software and hardware complex, which includes:
- gentry (the moving part of the apparatus containing scanning equipment);
- high voltage generator;
- operator console
- computing system.
Indications for computed tomography
CT is better than other techniques to visualize bone tissue. That is why this diagnostic method is used to identify various injuries and fractures in sick people. For example, a person turned to a doctor with a question: “Which is better - MRI or computed tomography of the spine?” If there is an injury, the specialist prescribes a CT scan. This study allows you to study the condition of the vertebrae, processes, intervertebral discs.
Computed tomography is also prescribed in the following cases:
- if you suspect a stroke;
- finding a person in serious condition;
- the presence of contraindications for MR imaging.
CT can be prescribed using a contrast agent. It is introduced into the body of the examined patient in order to improve the differentiation of internal organs from each other. The contrast agent also allows you to clarify the nature of the detected pathological structures and identify those changes that cannot be seen in a conventional study.
Contraindications to computed tomography
So, computed tomography or MRI - which is better? CT, like any other diagnostic method, has contraindications. A study carried out without contrast and with contrast is not prescribed:
- pregnant, because x-ray radiation negatively affects the fetus;
- too full people, because in the technical characteristics of tomographs there are indications of the maximum mass that the devices are able to withstand.
Computed tomography performed with the introduction of a contrast medium has additional contraindications. This is an allergy, and renal failure, and various thyroid diseases, and severe diabetes mellitus, and myeloma, and the serious condition of the patient being examined.
What is magnetic resonance imaging?
Another diagnostic method is MRI. This survey method was founded in 1973. Computed tomography or MRI - which is better? Answering this question, we can distinguish several advantages of magnetic resonance imaging over CT:
- excellent resolution;
- the possibility of obtaining slices in various planes;
- high contrast images.
The main advantage of magnetic resonance imaging is that there is no gamma ray exposure to the person being examined. This is explained by the fact that MRI is based on the phenomenon of nuclear magnetic resonance, and not on x-ray radiation. For magnetic resonance imaging, completely different tomographs are used. MRI devices consist of magnets, gradient, shim and RF coils, cooling systems, data reception, transmission and processing systems, shielding systems.
Indications for magnetic resonance imaging
MRI is given to people when indicated. These include:
- various inflammatory processes;
- congenital diseases, developmental abnormalities;
- injuries
- vascular disorders;
- neoplasms.
Computed tomography or MRI - which is better for detecting tumors? This question is asked by many people. Magnetic resonance imaging perfectly visualizes soft tissue. Bone structures have absolutely no effect on the quality of the resulting images. That is why doctors with suspected neoplasms prescribe an MRI.
Contraindications to magnetic resonance imaging
When answering the question: "Computed tomography or MRI - which is better?" - It is worth noting that magnetic resonance imaging may also not be assigned to all people. The absolute contraindications of this diagnostic method include:
- the presence of fixed electronic devices;
- the presence in the body of metal foreign bodies;
- the presence of intracranial aneurysms, clipped with ferromagnetic material;
- the presence of tattoos on the body containing metallic compounds.
Relative contraindications are:
- early pregnancy;
- fear of confined spaces;
- severe pain that does not allow to remain motionless during the study;
- inappropriate behavior due to drug or alcohol intoxication;
- the need to monitor indicators of vital functions.
Appointment of CT and MRI: examples
Which diagnostic method is the most informative? Answering this question, you can not do without examples. A kidney examination may be considered . Computed tomography or MRI? What is better for the kidneys? With complicated acute inflammatory processes, the doctor prescribes an ultrasound. This primary diagnostic method allows you to evaluate the size of the kidneys, the structure of the parenchyma, the state of the perinephral fiber. To assess and detail the prevalence of inflammatory changes, computed tomography is prescribed.
If during the ultrasound examination a solid formation or complicated cyst is detected, then CT is performed with contrasting in order to clarify the diagnosis (contrast medium significantly increases the information content). With mixed results, magnetic resonance imaging is shown.
The next example is an examination of a person with suspected ischemic stroke. Computed tomography or MRI? What is better for the brain, assessing its condition with the named disease? Computed tomography is performed on the first day. It allows you to exclude hemorrhages. But with the help of MRI, this is impossible. Magnetic resonance imaging is highly informative only in the subacute (3-14 days) and chronic (more than 14 days) stages.
Thus, it is impossible to say unequivocally which of the diagnostic methods is the most informative. Computed tomography or MRI - which is better for the spine, kidneys, brain and other internal organs? The answer to this question is found by the doctor for each specific case. Both computed tomography and magnetic resonance imaging are two informative methods. The specialist always makes a choice between them, taking into account the clinical picture, the condition of the sick person, and the presence of diseases.