The difference between MRI and CT of the brain: which is better?


  • Diagnostic features
  • Conclusion
  • MRI and CT are rapidly developing and improving, giving doctors new opportunities in the diagnosis of many diseases. Modern devices often compete for the leading position in the identification of pathology, and even doctors cannot come to a consensus on what study better.

    Presently, physicians all over the world MRI is recognized as the gold standard in the diagnosis of pathology of the brain, but there are some cases where the choice falls on the CT. Each method has its advantages and disadvantages, and restrictions apply. In order to understand when to prefer one of the methods you must determine what the difference between them.

    The principle of operation

    Despite the resemblance of computer and magnetic tomographs, there is a huge difference in the operating principle of the apparatus:

    • MRI receives and analyses information based on the second pulse of hydrogen protons in tissues when exposed to powerful electromagnetic fields. Method is completely safe for humans.
    • For the diagnosis CT scan uses x-rays which spiral to describe the human body, creating coherent tomography. Performing the procedure, the person receives a radiation dose.


    Because CT uses x-ray radiation, the method cannot be applied in pregnant women and it is better not to use for children. It is also not recommended to do some research one person for a short time.

    MRI is safe for pregnant women and children, but has its limitations:

    • claustrophobia and other diseases, if the patient cannot remain motionless inside the machine;
    • marked obesity;
    • the presence of metallic and electronic implants; implants of inert materials are not a contraindication to the study, but may affect the quality of images in the presence of non-removable metal constructions in the oral cavity, the radiologist will appreciate the ability to obtain reliable results;
    • young children study must be done under anesthesia, so the presence of contraindications to anesthesia, will also be a contraindication to the study.
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    Both methods for checking the state of the brain using a contrast agent. MRI is a salt of gadolinium for CT use x-ray contrasts. Allergic reactions and intolerance to contrast agents, are contraindications to the study. Thus, if the patient has absolute contraindications to one of the methods, the doctors can’t – appointed counterpart.


    Computed tomography

    • The procedure takes less time than MRI, and is better tolerated by patients in a serious condition.
    • The apparatus does not require a closed space – it is possible to examine patients with claustrophobia.
    • X-rays do not interact with the metals and electronic devices – to examine patients having pacemakers or metallic clips on blood vessels of the brain.
    • The design of the scanner allows to examine patients with a higher body weight.
    • Apparatus for CT is much cheaper, and therefore the procedure a CT scan is much more accessible, as it is equipped with computer tomography significantly more medical institutions.

    Magnetic resonance imaging

    The absence of radiation exposure allows you to study pregnant women and children, and you can take a test multiple times without risk to the health of the patient.

    Diagnostic features

    The diagnostic capability of the apparatus is difficult to compare, because both magnetic and computer tomography are significantly different resolving power depending on the generation of devices.

    MRI remains the leading method in the diagnosis of diseases of the brain and allows you to reveal any organic pathology of brain structures, even in the early stages of the disease. But with the help of modern computer tomograph can be seen as the most brain pathology, and often they can be replaced by magnetic resonance imaging.

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    Computed tomography is not rendering:

    • the area of ischemia in stroke in the first few days of the disease;
    • the lesions of multiple sclerosis;
    • hematoma and cerebral hemorrhage in the subacute and chronic stages;
    • other abnormal formations of small size.

    Both methods reveal:

    • acute hemorrhage and hematoma of the brain;

    • pockets of extensive ischemia after a stroke in the subacute and chronic stages;
    • large tumors;
    • obvious anomalies in the structure of the brain;
    • hydrocephalic syndrome (the change in size of the ventricular system, as well as the cavities between the meninges);
    • fractures of the skull;
    • the condition of the sinuses.


    Analyzing the features of MRI and CT you can make following conclusion that each has its place in the diagnosis of brain pathology. The decision about which procedure is better, takes the doctor, as he will interpret the results of the study.

    In the absence of contraindications to both methods, and with equal availability of vehicles, the preference, of course, MRI.

    Also it is better to do an MRI if study is important for the emergency treatment of for example, if you want to check which of the strokes happen on the patient: ischemic or hemorrhagic. Correct tactics, in this case, will save a man’s life.

    A competent doctor would not choose as the analogue of KT, if it is necessary to check whether the patient has multiple sclerosis.

    If the brain examination needs to be done to check for abnormalities of development, or to identify the cancer process, and to confirm hydrocephalic syndrome, then CT scan could be an alternative. Especially if the MRI is difficult, for example, the apparatus is not in the settlement where there lives the patient or the procedure can be done only in the paid center, which is undesirable for the patient.