Introduction: Today's medical technology means are changing with each passing day, and they are becoming more and more "smart", which has made people's way of seeing a doctor change dramatically.
The traditional pulse examination is gradually replaced by a variety of advanced machine examinations, especially for those internal diseases that are difficult to detect, magnetic resonance imaging technology has become a very important means of examination.
When people go to the hospital for a physical examination, the doctor usually prescribes a series of tests for them, and the tests will be different for different diseases.
However, among the many medical examinations, MRI examination seems to have become a topic of great concern, and doctors often advise patients to have as few MRIs as possible, why is this?
What diseases can MRI detect?
Magnetic resonance imaging (MRI) technology can help doctors examine and diagnose a wide range of diseases and conditions, and here are some of the most common diseases and conditions that can be examined and diagnosed with MRI:
tumor
MRI is a commonly used tumor examination method to help detect and localize tumors, assessing their size, shape, and location.
Fractures and osteomyelitis
MRI provides a good view of bone marrow, bones, and joints and can help detect fractures, osteomyelitis, and other bone lesions.
Neurological disorders
MRI can help to examine and diagnose neurological diseases of the brain and spine, such as stroke, brain tumor, multiple sclerosis, etc.
Problems with the spine and intervertebral discs
MRI can observe the condition of the spine and intervertebral discs, which can help diagnose problems such as herniated discs, spinal deformities, spinal cord compression, etc.
Cardiovascular disease
MRI can observe the structure and function of the heart and blood vessels, and is helpful in detecting cardiovascular diseases such as cardiac disease and coronary heart disease.
Other diseases
MRI can also be used to examine and diagnose kidney disease, liver lesions, breast disease, etc.
Does an MRI produce radiation?
MRIs usually do not produce radiation.
Nuclear magnetic resonance (NMR) is a medical imaging technique that produces magnetic resonance phenomena generated by hydrogen nuclei (i.e., hydrogen protons) in the human body under the action of specific radiofrequency pulses in a strong external magnetic field.
It does not irradiate the human body through ionizing radiation, so it does not produce radiation and is not damaged by radiation, and the patient is not damaged by radiation and does not cause harm to the body during an MRI examination.
However, it is important to note that although the MRI itself does not produce radiation, during the examination, the patient may experience discomfort such as dizziness, nausea, etc., due to the effects of the magnetic field.
Why is it advisable not to do "MRI"? Most people are kept in the dark, and there are four reasons related to this
Expensive
Considering the price factor, MRI is a high-precision medical examination technology, and its price is indeed more expensive than other routine tests, and doctors usually do not recommend patients for MRI unless it is necessary for the condition, because it is not necessary to perform MRI for unnecessary examination sites.
For most families, the cost of an MRI is indeed a significant expense, and many families with modest incomes find it difficult to afford such an expense.
However, doctors do not neglect the patient's health because of the cost, and they will reasonably recommend the necessary tests according to the patient's condition and needs to avoid delaying the condition.
Some organs are not suitable
Magnetic resonance imaging (MRI) is a diagnostic test that detects the amount of hydrogen atoms in the body, and the distribution and content of hydrogen atoms in the human body are essential for accurately determining the condition.
When the number of hydrogen atoms is sufficient, the inspection data will be more accurate and reliable, but it is worth noting that magnetic resonance examination is not a panacea, it has certain requirements for the object to be examined.
For organs with low water content, such as the heart and intestines, MRI may not be the best option, mainly because hydrogen atoms are relatively low in tissues with low water content, which can affect the accuracy of the results.
Affected by metallic substances
For people who have a pacemaker or have metal clips or stents, doctors usually don't recommend an MRI. This is because the magnetic field generated by the NMR machine and the examination chamber is very strong, strong enough to exert a strong attraction on a metal object.
During an MRI, metal objects in the patient's body are affected by a magnetic field and are likely to move.
This movement may not only cause serious consequences to the patient, such as organ damage, blood vessel rupture, etc., but may even bring fatal dangers, so the doctor's safety consideration for such patients takes precedence over the diagnostic value of MRI examination.
It takes a long time
In the current medical field, MRI examination is widely used in the diagnosis of various diseases with its high-tech characteristics, compared with traditional CT examination, MRI examination takes significantly longer, generally takes 15-30 minutes to examine a site, while ordinary CT examination only takes 2-5 minutes.
This difference in timing makes MRI not suitable for some emergency situations, where CT is the quicker option. CT is a commonly used imaging test that uses X-rays and computer technology to quickly produce images of the body's internal structures.
The advantage is that the examination time is short, usually only 2 minutes to complete, and it is ideal for emergencies that require quick access to diagnostic information. In addition, CT scans are of high diagnostic value for certain sites, such as the brain, chest, and abdomen.
What should I pay attention to when having an MRI?
Inform your doctor about your condition
Tell your doctor about your allergies, whether you have metal implants (such as pacemakers, artificial joints, etc.), whether you are pregnant or likely to become pregnant, and other important health information.
Remove metal objects
Since MRI uses a strong magnetic field, it is necessary to remove metal objects (such as jewelry, keys, coins, mobile phones, etc.) and hormonal patches from the body to avoid disturbing safety and image quality.
Guidance on taking medications
Follow your doctor's instructions to continue or pause specific medications as needed, some of which may interfere with MRI results or affect your health.
Holding bed rest
While performing the examination, remain calm and quiet, as movement or shaking may affect the image quality.
Relax your body
During the exam, relax your body and try not to feel nervous and anxious to get more accurate test results.
Who is MRI not suitable for?
People who have metal implants or foreign bodies in their bodies
MRI generates a strong magnetic field, and if there is a metal implant or foreign body in the body, it may be attracted or heated by the magnetic field, causing displacement, damage, or burns. For example, pacemakers, aneurysm clips, orthopedic nails, intraocular metallic foreign bodies, etc.
People who are allergic to contrast media
Some MRI examinations require the injection of a contrast agent, a compound containing gadolinium, which is safe for most people, but a few people may be allergic to it, experiencing reactions such as skin redness, difficulty breathing, and a drop in blood pressure to enhance image contrast.
Pregnant women within three months of pregnancy
MRI exams produce radiofrequency waves that may adversely affect fetal development, so it is generally recommended that pregnant women within 3 months of pregnancy avoid MRI unless there is a special need.
People with claustrophobia or mental instability
An MRI needs to be done in a completely enclosed, dimly lit, noisy environment, which can be uncomfortable or panicked for people with claustrophobia or mental instability.
Critically ill patients with severe cardiopulmonary dysfunction or life-threatening conditions
MRI requires the patient to remain still, which may aggravate or affect the life of critically ill patients with severe cardiopulmonary dysfunction or life-threatening conditions.
Why do I sometimes have to do an MRI after a CT?
CT and MRI are two commonly used medical imaging methods, each with different advantages and limitations, and sometimes doctors will ask patients to have another MRI after CT for several reasons:
1. There are significant differences between CT and magnetic resonance in imaging principles
CT mainly uses X-ray imaging, which can well show the structure of bones, lungs and other tissues, but it is not ideal for soft tissues such as muscles and nerves.
Magnetic resonance imaging (MRI), on the other hand, uses magnetic fields and radiofrequency pulses to clearly visualize soft tissue structures, so it is better in some cases, such as when examining neurological, muscle, or soft tissue tumors.
2. The focus of CT and magnetic resonance examination is different
CT is fast and is very suitable for cases that require rapid diagnosis such as acute chest pain and stroke, while magnetic resonance imaging is of high quality, and for some chronic diseases or conditions that require more accurate diagnosis, such as tumor staging, brain lesions, etc., doctors may require magnetic resonance examination.
3. Different diseases may require different imaging methods
For example, CT is the preferred test for fractures or lung disease, while magnetic resonance imaging may be more appropriate for brain disease or soft tissue lesions, so doctors will perform different imaging tests depending on the patient's specific situation and needs.
Read more: What is the difference between magnetic resonance and CT?
Magnetic resonance imaging (MRI) and CT (CT) are two commonly used medical imaging techniques, and they differ significantly in many ways.
First of all, in terms of imaging principle, magnetic resonance is to excite the hydrogen nuclei in the human body through magnetic fields and radio frequency pulses, generate resonance and release energy, and then receive these energies and display them in the form of images. CT, on the other hand, scans the human body with X-rays and processes the data by a computer to reconstruct tomography images.
Secondly, from the perspective of imaging effect, magnetic resonance can provide multi-plane and multi-angle imaging, and the resolution of soft tissues is very high, so it is especially suitable for examining soft tissue structures such as muscles, joints, and nerves. CT, on the other hand, has a high density resolution and spatial resolution, and has a higher detection rate for hard tissue lesions such as fractures and calcifications.
In addition, in terms of examination time, MRI examination time is relatively long, generally taking about 10-30 minutes, while CT examination time is relatively short, usually between a few minutes and more than ten minutes. In addition, in terms of price, the cost of MRI equipment and examination are relatively high, while CT is relatively affordable.
Finally, from the perspective of safety, MRI does not have radiation and is therefore less harmful to the human body, but it should be noted that MRI is not suitable for people with metal implants or metal foreign bodies. CT scans, on the other hand, have a certain amount of radiation, but in order to diagnose the disease, doctors usually weigh the pros and cons and choose the appropriate examination method according to the patient's specific situation.