Nuclear magnetic resonance imaging (NMR) is an advanced medical imaging technology that uses magnetic fields and radio frequency waves to resonate hydrogen nuclei in the human body, thereby obtaining detailed information about the internal structure and function of the human body.
With its high resolution, non-invasive and multi-parameter imaging, magnetic resonance imaging has become an indispensable tool in modern medical diagnosis.
The principles of NMR are quite profound, and they involve the basic principles of quantum mechanics and physics. Under the action of a strong magnetic field, the hydrogen nuclei in the human body undergo energy level splitting, and when radio frequency waves act on these nuclei, they absorb energy and jump from a lower energy level to a higher energy level.
When the RF waves stop, these nuclei release energy and return to lower energy levels, releasing RF signals at the same time. These signals are received and processed by a computer to form the NMR images we see.
MRI technology is widely used in the medical field and can be used to examine the anatomy of various parts of the human body, such as the brain, spine, joints, etc.
In the fields of nervous system diseases, tumors, cardiovascular diseases, etc., magnetic resonance imaging technology plays an important role. In addition, with the continuous advancement of technology, NMR technology has also made significant progress in functional imaging and molecular imaging, providing more powerful support for medical research and clinical practice.
01
Why don't you try to do "magnetic resonance"? Many people still don't understand, or it's related to the 4 points
First of all, the duration of the MRI is comparatively longer. Compared to conventional X-rays or ultrasonography, MRI usually takes tens of minutes or even longer.
This requires patients to remain still in a small space, which is undoubtedly a challenge for many people. Especially for those patients who are prone to anxiety or discomfort, prolonged examinations can bring unnecessary psychological stress.
Second, MRI is not available for all people. Patients with metal implants such as pacemakers and cochlear implants, as well as people with metal objects such as keys, cell phones, etc., are not suitable for MRI due to the influence of magnetic fields. In addition, pregnant women in the first trimester of pregnancy should also be cautious because of the potential effects that magnetic fields can have on the fetus.
In addition, the cost of MRI is relatively high. MRI is usually more expensive than some routine imaging tests. This not only increases the economic burden of patients, but also limits its wide application in clinical practice to a certain extent.
Finally, while MRI can provide a wealth of diagnostic information, not all conditions are suitable for MRI diagnosis. In some cases, other imaging tests (eg, CT, ultrasound) may be more appropriate.
Therefore, when choosing whether to undergo an MRI, doctors need to consider the patient's condition, financial situation, and other relevant factors.
02
When do I need an MRI?
First of all, when patients have neurological diseases, such as brain tumor, cerebral infarction, cerebral hemorrhage, cerebral atrophy, hydrocephalus, encephalitis, brain abscess, cerebrovascular malformation, cerebral aneurysm, epilepsy, Parkinson's disease, demyelinating disease, central nervous system infection, etc., MRI can clearly display the brain structure and lesions with its high-precision and high-resolution characteristics, and provide doctors with accurate diagnostic basis.
Secondly, in the field of orthopedics, MRI is also an indispensable diagnostic tool. It can not only detect intra-articular cartilage, ligaments, synovium, bursa, tendons, muscles and bone marrow, but also accurately diagnose avascular necrosis of the femoral head, meniscus and cruciate ligament injuries of the knee. Its unique imaging method makes it impossible to hide subtle lesions inside the joints.
In addition, MRI also has significant advantages in the diagnosis of abdominal diseases. Whether it is lesions of solid organs such as liver, gallbladder, pancreas, spleen, kidney, etc., or lesions in the abdominal cavity and retroperitoneal space, MRI can provide doctors with detailed lesion information with its excellent soft tissue resolution and multi-directional imaging characteristics.
In addition, in the field of gynecology and obstetrics, NMR also plays an important role. It can clearly show the structure and lesions of female pelvic organs, such as uterus, ovaries, fallopian tubes, etc., and is of great value for the diagnosis of pelvic tumors, endometriosis and other diseases.
At the same time, MRI can also provide important help in the diagnosis of obstetric problems such as congenital developmental abnormalities of the fetus and placenta accreta.
03
What is the difference between an MRI and a CT scan?
Magnetic resonance imaging (MRI), also known as MRI, is based on the magnetic resonance phenomenon of atomic nuclei to obtain detailed information about the internal tissue structure of the human body through a strong magnetic field and radiofrequency pulses.
The advantage of MRI is that it has a very high resolution of soft tissues, and can clearly show subtle changes in the structure of tissues such as brain, muscles, and joints. In addition, there is no need to use radioactive materials during MRI examinations, so there is no radiation damage to the human body.
However, MRI is expensive and time-consuming, and is not suitable for some patients with metal objects implanted in the body, such as pacemaker carriers.
In contrast, CT scanning, or computed tomography, uses X-rays and computer technology to obtain tomographic images of different parts of the body through rotating X-ray sources and detectors.
CT examination has the characteristics of fast scanning speed, high image resolution, and wide range of application. CT examination plays an important role in the rapid diagnosis of diseases such as cerebral hemorrhage and fractures in emergency situations.
However, the X-rays used in CT scans have some radiation damage to the human body, and although this damage is within reasonable limits, it is still a cause for concern.
04
Is there any radiation when doing magnetic resonance?
Magnetic resonance imaging is fundamentally different from what people often call X-ray, CT and other radiological imaging techniques. Magnetic resonance technology does not rely on radiation to imaging, so the fear of radiation is eliminated at the source.
It uses magnetic fields and radio frequency pulses to capture the movement of hydrogen nuclei in the human body in the magnetic field, and then constructs an image of the structure inside the human body.
Specifically, a magnetic resonance device creates a powerful magnetic field and sends radio frequency pulses within this magnetic field. When these pulses meet the nuclei of hydrogen atoms in the human body, they create a resonance effect that subsequently releases energy. This released energy is captured by the device and converted into an image that reveals the detailed structure of the human body.
Since magnetic resonance imaging does not rely on radiation, it does not cause any radiation damage to the human body. At the same time, MRI can also provide high-resolution images, which is of great value for the diagnosis of many diseases. Whether it's the brain, spine, muscles, or other parts of the body, MRI provides detailed and accurate diagnostic information.