Aunt Huang has liked to walk around the streets and alleys since she retired. She talks to this and that because she is helpful, cheerful, and knows how to chat, she has a very good relationship with her neighbors.
On a day, Aunt Huang just came out of home and was about to go for a walk downstairs, when she happened to meet Aunt Zhang who came back from outside. Seeing that Aunt Zhang was full of unhappiness, she hurried up to ask what happened and if there was any place she could help.
Aunt Zhang shook her head and said, "It's not a big deal, it's just that she feels uncomfortable recently. . She wanted to go to the hospital this morning to check what's wrong with it." But after a series of examinations by the doctor, she told her that she was very healthy and there was no problem.
But Aunt Zhang really felt uncomfortable. She heard that there is a magnetic resonance examination method that can be checked very carefully. She wanted the doctor to check it for her, but the doctor told her that there was no need for . Aunt Zhang felt that the doctor thought it was troublesome and didn't want to give her a checkup, so she came back directly.
Aunt Huang also found it strange after hearing this. Why doesn’t the doctor recommend Aunt Zhang to undergo magnetic resonance examination? She decided to ask her doctor friend. After hearing this, the friend smiled and said, "This is not a fault for the doctor." is for another reason."
Today, I will talk to you about "two and three things" about magnetic resonance through this article.
Understanding magnetic resonance: development and principles
magnetic resonance examination is believed to be familiar to everyone. Many people have more or less heard of this word, but if you ask them what magnetic resonance is, they probably can't say one, two, and three. So, before answering the question why many doctors do not recommend patients to do magnetic resonance examination, I will first take you to learn about the development of and the principle of magnetic resonance.
magnetic resonance is also called nuclear magnetic resonance . It is a physical phenomenon caused by the interaction between wireless geomagnetic waves at lower frequency and other substances.
In the early 1940s, an American scientist, , rabbi . In a high-temperature evaporation experiment, accidentally discovered nuclear magnetic resonance phenomenon, but due to evaporation under high temperature conditions, the structure of the substance was damaged, so it will be limited in practical applications. Despite this, the scientist rabbi won the highest honor of scientists - Nobel Prize because of this accidental discovery.
In the days that followed, scientists from various countries began to study hard based on the discovery of rabbi. Only six years after the rabbi discovered the NMR phenomenon, another American scientist, Cyborg , found a steady-state NMR signal in a sample of paraffin . Immediately after a year, another scientist, , Bloch, also discovered a steady-state nuclear magnetic resonance phenomenon in water.
The discovery of the two of them has pushed nuclear magnetic resonance technology to the "highway" of development. At this point, nuclear magnetic resonance technology has been changing with each passing day, providing great help to medical, biological, geological and other aspects.
After more than half a century of development, nuclear magnetic resonance has now become a stable technology. Especially in the medical field, it has become one of the most common medical imaging technology, providing strong support for biophysiology and medical imaging . The principle of
NMR is that in the space where the human body is in the strong magnetic field , the hydrogen atom of the moisture in the human body will be excited by pulses, thereby generating the nuclear magnetic resonance phenomenon. Finally, the electromagnetic signal is obtained. After positioning and computer processing through the gradient field X, Y, and Z, an image will be formed on the display.
Therefore, nuclear magnetic resonance has subverted the traditional medical imaging examination technology, which can examine the human body in any direction, thus being widely used.In clinical practice, the MRI technology can conduct comprehensive examinations of brain, neck, chest, abdomen and other parts, and can often find abnormalities that cannot be detected by other technologies.
For example, the nuclear magnetic resonance technology detects diseases such as cerebral infarction and brain tumor than CT examination , and the image resolution it presents is also clearer than CT technology. Especially on the top of the head, brain stem, and other parts, the advantages of MRI technology will be more obvious.
In addition, the MRI technology is very sensitive to blood . It can also clearly display the blood vessels in the brain without using contrast agents, so that doctors can more accurately judge the patient's condition of the static artery in the brain.
When the MRI is used to check for chest, it can clearly detect whether the heart function is abnormal, whether the myocardium is damaged, etc. At the same time, nuclear magnetic resonance technology can also clearly show the relationship between aortic blood vessels and mediastinal mass, thus helping doctors make diagnosis well.
In addition, nuclear magnetic resonance technology also has certain value in lung examination . It can not only accurately display pulmonary edema , pulmonary embolism , etc., but also distinguish the properties of pleural effusion , and can easily distinguish lymph node and vascular cross-section.
Of course, for the urinary system, NMR examination also has its unique features. Take the complex renal cyst as an example. The positive rate of MRI examination is higher than that of color ultrasound in the urinary tract and enhanced CT from both kidneys.
I believe that through the above introduction to MRI technology, everyone has some understanding of it. In this way, I will answer the question of why many doctors do not recommend patients to undergo magnetic resonance examinations, which makes it much easier for everyone to understand.
Why do many doctors do not recommend patients undergo magnetic resonance examinations?
In the opening story, Aunt Zhang thought it was the doctor who thought it was troublesome and did not want to give her a checkup. In fact, this is not the case, because although nuclear magnetic resonance is good, it also has some shortcomings.
. The image speed is slow
Generally speaking, it takes to detect a part of 1.5T to for 20 to 30 minutes to to image, which does not count the time before the NMR check and placement. If the MRI test is still performed, then the contrast agent must be injected before the test, which will take more time to to .
This leads to the limited number of times the patient can perform MRI every day, so in general, if the doctor determines that there is no need for MRI, it is not recommended that the patient undergo MRI examination.
. The cost is expensive
In our lives, many patients may spend a lot of money to treat the disease, which leads to a huge financial burden. If you do some extremely expensive examination items at this time, it may be a bit worse for them. In addition, cheap CT check can replace NMR to a certain extent.
Therefore, when it is not necessary, doctors generally do not recommend patients to undergo MRI.
. It is not applicable to some people
From the above we learned that during the MRI examination, the human body is in a space with a strong magnetic field. However, there are now some patients, , which have metal objects implanted in their bodies. If he takes these metal objects for MRI, he may cause harm to his body due to magnetic pulling during the inspection. In severe cases, may endanger life and .
This is also one of the reasons why doctors generally do not recommend patients to undergo MRI.
It can be seen from this that because of the long time, high cost, and some people who are not suitable for MRI, many doctors generally do not recommend patients to undergo MRI. However, when we have to do MRI, what should we pay attention to in ? ? Let's continue to look down.
What should I pay attention to when doing magnetic resonance inspection?
Although after years of development, the MRI technology has now matured a lot and is widely used in the examination of many diseases, it still has certain limitations. Before or during the examination, we need to pay more attention to some matters to avoid affecting the accuracy of the examination or endangering our own physical health.
First, before the examination, you must repeatedly confirm that the patient does not carry the metal object on or in the body.
This is because there is a very powerful magnetic field in the NMR machine and the NMR examination room. If there is metal in the patient's body, it may move due to the attraction of the metal by the powerful magnetic field during the examination, which may even endanger life.
It should be noted here that with the continuous improvement of medicine in recent years, many orthopedic repair surgeries have used titanium alloy or titanium . Because this type of metal will not move arbitrarily within the magnetic field due to the interference of magnetic fields, and this type of metal will not affect the imaging of nuclear magnetic resonance. Therefore, such patients can undergo MRI.
Secondly, do not put on makeup .
Some cosmetics contain metals, which will react with magnetic fields, affecting the accuracy of the inspection results. Therefore, it is best not to put on makeup on the day of the examination, and to ensure the accuracy of the examination as much as possible so as to facilitate the doctor's diagnosis.
Finally, should be mentally prepared for the NMR test.
Because the examination takes a long time, some people with claustrophobia will feel impatient and scared during the examination. Don’t worry at this time, think carefully about the doctor’s words and cooperate patiently.
is written at the end
In short, in the field of medicine, although nuclear magnetic resonance technology has been widely used in screening of various diseases, it also has certain disadvantages of , which cannot be done by anyone who wants to do. If the patient's condition is not suitable or does not need to undergo an MRI, the doctor will not recommend the patient to do .
So when patients are seeing a doctor, they must listen to the doctor. Doctors must be concerned about the patient's health and will definitely not refuse to do a certain examination for the patient because they find it troublesome.
References:
[1] Zhuo Weidong, Wang Binhao, Chu Huimin. Advances in the application of technology in atrial fibrillation [J]. Chinese Journal of Cardiovascular Disease , 2020, 48(08): 706-709.
[2] Tan Jianhua. A brief analysis of the clinical application and its harms of MIR [J]. Electronic Journal of Cardiovascular Diseases in Integrated Traditional Chinese and Western Medicine , 2016, 4(34):119.DOI:10.16282/j.cnki.cn11-9336/r.2016.34.201.
[3] Ge Wei. Application of nuclear magnetic resonance method in medical examination and diagnosis [J]. World Latest Medical Information Abstracts, 2015, 15(81):26+29.
