In this blog post, we’ll explore the evolution of medical devices used for brain screening, the characteristics of each screening method, and future directions for development.
When people catch a cold or fall ill, they visit a doctor. This shows just how much people care about their health and how consistently they strive to live healthy lives. To meet these needs, the medical industry has continued to evolve, and medical technology has made tremendous strides alongside advancements in science and technology. In fact, as medical research has flourished and science and technology have advanced, treatments for various diseases have been developed, and the development of new drugs has also progressed rapidly. In particular, advancements in science and technology have driven the development of medical devices used to diagnose and treat the human body, and among these, the development of devices capable of analyzing the human brain with greater precision stands out as a particularly notable field.
The most basic method for examining the brain is an electroencephalogram (EEG). An EEG records the electrical signals generated by brain activity; simply put, it can be viewed as an indicator of the brain’s condition, much like a pulse or blood pressure. Just as a pulse or blood pressure outside the normal range may indicate a physical abnormality, EEG readings outside the normal range help determine whether there is an abnormality in the brain. An EEG is a representative non-invasive test method for assessing the brain’s spontaneous electrical activity; it records the electrical signals generated by the activation of neurons through electrodes attached to the scalp. Because it is the most basic test, it is useful when brain dysfunction is suspected or when a seizure has occurred or is suspected. However, since EEGs reflect only a portion of brain function, it is difficult to directly assess higher mental functions such as thought, emotion, and volition. In other words, it is a test well-suited for determining the overall activity of the brain, the level of arousal, and whether the patient is asleep or awake.
With advances in science and technology, imaging tests such as CT and MRI have also emerged. These medical devices are characterized by their ability to examine not only the brain’s basic functions but also its structure in greater detail. CT, or computed tomography, involves the patient undergoing a scan inside a circular machine that uses X-rays to produce cross-sectional images of the body. It is widely used, particularly for the rapid diagnosis of emergency conditions such as cerebral hemorrhage or skull fractures. On the other hand, an MRI is a test that uses strong magnetic fields and radio waves to obtain images of the body’s interior. Compared to CT, MRI offers superior visualization of soft tissues and higher resolution, making it advantageous for more precise diagnosis of brain disorders. In other words, both CT and MRI are examination methods that allow for a detailed examination of the brain’s structure. While an EEG is a test that measures the brain’s electrical activity, CT and MRI can be described as tests that assess the brain’s form and structure. However, because CT uses X-rays, it involves exposure to radiation; furthermore, both CT and MRI may require the use of contrast agents when necessary. Although contrast agents are mostly excreted from the body, side effects such as allergic reactions or impaired kidney function can occur in rare cases, so careful evaluation by medical staff is required before the test.
As such, an EEG is a non-invasive and highly safe method suitable for assessing the brain’s basic functional state. CT and MRI scans are effective for identifying structural abnormalities in the brain rather than its function. However, fMRI uses a slightly different approach. While an MRI is a test that visualizes the structure of human tissue, fMRI—or functional magnetic resonance imaging—is a method that can also detect brain activity. When neurons are activated, oxygen consumption increases in the corresponding region, leading to changes in the oxygen concentration in the blood. fMRI analyzes which brain regions perform specific functions by measuring these changes in blood flow and oxygen concentration. In other words, while MRI is a test that observes the structure of the brain and nervous system, fMRI is a test that examines their function and activity. Its most significant feature is that it goes beyond simply diagnosing abnormalities to visually identify the brain regions that become active while performing specific functions. For example, during the process of smelling, activity increases in brain regions associated with the sense of smell, and during processes such as remembering or thinking, one can observe the activation of relevant areas, including the frontal lobe. In other words, it is an imaging method that allows for the analysis of the relationship between actual human activity and brain function.
As such, there are various methods for examining the brain, and with advances in science and technology, these methods are becoming increasingly sophisticated and diverse. There are tests that assess basic brain functions, tests that examine brain structure, and tests that have been developed to analyze both structure and function simultaneously. Advances in science and technology have led to advancements in medical devices, which are contributing significantly to the early diagnosis of diseases and improvements in treatment standards. Of course, some tests still have side effects or limitations, and there are many areas of the human brain that have not yet been fully elucidated. Therefore, it is expected that medical devices used for brain screening will continue to evolve toward greater accuracy and safety in the future.
