More often than not the PET scan technology is utilized to detect the presence of a brain tumor. But there is more to the tool than just recognizing Cancer. It can be used for:
- Internal injuries
- Bleeding in brain
- Infection detection
- Structural abnormalities inside the skull
Although a powerful invention, the device has limits which means at times, a pet scan brain tumor test is inclusive. In such circumstances, other medical tests are conducted such as X-Rays for a final diagnosis. But for the purpose of this writeup, we focus on only scanning technologies.
The Two Broad Types of Brain Scans
When loosely categorized there are only two kinds of technologies that can be used to scan the brain:
- computed tomography (CT)
- magnetic resonance imaging (MRI)
Within these two classes, there are numerous variations. Each kind is applied to detect and diagnose a different type of medical problem which device is wielded is dependent upon the symptoms the patient faces.
6 Varieties of Brain Imaging Tools
Every brain imaging technique has the same goal – to search for problems that are occurring inside the brain of a patient or view its activity. At present, there are six most often used methods to conduct the process.
- CT scan resorts to X-Ray for creating a picture of the brain. The actual device is a cylindrical apparatus which a sliding table on it. The patient lies on the table while an x-ray source moves in a semi-circle around the head of the person. The source is contained inside a tube. The image is created on the basis of differential absorption of the rays. As the beam passes through the brain, it is absorbed at different rates. While bone is good at it, air only takes in a small amount of x-ray, and soft tissue lies on the median. As a result, CT scans are great at creating an outline image of the brain but not apt for eliminating the structure of it.
- Functional Activity Testing
a) Functional magnetic resonance imaging is the method wielded when the activity of the brain has to be tested. The tool works by sensing the alterations in:
- oxygen level in the blood
- blood flow when neural activity occurs
- If the mind is active, then there is more flow of blood to it because it consumes more significant amounts of oxygen at this time.
Consequently, fMRI is perfect for creating activation maps that plot out the areas of the brain employed for specific cognitive functions.
b) Positron Emission Tomography is another application that is operated to check brain activity. In this technique, radioactive material is used. As the short-lived substance decays, it produces a positron. The PET scan brain machine recognizes this element. The higher the radioactivity, the more functional is the brain.
- Electrical Activity Testing
a) Magnetoencephalography is generally utilized in clinics and researches, but they are often helpful in aid surgeons to localize pathology. Analyzes use the technology to find what function each part of the brain processes and neurofeedback. To create an image, the MEG machine employs a gadget called SQUIDs that measure the magnetic field created via electrical movement in the brain.
b) Electroencephalography positions electrode on the scalp of a patient and then use them to create a map of mental electrical activity. EEG essentially traces the electrical signals that are produced by the neurons in any brain. It is one of the frequently applied technology because it is not invasive and is extremely sensitive. The technique can even pick a millisecond of cognitive activity. Furthermore, it is one of the rare few procedures that created a high temporal resolution, ie, precise measure with respect to time.
- Near-infrared spectroscopy puts into service infrared light which falls in the 700 to 900 nm spectrum. The light is shined on the brain from one side and measured as it emerges from the other. The level of oxygen in the blood present in mind defines the attenuation of the light which is a measure of the level of brain activity. NIRS is, therefore, an optical technique of scanning the brain.
The Necessity of Scanning Techniques
Besides the obvious need to spot Cancer, scanning techniques are beneficial for other ailments too. Let's say a patient has been suffering from painful but intermittent headaches for some time. A physical checkup fails to pinpoint the origin of it. Medication and other treatments do not cure pain.
A brain scan using one of the technologies explained above can detect the underlying issue. The image of the brain would be able to assist a physician in assessing the cause of a headache and thus help in medicating and resolving it.