Medical Neuroimaging: A Closer Look

This guide is for medical billing and coding.

Neuroimaging is discipline of medicine and neuroscience that uses various techniques to provide images of brain. The images can be either direct images or indirect structures. The technique is used to understand the function of the brain and to detect related medical condition. There are two ways of neuroimaging: structural and functional. Structural neuroimaging is used to view of the structure of the brain and functional imaging is used to diagnose a disease.

Computed Axial Tomography

Computed Axial Tomography (CAT) is a scanning method whereby X-rays are used to depict the internal structure of the brain. The images are taken from various directions. Computed Axial Tomography makes it possible to view brain injuries, especially swelling in parts of the brain. The method performs certain integral calculations to generate the images. The white region indicates the denser parts.

Diffuse Optical Imaging

The method uses rays close to infrared radiation for the generation of images. This form of imaging calculates the quantity of optical absorption of the hemoglobin to get the images. Diffuse Optical Imaging takes in the variation of absorption spectrum of blood. The detectors are made of optical fibers and the path of light is altered by scattering or absorption as it passes through the brain.

Electroencephalography

The method records the electric signals of the brain. Electrodes are placed on the scalp and the electrical activity of 20 to 40 minutes is recorded. It is used in the case of encephalopathy, epilepsy or brain death. Earlier, this method was used for diagnosis of tumors and stroke.

Event-related Optical Signal

It is a method in which infrared radiation is passed through optical fibers and the changes in the optical property of the active areas of brain are measured. Event-related Optical Signal uses the scattering property of neurons to estimate cellular activity. It is an inexpensive technique but it cannot probe deeper than a few centimeters.

Functional Magnetic Resonance Imaging

The method uses paramagnetic properties of hemoglobin to get images in different color patches. The images show activated and deactivated parts of the brains generated by the oxygenated and deoxygenated hemoglobin. The method is highly sensitive to the early changes in the brain caused by very low blood flow.

Magnetoencephalography

The method uses magnetic fields created by the electrical activities of brain to obtain the images. The magnetic field method has the advantage because it is not distorted by the surrounding environment so it can produce accurate results. Images of neural activities are produced by direct measurement and it is used by researchers to study the functions of various brain parts.

Magnetic Resonance Imaging

The method uses radio waves and magnetic fields to get 2D and 3D images of the brain. In the method, a large cylindrical magnet creates a magnetic field, which is created around the head of the patient. The detection mechanism is very precise and it can easily detect changes in the structure of brain over time.

Positron Emission Tomography

To get the images of brain from Positron Emission Tomography, certain chemical compounds, called radiotracer, are injected into the bloodstream of the patient. The chemicals used in the method are labeled with radioactive atoms and they are metabolically active. It generates multicolored 2 D and 3D images.

Single Photon Emission Computed Tomography

The method uses gamma rays to obtain 2D and 3D images of brain. The method is one of the preferred ways of brain imaging for epilepsy. It requires injection of the radioactive tracer and the images can be taken within thirty to sixty seconds. The major disadvantage of the method is the poor resolution of images.

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