Biology & Technology

CT which stands for Computed Tomography scan is a medical imagining method that uses computer processed X-rays to produce tomographic images or slices of specific areas of the human body. This scanner emits narrow beams through the human body as it moves through an arc. Inside of the scanner there's X-rays detector that can see tissues in a solid organ and different levels of densities. Then it sends  the data to the computer and the final 3-D picture full of details is made.CT scan is used in medicine for detecting chronic changes in the lung parenchyma and for showing structural changes in the brain (for example: structural changes due to a brain tumour). The case of Janet: after Janet's death doctors found out by using CT scan that a reason why she blew out the candles only on the right side of the cake and why she often used only the  right side of the page is due to brain tumour that damaged only one side of her.

Positron emission tomography (PET) is a nuclear medical imaging technique that requires the injection of a radioactive substance into the person. This radioactive substance which is usually a form of sugar, produces gamma rays as they are metabolized by the brain. The parts of the brain metabolize the sugar at different rates according to how much active they are.The gamma rays are detected by the machine in which the participant is placed and then the signal is turned into a computer image that shows the activity in different parts of the brain. PET is used for showing a dynamic image of the brain activity and it's a helpful diagnostic tool that can show abnormalities in activity levels. When someone has Alzheimer's disease, PET is able to show doctors dramatic differences in the brain structure when the disease has progressed and then it can easier explain the person's behavior.

fMRI or, in other words, functional magnetic resonance imaging is a procedure that measures brain activity by detecting the changes in blood flow. fMRI is based on the discovery that when the body is exposed to a strong magnetic field, the protons in the water inside of the body change their alignment. By using radio frequency fields, hydrogen atoms are changed so they can be detected by a scanner that eventually creates an image of a part of the body or the brain being studied. The image shows which parts of the brain are active while certain activities are being performed. It can be used to make a three-dimensional image of the brain as well. fMRI allows human behavior, thoughts and emotions to be correlated with brain activity as they happen. It helps us to understand the way certain parts of the brain function. fMRI is much flexible than original MRI and it's able to provide dynamic information.