1. Diffusion tensor imaging (DTI) of the brain in schizophrenic patients A new method of describing the structure of the brain is called diffusion tensor imaging (DTI). This image was created by medical professionals using diffusion tensor imaging when studying patients with schizophrenia. Diffusion tensor imaging images like this (which are presented differently than previous images) can reveal how brain tumors affect nerve cell connections and guide medical staff in brain surgery. Diffusion tensor imaging is actually a special form of magnetic resonance imaging (MRI). For example, if MRI tracks hydrogen atoms in water molecules, diffusion tensor imaging maps water molecules based on their direction of movement. Nerve cell fibers are long and thin, and molecules typically diffuse along nerve cell fibers. Researchers can highlight areas where water molecules and groups of nerve cell fibers are running in the same direction. Diffusion tensor imaging maps like this (presented differently than previous images) could reveal how brain tumors affect nerve cell connections and guide medical personnel in brain surgery. It can also reveal subtle anomalous changes associated with stroke, multiple sclerosis, schizophrenia, and dyslexia. 2. MRI Under the MRI instrument, the patient lies inside a cylindrical magnet and is exposed to a powerful magnetic field. Once exposed to the magnetic field, the protons of the water molecules line up, and if they are attacked by radio waves, they immediately become disorganized and out of alignment. As the protons rearrange themselves, the computer collects their signals and processes them into images. Water-rich tissue emits a stronger signal and appears brighter in the resulting image, while bone is relatively dark. This technique is used here to describe the brain and carotid arteries. After the imaging agent for contrast is injected, radiologists repeat the scan, at which point the imaging agent moves through the blood vessels, allowing them to see clearly the blockages that cause strokes, brain aneurysms and various traumas. Bright areas at the spinal canal and brain indicate cerebrospinal fluid. MRI is also often used for neuroimaging. The bright areas at the spinal canal and brain represent the cerebrospinal fluid; the long strips extending down the body are the spinal cord. 3, X-ray angiography X-ray angiography allows the hand so small blood vessels are presented. The image quality generated by this latest digital detector allows radiologists to see the subtleties of the organ without the use of high doses of radiation. This image shows the immediate effects of hand trauma – no blood flowing to the fourth finger, while the small blood vessels in the other fingers are clearly visible. Creating useful medical images involves two main steps: first, gathering data, and second, converting that data into images that can be quickly and accurately interpreted. This image, generated by an advanced X-ray technique called X-ray tomography (CT for short), highlights advances in both of these areas. Body mapping software combined with CT angiography allows identification of abnormalities in the aorta (the large pink blood vessel that extends from the top of the image to the lower part of the body, around the heart) near the heart. Further down, the liver (purple) and kidneys (bright red) can be clearly seen. Accurate determination of the aortic diameter is critical because surgeons can use it to determine whether the aorta is at risk of rupture. 4, CT angiography For the CT angiography used here to visualize the pelvis, the imaging agent is injected into the vein to contrast the blood vessels with the soft tissue. Computer software can further highlight the difference between bone and blood vessels, allowing the doctor to make a clearer and faster diagnosis. The two hands in this image are the result of an autopsy scan. Typically, CT uses one X-ray source, but researchers can combine two X-ray sources of different energies to present soft tissue more clearly. Depending on the fact that specific tissues (such as the tendons and ligaments in the two hands pictured) absorb different amounts of energy, the instrument can highlight their images. To test the accuracy of this presentation, the researchers scanned the cadavers and compared the results with their “virtual” findings. The two hands in this image are the results of the autopsy scans. Of course, the main goal of CT technology is to improve health, but there is also the possibility of using it for virtual autopsies. As part of a forensic examination, CT scans like this can reveal the path of objects such as pocket knives. 5. positron emission tomography (PET) While many medical imaging techniques focus on anatomical structures, positron emission tomography (PET) is different: the images generated by this technique highlight cellular activity. The doctor first injects the patient with a radioactive tracer, and then the cells that absorb the most tracer emit a bright light. The tracer in this image is glucose. Cancer cells grow and divide rapidly, so they use a lot of energy and absorb glucose. The red color indicates that the patient has problems with the liver and shoulders. The brain and heart (the C-shaped red block is the heart muscle wall, the myocardial layer) also consume a lot of energy and so are also shown. the combination of both the PET scan and the CT scan is able to highlight the body structures in the figure. Figure 1 is a PET scan, Figure 2 is a CT scan, and Figure 3 is a combination of a PET scan and a CT scan, which allows the doctor to see more accurately what is wrong. As with MRI, the positron emission layer scanner can acquire data in multiple planes. In each of these three images, only one “slice” is shown, and by combining all of these slices, a three-dimensional image can be created. PET technology is most commonly used in oncology, but is also used in cardiology and neurology. GEHealthcare, the manufacturer of the instrument that generates this image, has introduced two systems to help researchers explore new clinical applications. According to Bruce Hillman of the American College of Radiology, PET is typical of a range of new tools used to monitor human cells and sub-cells because of the ability to monitor cellular function.