Pros and cons of gamma ray imaging
Gamma imaging can obtain reliable porosity and saturation information in quite wide range of model size from couple centimeters to several meters. However designing a well calibrated system is a challenge and may take several days to achieve. Another concern is the acquisition time that can take up to one minute for capturing a single location with the plane size of 1 cm2. Therefore in bench scale scanning time will exceed hours and therefore studying steady state problems is impractical and presence of noises would be expected in the reconstructed model. Despite all these difficulties, the cost of running an experiment with this technology is relatively high compare to other available techniques.
2.3 Radio Waves
In terms of the electromagnetic spectrum, radio waves are slightly longer than infrared in the wide range of 10-2m to 105m, corresponding to frequencies from 300 GHz to as low as 3 kHz. The application of radio waves in imaging comes from the concept of nuclear magnetic resonance (NMR). NMR, a physical phenomenon utilized to investigate the molecular properties of matter with the use of the absorption of electromagnetic energy, is similar to VHF and UHF television broadcasts (60–1000 MHz) by the placing of atomic nuclei in a strong magnetic field. This concept can be implemented on many different scientific studies such as medical imaging. Since NMR does not have any harmful side effects on humans it has seen an increase in laboratory use. Commonly used NMR applications in contaminant transport imaging and environmental studies are discussed below.
Magnetic resonance imaging (MRI)
Magnetic resonance imaging (MRI), magnetic resonance tomography (MRT), or nuclear magnetic resonance ima...
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...he pore space of a packed bed of glass beads as they dissolved into a flowing aqueous phase at the pore-scale. The same study was performed in different media such as estuarine sediments (Reeves and Chudek, 2001), silica gel (Zhang et al., 2002), rock fractures (Becker et al., 2003), and organic-rich soil cores (Simpson et al., 2007). In water and NAPL distributions, hydrocarbons such as fluorinated NAPLS have been used to distinguish NAPL from water and air and enhance the imaging contrast and quality. This idea has been implemented in evaluation of water and NAPL saturations in heterogeneous media (Zhang, 2006); and NAPL dissolution under water flushing (Zhang et al., 2007, 2008a). Another application of this technique is on evaluation of surfactant-enhanced remediation (Zhang et al., 2008b). Examples of results and images from these studies are shown in figure X.
According to Helibron and Seidel (2011) nuclear medicine began as a simple experiment in the early twentieth century by George de Hevesy. De Hevesy started the experiment by deciding to test the effects of radiation on living things, beginning with bean plants, then onto furred animals, and then continued onto finding the effects of radiation on the human body, when he did this he became the first person to ever use radiation on a human being. He along with his partner E. Hofer, in 1931, consumed Deuterium which they had diluted with tea and found that traces of radioactivity stayed within their bodies for between eight to eighteen days. This was the first known use of radiation on humans (p. 1). This was just the beginning though, as time moved on the use of nuclear energy advanced and as it advanced it began to bleed into more subjects than those that it had been used in before, such as, nuclear medicine. Although it has its drawbacks, such as nuclear waste, there are many different benefits to nuclear medicine. Examples of such would be advances in therapy and treatment of disease...
My interest in MRI started when I first read the book “MRI, The Basics” written by the author Ray Hashemi. By the time I successfully finished my MRI clinical placement in Tehran University of Medical Sciences, I knew for sure that MRI would be the field I would be choosing to take on. What attracts me most about MRI is how beautifully scientist could create a technology that can take advantage of the magnetic moments of human body for imaging it without any harms of ionizing radiation. Although there are drawbacks to MRI, combining it with other modalities would be a more effective approach to an accurate diagnosis.
The MRI, on the other hand is less expensive and much safer (as it doesn’t expose the patient to potentially harmful radioactive chemicals). The MRI or magnetic resonance imaging device, as an safer alternative, applies a powerful magnetic field around the head of the patient.
The role of the radiologist is one that has undergone numerous changes over the years and continues to evolve a rapid pace. Radiologists specialize in the diagnoses of disease through obtaining and interpreting medical images. There are a number of different devices and procedures at the disposal of a radiologist to aid him or her in these diagnoses’. Some images are obtained by using x-ray or other radioactive substances, others through the use of sound waves and the body’s natural magnetism. Another sector of radiology focuses on the treatment of certain diseases using radiation (RSNA). Due to vast clinical work and correlated studies, the radiologist may additionally sub-specialize in various areas. Some of these sub-specialties include breast imaging, cardiovascular, Computed Tomography (CT), diagnostic radiology, emergency, gastrointestinal, genitourinary, Magnetic Resonance Imaging (MRI), musculoskeletal, neuroradiology, nuclear medicine, pediatric radiology, radiobiology, and Ultrasound (Schenter). After spending a vast amount of time on research and going to internship at the hospital, I have come to realize that my passion in science has greatly intensified. Furthermore, both experiences helped to shape up my future goals more prominently than before, which is coupled with the fact that I have now established a profound interest in radiology, or rather nuclear medicine.
...ysis is required. The use of non selective detectors with gas samplers is also a good selective technique to measure ammonia accurately. Table 1 (Timmer et al., 2005) summarizes all the parameters of different types of sensors used for the detection of ammonia. In the methodology section plan of experiments using sensors to detect ammonia in water will be presented. However there are two methods described by the EPA to detect ammonia in water bodies. The first method (Method 350.1) is the distillation method in which the sample is first buffered and then is distilled into boric acid. The ammonia concentration is directly proportional to the indophenol blue which is formed (SEMI, 1993). In the second EPA method (Method 350.2) the sample is distilled into boric acid and the ammonia concentration is determined either titrimetrically or colorimetrically (SEMI, 1993) .
Dubey, R.B., et al. “The Current CAD and PACS Technologies in Medical Imaging.” International Journal of Applied Engineering Research 4.8 (2009): 1439-1456. Academic Search Complete. Web. 20 Feb. 2011.
The machine is a 100% accurate method of disease detection throughout the body and is most often used after other testing methods have failed to provide sufficient information to confirm a patient’s diagnosis. According to journalist Mary Bellis, two brilliant men Felix Block of Stanford University and Edward Purcell of Harvard University discovered MRI in the 1930s. Because of their discoveries they used nuclear magnetic resonance (NMR) to study composition of chem...
Nearly every medical facility has an X-Ray machine. These machines give an outline of you bones and organs using X-rays. People argue the pros and cons of using X-rays.
Electron microscope is a powerful tool that enables the study of particles in nanometer range.
Nuclear Medicine is the use of radioisotopes for diagnosis, treatment, and research. Radioactive chemical tracers emit gamma rays which provides diagnostic information about a person's anatomy and the functioning of specific organs. Radioisotopes are also utilizes in treatments of diseases such as cancer. It is estimated that approximately one in two people in Western countries are likely to experience the benefits of nuclear medicine in their lifetime.
During the late 1970's, the world of diagnostic imaging changed drastically due to the introduction of Magnetic Resonance Imaging, also known as MRI. For over 30 years, they have grown to become one of the most significant imaging modalities found in the hospitals and clinics ("EDUCATIONAL OBJECTIVES AND FACULTY INFORMATION"). During its ancient days, these machines were referred to as NMRI machines or, “Nuclear Magnetic Resonance Imaging.” The term “nuclear” comes from the fact that the machine has the capability of imaging an atom's nucleus. Eventually, the term was dropped and replaced with just MRI, because “nuclear” did not sit well with the public view ("EDUCATIONAL OBJECTIVES AND FACULTY INFORMATION"). Many people interpreted the machine to produce an excess amount of radiation in comparison to the traditional X-ray machine. What many of them were unaware of, MRI does not disperse a single ounce of ionizing radiation making it one of the safest diagnostic imaging machine available to this date. MRI machines actually use strong magnetic fields and radio waves to produce high quality images consisting of precise details that cannot be seen on CT (Computed Tomography) or X-ray. The MRI magnet is capable of fabricating large and stable magnetic fields making it the most important and biggest component of MRI. The magnet in an MRI machine is measured on a unit called Tesla. While regular magnets commonly use a unit called gauss (1 Tesla = 10,000 gauss). Compared to Earth's magnetic field (0.5 gauss), the magnet in MRI is about 0.5 to 3.0 tesla range meaning it is immensely strong. The powerful magnetic fields of the machine has the ability to pull on any iron-containing objects and may cause them to abruptly move with great for...
Radiology technology is a science of using radiation to produce images. There are many jobs you can perform in diagnostic imaging usually a radiologic technologist will oft...
This can be further illustrated by our inability to detect radio waves which are passing through our bodies and homes continuously. A radio receptor found in the simplest radio devices, have...
The city of Berkeley passed a law that goes into the effect of cell phones. (Hill) So people are talking about how the RF waves have like a little microwave in the cell phones so they give off a little bit of radiation in the cell phones because the more you use the cell phone the more radiation you can have and when it happens to little kids because their tissue in their brain are very thin in which they can get brain tumors when using a cell phones. (Hill) He found that about 50 percent of the 326 studies showed a biological effect when the radio-frequency radiation but people found the the wireless industry he found the split was 70 - 30. (Hill) Lab studies usually expose animals to something like RF energy to see if it causes tumors or other health problems. (American Cancer Society) Researchers might also expose normal cells in a lab dish to RF energy to see if it causes the types of changes that are seen in cancer cells. (American Cancer Society) A large study now being done by the US National Toxicology Program should help address some of the questions about whether exposure to RF energy could lead to health issues. Researchers will expose large groups of lab mice and rats to RF energy for several hours a day for up to 2 years and follow (observe) the animals from birth to old
Gamma cameras and Single Photon emission computerized Tomography (SPECT) scanners are used for planer and tomographic imaging of gamma