Nt1310 Lab Report Material

MRI provides both anatomic and physiologic information. It is the modality of choice when cartilage, nerves, or organs are of interest. Magnetic resonance imaging does not give off any ionizing radiation. Instead, the magnetic force reacts with the hydrogen in our bodies to show the images. Because of this fact, it is the least harmful to the patient.

Magnetic resonance imaging (MRI) - This technique uses a magnetic field and radio waves to create detailed images in cross section of the brain. The MRI machine allows producing 3-D images that can be viewed from different angles.

Magnetic Resonance Imaging (MRI) is a way of medically imaging the body with the use of a magnetic field and radiofrequency waves. (1) As image quality of MRI continues to improve, more MRI exams are being ordered. Increasing MRI exams leads to increased wait times. Due to current wait lists, the health status of patients may decrease, influencing the type of treatment the patient will require once removed from the wait list. (7) The advances in technology have increased in the past decade, with MRI procedures are vastly growing to provide superior diagnostic quality compared to other modalities. New technologies are also allowing for faster scan times and further increased image quality. (9)

“This MRI machine, or magnetic resonance imaging machine, is the most advanced and safest way to produce a magnetic image of the human body. Strong magnetic waves align the patients hydrogen atoms within the bodily tissues and cause them to vibrate and point in the same direction. Radio wave frequencies then disturb the hydrogen atoms so that they return to their natural randomized order. The imaging part of the machine then records and translates the data onto this screen here so that we are able to examine the patient’s brain, spine, soft tissues,and joints, which are the most common uses for an MRI (Sternlof). Why are we able to determine where the cancer or the tumor is by the image that is produced?” I asked. I was curious if anyone was slightly familiar with the information I had been talking about. A tall, brown haired man in the back of the

A key property is the spin of the proton. The spin of a proton is expressed in ± k (1/2), where k is a coefficient. During the NMR process, an external magnetic field is applied on the protons, partially polarizing them. This will cause them to all align in the same orientation, around the magnetic field direction, as it is the easiest to maintain that position. This is called the Minimum Magnetic Potential Energy. Its other spin state is its high energy spin state, where it spins in the opposite direction around the magnetic field.

In the medical world, there are several imaging modalities that are being used in order to diagnose various pathologies. This research paper will talk about some of these different imaging ways, as well as how an MRI functions in detail.

It all started with Dr. Garnette Sutherland, Professor of Neurosurgery (Faculty of Medicine, University of Calgary) asking “Wouldn’t it be great if we could continue to operate while images are being taken, in the bore of the magnet?”

Visual inspection of the MRI image is used to determine intensity thresholds or the fatty, fibroglandular, and transition regions in the histogram of Fig. 2(b). The intensity at which the local peak occurs within the higher end of the intensity spectrum of Fig. 2(b) is mapped to the median Debye parameters chosen for fatty tissue. The maximum pixel intensity within this fatty region of the histogram is mapped to the minimum fatty tissue Debye parameters, and the minimum fatty tissue pixel intensity is mapped to the maximum fatty tissue Debye parameters. The same process is applied to the fibroglandular tissue region clustered at the lower end of the pixel intensity spectrum. Pixel intensities within the transition region are mapped to Debye parameters that span the range between the fatty maximum and fibroglandular minimum. Fig. 3(b) shows a histogram of the resulting dielectric constant at 6 GHz when the median Debye parameters are assigned the values listed in Table I for fatty and fibroglandular tissue and the variation about each of the two medians is chosen to be

The spatial resolution is 1.0 mm, and the temporal resolution is usual several seconds. All useful planes of images including axial, sagittal, and coronal planes can be used to visualize the morphology and function of the segment of the body being visualized since MRI scanners can detect motion. This makes MRI particularly useful for a wide variety of diagnoses of disorders throughout the entire body. MRI does not use ionizing radiation to generate images. However, MRI can be prohibitively expensive for patients and take several hours to complete.

Magnetic resonance imaging (MRI) is a technique that uses a magnetic field and radio waves to create detailed images of the organs and tissues within your body. MRIs are largely used in the medical field today because of their ability to create detailed images of the human body which can be used for diagnostic purposes. In 1971 a paper in the journal Science Raymond Damadian, an American physician and professor at the Downstate Medical Center State University of New York reported that tumors and normal tissue can be distinguished by nuclear magnetic resonance (NMR). He suggested that these differences could be used to diagnose cancer, though later research would find that these differences, while real, aren’t consistent enough for diagnostic purposes. Damadian 's initial methods were flawed for practical use, relying on a point-by-point scan of the entire body and using relaxation rates of the tissue in your body, which turned out not to be an effective indicator of cancerous tissue.

The human body consists of 70% of water. Water molecule composes of two hydrogen atoms and one oxygen atom. The MRI machine can only detect hydrogen nuclei to compose an image. Hydrogen nuclei have a quantum physic property which is called “spin” that can be oriented in a certain way although they do not spin. However, the MRI machine has to use a strong magnetic field to detect the presence of the hydrogen nuclei. A strong magnetic field makes the “spin” to line-up along the magnetic field direction. Yet, some hydrogen nuclei line up in the direction of the magnetic field and some are not. The hydrogen nuclei with low energy are in the same direction of the magnetic field and the hydrogen nuclei with high energy are in the opposite direction

Magnetic resonance imaging (MRI) is a sophisticated computerized imaging technique, which has been a clinical diagnostic tool since 1980. MRI is used to create images with extraordinary detail of the body or brain by applying nuclear magnetic resonance phenomena. The distribution of hydrogen nuclei (protons), found in cellular water, depends on the tissue type and whether or not the tissue is healthy or diseased. MRI measures and records changes in the magnetic properties of these protons. The MRI technique uses a strong magnetic field, pulsed electromagnetic fields known as gradients, and radio waves to excite the protons and produce the image in the region of interest. The image is produced then displayed on a gray scale

In 1976, science and medicine effectively crossed paths to create the full-body magnetic resonance scanner. This groundbreaking invention, completed by Dr. Raymond Damadian, turned out to be one of the most important discoveries in the history of medicine. Dr. Damadian’s scanner applied the principles of nuclear magnetic resonance to the human body for the first time, in order to detect cancerous cells in the body without the use of X-rays or surgery. Dr. Damadian’s first full-body scanner, named “Indomitable”, gave rise to the practice of magnetic resonance imaging (MRI) in all fields of medicine. Nuclear magnetic resonance imaging, which is often simply referred to as magnetic resonance imaging due to the negative connotations that are associated with “nuclear” (Kleinfield 224), uses a technique in which atoms absorb magnetic waves and then subsequently emit specific frequencies of waves that can be used to create images (Edelson). Dr. Damadian formulated the controversial idea of applying NMR to the human body at a much larger scale than ever before based on prior research that indicated that cancerous cells emit noticeably different levels of radiation than normal cells do.

Rather than using ionising radiation like the X-ray or CT scan, the MRI uses a strong magnetic field and radio waves to image both soft tissue and bone structures. The strong magnetic field is created by passing an electric current through wire coils located in the machine and around the body part being imaged. The body is made up of around 60% water, and water molecules contain hydrogen protons which become aligned in a magnetic field. Hydrogen protons are also abundant in fat, making them ideal for imaging purposes. The strong magnetic field from the MRI aligns the proton ‘spins’ – “The hydrogen proton can be likened to the planet earth, spinning on its axis, with a north-south pole. In this respect it behaves like a small bar magnet. Under normal circumstances, these hydrogen proton “bar magnets” spin in the body with their axes randomly aligned.” (Berger, 2002) Under the MRI’s strong magnetic field, the protons’ axes align, creating a magnetic vector oriented along the axis of the MRI machine. The machine also produces additional energy in the form of radio waves that redirect the uniformed alignment of the hydrogen protons. The protons absorb the energy from the radio frequency and flip their spins. When the radio frequency source is turned off, the protons gradually return to alignment, and the magnetic vector returns to its resting state. This causes a radio signal to be emitted that is measured by receivers in the machine and used to create an

MRIs work by measuring the electrons and protons by using magnets. MRI is good for soft portions of the organs but carry more noise. It provides much more contrast between the soft tissues. It provides clear pictures of the body parts that are close to bone tissue. It is more useful for brain and spinal cord. An MRI can take up to 30 minutes. MRI is used to examine a large variety of medical conditions from almost every angle with more detail.