Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: When was the MRI invented?
Damadian's research into sodium and potassium in living cells led him to his first experiments with nuclear magnetic resonance (NMR) which caused him to first propose the MR body scanner in 1969. Damadian discovered that tumors and normal tissue can be distinguished in vivo by nuclear magnetic resonance (NMR) because of their prolonged relaxation times, both T1 (spin-lattice relaxation) or T2 (spin-spin relaxation). Damadian was the first to perform a full body scan of a human being in 1977 to diagnose cancer. Damadian invented an apparatus and method to use NMR safely and accurately to scan the human body, a method now well known as magnetic resonance imaging (MRI).[2]
Damadian has received several prizes. In 2001, the Lemelson-MIT Prize Program bestowed its $100,000 Lifetime Achievement Award on Damadian as "the man who invented the MRI scanner."[3] He went on to collaborate with Wilson Greatbach, one early developer of the implantable pacemaker, to develop an MRI-compatible pacemaker. The Franklin Institute in Philadelphia gave its recognition of Damadian's work on MRI with the Bower Award in Business Leadership.[4] He was also named Knights of Vartan 2003 "Man of the Year".[5] He received a National Medal of Technology in 1988 and was inducted in the National Inventors Hall of Fame in 1989.[6]
Soon after they have left Kesrith, Melein lays down a mandate that nothing that is not mri can make the return to the ancient mri homeworld. As a result, Duncan must become Mri or die. With Niun as his teacher, Duncan learns the stern rules of the Mri warrior caste, the Kel. Retracing the voyages of the Mri takes years, jump after jump, giving Duncan time to become Mri. With each jump, they find evidence of previous Mri civilizations, each one destroyed, further and further back in time. Eventually, they realize that this is not the first time that the Mri have been almost exterminated; in fact, the entire Mri history has been made up of the Mri fighting as mercenaries for other races, then being turned upon once their usefulness has ended, as the race(s) employing the Mri did not wish the possibility that the Mri might go and work for their enemies and be used against their former employers.
Damadian is the company's largest shareholder, with 8% of stock worth $6.5 million.[7] Despite owning only 8% of the stock, he maintains almost 100% control of the company through a separate class of shares (Class C) that only Damadian controls 2007.[28] Damadian later collaborated with Wilson Greatbatch, one early developer of the implantable pacemaker, to develop an MRI-compatible pacemaker. He invented a stand-up MRI system and has 15 MRI scanning centers across the United States. There are a number of independent MRI centers that use this technology both in the U.S. and around the world. The company conceived and built the world's first Upright Multi-Positional MRI, which was recognized as The Invention of the Year in 2007 by the Intellectual Properties Owners Association Education Foundation.[29]
The diagnostic performance of MRI in the detection of occult fractures has been shown to be comparable, or better than MDCT. Indeed, while the specificity of both CT and MRI for the diagnosis of fracture can be as high as 100%, the sensitivity was reported to be higher for MRI. The superiority of MRI over any other imaging modality including MDCT for the detection of occult hip fractures is now recognised. For instance, an occult intertrochanteric extension of a greater trochanter fracture can be most effectively appreciated on MRI Moreover, MRI is extremely helpful in detecting associated soft tissue abnormalities, especially ligamentous lesions. MRI is now considered as the standard in this context. However, because of its relative unavailability in emergency settings and high costs, MRI may only be performed in "high risk patients" with negative X-rays. For example, when a hip occult fracture is suspected, patients with reduced baseline mobility and pain on axial compression are considered at risk and, therefore, should be examined by MRI. MRI signs of occult fractures are evident several weeks before radiographic signs appear. In the hip, a limited and cost effective MR protocol, with only T1 weighted () coronal images, may enable a reliable diagnosis or exclusion of occult fracture in very little time, for example, 7 minutes. Typically, a linear hypointensity is observed on T1 W images. MRI is also highly sensitive to marrow abnormalities surrounding the fracture line, which appear as hypointensity on T1 W images and hyperintensity on fluid-sensitive sequences. Such signal changes are thought to be a combination of bone marrow edema, intraosseous haemorrhage, and/or granulation tissue and help to identify even undisplaced fractures. However, in the absence of a history of trauma and linear hypointensities on T1 W images, isolated bone marrow edema may represent other pathologies such as osteoid osteoma and sclerosing osteomyelitis.
FLASH MRI was invented in 1985 by Jens Frahm, Axel Haase, W Hänicke, KD Merboldt, and D Matthaei (German Patent Application P 35 04 734.8, February 12, 1985) at the Max-Planck-Institut für biophysikalische Chemie in Göttingen, Germany. The technique is revolutionary in shortening MRI measuring times by up to two orders of magnitude.
Raymond Damadian, a recipient of the National Medal of Technology, had a significant contribution to the invention of the MRI.
A relatively new approach in the diagnosis is magnetic resonance imaging (MRI), which is noninvasive. MRI uses the property of nuclear magnetic resonance to image nuclei of atoms inside the body. MRI is non-radiographic and therefore can be repeated more often in short periods of time. In addition, different studies show that the MRI is better as an imaging tool than videofluoroscopy for visualizing the anatomy of the velopharynx. There are some limitations of the MRI however. Unlike videofluoroscopy and nasopharyngoscopy, MRI does not show the movement of the velopharyngeal structures during speech. In addition, artifacts can be shown on the images when the patient moves while imaging or if the patient has orthodontic appliances. MRI is limited in children who are claustrophobic. Finally, MRI is much more expensive than videofluoroscopy or nasopharyngoscopy. Because of these limits, MRI is currently not widely used for clinical diagnostic purposes. 
MRI is in general a safe technique, although injuries may occur as a result of failed safety procedures or human error.[94] Contraindications to MRI include most cochlear implants and cardiac pacemakers, shrapnel, and metallic foreign bodies in the eyes. The safety of MRI during the first trimester of pregnancy is uncertain, but it may be preferable to other options.[95] Since MRI does not use any ionizing radiation, its use is generally favored in preference to CT when either modality could yield the same information.[96] In certain cases, MRI is not preferred as it may be more expensive, time-consuming, and claustrophobia-exacerbating.
As a result, they were reunited with the mri of Kutath, and Melein took command of one tribe. Humans and regul had followed them on their journey, and the regul were ready to commit genocide again to ensure that the mri did not hire on with the humans. However, their murderous plans were foiled, and humans ultimately established an understanding with the mri when a human scholar learned to play "shon’ai".
The primary aim of the projects was a more sophisticated development of the rather modest MRI techniques available in the early eighties - mainly with respect to speed and specificity. Already in 1985 the group presented a major breakthrough for the future development of MRI in both science and medicine. The invention of a rapid imaging principle, the FLASH MRI (fast low angle shot) technique, allowed for a 100-fold reduction of the measuring times of cross-sectional and three-dimensional images. The FLASH acquisition technique led the ground for many modern MRI applications in diagnostic imaging. Examples include breathhold imaging of the abdomen, electrocardiogram-synchronized quasi-real time movies of the beating heart, dynamic scanning of contrast media uptake, 3D imaging of complex anatomic structures such as the brain that allow for unprecedented high spatial resolution and arbitrary view angles, and magnetic resonance angiography (MRA) of the vasculature. Other achievements extended to MRI and localized magnetic resonance spectroscopy (MRS) techniques based on stimulated echoes - another invention from 1984.
Several different types of magnetic resonance imaging (MRI) may be employed in diagnosis: MRI without contrast, Gd contrast enhanced T1-weighted MRI (GdT1W) or T2-weighted enhanced MRI (T2W or T2*W). Non-contrast enhanced MRI is considerably less expensive than any of the contrast enhanced MRI scans. The gold standard in diagnosis is GdT1W MRI.
The reliability of non-contrast enhanced MRI is highly dependent on the sequence of scans, and the experience of the operator.
A number of different pulse sequences can be used for specific MRI diagnostic imaging (multiparametric MRI or mpMRI). It is possible to differentiate tissue characteristics by combining two or more of the following imaging sequences, depending on the information being sought: T1-weighted (T1-MRI), T2-weighted (T2-MRI), diffusion weighted imaging (DWI-MRI), dynamic contrast enhancement (DCE-MRI), and spectroscopy (MRI-S). For example, imaging of prostate tumors is better accomplished using T2-MRI and DWI-MRI than T2-weighted imaging alone. The number of applications of mpMRI for detecting disease in various organs continues to expand, including liver studies, breast tumors, pancreatic tumors, and assessing the effects of vascular disruption agents on cancer tumors.
Despite the aids provided from MRIs, there are some disadvantages. For example, although it is 27–36% more sensitive, it has been claimed to be less specific than mammography. As a result, MRI studies may have up to 30% more false positives, which may have undesirable financial and psychological costs on the patient. Also, MRI procedures are expensive and include an intravenous injection of a gadolinium contrast, which has been implicated in a rare reaction called nephrogenic systemic fibrosis (NFS). Although NSF is uncommon, other patients with a history of renal failure/disease would not be able to undergo an MRI scan. Breast MRI is not recommended for screening all breast cancer patients, yet limited to patients with high risk of developing breast cancer that may have high familial risk or mutations in BCRA1/2 genes. Breast MRI is not a perfect tool despite its increased sensitivity for detecting breast cancer masses when compared to mammography. This due to the ability of MRIs to miss some cancers that would have been detected with conventional mammography, as a result, MRI screening for breast cancer is most affective as a combination with other tests and for certain breast cancer patients. In contrast, the use of MRIs are often limiting to patients with any body metal integration such as patients with tattoos, pacemakers, tissue expanders, and so on.
A person with a penetrating head injury may be evaluated using X-ray, CT scan, or MRI (MRI can only be used when the penetrating object would not be magnetic, because MRI uses magnetism and could move the object, causing further injury).
The first neuroimaging technique ever is the so-called ‘human circulation balance’ invented by Angelo Mosso in the 1880s and able to non-invasively measure the redistribution of blood during emotional and intellectual activity. 
Then, in the early 1900s, a technique called pneumoencephalography was set. This process involved draining the cerebrospinal fluid from around the brain and replacing it with air, altering the relative density of the brain and its surroundings, to cause it to show up better on an x-ray, and it was considered to be incredibly unsafe for patients (Beaumont 8). A form of magnetic resonance imaging (MRI) and computed tomography (CT) were developed in the 1970s and 1980s. The new MRI and CT technologies were considerably less harmful and are explained in greater detail below. Next came SPECT and PET scans, which allowed scientists to map brain function because, unlike MRI and CT, these scans could create more than just static images of the brain's structure. Learning from MRI, PET and SPECT scanning, scientists were able to develop functional MRI (fMRI) with abilities that opened the door to direct observation of cognitive activities.
Current methodologic projects focus on the use of iterative image reconstruction techniques for non-cartesian MRI (e.g., undersampled radial MRI) and parallel MRI that define the reconstruction process as a nonlinear inverse problem. Other developments address the possibility of real-time MRI in order to overcome the motion sensitivity of conventional MRI acquisitions and to monitor organ movements in real time. Most recent achievements in real-time MRI are based on FLASH techniques with highly undersampled radial data encodings. When combined with image reconstruction by nonlinear inversion with temporal regularization, they allow for movies of the human heart with image acquisition times as short as 10 to 30 milliseconds, which correspond to MRI movies with up to 100 frames per second. Such real-time movies may continuously be recorded during free breathing, without ECG synchronization, and without motion artifacts. Apart from cardiac applications and quantitative measurements of blood flow in real time, novel possibilities range from studies of joint movements, bowel motility and swallowing mechanics (e.g., dysphagia and reflux disorders) to speech generation and brass playing. Interactive real-time MRI will also revitalize "interventional" MRI which refers to MRI monitoring of minimally invasive procedures. A selection of example MRI videos can be found here: Biomedizinische NMR Forschungs GmbH. The development of a high-quality and robust real-time MRI technique must be considered another breakthrough in MRI that promises to shape its future. Real-time MRI will again broaden the diagnostic potential of MRI by adding completely new, hitherto impossible scientific and clinical applications as well as by simplifying and shortening existing procedures.
Since an MRI provides excellent imaging of blood vessels and tissues, it is recognized as the best type of imaging to observe signs associated with lumbar compression. The precise measurement of the diameter of the spinal canal is a particularly important component when determining the severity of the stenosis itself. High strength 3-Tesla MRI machines are being utilized due to the increased vascular imaging capabilities. Better resolution capacity allows for more detailed observations by the healthcare provider. The sharp contrast of the high power MRI outlines details in the vertebra that are critical when examining a patient with lumbar spinal stenosis who may need a laminotomy. MRI scanning post invasive surgery is used to see the quality of the surgery itself, yet the appropriate postoperative time elapsed before conducting an MRI is a debated topic.
The situation changed when the regul encountered humans and war broke out. Atrocities occurred on both sides, at least in part due to the inability of the regul to imagine the future. After forty years of war, the mri were nearly exterminated. The regul negotiated a peace which involved handing Kesrith over to humanity, then betrayed the mri to prevent the mercenaries from switching sides. All the mri save two were murdered.
New methods and variants of existing methods are often published when they are able to produce better results in specific fields. Examples of these recent improvements are "T"-weighted turbo spin-echo ("T" TSE MRI), double inversion recovery MRI (DIR-MRI) or phase-sensitive inversion recovery MRI (PSIR-MRI), all of them able to improve imaging of brain lesions. Another example is MP-RAGE (magnetization-prepared rapid acquisition with gradient echo), which improves images of multiple sclerosis cortical lesions.
Magnetic resonance imaging (MRI) is in general a safe technique, although injuries may occur as a result of failed safety procedures or human error. Contraindications to MRI include most cochlear implants and cardiac pacemakers, shrapnel, and metallic foreign bodies in the eyes. The safety of MRI during the first trimester of pregnancy is uncertain, but it may be preferable to other options. Since MRI does not use any ionizing radiation, its use generally is favored in preference to CT when either modality could yield the same information. (In certain cases, MRI is not preferred as it may be more expensive, time-consuming, and claustrophobia-exacerbating).
No effects of MRI on the fetus have been demonstrated. In particular, MRI avoids the use of ionizing radiation, to which the fetus is particularly sensitive. As a precaution, however, many guidelines recommend pregnant women only undergo MRI when essential, especially during the first trimester. The concerns in pregnancy are the same as for MRI in general, but the fetus may be more sensitive to the effects—particularly to heating and to noise. The use of gadolinium-based contrast media in pregnancy is an off-label indication and may be administered only in the lowest dose required to provide essential diagnostic information.
In 1964 he returned to England to take up a place as a Lecturer at Nottingham University where he could continue his studies in multiple-pulse NMR. He was successively appointed Senior Lecturer in 1968 and Reader in 1970. During this period his team developed the MRI equipment with the help of grants from the Medical Research Council. It was not until the 1970s with Paul Lauterbur's and Mansfield's developments that NMR could be used to produce images of the body. In 1979 Mansfield was appointed Professor of the Department of Physics until his retirement in 1994.Mansfield is credited with inventing 'slice selection' for MRI and understanding how the radio signals from MRI can be mathematically analysed, making interpretation of the signals into a useful image a possibility. He is also credited with discovering how fast imaging could be possible by developing the MRI protocol called echo-planar imaging. Echo-planar imaging allows T2* weighted images to be collected many times faster than previously possible. It also has made functional magnetic resonance imaging (fMRI) feasible.
Diagnosis is generally made by magnetic resonance imaging (MRI), particularly using a specific imaging technique known as a gradient-echo sequence MRI, which can unmask small or punctate lesions that may otherwise remain undetected. These lesions are also more conspicuous on FLAIR imaging compared to standard T2 weighing. FLAIR imaging is different from gradient sequences. Rather, it is similar to T2 weighing but suppresses free-flowing fluid signal. Sometimes quiescent CCMs can be revealed as incidental findings during MRI exams ordered for other reasons. Many cavernous hemangiomas are detected "accidentally" during MRIs searching for other pathologies. These "incidentalomas" are generally asymptomatic. In the case of hemorrhage, however, a CT scan is more efficient at showing new blood than an MRI, and when brain hemorrhage is suspected, a CT scan may be ordered first, followed by an MRI to confirm the type of lesion that has bled.
Damadian received a National Medal of Technology in 1988 and was inducted into the National Inventors Hall of Fame[15] in 1989. His original MRI full-body scanner was given to the Smithsonian Institution in the 1980s and is now on loan and on display at the National Inventors Hall of Fame in Ohio.[32] In 2001, the Lemelson-MIT Prize Program bestowed its $100,000 Lifetime Achievement Award on Damadian as "the man who invented the MRI scanner."[3]