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Sample records for resonance images mri

  1. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Magnetic Resonance Imaging (MRI) is a medical imaging procedure for ...

  2. Magnetic Resonance Imaging (MRI) Safety

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) Safety What is MRI and how ... What is MRI and how does it work? Magnetic resonance imaging, or MRI, is a way of obtaining ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  4. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... are the limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging ( ... brain) in routine clinical practice. top of page What are some common uses of the procedure? MR ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... As the hydrogen atoms return to their usual alignment, they emit different amounts of energy that vary ... story about radiology? Share your patient story here Images × Image Gallery Magnetic Resonance Imaging (MRI) procedure View ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... it is useful to bring that to the attention of the scheduler before the exam and bring ... Image Gallery Magnetic Resonance Imaging (MRI) procedure View full size with caption Pediatric Content Some imaging tests ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association ... MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging ( ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... by the interpreting radiologist. Frequently, the differentiation of abnormal (diseased) tissue from normal tissues is better with ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose medical conditions. MRI ...

  11. Magnetic resonance imaging (MRI

    Directory of Open Access Journals (Sweden)

    Takavar A

    1993-04-01

    Full Text Available Basic physical principles of nuclear magnetic resonance imaging (N.M.R.I, a nonionizing medical imaging technique, are described. Principles of NMRI with other conventional imaging methods, ie, isotope scanning, ultrasonography and radiography have been compared. T1 and T2 and spin density (S.D. factors and different image construction techniques based on their different combinations is discussed and at the end physical properties of some N.M.R images is mentioned.

  12. Magnetic resonance imaging (MRI)

    OpenAIRE

    Takavar A

    1993-01-01

    Basic physical principles of nuclear magnetic resonance imaging (N.M.R.I), a nonionizing medical imaging technique, are described. Principles of NMRI with other conventional imaging methods, ie, isotope scanning, ultrasonography and radiography have been compared. T1 and T2 and spin density (S.D.) factors and different image construction techniques based on their different combinations is discussed and at the end physical properties of some N.M.R images is mentioned.

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... is not harmful, but it may cause some medical devices to malfunction. Most orthopedic implants pose no ... Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose medical conditions. ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... structures of the brain and can also provide functional information (fMRI) in selected cases. MR images of ... Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - ...

  16. Magnetic Resonance Imaging (MRI): Brain (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Brain KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Brain What's in this article? What ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... or patients with claustrophobia. Other MRI machines are open on the sides (open MRI). Open units are especially helpful for examining larger patients or those with claustrophobia. Newer open MRI units provide very high quality images for ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... to a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive imaging ... over time. top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging ...

  19. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... claustrophobia. Newer open MRI units provide very high quality images for many types of exams. Older open MRI units may not provide this same image quality. Certain types of exams cannot be performed using ...

  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings In most cases, an MRI exam is safe for patients with metal implants, except for a few types. ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings In most cases, an MRI exam is safe for patients with metal implants, except for a ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings ... tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that ...

  3. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... room. In addition to affecting the MRI images, these objects can become projectiles within the MRI scanner ... may cause you and/or others nearby harm. These items include: jewelry, watches, credit cards and hearing ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... claustrophobia. Newer open MRI units provide very high quality images for many types of exams. Older open ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... MRI an invaluable tool in early diagnosis and evaluation of many conditions, including tumors. MRI enables the ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... or headphones during the exam. MRI scanners are air-conditioned and well-lit. Music may be played ... the limitations of MRI of the Head? High-quality images are assured only if you are able ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... used in tattoos may contain iron and could heat up during an MRI scan, but this is ... imaging based on the electrical activity of the heart, such as electrocardiography (EKG). MRI generally is not ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging technique that ... than 30 minutes from the onset of symptoms. Risks The MRI examination poses almost no risk to ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... bear denotes child-specific content. Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain ... the web pages found at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... can also provide functional information (fMRI) in selected cases. MR images of the brain and other cranial structures are clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in early diagnosis and evaluation of many conditions, ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... Imaging (MRI) procedure View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  12. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... six weeks) before being safe for MRI examinations. Examples include but are not limited to: artificial heart ... the area to be imaged. Furthermore, the examination takes longer than other imaging modalities (typically x-ray ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... Most MRI exams are painless. However, some patients find it uncomfortable to remain still during MR imaging. ... anxious, confused or in severe pain, you may find it difficult to lie still during imaging. A ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... are clearer and more detailed than other imaging methods. This exam does not use ionizing radiation and ... clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... other imaging methods. This exam does not use ionizing radiation and may require an injection of a contrast ... other internal body structures. MRI does not use ionizing radiation (x-rays). Detailed MR images allow physicians to ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... fitting and has no metal fasteners. Guidelines about eating and drinking before an MRI exam vary with the specific exam and with the imaging facility. Unless you are told otherwise, you may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings In most cases, an MRI exam is safe for patients with metal implants, except for a few types. People with the ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us ... absolutely necessary for medical treatment. See the MRI Safety page for more information about pregnancy and MRI. ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI can detect stroke at a very early stage by mapping the motion of water molecules in ... is because traction devices and many types of life support equipment may distort the MR images and ...

  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... images removable dental work pens, pocket knives and eyeglasses body piercings In most cases, an MRI exam ... and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... the exam. MRI scanners are air-conditioned and well-lit. Music may be played through the headphones ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings ... and send a signed report to your primary care or referring physician, who will share the results ...

  3. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... a risk, depending on their nature and the strength of the MRI magnet. Many implanted devices will ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... tissue from which they come. The MR scanner captures this energy and creates a picture of the ... imaging based on the electrical activity of the heart, such as electrocardiography (EKG). MRI generally is not ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... it may cause some medical devices to malfunction. Most orthopedic implants pose no risk, but you should ... a digital cloud server. Currently, MRI is the most sensitive imaging test of the head (particularly the ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... and may add approximately 15 minutes to the total exam time. top of page What will I ... the limitations of MRI of the Head? High-quality images are assured only if you are able ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... distort images of the facial area or brain, so you should let the radiologist know about them. ... MRI units, called short-bore systems , are designed so that the magnet does not completely surround you. ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... to a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive imaging ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... an MRI scan, but this is rare. Tooth fillings and braces usually are not affected by the magnetic field, but they may distort images of the facial area or brain, so you should let the ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive imaging test ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... others nearby harm. These items include: jewelry, watches, credit cards and hearing aids, all of which can ... top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging technique that ...

  12. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures. MRI ... discovery of abnormalities that might be obscured by bone with other imaging methods. The contrast material used ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... top of page Additional Information and Resources RTAnswers.org : Radiation Therapy for Brain Tumors Radiation Therapy for ... Imaging (MRI) - Head Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... used in tattoos may contain iron and could heat up during an MRI scan, but this is ... called MR angiography (MRA) provides detailed images of blood vessels in the brain—often without the need ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... On very rare occasions, a few patients experience side effects from the contrast material, including nausea, headache and ... structures of the brain and can also provide functional information (fMRI) in selected cases. MR images of ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... Examples include but are not limited to: artificial heart valves implanted drug infusion ports artificial limbs or ... imaging based on the electrical activity of the heart, such as electrocardiography (EKG). MRI generally is not ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI) procedure View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media MR Angiography (MRA) Magnetic ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... structures of the brain and can also provide functional information (fMRI) in selected cases. MR images of the brain and other cranial structures are clearer and more detailed than with other ...

  19. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... tissue and fluid, known as edema . MRI typically costs more and may take more time to perform ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  20. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI. For more information, consult your radiologist. The computer workstation that processes the imaging information is located ... not come in contact with the patient. A computer then processes the signals and generates a series ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... of which shows a thin slice of the body. The images can then be studied from different angles by ... information please consult the ACR Manual on Contrast Media and its references. top of page What are the limitations of MRI of the Head? High-quality images are assured only if you are able to ...

  2. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... be necessary. Your doctor will explain the exact reason why another exam is requested. Sometimes a follow- ... necessary in trauma situations. Although there is no reason to believe that magnetic resonance imaging harms the ...

  3. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... types of clips used for brain aneurysms some types of metal coils placed within blood vessels nearly all cardiac defibrillators and pacemakers You ... called MR angiography (MRA) provides detailed images of blood vessels in the ... the opening of certain types of MRI machines. The presence of an implant ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... provides detailed images of blood vessels in the brain—often without the need for contrast material. See the MRA page for more information. MRI can detect stroke at a very early stage by mapping the motion of water molecules in the tissue. ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... internal body structures. MRI does not use ionizing radiation (x-rays). Detailed MR images allow physicians to evaluate various ... kind, such as an allergy to iodine or x-ray contrast material, drugs, food, or the environment, or ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... very early stage by mapping the motion of water molecules in the tissue. This water motion, known as diffusion, is impaired by most ... the limitations of MRI of the Head? High-quality images are assured only if you are able ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... body structures. MRI does not use ionizing radiation (x-rays). Detailed MR images allow physicians to evaluate various ... kind, such as an allergy to iodine or x-ray contrast material, drugs, food, or the environment, or ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us ... the equipment look like? How does the procedure work? How is the ... use to diagnose medical conditions. MRI uses a powerful magnetic field, radio frequency ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... does not completely surround you. Some newer MRI machines have a larger diameter bore which can be ... size patients or patients with claustrophobia. Other MRI machines are open on the sides (open MRI). Open ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... in the first three to four months of pregnancy unless the potential benefit from the MRI exam ... the MRI Safety page for more information about pregnancy and MRI. If you have claustrophobia (fear of ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... information on the chemicals present in the body's cells, may also be performed during the MRI exam ... medically necessary. MRI may not always distinguish between cancer tissue and fluid, known as edema . MRI typically ...

  12. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... interfere with the magnetic field of the MRI unit, metal and electronic items are not allowed in ... does the equipment look like? The traditional MRI unit is a large cylinder-shaped tube surrounded by ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... women should not have this exam in the first three to four months of pregnancy unless the ... not to have an MRI exam during the first trimester unless medically necessary. MRI may not always ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... conditions. MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures ... may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... used in MRI exams is less likely to produce an allergic reaction than the iodine-based contrast ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... medically necessary. MRI may not always distinguish between cancer tissue and fluid, known as edema . MRI typically ... Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association top ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... tissue and fluid, known as edema . MRI typically costs more and may take more time to perform ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI examination poses almost no risk to the average patient when appropriate safety guidelines are followed. If ... tissue and fluid, known as edema . MRI typically costs more and may take more time to perform ...

  19. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... as severe kidney disease, may prevent you from being given gadolinium contrast for an MRI. If you ... of time after placement (usually six weeks) before being safe for MRI examinations. Examples include but are ...

  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... This detail makes MRI an invaluable tool in early diagnosis and evaluation of many conditions, including tumors. ... information. MRI can detect stroke at a very early stage by mapping the motion of water molecules ...

  1. Developments in boron magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Schweizer, M.

    1995-01-01

    This report summarizes progress during the past year on maturing Boron-11 magnetic resonance imaging (MRI) methodology for noninvasive determination of BNCT agents (BSH) spatially in time. Three major areas are excerpted: (1) Boron-11 MRI of BSH distributions in a canine intracranial tumor model and the first human glioblastoma patient, (2) whole body Boron-11 MRI of BSH pharmacokinetics in a rat flank tumor model, and (3) penetration of gadolinium salts through the BBB as a function of tumor growth in the canine brain

  2. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info About Us News Physician ... absolutely necessary for medical treatment. See the MRI Safety page for more information about pregnancy and MRI. ...

  3. Magnetic Resonance Imaging (MRI): Lumbar Spine (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Lumbar Spine KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Lumbar Spine What's in this article? ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... told otherwise, take your regular medications as usual. Leave jewelry at home and wear loose, comfortable clothing. ... contrast material except when absolutely necessary for medical treatment. See the MRI Safety page for more information ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... any recent surgeries. Some conditions, such as severe kidney disease, may prevent you from being given gadolinium contrast ... an MRI. If you have a history of kidney disease or liver transplant, it will be necessary to ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... scans, MRI does not utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that naturally exist ... thumping sounds when the coils that generate the radiofrequency pulses are activated. Some centers provide earplugs, while ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... tumors stroke infections developmental anomalies hydrocephalus — dilatation of fluid spaces within the brain (ventricles) causes of epilepsy ( ... may not always distinguish between cancer tissue and fluid, known as edema . MRI typically costs more and ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... the head (particularly the brain) in routine clinical practice. top of page What are some common uses ... gadolinium contrast material except when absolutely necessary for medical treatment. See the MRI Safety page for more ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... devices or metal in your body. Guidelines about eating and drinking before your exam vary between facilities. ... fitting and has no metal fasteners. Guidelines about eating and drinking before an MRI exam vary with ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... three to four months of pregnancy unless the potential benefit from the MRI exam is assumed to outweigh the potential risks. Pregnant women should not receive injections of ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... traditional MRI unit is a large cylinder-shaped tube surrounded by a circular magnet. You will lie ... your skin at the site of the IV tube insertion. Some patients may sense a temporary metallic ...

  12. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... metal in your body. Guidelines about eating and drinking before your exam vary between facilities. Unless you ... has no metal fasteners. Guidelines about eating and drinking before an MRI exam vary with the specific ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... not use ionizing radiation and may require an injection of a contrast material called gadolinium, which is ... MRI examinations may require you to receive an injection of contrast material into the bloodstream. The radiologist , ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... will be removed. MRI exams generally include multiple runs (sequences), some of which may last several minutes. ... top of page Who interprets the results and how do I get them? A radiologist, a physician ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... you should let the radiologist know about them. Parents or family members who accompany patients into the ... intercom. Many MRI centers allow a friend or parent to stay in the room as long as ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... will hear and feel loud tapping or thumping sounds when the coils that generate the radiofrequency pulses ... use headphones to reduce the intensity of the sounds made by the MRI machine. You may be ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... are not limited to: artificial heart valves implanted drug infusion ports artificial limbs or metallic joint prostheses ...

  19. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... take food and medications as usual. Some MRI examinations may require you to receive an injection of ... for a mild sedative prior to your scheduled examination. Jewelry and other accessories should be left at ...

  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... stroke infections developmental anomalies hydrocephalus — dilatation of fluid spaces within the brain (ventricles) causes of epilepsy (seizure) ... MRI. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... The magnetic field is produced by passing an electric current through wire coils in most MRI units. ... signals that are detected by the coils. The electric current does not come in contact with the ...

  3. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... have any devices or metal in your body. Guidelines about eating and drinking before your exam vary ... is loose-fitting and has no metal fasteners. Guidelines about eating and drinking before an MRI exam ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... the head (particularly the brain) in routine clinical practice. top of page What are some common uses ... may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... can help diagnose conditions such as: brain tumors stroke infections developmental anomalies hydrocephalus — dilatation of fluid spaces ... MRA page for more information. MRI can detect stroke at a very early stage by mapping the ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... procedure performed? MRI examinations may be performed on outpatients or inpatients. You will be positioned on the ... and send a signed report to your primary care or referring physician, who will share the results ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... about pregnancy and MRI. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want ... also screened for safety in the magnetic environment. Children will be given appropriately sized earplugs or headphones ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... used in tattoos may contain iron and could heat up during an MRI scan, but this is ... injection. If you do not require sedation, no recovery period is necessary. You may resume your usual ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI exam, a physician, nurse or technologist will insert an intravenous (IV) catheter, also known as an ... physicians with expertise in several radiologic areas. Outside links: For the convenience of our users, RadiologyInfo .org ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... you have any devices or metal in your body. Guidelines about eating and drinking before your exam ... soft tissues, bone and virtually all other internal body structures. MRI does not use ionizing radiation (x- ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI) of the head uses a powerful magnetic field, radio waves and a computer to produce detailed ... there’s a possibility you are pregnant. The magnetic field is not harmful, but it may cause some ...

  12. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... their nature and the strength of the MRI magnet. Many implanted devices will have a pamphlet explaining ... large cylinder-shaped tube surrounded by a circular magnet. You will lie on a moveable examination table ...

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    Full Text Available ... allergies and whether there’s a possibility you are pregnant. The magnetic field is not harmful, but it ... if there is any possibility that they are pregnant. MRI has been used for scanning patients since ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... of many conditions, including tumors. MRI enables the discovery of abnormalities that might be obscured by bone ... Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise in several radiologic ...

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help you pass the time. In some cases, intravenous injection of contrast material ...

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... The contrast material used in MRI exams is less likely to produce an allergic reaction than the ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... detailed pictures of the brain and other cranial structures that are clearer and more detailed than other ... tissues, bone and virtually all other internal body structures. MRI does not use ionizing radiation (x-rays). ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... and send a signed report to your primary care or referring physician, who will share the results ...

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... page Additional Information and Resources RTAnswers.org : Radiation Therapy for Brain Tumors Radiation Therapy for Head and ...

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    Full Text Available ... The magnetic field is produced by passing an electric current through wire coils in most MRI units. Other coils, located in the machine and in some cases, placed around the part ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... into the bloodstream. The radiologist , technologist or a nurse may ask if you have allergies of any ... be used in the MRI exam, a physician, nurse or technologist will insert an intravenous (IV) catheter, ...

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    Full Text Available ... may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ... to iodine or x-ray contrast material, drugs, food, or the environment, or if you have asthma. ...

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    Full Text Available ... any recent surgeries. Some conditions, such as severe kidney disease, may prevent you from being given gadolinium ... an MRI. If you have a history of kidney disease or liver transplant, it will be necessary ...

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    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... data suggest that it is safe to continue breastfeeding after receiving intravenous contrast. For further information please ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... used in tattoos may contain iron and could heat up during an MRI scan, but this is ... from the contrast material, including nausea, headache and pain at the site of injection. Similarly, patients are ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... contrast material in patients with very poor kidney function. Careful assessment of kidney function before considering a ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... it is useful to bring that to the attention of the scheduler before the exam and bring ... bore which can be more comfortable for larger size patients or patients with claustrophobia. Other MRI machines ...

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    Full Text Available ... procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of MRI ...

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    Full Text Available ... have allergies of any kind, such as an allergy to iodine or x-ray contrast material, drugs, food, or the environment, or if you have asthma. The contrast material most commonly used for an MRI exam contains a metal ... in patients with iodine contrast allergy. It is far less common for a patient ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... also screened for safety in the magnetic environment. Children will be given appropriately sized earplugs or headphones during the exam. MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ...

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    Full Text Available ... to have an allergy to a gadolinium-based contrast agent used for MRI than the iodine-containing contrast ... more information on adverse reactions to gadolinium-based contrast agents, please consult the ACR Manual on Contrast Media . ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... which they come. The MR scanner captures this energy and creates a picture of the tissues scanned based on this information. The magnetic field is produced by passing an electric current through wire coils in most MRI units. ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will be necessary to perform a blood test to determine whether the kidneys are functioning adequately. Women should always inform their physician or technologist if ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... able to see, hear and speak with you at all times using a two-way intercom. Many MRI centers allow a friend or parent to stay in the room as long as they are also screened for safety in the magnetic environment. Children will be given ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... you! Do you have a personal story about radiology? Share your patient story here Images × Image Gallery ... reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of North America ( ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... imaging modalities. top of page Additional Information and Resources RTAnswers.org : Radiation Therapy for Brain Tumors Radiation ... To locate a medical imaging or radiation oncology provider in your community, you can search the ACR- ...

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    Full Text Available ... practice. top of page What are some common uses of the procedure? MR imaging of the head ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ...

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    Full Text Available ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ... not provide cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic ...

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    Full Text Available ... metallic objects. Patient movement can have the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that time the imaging based on the electrical activity of ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... you, notify the radiologist or technologist. It is important that you remain perfectly still while the images are being obtained, which is typically only a few seconds to a few minutes at a time. You will know when images are being recorded ...

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    Full Text Available ... examination poses almost no risk to the average patient when appropriate safety guidelines are followed. If sedation is used, there ... have a personal story about radiology? Share your patient story here Images ... Disease Head Injury Brain Tumors Images related ...

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... the body and determine the presence of certain diseases. The images can then be examined on a ...

  4. Pharmaceutical applications of magnetic resonance imaging (MRI).

    Science.gov (United States)

    Richardson, J Craig; Bowtell, Richard W; Mäder, Karsten; Melia, Colin D

    2005-06-15

    Magnetic resonance imaging (MRI) is a powerful imaging modality that provides internal images of materials and living organisms on a microscopic and macroscopic scale. It is non-invasive and non-destructive, and one of very few techniques that can observe internal events inside undisturbed specimens in situ. It is versatile, as a wide range of NMR modalities can be accessed, and 2D and 3D imaging can be undertaken. Despite widespread use and major advances in clinical MRI, it has seen limited application in the pharmaceutical sciences. In vitro studies have focussed on drug release mechanisms in polymeric delivery systems, but isolated studies of bioadhesion, tablet properties, and extrusion and mixing processes illustrate the wider potential. Perhaps the greatest potential however, lies in investigations of pharmaceuticals in vivo, where pilot human and animal studies have demonstrated we can obtain unique insights into the behaviour of gastrointestinal, topical, colloidal, and targeted drug delivery systems.

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site ...

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... medical imaging or radiation oncology provider in your community, you can search the ACR-accredited facilities database . ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... experience some bruising. There is also a very small chance of irritation of your skin at the ... a result, must be kept away from the area to be imaged. Furthermore, the examination takes longer ...

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    Full Text Available ... processes the imaging information is located in a separate room from the scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... images can then be examined on a computer monitor, transmitted electronically, printed or copied to a CD ... excessive sedation. However, the technologist or nurse will monitor your vital signs to minimize this risk. Although ...

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    Full Text Available ... eating and drinking before your exam vary between facilities. Unless you are told otherwise, take your regular ... with the specific exam and with the imaging facility. Unless you are told otherwise, you may follow ...

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    Full Text Available ... This website does not provide cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic region. Discuss the fees associated with your prescribed procedure with your doctor, ...

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    Full Text Available ... radiation oncology provider in your community, you can search the ACR-accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, treatments ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... with metal implants, except for a few types. People with the following implants cannot be scanned and ... it difficult to lie still during imaging. A person who is very large may not fit into ...

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Magnetic ...

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    Full Text Available ... practice. top of page What are some common uses of the procedure? MR imaging of the head ... gadolinium contrast, it may still be possible to use it after appropriate pre-medication. Patient consent will ...

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    Full Text Available ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank ... View full size with caption Pediatric Content Some imaging tests ...

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    Full Text Available ... determine the presence of certain diseases. The images can then be examined on a computer monitor, transmitted ... of abrupt onset or long-standing symptoms. It can help diagnose conditions such as: brain tumors stroke ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... for scanning patients since the 1980s with no reports of any ill effects on pregnant women or ... will analyze the images and send a signed report to your primary care or referring physician, who ...

  19. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... you should let the radiologist know about them. Parents or family members who accompany patients into the ... part of the body being imaged, send and receive radio waves, producing signals that are detected by ...

  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... practice. top of page What are some common uses of the procedure? MR imaging of the head ... for immediate assistance. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... the area of your body being imaged to feel slightly warm, but if it bothers you, notify ... are being recorded because you will hear and feel loud tapping or thumping sounds when the coils ...

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... is because traction devices and many types of life support equipment may distort the MR images and ...

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... images and send a signed report to your primary care or referring physician, who will share the ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... a computer to produce detailed pictures of the brain and other cranial structures that are clearer and ... sensitive imaging test of the head (particularly the brain) in routine clinical practice. top of page What ...

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    Full Text Available ... practice. top of page What are some common uses of the procedure? MR imaging of the head ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... no: Thank you! Do you have a personal story about radiology? Share your patient story here Images × ... Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 Radiological Society of North America, Inc. ( ...

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    Full Text Available ... produce detailed pictures of the brain and other cranial structures that are clearer and more detailed than ... cases. MR images of the brain and other cranial structures are clearer and more detailed than with ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... have a history of kidney disease or liver transplant, it will be necessary to perform a blood ... discovery of abnormalities that might be obscured by bone with other imaging methods. The contrast material used ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... Detailed MR images allow physicians to evaluate various parts of the body and determine the presence of ... Patients who might have metal objects in certain parts of their bodies may also require an x- ...

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    Full Text Available ... radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will share the results with you. Follow-up examinations may be necessary. Your doctor will ... exam is requested. Sometimes a follow-up exam is done because a potential ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... epilepsy (seizure) hemorrhage in selected trauma patients certain chronic conditions, such as multiple sclerosis disorders of the ... a very small chance of irritation of your skin at the site of the IV tube insertion. Some ... Images related to Magnetic ...

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us ... they may move during the scan, possibly causing blindness. Dyes used in tattoos may contain iron and ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... the head uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of the brain and other cranial structures that are clearer and more detailed than other imaging methods. This exam does not use ionizing radiation and may require an injection of a ...

  16. Indications for fetal magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Prayer, D.

    2006-01-01

    Indications to perform fetal magnetic resonance imaging (MRI) are composed of common ones related to methodological problems of ultrasound (US) assessment (such as for instance hydramnios) and special ones. The latter are related to MR capability of high-resolution soft tissue contrast and an extended field of view that allows visualization of the whole fetus, even in later stages of pregnancy. The most important indications include confirmation of US findings, work-up of malformations with respect to individual prognosis and genetic background, differentiation between acquired conditions and malformations, visualization of pathologies that have to be treated surgically immediately after birth, and morphological changes of the placenta. (orig.) [de

  17. Magnetic Resonance Imaging (MRI): Dynamic Pelvic Floor

    Science.gov (United States)

    ... to a CD or uploaded to a digital cloud server. Dynamic pelvic floor MRI provides detailed pictures ... with you. top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging ...

  18. Clinically relevant magnetic resonance imaging (MRI) findings in ...

    African Journals Online (AJOL)

    Background: Shoulder pain is the most common and well-documented site of musculoskeletal pain in elite swimmers. Structural abnormalities on magnetic resonance imaging (MRI) of elite swimmers' symptomatic shoulders are common. Little has been documented about the association between MRI findings in the ...

  19. Visualization of pulmonary nodules with magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Plathow, C.; Deutsches Krebsforschungszentrum; Meinzer, H.-P.; Kauczor, H.-U.

    2006-01-01

    Visualization of pulmonary nodules using magnetic resonance imaging (MRI) plays a minor role compared with computed tomography (CT). Technical developments made it possible to apply MRI more and more frequently in functional imaging. Imaging of the motion of pulmonary nodules during respiration, e.g., to optimize high precision therapy techniques, is a new field of research. This paper describes developments in analysis and visualization of pulmonary nodules during respiration using MRI. Besides actual 2D techniques new 3D techniques to quantify motion of pulmonary nodules during respiration are presented. (orig.) [de

  20. The OMERACT rheumatoid arthritis magnetic resonance imaging (MRI) scoring system

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Peterfy, Charles G.; Bird, Paul

    2017-01-01

    Objective: The Outcome Measures in Rheumatology (OMERACT) Rheumatoid Arthritis (RA) Magnetic Resonance Imaging (MRI) scoring system (RAMRIS), evaluating bone erosion, bone marrow edema/osteitis, and synovitis, was introduced in 2002, and is now the standard method of objectively quantifying...... inflammation and damage by MRI in RA trials. The objective of this paper was to identify subsequent advances and based on them, to provide updated recommendations for the RAMRIS. Methods: MRI studies relevant for RAMRIS and technical and scientific advances were analyzed by the OMERACT MRI in Arthritis Working...... Group, which used these data to provide updated considerations on image acquisition, RAMRIS definitions, and scoring systems for the original and new RA pathologies. Further, a research agenda was outlined. Results: Since 2002, longitudinal studies and clinical trials have documented RAMRIS variables...

  1. Safety recommendations in magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Nikolaou, K.I.; Plataniotis, T.N; Syrgiamiotis, G.V.; Dousi, M.; Panou, T.; Georgiadis, K.; Bougias, C.

    2008-01-01

    Full text: In order to discuss the long-term biological effects of MRI in the radiological department, all the components of the acquisition process must be considered. Those elements include: the main magnetic field, time varying magnetic fields and radio-frequency fields (RF). Also must be referred other types of hazards obtained by the utilization of contrast materials as gadolinium or pregnancy. The primary concern with the static magnetic field is the possibility of potential biological effects. The majority of studies show no effects on cell growth and morphology at field strengths below 2T. Data accumulated by the National Institute for Occupational Safety, the World Health Organization, and the US State Department, show no evidence of leukemia or other carcinogenesis. The secondary concern of the effects of the main magnetic field is the hazards associated with the sitting of MR systems. The static magnetic field has no respect for the confines of conventional walls, floors or ceilings. Some reversible effects have been noted on Electrocardiogram gating (ECG) at these field strengths. An increase in the amplitude of the T-wave can be noted on an ECG due to the magnetohydrodynamic effect. This is produced when a conductive fluid, such as blood, moves across a magnetic field. Some reversible biological effects including fatigue, headaches, hypotension and accounts of irritability have been observed on human subjects exposed to 2T and above. As yet, there are no known biological effects of MRI on fetuses. Also MR facilities have established individual guidelines for pregnant employees in the MR environment. Ferromagnetic metal objects can become airborne as projectiles in the presence of a strong static magnetic field. Metallic implants pose serious effects which include torque, heating and artifacts on MR images.There have been a large number of studies performed on the biological effects from Time-varying magnetic field (TVMF), since they exist around power

  2. Magnetic resonance imaging (MRI) in obstetrics. II. Fetal anatomy.

    Science.gov (United States)

    Powell, M C; Worthington, B S; Buckley, J M; Symonds, E M

    1988-01-01

    Magnetic resonance imaging (MRI) was performed in 36 patients at between 10 and 38 weeks gestation to determine the fetal anatomy that could be identified at different gestations. Fetal motion significantly degraded the image quality in the first and second trimesters, but in the final trimester fetal anatomy was clearly demonstrated. T2 weighted sequences showed the fetal brain and lungs to have a high signal intensity. Shorter TR leading to a T1 weighting gave better resolution of the overall anatomy. MRI has revealed the potential for assessment of lung maturity and the growth-retarded fetus.

  3. Diagnosis of magnetic resonance imaging (MRI) for blowout fracture. Three advantages of MRI

    International Nuclear Information System (INIS)

    Nishida, Yasuhiro; Aoki, Yoshiko; Hayashi, Osamu; Kimura, Makiko; Murata, Toyotaka; Ishida, Youichi; Iwami, Tatsuya; Kani, Kazutaka

    1999-01-01

    Magnetic resonance imaging (MRI) gives a much more detailed picture of the soft tissue than computerized tomography (CT). In blowout fracture cases, it is very easy to observe the incarcerated orbital tissue. We performed MRI in 19 blowout fracture cases. After evaluating the images, we found three advantages of MRI. The first is that even small herniation of the orbital contents can easily be detected because the orbital fatty tissue contrasts well around the other tissues in MRI. The second is that the incarcerated tissues can be clearly differentiated because a clear contrast between the orbital fatty tissue and the extraocular muscle can be seen in MRI. The third is that the running images of the incarcerated muscle belly can be observed because any necessary directional slies can be taken in MRI. These advantages are very important in the diagnosis of blowout fractures. MRI should be employed in blowout fracture cases in addition to CT. (author)

  4. Magnetic Resonance Medical Imaging (MRI)-from the inside

    Science.gov (United States)

    Bottomley, Paul

    There are about 36,000 magnetic resonance imaging (MRI) scanners in the world, with annual sales of 2500. In the USA about 34 million MRI studies are done annually, and 60-70% of all scanners operate at 1.5 Tesla (T). In 1982 there were none. How MRI got to be-and how it got to1.5T is the subject of this talk. Its an insider's view-mine-as a physics PhD student at Nottingham University when MRI (almost) began, through to the invention of the 1.5T clinical MRI scanner at GE's research center in Schenectady NY.Before 1977 all MRI was done on laboratory nuclear magnetic resonance instruments used for analyzing small specimens via chemical shift spectroscopy (MRS). It began with Lauterbur's 1973 observation that turning up the spectrometer's linear gradient magnetic field, generated a spectrum that was a 1D projection of the sample in the direction of the gradient. What followed in the 70's was the development of 3 key methods of 3D spatial localization that remain fundamental to MRI today.As the 1980's began, the once unimaginable prospect of upscaling from 2cm test-tubes to human body-sized magnets, gradient and RF transmit/receive systems, was well underway, evolving from arm-sized, to whole-body electromagnet-based systems operating at plan was to drop the field to 0.3T. We opted to make MRI work at 1.5T instead. The result was a scanner that could study both anatomy and metabolism with a SNR way beyond its lower field rivals. MRI's success truly reflects the team efforts of many: from the NMR physics to the engineering of magnets, gradient and RF systems.

  5. Magnetic resonance imaging (MRI) of intracranial chordomas

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Teruo; Inoue, Yuichi; Shakudo, Miyuki and others

    1988-03-01

    MR images of 5 patients with intracranial chordoma were evaluated and compared with those of other clival lesions (1 clival osteomyelitis, 1 metastatic clival tumor, 3 clival meningiomas). The MR examination was performed using a 0.5 T superconductive magnet, with approximately 10 mm section thickness, one average and a 256 x 256 matrix. T1 weighted images were obtainned by inversion recovery (IR) with TR 2100 - 2500 msec, TI 600 msec and TE 40 msec. T2 weighted images were obtained by spin echo pulse sequence with TR 1800 - 2500 msec and TE 120 msec (long SE). In several cases, the spin echo pulse sequences with TR 1000 msec and TE 40 msec (short SE) were also done. Multiplaned images were obtained. Four of 5 intracranial chordomas were low in intensity compared to cerebral gray matter on T1 weighted images, and all of 5 chordomas were as high in intensity as cerebrospinal fluid or higher than that of cerebrospinal fluid on T2 weighted images. Clival fatty marrow is high intensity on T1 weighted images. Clival involvement by a tumor was a clearly demonstrated as disappearance of this high intensity in all cases. In two cases, the tumor extended to the retropharyngeal space and this was detected clearly on short SE image. Although clival fatty marrow was disappeared, osteomyelitis and metastatic tumor in clivus were iso-intense to cerebral gray matter on both T1 and T2 weighted images. All of 3 clival meningiomas showed iso-intensity to cerebral gray matter on T1 weighted images and slightly high intensity to brain on T2 weighted images, and clival fatty marrow was normal in all 3 cases. Although our experiences are limited in number, intracranial chordoma appeared to be differentiated from other clival lesions.

  6. Degeneration of pyramidal tract of MRI (magnetic resonance imaging)

    International Nuclear Information System (INIS)

    Yamagami, Tatsuhito; Harada, Noboru; Gotoh, Yasunobu; Imataka, Kiyoharu; Kinuta, Yuji; Okumura, Teizo; Niijima, Kyo; Taki, Waro; Kikuchi, Haruhiko.

    1988-01-01

    MRI (magnetic resonance imaging) examinaion was performed on cases of hemiplegia and hemiparesis. These included seven cases of intracerebral hemorrhage, four cases of subarachnoid hemorrhage, one case of cerebral infarct, and two cases of head trauma. The pyramidal tract in the brain stem was studied in five patients with complete hemiplegia and in nine with incomplete hemiparesis. The scanner of the MRI was a resistive type operating at a field of 0.2 Tesla. The inversion recovery (IR) and saturation recovery (SR) techniques were utilized. The pyramidal tract at the level of the midbrain and the pons was recognized as a low intensity area on the T 1 image (IR 1500/43) in the cases of complete hemiplegia. However, it was recognized as a high intensity area on the SR image (SR 1000/60) and the T 2 image (SR 2000/100). No abnormal signal intensity was found in the cases of incomplete hemiparesis. A low intensity area on the T 1 image and a high intensity area on the T 2 image were recognized in the ventral portion of the midbrain and the pons on the affected side. These findings indicate a degeneration of the pyramidal tract at the level of the brain stem in patients with complete hemiplegia. (author)

  7. Magnetic Resonance Imaging (MRI and Spectroscopy (MRS in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Uma Sharma

    2008-01-01

    Full Text Available Breast cancer is a major health problem in women and early detection is of prime importance. Breast magnetic resonance imaging (MRI provides both physical and physiologic tissue features that are useful in discriminating malignant from benign lesions. Contrast enhanced MRI is valuable for diagnosis of small tumors in dense breast and the structural and kinetic parameters improved the specificity of diagnosing benign from malignant lesions. It is a complimentary modality for preoperative staging, to follow response to therapy, to detect recurrences and for screening high risk women. Diffusion, perfusion and MR elastography have been applied to breast lesion characterization and show promise.In-vivo MR spectroscopy (MRS is a valuable method to obtain the biochemical status of normal and diseased tissues. Malignant tissues contain high concentration of choline containing compounds that can be used as a biochemical marker. MRS helps to increase the specificity of MRI in lesions larger than 1cm and to monitor the tumor response. Various MR techniques show promise primarily as adjunct to the existing standard detection techniques, and its acceptability as a screening method will increase if specificity can be improved. This review presents the progress made in different MRI and MRS techniques in breast cancer management.

  8. Magnetic Resonance Imaging (MRI and Spectroscopy (MRS in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Uma Sharma

    2008-01-01

    Full Text Available Breast cancer is a major health problem in women and early detection is of prime importance. Breast magnetic resonance imaging (MRI provides both physical and physiologic tissue features that are useful in discriminating malignant from benign lesions. Contrast enhanced MRI is valuable for diagnosis of small tumors in dense breast and the structural and kinetic parameters improved the specificity of diagnosing benign from malignant lesions. It is a complimentary modality for preoperative staging, to follow response to therapy, to detect recurrences and for screening high risk women. Diffusion, perfusion and MR elastography have been applied to breast lesion characterization and show promise. In-vivo MR spectroscopy (MRS is a valuable method to obtain the biochemical status of normal and diseased tissues. Malignant tissues contain high concentration of choline containing compounds that can be used as a biochemical marker. MRS helps to increase the specificity of MRI in lesions larger than 1cm and to monitor the tumor response. Various MR techniques show promise primarily as adjunct to the existing standard detection techniques, and its acceptability as a screening method will increase if specificity can be improved. This review presents the progress made in different MRI and MRS techniques in beast cancer management.

  9. Technique of obstetric pelvimetry by magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Sigmund, G.; Wenz, W.; Bauer, M.; DeGregorio, G.; Henne, K.

    1991-01-01

    Magnetic resonance imaging (MRL) allows for the first time direct determination of maternal pelvic dimensions without ionising radiation. Phantom measurements and the correlation with traditional pelvimetric measurements in 10 patients after Caesarean section have shown mean differences of ± 2 mm, with a maximum of 5 mm. The evaluation of pelvic configuration is obtained analogous to the conventional roentgenogram. In addition to conventional or digital X-ray pelvimetry, the soft tissues of the maternal pelvis and the presenting part of the foetus is delineated with high contrast. Positioning in the body coil can be accomplished even late in pregnancy or in impending labour, acceptance by the pregnant women being high. Whereas in a given indication after delivery conventional X-ray pelvimetry continues to be performed, antenatally MRI pelvimetry has now been established in our Departments as the method of choice - based on meanwhile 107 examinations. Present drawbacks are the relatively high cost and the limited availability of MR units. (orig.) [de

  10. Virtual phantom magnetic resonance imaging (ViP MRI) on a clinical MRI platform.

    Science.gov (United States)

    Saint-Jalmes, Hervé; Bordelois, Alejandro; Gambarota, Giulio

    2018-01-01

    The purpose of this study was to implement Virtual Phantom Magnetic Resonance Imaging (ViP MRI), a technique that allows for generating reference signals in MR images using radiofrequency (RF) signals, on a clinical MR system and to test newly designed virtual phantoms. MRI experiments were conducted on a 1.5 T MRI scanner. Electromagnetic modelling of the ViP system was done using the principle of reciprocity. The ViP RF signals were generated using a compact waveform generator (dimensions of 26 cm × 18 cm × 16 cm), connected to a homebuilt 25 mm-diameter RF coil. The ViP RF signals were transmitted to the MRI scanner bore, simultaneously with the acquisition of the signal from the object of interest. Different types of MRI data acquisition (2D and 3D gradient-echo) as well as different phantoms, including the Shepp-Logan phantom, were tested. Furthermore, a uniquely designed virtual phantom - in the shape of a grid - was generated; this newly proposed phantom allows for the investigations of the vendor distortion correction field. High quality MR images of virtual phantoms were obtained. An excellent agreement was found between the experimental data and the inverse cube law, which was the expected functional dependence obtained from the electromagnetic modelling of the ViP system. Short-term time stability measurements yielded a coefficient of variation in the signal intensity over time equal to 0.23% and 0.13% for virtual and physical phantom, respectively. MR images of the virtual grid-shaped phantom were reconstructed with the vendor distortion correction; this allowed for a direct visualization of the vendor distortion correction field. Furthermore, as expected from the electromagnetic modelling of the ViP system, a very compact coil (diameter ~ cm) and very small currents (intensity ~ mA) were sufficient to generate a signal comparable to that of physical phantoms in MRI experiments. The ViP MRI technique was successfully implemented on a clinical MR

  11. Magnetic resonance imaging (MRI) and relaxation time mapping of concrete

    Science.gov (United States)

    Beyea, Steven Donald

    2001-07-01

    The use of Magnetic Resonance Imaging (MRI) of water in concrete is presented. This thesis will approach the problem of MR imaging of concrete by attempting to design new methods, suited to concrete materials, rather than attempting to force the material to suit the method. A number of techniques were developed, which allow the spatial observation of water in concrete in up to three dimensions, and permits the determination of space resolved moisture content, as well as local NMR relaxation times. These methods are all based on the Single-Point Imaging (SPI) method. The development of these new methods will be described, and the techniques validated using phantom studies. The study of one-dimensional moisture transport in drying concrete was performed using SPI. This work examined the effect of initial mixture proportions and hydration time on the drying behaviour of concrete, over a period of three months. Studies of drying concrete were also performed using spatial mapping of the spin-lattice (T1) and effective spin-spin (T2*) relaxation times, thereby permitting the observation of changes in the water occupied pore surface-to-volume ratio (S/V) as a function of drying. Results of this work demonstrated changes in the S/V due to drying, hydration and drying induced microcracking. Three-dimensional MRI of concrete was performed using SPRITE (Single-Point Ramped Imaging with T1 Enhancement) and turboSPI (turbo Single Point Imaging). While SPRITE allows for weighting of MR images using T 1 and T2*, turboSPI allows T2 weighting of the resulting images. Using relaxation weighting it was shown to be possible to discriminate between water contained within a hydrated cement matrix, and water in highly porous aggregates, used to produce low-density concrete. Three dimensional experiments performed using SPRITE and turboSPI examined the role of self-dessication, drying, initial aggregate saturation and initial mixture conditions on the transport of moisture between porous

  12. Focal Pancreatitis Mimicking Pancreatic Mass: Magnetic Resonance Imaging (MRI)/Magnetic Resonance Cholangiopancreatography (MRCP) Findings Including Diffusion-Weighted MRI

    International Nuclear Information System (INIS)

    Momtahen, A.J.; Balci, N.C.; Alkaade, S.; Akduman, E.I.; Burton, F.R.

    2008-01-01

    Background: Focal pancreatitis (FP) is a confined inflammation that mimics a pancreatic mass. Its imaging diagnosis is important to avoid unnecessary procedures. Purpose: To describe the spectrum of magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted MRI (DWI) findings of focal pancreatitis mimicking pancreatic masses. Material and Methods: Findings of MRI/MRCP including DWI with a b value of 0 and 600 s/mm2 in 14 patients with pancreatic masses on MRI were retrospectively reviewed and compared to normal pancreas in 14 patients as a control group. Results: FP revealed hypointense signal intensity (SI) (3/14), hypo- to isointense SI (7/14), or isointense SI (4/14) on T1-weighted images, and hypointense SI (1/14), isointense SI (5/14), iso- to hyperintense SI (7/14), or hyperintense SI (1/14) on T2-weighted images compared to remaining pancreas (RP). MRCP images revealed dilatation of the common bile duct (CBD) and main pancreatic duct (MPD) (5/14), dilatation of the MPD only (3/14), dilatation of the CBD only (3/14), and normal MPD and CBD (3/14). Both FP and RP revealed three types of time-signal intensity curves: 1) rapid rise to a peak, with a rapid decline (FP=2, RP=4), 2) slow rise to a peak, followed by a slow decline (FP=5, RP=4), and 3) slower rise to a peak, with a slow decline or plateau (FP=7, RP=6). Mean apparent diffusion coefficient (ADC) values for FP and RP were 2.09±0.18 and 2.03±0.2x10 -3 mm 2 /s, respectively. ADC values of FP and RP revealed no significant difference. Conclusion: The spectrum of imaging findings of focal pancreatitis on MRI/MRCP including DWI was described. Findings of FP were not distinctive as compared to the remaining pancreas

  13. How does MRI work? An introduction into physics and functionality of magnetic resonance imaging. 6. ed.

    International Nuclear Information System (INIS)

    Weishaupt, Dominik; Marincek, Borut

    2009-01-01

    The book provides the basic physics and describes the functionality of magnetic resonance tomography in a very illustrative way. The following topics are covered: Spins and the magnetic resonance phenomenon, image contrast, three-dimensional structure, signal-to-noise ratio, description of a magnetic resonance tomography, basic pulse sequences, fast pulse sequences, methods for fat suppression, parallel imaging, cardiovascular imaging, MR contrast media, MR image artifacts, high-field MRI, imaging beyond morphology and structure, safety and risks [de

  14. Magnetic resonance imaging (MRI) of an intraventricular hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ryungchan; Higashi, Tooru; Ito, Shotaro; Kadoya, Satoru; Takarada, Akira; Sato, Shuji; Kurauchi, Manabu.

    1987-08-01

    The utility of MRI was investigated in 10 patients with intraventricular hemorrhage. MRI was found to be, in many respects, superior to CT: 1) MRI is able to detect to some extent the aging of an intraventricular hematoma. 2) It can determine the character of intraventricular cerebrospinal fluid, whether it is normal, bloody, or hyperprotein. 3) It can detect the cause of hemorrhage in the case of arterio-venous malformation. 4) MRI permits the detection of the penetration course and the location of a ventricular hematoma. 5) It can clearly detect periventricular lesions of early-stage hydrocephalus, accompanied by increased intracranial pressure and followed by intraventricular hemorrhage, by imaging the periventricular high-signal-intensity area. 6) MRI can clearly diagnose complications of intracranial lesions. For instance, it can distinguish subdural fluid collection from chronic subdural hematoma and can detect whether a cerebral infarction is new or old. On the other hand, MRI also has some disadvantages: 1) The imaging time is long, and clinical application is difficult, in serious and/or infant cases. 2) It is impossible to use MRI in some patients who have magnetic material in their bodies. 3) The spatial-image resolution is not good.

  15. Magnetic resonance imaging (MRI) of congenital cardiovascular malformations

    International Nuclear Information System (INIS)

    Sakakibara, Makoto; Kobayashi, Shirou; Imai, Hitoshi; Watanabe, Shigeru; Masuda, Yoshiaki; Inagaki, Yoshiaki; Morita, Huminori; Uematsu, Sadao; Arimizu, Noboru

    1986-01-01

    In order to determine the value of MRI in diagnosing congenital cardiovascular malformations, MR Images were obtained in 25 adult patients with congenital cardiovascular malformations. Gated MRI detected all of 13 atrial septal defects, and all of 4 ventricular septal defects, but ungated MRI detected none of 3 atrial septal defects. Other congenital cardiovascular malformations (2 with Ebstein's disease, 1 with Fallot's pentalogy, and 1 with Pulmonary stenosis) were well visualized. Vascular malformations (1 with Patent ducts arteriosus, 1 with Supravalvelar aortic stenosis, 1 with Coarctation of Aorta, 1 with Right Aortic Arch) were well visualized in all of 7 patients by ungated MRI. MRI was a valuable noninvasive method of diagnosing congenital heart disease. (author)

  16. Magnetic resonance imaging (MRI) of the cardiovascular system

    International Nuclear Information System (INIS)

    Yoshida, Shigeru

    1991-01-01

    Qualitative assessments of the hypertrophied myocardium were performed using spin-lattice relaxation time (T1) and spin-spin relaxation time (T2) obtained by magnetic resonance imaging (MRI) in 15 normotensive patients with asymmetric septal hypertrophy (ASH), 10 hypertensive patients with concentric hypertrophy (CH) and 5 normal subjects (N). The changes of these values were evaluated related to cardiac cycle, and their usefulness in differentiating diseases. The wall thickness and internal dimension of the left ventricle (LV) in 10 cases were obtained using echocardiography and MRI, and there was a good correlation coefficient in wall thickness (r=0.987) and in internal dimension (r=0.991). Left ventricular short-axis images were obtained using ECG-gated spin-echo sequence (Te=30, 80 msec) and using inversion recovery sequence. T1 and T2 images were calculated at endsystolic and diastolic cardiac phases. The regional wall thickness (WT) and T1 and T2 values were measured in the anterior septum, anterior wall, lateral wall, posterior wall and posterior septum. Myocardial T1 and T2 values were significantly decreased in systole (T1: 185.6±37.9 msec, T2: 24.4±6.3 msec) compared to those in diastole (T1: 249.2±56.7 msec, T2: 31.7±9.4 msec). In both ASH and CH groups, significant correlations were observed between diastolic T1 values and WT (ASH: r=0.80, CH: r=0.45), and between diastolic T2 values and WT (ASH: r=0.58, CH: r=0.60). In the regions where diastolic WT were more than 17 mm, T1 values in the ASH group (343.4±40.5 msec) were significantly higher than those of the CH group (247.3±21.4 msec), although the mean wall thickness values were similar in both groups. These results indicate that myocardial relaxation times are related to cardiac cycle, wall thickness and types of hypertrophy. The T1 and T2 values at diastolic cardiac phase might be useful for distinguishing hypertrophic cardiomyopathy from hypertrophy due to hypertension. (author)

  17. Wavelet-based de-noising algorithm for images acquired with parallel magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Delakis, Ioannis; Hammad, Omer; Kitney, Richard I

    2007-01-01

    Wavelet-based de-noising has been shown to improve image signal-to-noise ratio in magnetic resonance imaging (MRI) while maintaining spatial resolution. Wavelet-based de-noising techniques typically implemented in MRI require that noise displays uniform spatial distribution. However, images acquired with parallel MRI have spatially varying noise levels. In this work, a new algorithm for filtering images with parallel MRI is presented. The proposed algorithm extracts the edges from the original image and then generates a noise map from the wavelet coefficients at finer scales. The noise map is zeroed at locations where edges have been detected and directional analysis is also used to calculate noise in regions of low-contrast edges that may not have been detected. The new methodology was applied on phantom and brain images and compared with other applicable de-noising techniques. The performance of the proposed algorithm was shown to be comparable with other techniques in central areas of the images, where noise levels are high. In addition, finer details and edges were maintained in peripheral areas, where noise levels are low. The proposed methodology is fully automated and can be applied on final reconstructed images without requiring sensitivity profiles or noise matrices of the receiver coils, therefore making it suitable for implementation in a clinical MRI setting

  18. Non-invasive imaging of plant roots in different soils using magnetic resonance imaging (MRI

    Directory of Open Access Journals (Sweden)

    Daniel Pflugfelder

    2017-11-01

    Full Text Available Abstract Background Root systems are highly plastic and adapt according to their soil environment. Studying the particular influence of soils on root development necessitates the adaptation and evaluation of imaging methods for multiple substrates. Non-invasive 3D root images in soil can be obtained using magnetic resonance imaging (MRI. Not all substrates, however, are suitable for MRI. Using barley as a model plant we investigated the achievable image quality and the suitability for root phenotyping of six commercially available natural soil substrates of commonly occurring soil textures. The results are compared with two artificially composed substrates previously documented for MRI root imaging. Results In five out of the eight tested substrates, barley lateral roots with diameters below 300 µm could still be resolved. In two other soils, only the thicker barley seminal roots were detectable. For these two substrates the minimal detectable root diameter was between 400 and 500 µm. Only one soil did not allow imaging of the roots with MRI. In the artificially composed substrates, soil moisture above 70% of the maximal water holding capacity (WHCmax impeded root imaging. For the natural soil substrates, soil moisture had no effect on MRI root image quality in the investigated range of 50–80% WHCmax. Conclusions Almost all tested natural soil substrates allowed for root imaging using MRI. Half of these substrates resulted in root images comparable to our current lab standard substrate, allowing root detection down to a diameter of 300 µm. These soils were used as supplied by the vendor and, in particular, removal of ferromagnetic particles was not necessary. With the characterization of different soils, investigations such as trait stability across substrates are now possible using noninvasive MRI.

  19. Complete Fourier Direct Magnetic Resonance Imaging (CFD-MRI for Diffusion MRI

    Directory of Open Access Journals (Sweden)

    Alpay eÖzcan

    2013-04-01

    Full Text Available The foundation for an accurate and unifying Fourier based theory of diffusion weighted magnetic resonance imaging (DW-MRI is constructed by carefully re-examining the first principles of DW-MRI signal formation and deriving its mathematical model from scratch. The derivations are specifically obtained for DW-MRI signal by including all of its elements (e.g., imaging gradients using complex values. Particle methods are utilized in contrast to conventional partial differential equations approach. The signal is shown to be the Fourier transform of the joint distribution of number of the magnetic moments (at a given location at the initial time and magnetic moment displacement integrals. In effect, the k-space is augmented by three more dimensions, corresponding to the frequency variables dual to displacement integral vectors. The joint distribution function is recovered by applying the Fourier transform to the complete high-dimensional data set. In the process, to obtain a physically meaningful real valued distribution function, phase corrections are applied for the re-establishment of Hermitian symmetry in the signal. Consequently, the method is fully unconstrained and directly presents the distribution of displacement integrals without any assumptions such as symmetry or Markovian property. The joint distribution function is visualized with isosurfaces, which describe the displacement integrals, overlaid on the distribution map of the number of magnetic moments with low mobility. The model provides an accurate description of the molecular motion measurements via DW-MRI. The improvement of the characterization of tissue microstructure leads to a better localization, detection and assessment of biological properties such as white matter integrity. The results are demonstrated on the experimental data obtained from an ex-vivo baboon brain.

  20. Magnetic resonance imaging (MRI) in the diagnosis of neuromuscular diseases

    International Nuclear Information System (INIS)

    Schalke, B.C.G.; Rohkamm, R.; Kaiser, W.

    1990-01-01

    In the last few years imaging procedures became also important in the diagnosis of neuromuscular diseases. We examined more than 150 patients with different neuromuscular diseases with MRI. Conventional diagnostic procedures like EMG, muscle biopsy can not be replaced by imaging procedures. MRI gives the chance to get additional diagnostic informations. It is possible to determine exact distribution and intensity of pathological changes in the muscle. Inflammatory muscle diseases can be differrentiated by T1/T2 values from atrophic/dystrophic diseases. The resolving power is very high and allows the exact detection of affected areas even in a single muscle. This can help to reduce false negative muscle biopsies. This is very useful in children and young adults. MRI can be used for the early detection of genetic myopathies and neuropathies. MRI allows to examine all muscles, including the heart, bone artefacts are absent. Heart muscle involvement in neuromuscular diseases can directly be shown by this method without any risk for the patient. In addition P-spectroscopy can be done for better understanding of pathogenesis, especially if the exact distribution of pathological changes is known. (author)

  1. Synthese und Charakterisierung amphiphiler Porphyrinoide als Kontrastmittel für das Magnetic Resonance Imaging (MRI)

    OpenAIRE

    Neumann, Yvonne

    2011-01-01

    Magnetic resonance imaging (MRI) is a diagnostic tool, which is commonly used in visualization of internal procedures in the living tissue. Used in visualizing procedures, MRI shows an increased contrast-enhancing effect in soft tissue in contrast to other techniques like computer tomography (CT). MRI does not need any ionizing radiation and provides three dimensional tomographic shots. One of the first commonly used porphyrin-based contrast agents was Gadophrin-2, which has a high affinity t...

  2. Magnetic resonance imaging (MRI) of primary liver cancer

    International Nuclear Information System (INIS)

    Ohtomo, Kuni; Itai, Yuji; Furui, Shigeru; Yoshikawa, Kohki; Yashiro, Naobumi; Iio, Masahiro

    1985-01-01

    In seven primary liver cancers (HCC 5, CCC 1, mixed 1), MR images (0.35 Tesla superconducting) were compared with macroscopic appearances, and relaxation times (T 1 and T 2 ) with microscopic characteristics. MRI was able to reveal the gross appearance of five nodular lesions, but did not reveal one diffuse HCC and one nodular HCC with marked extracapsular extension. T 2 -weighted SE images could not demonstrate fibrous capsules around the tumor in four nodular HCCs. The T 1 and T 2 values of the tumors were longer than those of the surrounding liver parenchyma, and the T 1 elongation corresponded roughly to the degree of necrosis and fibrosis within the tumors. (author)

  3. Application of magnetic resonance imaging (MRI) technique on monitoring flower bud differentiation of tulip

    International Nuclear Information System (INIS)

    Han Haojun; Yang Hongguang; Han Hongbin; Sun Xiaomei

    2009-01-01

    Magnetic resonance imaging (MRI) was used for observing morphogenesis process in the living specimen situation of tulip flower buds. Through a comparison of different MRI imaging formation technique (longitudinal relaxation-T1WI, transverse relaxation time weighted imaging-T2WI, proton density weighted imaging-PDWI), seeking for an accurate and practical MRI technique to observe tulip bulb and differentiation period of flower bud. The results showed that in the demonstration of the morphological characters as well as morphogenesis process of flower bud differentiation, the T1WI was completely consistent with the results of rough slice, PDWI and T1WI also had obviously higher map quality than the T2WI (P<0.05). It is indicated that the magnetic resonance imaging technique could monitor the development of flower bud differentiation in vivo. (authors)

  4. Magnetic resonance imaging (MRI) of the renal sinus.

    Science.gov (United States)

    Krishna, Satheesh; Schieda, Nicola; Flood, Trevor A; Shanbhogue, Alampady Krishna; Ramanathan, Subramaniyan; Siegelman, Evan

    2018-04-09

    This article presents methods to improve MR imaging approach of disorders of the renal sinus which are relatively uncommon and can be technically challenging. Multi-planar Single-shot T2-weighted (T2W) Fast Spin-Echo sequences are recommended to optimally assess anatomic relations of disease. Multi-planar 3D-T1W Gradient Recalled Echo imaging before and after Gadolinium administration depicts the presence and type of enhancement and relation to arterial, venous, and collecting system structures. To improve urographic phase MRI, concentrated Gadolinium in the collecting systems should be diluted. Diffusion-Weighted Imaging (DWI) should be performed before Gadolinium administration to minimize T2* effects. Renal sinus cysts are common but can occasionally be confused for dilated collecting system or calyceal diverticula, with the latter communicating with the collecting system and filling on urographic phase imaging. Vascular lesions (e.g., aneurysm, fistulas) may mimic cystic (or solid) lesions on non-enhanced MRI but can be suspected by noting similar signal intensity to the blood pool and diagnosis can be confirmed with MR angiogram/venogram. Multilocular cystic nephroma commonly extends to the renal sinus, however, to date are indistinguishable from cystic renal cell carcinoma (RCC). Solid hilar tumors are most commonly RCC and urothelial cell carcinoma (UCC). Hilar RCC are heterogeneous, hypervascular with epicenter in the renal cortex compared to UCC which are centered in the collecting system, homogeneously hypovascular, and show profound restricted diffusion. Diagnosis of renal sinus invasion in RCC is critically important as it is the most common imaging cause of pre-operative under-staging of disease. Fat is a normal component of the renal sinus; however, amount of sinus fat correlates with cardiovascular disease and is also seen in lipomatosis. Fat-containing hilar lesions include lipomas, angiomyolipomas, and less commonly other tumors which engulf sinus

  5. Asymptomatic cerebral infarction examined by magnetic resonance imaging (MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Ohsawa, Tamiko; Matsubara, Etsuro; Shoji, Mikio; Okamoto, Koichi; Hirai, Shunsaku [Gunma Univ., Maebashi (Japan). School of Medicine

    1994-02-01

    To find the real incidence and risk factors in asymptomatic cerebral infarction, a retrospective review was made on magnetic resonance (MR) images, which were obtained from 713 outpatients seen at the Geriatrics Research Institute Hospital between March and November of 1990. The criteria for asymptomatic cerebral infarction are: high signal intensity areas larger than 3 mm in diameter on T2-weighted image; no history of stroke; no neurological and psychological signs or symptoms with or without subjective symptoms. Symptomatic cerebral stroke was defined as stroke episodes associated with neurological signs and infarction lesions on CT or MR imaging. Of a total of 713 patients, 215 (30.2%) had symtomatic cerebral infarction and 384 (53.9%) had no cerebral lesions. The incidence of asymptomatic cerebral infarction increased with aging. Cerebral risk factors, i.e. hypertension, atrial fibrillation, and diabetes mellitus, were more significantly common in both symptomatic and asymptomatic groups than the normal control group. In the group of asymptomatic patients, T2-weighted images showed hyperintensity in the corona radiata in 60.9%, in the frontal lobe in 32.1%, in the semioval center in 28.8%, and in the basal ganglia in 23.7%. Periventricular hyperintensity was present in 124 of all 713 patients (17.4%). Common complaints in asymptomatic patients were headache (40.0%), dizziness (14.4%), and neck muscle contraction (9.8%). In conclusion, MR imaging may contribute to manage asymptomatic patients. (N.K.).

  6. Asymptomatic cerebral infarction examined by magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Ohsawa, Tamiko; Matsubara, Etsuro; Shoji, Mikio; Okamoto, Koichi; Hirai, Shunsaku

    1994-01-01

    To find the real incidence and risk factors in asymptomatic cerebral infarction, a retrospective review was made on magnetic resonance (MR) images, which were obtained from 713 outpatients seen at the Geriatrics Research Institute Hospital between March and November of 1990. The criteria for asymptomatic cerebral infarction are: high signal intensity areas larger than 3 mm in diameter on T2-weighted image; no history of stroke; no neurological and psychological signs or symptoms with or without subjective symptoms. Symptomatic cerebral stroke was defined as stroke episodes associated with neurological signs and infarction lesions on CT or MR imaging. Of a total of 713 patients, 215 (30.2%) had symtomatic cerebral infarction and 384 (53.9%) had no cerebral lesions. The incidence of asymptomatic cerebral infarction increased with aging. Cerebral risk factors, i.e. hypertension, atrial fibrillation, and diabetes mellitus, were more significantly common in both symptomatic and asymptomatic groups than the normal control group. In the group of asymptomatic patients, T2-weighted images showed hyperintensity in the corona radiata in 60.9%, in the frontal lobe in 32.1%, in the semioval center in 28.8%, and in the basal ganglia in 23.7%. Periventricular hyperintensity was present in 124 of all 713 patients (17.4%). Common complaints in asymptomatic patients were headache (40.0%), dizziness (14.4%), and neck muscle contraction (9.8%). In conclusion, MR imaging may contribute to manage asymptomatic patients. (N.K.)

  7. Usefulness of magnetic resonance imaging (MRI) for patients with unilateral tinnitus

    Energy Technology Data Exchange (ETDEWEB)

    Katsura, Motoyasu [Sasebo Central Hospital, Nagasaki (Japan); Yoshida, Haruo; Kumagami, Hidetaka; Takahashi, Haruo [Nagasaki Univ. (Japan). Graduate School of Biomedical Sciences; Oosato, Yasuo [Sasebo City Hospital, Nagasaki (Japan); Dotsu, Mitsuru [National Nagasaki Medical Center, Omura (Japan)

    2004-06-01

    Audiography, X-ray (Stenvers view) and Magnetic Resonance Imaging (MRI) were performed on 88 patients exhibiting unilateral tinnitus. We diagnosed 4 cases (4.5%) of vestibular schwannoma and 41 cases (46.6%) of other abnormalities, including 2 cases of meningioma, 24 cases of old cerebral infarction, and 5 cases of mastoiditis. MRI was considered to be a first-line clinical examination for patients with unilateral tinnitus. (author)

  8. Usefulness of magnetic resonance imaging (MRI) for patients with unilateral tinnitus

    International Nuclear Information System (INIS)

    Katsura, Motoyasu; Yoshida, Haruo; Kumagami, Hidetaka; Takahashi, Haruo; Dotsu, Mitsuru

    2004-01-01

    Audiography, X-ray (Stenvers view) and Magnetic Resonance Imaging (MRI) were performed on 88 patients exhibiting unilateral tinnitus. We diagnosed 4 cases (4.5%) of vestibular schwannoma and 41 cases (46.6%) of other abnormalities, including 2 cases of meningioma, 24 cases of old cerebral infarction, and 5 cases of mastoiditis. MRI was considered to be a first-line clinical examination for patients with unilateral tinnitus. (author)

  9. Contribution of brain imaging techniques: CT-scan and magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Pasco-Papon, A.; Gourdier, A.L.; Papon, X.; Caron-Poitreau, C.

    1996-01-01

    In light of the current lack of consensus on the benefit of carotid artery surgery to treat asymptomatic carotid artery stenosis, the decision to operate on a patient depends on individual evaluation and characterization of risk factors on carotid artery stenosis greater than 70 %. The assessment of such risk factors is based especially on non-invasive brain imaging techniques.Computed tomography scanning (CT-scan) and magnetic resonance imaging (MRI) enable two types of stenosis to be differentiated, i.e. stenoses which are symptomatic and those that are radiologically proven versus those which are clinically and radiologically silent. CT-scan investigation (with and without injection of iodinated contrast media) still continues to be a common routine test in 1996 whenever a surgical revascularization procedure is planned. The presence of deep lacunar infarcts ipsilateral to the carotid artery stenosis generally evidence the reality of stenosis and thus are useful to the surgeon in establishing whether surgery is indicated. In the absence a consensus on indications for surgical management, the surgeon could use the CT-scan and MRI as medicolegal records which could be compared to a subsequent postoperative CT-scan in case of ischemic complications associated with the surgical procedure. Furthermore, recent cerebral ischemia as evidenced by filling with contrast material, will call for postponing treatment by a few weeks. Although conventional MRI is more contributive than brain CT-scan in terms of sensibility and specificity, its indications are narrower because of its limited availability and cost constraints. But, development of angio-MRI and functional imaging promise that its future is assured and even perhaps as the sole diagnostic method if its indications are expanded to include preoperative angiographic evaluation of atheromatous lesions of supra-aortic trunks. (authors). 37 refs

  10. Structural Image Analysis of the Brain in Neuropsychology Using Magnetic Resonance Imaging (MRI) Techniques.

    Science.gov (United States)

    Bigler, Erin D

    2015-09-01

    Magnetic resonance imaging (MRI) of the brain provides exceptional image quality for visualization and neuroanatomical classification of brain structure. A variety of image analysis techniques provide both qualitative as well as quantitative methods to relate brain structure with neuropsychological outcome and are reviewed herein. Of particular importance are more automated methods that permit analysis of a broad spectrum of anatomical measures including volume, thickness and shape. The challenge for neuropsychology is which metric to use, for which disorder and the timing of when image analysis methods are applied to assess brain structure and pathology. A basic overview is provided as to the anatomical and pathoanatomical relations of different MRI sequences in assessing normal and abnormal findings. Some interpretive guidelines are offered including factors related to similarity and symmetry of typical brain development along with size-normalcy features of brain anatomy related to function. The review concludes with a detailed example of various quantitative techniques applied to analyzing brain structure for neuropsychological outcome studies in traumatic brain injury.

  11. The hypofunctioning thyroid nodule: Radiography, computed tomography (CT) and magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Dorn, R.; Wagner-Manslau, C.

    1992-01-01

    The hyperfunctioning thyroid nodule is a scintigraphic diagnosis by definition. Its dignity is assessed by fine needle aspiration biopsy. Radiographic methods and magnetic resonance imaging (MRI) are no primary tools in diagnosis of the hypofunctioning thyroid nodule but may reveal additional information, especially in cases of retrosternal goiter and thyroid malignomas. (orig.) [de

  12. Physiological and technical limitations of functional magnetic resonance imaging (fMRI) - consequences for clinical use

    International Nuclear Information System (INIS)

    Wuestenberg, T.; Jordan, K.; Giesel, F.L.; Villringer, A.

    2003-01-01

    Functional magnetic resonance imaging (fMRI) is the most common noninvasive technique in functional neuroanatomy. The capabilities and limitations of the method will be discussed based on a short review of the current knowledge about the neurovascular relationship. The focus of this article is on current methodical and technical problems regarding fMRI-based detection and localization of neuronal activity. Main error sources and their influence on the reliability and validity of fMRI-methods are presented. Appropriate solution strategies will be proposed and evaluated. Finally, the clinical relevance of MR-based diagnostic methods are discussed. (orig.) [de

  13. Magnetic resonance imaging (MRI) in diffuse liver diseases. Comparison with CT

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Masaharu; Ebara, Masaaki; Ohto, Masao

    1987-06-01

    MRI (Magnetic Resonance Imaging) was performed in 74 patients with chronic hepatitis, liver cirrhosis, idiopathic portal hypertension, Budd-Chiari syndrome, extrahepatic protal vein occlusion, Wilson disease and hemochromatosis. We measured relaxation time of the liver and the spleen in these patients and compared MRI with CT in the diagnostic capability. MRI was superior to plain CT in the detection of collateral vessels in liver cirrhosis and extrahepatic protal vein occlusion. MRI could also demonstrate the occluded part of the inferior vena cava in Budd-Chiari syndrome. However, MRI was almost the same as CT in the visualization of the hepatic configuration in liver cirrhosis. In liver cirrhosis, T1 values of the liver and the spleen were longer than those in normal controls, and T1 values of the liver were correlated with ICG R-15. Hepatic T1 values in Budd-Chiari syndrome were longer than those in normal controls.

  14. Role of magnetic resonance imaging (MRI), MR spectroscopy (MRS) and other imaging modalities in breast cancer

    International Nuclear Information System (INIS)

    Sharma, Uma; Virendra Kumar; Jagannathan, N.R.

    2004-01-01

    Breast cancer is the commonest cancer among women world over and the diagnosis continues to generate fear and turmoil in the life of patients and their families. This article describes the currently available techniques used for screening primary and recurrent breast cancers and the evaluation of therapeutic response of breast cancer with special emphasis on MRI and MRS techniques. MRI, a noninvasive technique, provides anatomic images in multiple planes enabling tissue characterization. Contrast enhanced MR studies have been found to be useful in the diagnosis of small tumors in dense breast benign diseases from malignant ones. In vivo magnetic resonance spectroscopy (MRS) is another useful technique for diagnosis and for assessing the biochemical status of normal and diseased tissues. Being noninvasive, MR techniques can be used repetitively for assessment of response of the tumor to various therapeutic regimens and for evaluating the efficacy of drugs at both the structural and molecular level. An overview of the various aspects of different imaging modalities used in breast cancer research including various in vivo MR methodologies with clinical examples is presented in this review. (author)

  15. Magnetic resonance imaging (MRI) of avascular necrosis of the femoral head

    International Nuclear Information System (INIS)

    Kokubo, Takashi; Yoshikawa, Kohki; Aoki, Shigeki

    1987-01-01

    Thirty-seven patients with the clinical diagnosis of or suspicious of avascular necrosis (AN) of the femoral head were examined by magnetic resonance imaging (MRI). In all patients with AN confirmed from clinical symptoms, past history and plain radiographs, MRI demonstrated abnormal low intensity area in the necrosed femoral head. The abnormal findings on MRI were divided into three patterns: low signal intensity occupying the greater part of the femoral head (type A), low signal intensity localized in the periphery (type B), ring-shaped or band-like low signal intensity (type C). No correlation was found among MRI patterns, radiographic findings and radionuclide bone scan images, except that the type C was not found in the stage IV determined radiographically. In the patients suspicious of AN, the positive rate of MRI was higher than that of radionuclide scan. Abnormal findings on only MRI may not necessarily indicate AN. However, such a patient must be kept under observation, because the possibility exists that only MRI detects early or asymptomatic AN of the femoral head. (author)

  16. Magnetic resonance imaging (MRI) of avascular necrosis of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Kokubo, Takashi; Yoshikawa, Kohki; Aoki, Shigeki

    1987-05-01

    Thirty-seven patients with the clinical diagnosis of or suspicious of avascular necrosis (AN) of the femoral head were examined by magnetic resonance imaging (MRI). In all patients with AN confirmed from clinical symptoms, past history and plain radiographs, MRI demonstrated abnormal low intensity area in the necrosed femoral head. The abnormal findings on MRI were divided into three patterns: low signal intensity occupying the greater part of the femoral head (type A), low signal intensity localized in the periphery (type B), ring-shaped or band-like low signal intensity (type C). No correlation was found among MRI patterns, radiographic findings and radionuclide bone scan images, except that the type C was not found in the stage IV determined radiographically. In the patients suspicious of AN, the positive rate of MRI was higher than that of radionuclide scan. Abnormal findings on only MRI may not necessarily indicate AN. However, such a patient must be kept under observation, because the possibility exists that only MRI detects early or asymptomatic AN of the femoral head.

  17. Magnetic resonance imaging (MRI) in the diagnosis of optic neuritis and neuropathy

    International Nuclear Information System (INIS)

    Kakisu, Yonetsugu; Adachi-Usami, Emiko; Kojima, Shigeyuki; Hirayama, Keizo

    1989-01-01

    Magnetic resonance imaging (MRI) was performed in thirty patients who had been suffering from optic neuritis (ON). Twenty-one cases were caused by multiple sclerosis (MS) and in 9 cases the causes been defined. In MRI, abnormalities were found in 17 out of 21 MS cases in several places such as near the ventricles, mid-brain, spinal cord etc. Increased signals from the optic chiasm to optic radiation were found in 5 cases. However, abnormal MRI findings did not always correspond to Goldmann visual field defects. In 3 out of 9 cases of ON with unknown causes, high signals in the white matter of the brain were found, and it was suggested that those may develop to MS. MRI was, thus, proved to be very useful for the diagnois of MS. (author)

  18. Magnetic resonance imaging (MRI) in the diagnosis of optic neuritis and neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kakisu, Yonetsugu; Adachi-Usami, Emiko; Kojima, Shigeyuki; Hirayama, Keizo

    1989-02-01

    Magnetic resonance imaging (MRI) was performed in thirty patients who had been suffering from optic neuritis (ON). Twenty-one cases were caused by multiple sclerosis (MS) and in 9 cases the causes been defined. In MRI, abnormalities were found in 17 out of 21 MS cases in several places such as near the ventricles, mid-brain, spinal cord etc. Increased signals from the optic chiasm to optic radiation were found in 5 cases. However, abnormal MRI findings did not always correspond to Goldmann visual field defects. In 3 out of 9 cases of ON with unknown causes, high signals in the white matter of the brain were found, and it was suggested that those may develop to MS. MRI was, thus, proved to be very useful for the diagnois of MS.

  19. Magnetic resonance imaging goes postmortem: noninvasive detection and assessment of myocardial infarction by postmortem MRI

    International Nuclear Information System (INIS)

    Jackowski, Christian; Warntjes, Marcel J.B.; Persson, Anders; Berge, Johan; Baer, Walter

    2011-01-01

    To investigate the performance of postmortem magnetic resonance imaging (pmMRI) in identification and characterization of lethal myocardial infarction in a non-invasive manner on human corpses. Before forensic autopsy, 20 human forensic corpses were examined on a 1.5-T system for the presence of myocardial infarction. Short axis, transversal and longitudinal long axis images (T1-weighted; T2-weighted; PD-weighted) were acquired in situ. In subsequent autopsy, the section technique was adapted to short axis images. Histological investigations were conducted to confirm autopsy and/or radiological diagnoses. Nineteen myocardial lesions were detected and age staged with pmMRI, of which 13 were histologically confirmed (chronic, subacute and acute). Six lesions interpreted as peracute by pmMRI showed no macroscopic or histological finding. Five of the six peracute lesions correlated well to coronary pathology, and one case displayed a severe hypertrophic alteration. pmMRI reliably demonstrates chronic, subacute and acute myocardial infarction in situ. In peracute cases pmMRI may display ischemic lesions undetectable at autopsy and routine histology. pmMRI has the potential to substantiate autopsy and to counteract the loss of reliable information on causes of death due to the recent disappearance of the clinical autopsy. (orig.)

  20. Defining active sacroiliitis on magnetic resonance imaging (MRI) for classification of axial spondyloarthritis: a consensual approach by the ASAS/OMERACT MRI group

    NARCIS (Netherlands)

    Rudwaleit, M.; Jurik, A. G.; Hermann, K.-G. A.; Landewé, R.; van der Heijde, D.; Baraliakos, X.; Marzo-Ortega, H.; Ostergaard, M.; Braun, J.; Sieper, J.

    2009-01-01

    Magnetic resonance imaging (MRI) of sacroiliac joints has evolved as the most relevant imaging modality for diagnosis and classification of early axial spondyloarthritis (SpA) including early ankylosing spondylitis. To identify and describe MRI findings in sacroiliitis and to reach consensus on

  1. The OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging (MRI) Scoring System: Updated Recommendations by the OMERACT MRI in Arthritis Working Group.

    Science.gov (United States)

    Østergaard, Mikkel; Peterfy, Charles G; Bird, Paul; Gandjbakhch, Frédérique; Glinatsi, Daniel; Eshed, Iris; Haavardsholm, Espen A; Lillegraven, Siri; Bøyesen, Pernille; Ejbjerg, Bo; Foltz, Violaine; Emery, Paul; Genant, Harry K; Conaghan, Philip G

    2017-11-01

    The Outcome Measures in Rheumatology (OMERACT) Rheumatoid Arthritis (RA) Magnetic Resonance Imaging (MRI) scoring system (RAMRIS), evaluating bone erosion, bone marrow edema/osteitis, and synovitis, was introduced in 2002, and is now the standard method of objectively quantifying inflammation and damage by MRI in RA trials. The objective of this paper was to identify subsequent advances and based on them, to provide updated recommendations for the RAMRIS. MRI studies relevant for RAMRIS and technical and scientific advances were analyzed by the OMERACT MRI in Arthritis Working Group, which used these data to provide updated considerations on image acquisition, RAMRIS definitions, and scoring systems for the original and new RA pathologies. Further, a research agenda was outlined. Since 2002, longitudinal studies and clinical trials have documented RAMRIS variables to have face, construct, and criterion validity; high reliability and sensitivity to change; and the ability to discriminate between therapies. This has enabled RAMRIS to demonstrate inhibition of structural damage progression with fewer patients and shorter followup times than has been possible with conventional radiography. Technical improvements, including higher field strengths and improved pulse sequences, allow higher image resolution and contrast-to-noise ratio. These have facilitated development and validation of scoring methods of new pathologies: joint space narrowing and tenosynovitis. These have high reproducibility and moderate sensitivity to change, and can be added to RAMRIS. Combined scores of inflammation or joint damage may increase sensitivity to change and discriminative power. However, this requires further research. Updated 2016 RAMRIS recommendations and a research agenda were developed.

  2. Magnetic Resonance Imaging (MRI) Evaluation of Developmental Delay in Pediatric Patients

    OpenAIRE

    Ali, Althaf S.; Syed, Naziya P.; Murthy, G.S.N.; Nori, Madhavi; Abkari, Anand; Pooja, B.K.; Venkateswarlu, J.

    2015-01-01

    Introduction: Developmental delay is defined as significant delay in one or more developmental domains. Magnetic Resonance Imaging (MRI) is the best modality to investigate such patients. Evaluation of a child with developmental delay is important not only because it allows early diagnosis and treatment but also helpful for parental counseling regarding the outcome of their child and to identify any possible risk of recurrence in the siblings. Thus this study was undertaken to evaluate the de...

  3. Studies on improvement of diagnosis of neurosurgical lesions by magnetic resonance imaging (MRI), 2

    International Nuclear Information System (INIS)

    Shimizu, Kotoyuki

    1989-01-01

    Findings of magnetic resonance (MRI) imaging in 46 patients with sellar or parasellar mass were reviewed and compared with those of concurrently available X-ray CT. Intrasellar contents, the hypothalamic pituitary region, adjacent brain stem, optic nerves, and the surrounding cerebrospinal fluid were clearly depicted on T1-weighted images. The cavernous sinus and blood vessels, including the Willis circle, were visualized on T2-weighted images. In detecting pituitary macroadenoma, MRI seemed to be the most userful modality, because it was superior to CT in identifying abnormal changes of the infundibulum, diaphragma sellae, cavernous sinus and optic chiasm. Macroadenoma of the pituitary gland was usually isointense to the normal cerebral cortex on T1- and T2-weighted images. T1- and T2-weighted relaxation times for pituitary adenoma were slightly prolonged. The normal pituitary gland was distinguishable from adenomatous tissues. For microadenoma, MRI failed to show lesions or erosion of the sellar floor. Craniopharyngioma, meningioma of the tuberculum sellae, hypothalamic tumor, such as glioma and germinoma, and the other parasellar masses were clearly visualized on MRI. MRI was superior to CT in detecting tumor and its involvement, but inferior in detecting presence of calcification. T1-weighted imaging was useful in identifing the presence of intratumoral hemorrhage. Cysts of craniopharyngioma had various appearances on T1-weighted images. High signal cyst intensity corresponded to a high cholesterol content or the presence of methemoglobin. MRI depicted empty sella. The intrasellar content had the same appearance as that of the cerebrospinal fluid space, and the flattened pituitary gland and pituitary stalk were detected on T1-weighted images. (N.K.)

  4. Analysis of systemic lupus erythematosus (SLE) involving the central nervous system by magnetic resonance imaging (MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kimihiro; Hara, Masako; Nakajima, Shinji and others

    1989-04-01

    Involvement of the central nervous system (CNS) commonly occurs in systemic lupus erythematosus (SLE). But definitive diagnosis remains difficult even with computed tomography (CT). In this study, we used the recently developed technique, magnetic resonance imaging (MRI) for CNS lupus and compared it with CT scans. CT was performed with a General Electric 8800 CT/T scanner. MRI was performed using a Mitsubishi Electric MMI-150 S. Ten patients with CNS lupus were divided into 3 groups. Group I included 4 cases with neurological manifestations alone. All lesions seen on CT were also detected by MRI, with greater clarity and extent. Furthermore, MRI depicted several microinfarcts in white matter without symptoms. Group II included 5 cases with psychiatric features alone. MRI detected a thalamic microinfarct in only one case while CT showed no abnormality in all cases. Group III included 1 case with both neurological and psychiatric symptoms. MRI demonstrated a small infarct of midbrain corresponding with neurological symptoms, more clearly than CT. Therefore MRI demonstrates the degree of brain involvement in SLE more accurately than CT. (author).

  5. Analysis of systemic lupus erythematosus (SLE) involving the central nervous system by magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Suzuki, Kimihiro; Hara, Masako; Nakajima, Shinji

    1989-01-01

    Involvement of the central nervous system (CNS) commonly occurs in systemic lupus erythematosus (SLE). But definitive diagnosis remains difficult even with computed tomography (CT). In this study, we used the recently developed technique, magnetic resonance imaging (MRI) for CNS lupus and compared it with CT scans. CT was performed with a General Electric 8800 CT/T scanner. MRI was performed using a Mitsubishi Electric MMI-150 S. Ten patients with CNS lupus were divided into 3 groups. Group I included 4 cases with neurological manifestations alone. All lesions seen on CT were also detected by MRI, with greater clarity and extent. Furthermore, MRI depicted several microinfarcts in white matter without symptoms. Group II included 5 cases with psychiatric features alone. MRI detected a thalamic microinfarct in only one case while CT showed no abnormality in all cases. Group III included 1 case with both neurological and psychiatric symptoms. MRI demonstrated a small infarct of midbrain corresponding with neurological symptoms, more clearly than CT. Therefore MRI demonstrates the degree of brain involvement in SLE more accurately than CT. (author)

  6. Magnetic resonance imaging of the triangular fibrocartilage complex. Usefulness of the fat suppression MRI

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Toshiyasu [Fujita Health Univ., Nagoya (Japan). Second Hospital; Yabe, Yutaka; Horiuchi, Yukio; Kikuchi, Yoshito; Makita, Satoo

    1996-08-01

    Advances in magnetic resonance imaging (MRI) now allow for the visualization of small structures, such as the triangular fibrocartilage complex (TFCC) of the wrist. Recent investigators suggested that MRI is useful in delineation of the TFCC itself and its abnormality, and supported that diagnostic value of MRI for the TFCC tears is almost equal to those of arthrography and arthroscopy. In contrast, there were several reports that representation of the TFCC in MRI was less worth than in arthrography. Further, it was reported that MRI was not useful because abnormal findings existed at normal volunteers` wrists. Recent development of the pulse sequence is remarkable, such as gradient echo, fast spin echo and fat suppression method. However, as the previous MR studies of the TFCC mainly using conventional spin echo pulse sequence, there were a few comparison of each pulse sequence and we do not know how each pulse sequence delineates the TFCC. Therefore, we studied MRI of the TFCC using several pulse sequence in normal volunteers, and compared MR slices of the TFCC with corresponding histological sections to evaluate shape detectability of MRI. (J.P.N.)

  7. Children's (Pediatric) Magnetic Resonance Imaging

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

  8. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

  9. Fat ViP MRI: Virtual Phantom Magnetic Resonance Imaging of water-fat systems.

    Science.gov (United States)

    Salvati, Roberto; Hitti, Eric; Bellanger, Jean-Jacques; Saint-Jalmes, Hervé; Gambarota, Giulio

    2016-06-01

    Virtual Phantom Magnetic Resonance Imaging (ViP MRI) is a method to generate reference signals on MR images, using external radiofrequency (RF) signals. The aim of this study was to assess the feasibility of ViP MRI to generate complex-data images of phantoms mimicking water-fat systems. Various numerical phantoms with a given fat fraction, T2* and field map were designed. The k-space of numerical phantoms was converted into RF signals to generate virtual phantoms. MRI experiments were performed at 4.7T using a multi-gradient-echo sequence on virtual and physical phantoms. The data acquisition of virtual and physical phantoms was simultaneous. Decomposition of the water and fat signals was performed using a complex-based water-fat separation algorithm. Overall, a good agreement was observed between the fat fraction, T2* and phase map values of the virtual and numerical phantoms. In particular, fat fractions of 10.5±0.1 (vs 10% of the numerical phantom), 20.3±0.1 (vs 20%) and 30.4±0.1 (vs 30%) were obtained in virtual phantoms. The ViP MRI method allows for generating imaging phantoms that i) mimic water-fat systems and ii) can be analyzed with water-fat separation algorithms based on complex data. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Assessment of congenital heart disease (CHD): Is there a role for fetal magnetic resonance imaging (MRI)?

    Energy Technology Data Exchange (ETDEWEB)

    Manganaro, L. [Department of Radiological Sciences, UMBERTO I Hospital, SAPIENZA University of Rome, Viale del Policlinico 155, 00161 Rome (Italy); Savelli, S. [Department of Radiological Sciences, UMBERTO I Hospital, SAPIENZA University of Rome, Viale del Policlinico 155, 00161 Rome (Italy)], E-mail: sarasavelli@hotmail.it; Di Maurizio, M.; Perrone, A.; Francioso, A.; La Barbera, L.; Totaro, P.; Fierro, F.; Tomei, A.; Coratella, F. [Department of Radiological Sciences, UMBERTO I Hospital, SAPIENZA University of Rome, Viale del Policlinico 155, 00161 Rome (Italy); Giancotti, A. [Department of Gynaecological Sciences, UMBERTO I Hospital, SAPIENZA University of Rome, Viale del Policlinico 155, 00161 Rome (Italy); Ballesio, L. [Department of Radiological Sciences, UMBERTO I Hospital, SAPIENZA University of Rome, Viale del Policlinico 155, 00161 Rome (Italy); Ventriglia, F. [Department of Pediatric Cardiology, UMBERTO I Hospital, SAPIENZA University of Rome, Viale del Policlinico 155, 00161 Rome (Italy)

    2009-10-15

    Purpose: To review our experience with fetal magnetic resonance imaging (MRI) to evaluate congenital heart disease (CHD). Methods: We performed fetal MRI in 32 fetuses with an echocardiographically assessed CHD. Both direct and indirect signs of CHD were investigated. Direct signs considered were: morpho-volumetric abnormalities of the heart; malrotations; ventricular and atrial septal defects; anomalies of the origin, size and course of the great arteries. Indirect signs considered were: difficulty to recognize a 'normal' anatomical structures in the reference projections; increase of the vascular size before a stenosis; hypertrophy of the papillary muscles; cardiomegaly and pericardial effusion. All MRI findings were compared with postnatal or autoptic findings. Results: MRI allowed the CHD to be visualised by direct signs in 17 fetuses, indirect signs in 5 and both direct and indirect signs in 9 fetuses, excluding the prenatal echocardiographic suspect of hypoplastic left heart syndrome in 1 fetus. Postnatal echocardiograms or autoptic findings confirmed a normal heart in 1 fetus and CHD in 31 fetuses including a single cardiac anomaly or syndrome in 19 fetuses, 2 associated cardiac abnormalities in 11 and 3 cardiac anomalies in 1 fetus. However, in 2 fetuses MRI detected a ventricular septal defect successively disclosed by gold standard. Conclusions: MRI is a promising method for further assessment of the cardiovascular pathologies diagnosed by echocardiography, and may be a valuable tool in assessing associated extracardiac anomalies.

  11. Development of Laser-Polarized Noble Gas Magnetic Resonance Imaging (MRI) Technology

    Science.gov (United States)

    Walsworth, Ronald L.

    2004-01-01

    We are developing technology for laser-polarized noble gas nuclear magnetic resonance (NMR), with the aim of enabling it as a novel biomedical imaging tool for ground-based and eventually space-based application. This emerging multidisciplinary technology enables high-resolution gas-space magnetic resonance imaging (MRI)-e.g., of lung ventilation, perfusion, and gas-exchange. In addition, laser-polarized noble gases (3He and 1BXe) do not require a large magnetic field for sensitive NMR detection, opening the door to practical MRI with novel, open-access magnet designs at very low magnetic fields (and hence in confined spaces). We are pursuing two specific aims in this technology development program. The first aim is to develop an open-access, low-field (less than 0.01 T) instrument for MRI studies of human gas inhalation as a function of subject orientation, and the second aim is to develop functional imaging of the lung using laser-polarized He-3 and Xe-129.

  12. Contactless Abdominal Fat Reduction With Selective RF™ Evaluated by Magnetic Resonance Imaging (MRI): Case Study.

    Science.gov (United States)

    Downie, Jeanine; Kaspar, Miroslav

    2016-04-01

    Noninvasive body shaping methods seem to be an ascending part of the aesthetics market. As a result, the pressure to develop reliable methods for the collection and presentation of their results has also increased. The most used techniques currently include ultrasound measurements of fat thickness in the treated area, caliper measurements, bioimpedance-based scale measurements or circumferential tape measurements. Although these are the most used techniques, almost all of them have some limitations in reproducibility and/or accuracy. This study shows Magnetic Resonance Imaging (MRI) as the new method for the presentation of results in the body shaping industry. Six subjects were treated by a contactless selective radiofrequency device (BTL Vanquish ME, BTL Industries Inc., Boston, MA). The MRI fat thickness was measured at the baseline and at 4-weeks following the treatment. In addition to MRI images and measurements, digital photographs and anthropometric evaluations such as weight, abdominal circumference, and caliper fat thickness measurements were recorded. Abdominal fat thickness measurements from the MRI were performed from the same slices determined by the same tissue artefacts. The MRI fat thickness difference between the baseline measurement and follow up visit showed an average reduction of 5.36 mm as calculated from the data of 5 subjects. One subject dropped out of study due to non-study related issues. The results were statistically significant based on the Student's T-test evaluation. Magnetic resonance imaging abdominal fat thickness measurements seems to be the best method for the evaluation of fat thickness reduction after non-invasive body shaping treatments. In this study, this method shows average fat thickness reduction of 5.36 mm while the weight of the subjects didn't change significantly. A large spot size measuring 1317 cm(2) (204 square inches) covers the abdomen flank to flank. The average thickness of 5.36 mm of the fat layer reduced

  13. Reliability of Early Magnetic Resonance Imaging (MRI) and Necessity of Repeating MRI in Noncooled and Cooled Infants With Neonatal Encephalopathy.

    Science.gov (United States)

    Chakkarapani, Elavazhagan; Poskitt, Kenneth J; Miller, Steven P; Zwicker, Jill G; Xu, Qi; Wong, Darren S T; Roland, Elke H; Hill, Alan; Chau, Vann

    2016-04-01

    In cooled newborns with encephalopathy, although late magnetic resonance imaging (MRI) scan (10-14 days of age) is reliable in predicting long-term outcome, it is unknown whether early scan (3-6 days of life) is. We compared the predominant pattern and extent of lesion between early and late MRI in 89 term neonates with neonatal encephalopathy. Forty-three neonates (48%) were cooled. The predominant pattern of lesions and the extent of lesion in the watershed region agreed near perfectly in noncooled (kappa = 0.94; k = 0.88) and cooled (k = 0.89; k = 0.87) infants respectively. There was perfect agreement in the extent of lesion in the basal nuclei in noncooled infants (k = 0.83) and excellent agreement in cooled infants (k = 0.67). Changes in extent of lesions on late MRI occurred in 19 of 89 infants, with higher risk in infants with hypoglycemia and moderate-severe lesions in basal nuclei. In most term neonates with neonatal encephalopathy, early MRI (relative to late scan) robustly predicts the predominant pattern and extent of injury. © The Author(s) 2015.

  14. Preoperative functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS)

    DEFF Research Database (Denmark)

    Hartwigsen, G.; Siebner, Hartwig R.; Stippich, C.

    2010-01-01

    Neurosurgical resection of brain lesions aims to maximize excision while minimizing the risk of permanent injury to the surrounding intact brain tissue and resulting neurological deficits. While direct electrical cortical stimulation at the time of surgery allows the precise identification...... of essential cortex, it cannot provide information preoperatively for surgical planning.Brain imaging techniques such as functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG) and transcranial magnetic stimulation (TMS) are increasingly being used to localize functionally critical cortical......, if the stimulated cortex makes a critical contribution to the brain functions subserving the task. While the relationship between task and functional activation as revealed by fMRI is correlative in nature, the neurodisruptive effect of TMS reflects a causal effect on brain activity.The use of preoperative f...

  15. The role of magnetic resonance imaging (MRI) in focal therapy for prostate cancer: recommendations from a consensus panel

    NARCIS (Netherlands)

    Muller, Berrend G.; Fütterer, Jurgen J.; Gupta, Rajan T.; Katz, Aaron; Kirkham, Alexander; Kurhanewicz, John; Moul, Judd W.; Pinto, Peter A.; Rastinehad, Ardeshir R.; Robertson, Cary; de la Rosette, Jean; Sanchez-Salas, Rafael; Jones, J. Stephen; Ukimura, Osamu; Verma, Sadhna; Wijkstra, Hessel; Marberger, Michael

    2014-01-01

    To establish a consensus on the utility of multiparametric magnetic resonance imaging (mpMRI) to identify patients for focal therapy. Urological surgeons, radiologists, and basic researchers, from Europe and North America participated in a consensus meeting about the use of mpMRI in focal therapy of

  16. Approximate fuzzy C-means (AFCM) cluster analysis of medical magnetic resonance image (MRI) data

    International Nuclear Information System (INIS)

    DelaPaz, R.L.; Chang, P.J.; Bernstein, R.; Dave, J.V.

    1987-01-01

    The authors describe the application of an approximate fuzzy C-means (AFCM) clustering algorithm as a data dimension reduction approach to medical magnetic resonance images (MRI). Image data consisted of one T1-weighted, two T2-weighted, and one T2*-weighted (magnetic susceptibility) image for each cranial study and a matrix of 10 images generated from 10 combinations of TE and TR for each body lymphoma study. All images were obtained with a 1.5 Tesla imaging system (GE Signa). Analyses were performed on over 100 MR image sets with a variety of pathologies. The cluster analysis was operated in an unsupervised mode and computational overhead was minimized by utilizing a table look-up approach without adversely affecting accuracy. Image data were first segmented into 2 coarse clusters, each of which was then subdivided into 16 fine clusters. The final tissue classifications were presented as color-coded anatomically-mapped images and as two and three dimensional displays of cluster center data in selected feature space (minimum spanning tree). Fuzzy cluster analysis appears to be a clinically useful dimension reduction technique which results in improved diagnostic specificity of medical magnetic resonance images

  17. Magnetic Resonance Imaging of Stroke

    NARCIS (Netherlands)

    Bouts, Mark. J. R. J.; Wu, O.; Dijkhuizen, R. M.

    2017-01-01

    Magnetic resonance imaging (MRI) provides a powerful (neuro)imaging modality for the diagnosis and outcome prediction after (acute) stroke. Since MRI allows noninvasive, longitudinal, and three-dimensional assessment of vessel occlusion (with magnetic resonance angiography (MRA)), tissue injury

  18. Developing Criteria for Lumbar Spine Magnetic Resonance Imaging (MRI) Using RAND Appropriateness Method (RAM)

    International Nuclear Information System (INIS)

    Keshtkaran, Ali; Bagheri, Mohammad Hadi; Ostovar, Rahim; Salari, Hedayat; Farokhi, Majid Reza; Esfandiari, Atefeh; Yousefimanesh, Hossein

    2012-01-01

    Studies show that a large proportion of healthcare offered may be inappropriate or unnecessary. Magnetic resonance imaging (MRI) is a new and expensive diagnostic technology which has been increasingly used all over the world. Moreover, this trend has been more rapidly increasing in Iran. Low back pain is a common disorder all over the world and MRI technique is one of the several ways to assess its cause. The present study aims to develop scenarios for lumbar spine MRI. In the present study, the RAND Appropriateness Method (RAM) was used in order to reach consensus regarding developing scenarios for lumbar spine MRI. We generated scenarios from valid clinical guidelines as well as the experts’ opinion. The panel members included nine specialists from various medical specialties that had scored scenarios in two rounds, the first of which was without interaction, while the second one was with interaction. We extracted 97 scenarios for the lumbar spine MRI in the scenario extracting phase of the study and the panel members added 18 scenarios. After implementation of two rounds, the scenarios were categorized into three ranges. Sixty seven (58%) of the scenarios were considered as appropriate, 45 (39%) as uncertain, and three (2.6%) as inappropriate. RAM is useful for identifying stakeholder views in settings with limited resources. Since RAM has precise instructions for consensus developing, a large number of scenarios were considered as uncertain. Therefore, more research has to be conducted on the issue

  19. Fundamental Tongue Motions for Trumpet Playing: A Study Using Cine Magnetic Resonance Imaging (Cine MRI).

    Science.gov (United States)

    Furuhashi, Hiroko; Chikui, Toru; Inadomi, Daisuke; Shiraishi, Tomoko; Yoshiura, Kazunori

    2017-12-01

    Though the motions of structures outside the mouth in trumpet performance have been reported, the dynamics of intraoral structures remain unelucidated. This study explored the tongue's movement in trumpet playing using cine magnetic resonance imaging (cine MRI) and demonstrated the effects of intraoral anatomical structures on changes in pitch and dynamics. Cine MRI was applied to 18 trumpet players, who were divided into two groups (7 beginner, 11 advanced) based on their ability to play a certain high note. They were instructed to play a custom-made MRI-compatible simulated trumpet. Pitch-change tasks and dynamics-change tasks were assigned. The positions of the anatomical points and intraoral areas were identified on outlined images, and the changes associated with each task were evaluated. A forward and upward projection of the tongue was observed in the production of higher pitches, and there were no significant differences in all areas. In louder dynamics, a backward and downward bending of the tongue occurred, the tongue area became smaller (pcine MRI that certain tongue movements were associated with each task. Tongue protrusion in the production of higher pitch and bending in louder dynamics can be rationalized using acoustics theory and the movements of anatomical structures. These findings seem to be consistent regardless of the player's proficiency.

  20. The studies on the salivary scintigraphy and magnetic resonance imaging (MRI) in patients with Sjoegren's syndrome

    International Nuclear Information System (INIS)

    Ogawa, Yoshimi

    1997-01-01

    In order to establish more precise diagnostic criteria for the salivary gland disorder in patients with Sjoegren's syndrome (SS), the scintigraphic (SG) and magnetic resonance imaging (MRI) studies were performed on the salivary glands. The subjects consisted to 180 SS patients, 26 suspected of having SS and 27 normal subjects. Judging from the the grade 1.5 disorder which was set by our new grading of SG, the diagnostic sensitivity of SS was 80.6% and the specificity was 88.9%. This result was better than criteria reported in previous literature. The Speaman rank correlation coefficient of the grading of SG with the Saxon test was 0.56, with the gum test 0.47 and the focus score of the labial gland biopsy 0.40. There was a weak correlation of SG with other serologic tests such as the level of the gamma globulin, IgG and anti-Ro/SS-A autoantibody. The MRI was graded from 0 to 4 according to the change of the signal intensity and the pattern evaluated by T1- and T2-weighted images. There was a correlation of the MRI grading with SG, the focus score and the gum test. This result indicates that MRI is a useful tool to evaluate salivary gland disorders in SS patients. According to our results, a proposal of a revised criteria of salivary gland disorders in SS was presented. (author)

  1. A study on utility of magnetic resonance imaging for female pelvic cavity using enteral MRI contrast media

    International Nuclear Information System (INIS)

    Kim, Ham Gyum

    1997-01-01

    For radiological test in soft tissue or neighboring part with same signal intensity, proper test method and equipment shall be selected as needed. In case of female pelvic cavity, ultrasonography or computed tomography alternatively used, but MRI can be more usefully applied to design treatment method or operation plan by improving the diagnostic accuracy and careful observation of lesion characteristics. Magnetic Resonance Imaging using recently developed Enteral MRI contrast media can acquire more diagnostic information than using only intravenous contrast media. Thus this study attempted to examine the utility of anatomic structure and diagnostic acquisition by imaging the female pelvic cavity using Enteral MRI contrast media. As a result of analyzing magnetic resonance imaging after administering Enteral MRI contrast media to pelvic cavity suspect patients, more diagnostic information media could be acquired than only using intravenous contrast. Especially, in the diagnosis of lesion position, shape, distinction from neighboring tissues it is thought that external Enteral MRI contrast media should be used

  2. Trends in magnetic resonance imaging. Technical trends in MRI, noise reduction and fast imaging

    International Nuclear Information System (INIS)

    Sugimoto, Hiroshi

    2007-01-01

    At MRI examination, patients suffer the machine noise and long tight lying as well as an oppressive feeling. This paper describes the technological efforts against the former two. The noise is generated from the force (thumb-ward) to vibrate the magnetic field gradient coil according to the left-hand rule. Authors have developed a MRI machine (Pianissimo) where the coil is placed in vacuum and its actual noise level is found reduced from 105 - 112 to 84 dB(A) at 1.5T. Fast imaging to shorten the imaging time is attained by combination of parallel imaging where MR signals are into multiple high frequency receiver coils, and the usual pulse sequence imaging, which results in the increased encoding in a given time. Together with these, MR angiography and diffusion weighted imaging of abdomen for cancer examination are becoming popular as an additional MRI diagnosis, also acceptable to patients. Future progress of MRI machines conceivably accompanies the unavoidable noise increase and possibly significant magnetic effects on human body, and efforts for their reduction will be continued at patients' viewpoint. (T.I.)

  3. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging ( ... the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a ...

  4. Clinical significance of magnetic resonance imaging (MRI) in evaluation of the extension of uterine cervical cancer

    International Nuclear Information System (INIS)

    Matsubara, Masaru

    1993-01-01

    Magnetic resonance imaging (MRI) was performed in 62 patients with uterine cervical cancer and the preoperative MRI findings were compared with the pathological findings following surgery. The surgical stages of 62 patients were 2 at stage 0, 18 at stage Ia, 19 at stage Ib, 9 at stage IIa, 11 at stage IIb, 2 at stage IIIa, and 1 at stage IIIb. The MRI findings in the present study included: (1) the existence of a high intensity area (HIA) in the uterine cervix or minimum thickness of residual normal cervical tissue, (2) necrotic cavity, (3) pyometra, (4) irregular margin of the cervix, (5) parametrial invasion, (6) vaginal invasion, (7) bladder invasion, and (8) lymph node enlargement. No HIA was observed in any patient with stage 0 or stage Ia, in 8 patients with stage Ib, and in 2 patients with stage IIa, while all patients with cancer tissues greater than 10 mm in diameter had a HIA. In 39 patients in whom hysterectomy was undergone without conization, the findings of MRI correlated significantly (r=0.929, p<0.001) with the minimum thickness of residual normal cervical tissue by the pathological measurement. When the irregular margin of the cervix was regarded as a disruption of the cervical myo-metrium by cancer tissue, accuracy was 87%. Furthermore, the degrees of accuracy for parametrial invasion, vaginal invasion and bladder invasion were 92%, 90% and 94%, respectively. When lymphnodes greater than 15 mm in diameter were regarded as a positive in MRI, accuracy was 88%. The present results indicate that MRI is clinically effective in preoperatively evaluating the extension of uterine cervical cancer. (author)

  5. Use of personal computer image for processing a magnetic resonance image (MRI)

    International Nuclear Information System (INIS)

    Yamamoto, Tetsuo; Tanaka, Hitoshi

    1988-01-01

    Image processing of MR imaging was attempted by using a popular personal computer as 16-bit model. The computer processed the images on a 256 x 256 matrix and 512 x 512 matrix. The softwer languages for image-processing were those of Macro-Assembler performed by (MS-DOS). The original images, acuired with an 0.5 T superconducting machine (VISTA MR 0.5 T, Picker International) were transfered to the computer by the flexible disket. Image process are the display of image to monitor, other the contrast enhancement, the unsharped mask contrast enhancement, the various filter process, the edge detections or the color histogram was obtained in 1.6 sec to 67 sec, indicating that commercialzed personal computer had ability for routine clinical purpose in MRI-processing. (author)

  6. 3D Modeling of Vascular Pathologies from contrast enhanced magnetic resonance images (MRI)

    International Nuclear Information System (INIS)

    Cantor Rivera, Diego; Orkisz, Maciej; Arias, Julian; Uriza, Luis Felipe

    2007-01-01

    This paper presents a method for generating 3D vascular models from contrast enhanced magnetic resonance images (MRI) using a fast marching algorithm. The main contributions of this work are: the use of the original image for defining a speed function (which determines the movement of the interface) and the calculation of the time in which the interface identifies the artery. The proposed method was validated on pathologic carotid artery images of patients and vascular phantoms. A visual appraisal of vascular models obtained with the method shows a satisfactory extraction of the vascular wall. A quantitative assessment proved that the generated models depend on the values of algorithm parameters. The maximum induced error was equal to 1.34 voxels in the diameter of the measured stenoses.

  7. Menstrual cyclic changes of human physiological uterus analized by MRI (magnetic resonance imaging)

    International Nuclear Information System (INIS)

    Yasuzawa, Michio

    1989-01-01

    MRI (Magnetic Resonance Imaging) is useful facilitation to perform analysis of tissue structures with the gray scale. By use of super-conducting MRI with 0.5T resistive magnet, present study was designed to analyse characteristic features of the human uterus throughout menstrual cycle. Both T 1 and T 2 values of the endometrium, the junctional zone and the myometrium were estimated on total nine volunteers of nomal healthy women aged from 21 to 30 y.o. during menstrual cycle. MRI was taken in the mid ∼ late proliferative, the secretory, and the menstrual stage. Moreover, relative square ratio of the endometrium and the junctional zone to the corpus uteri were measured by computed image analyser (Lusex 500). Following results were obtained. 1) Both T 1 and T 2 values of the endometrium and the junctional zone were lowest in the menstrual phase. In the myometrium, T 1 values were shown as same tendency comparing with the above two layers but T 2 values were lowest in the proliferative phase and the menstrual one. 2) Proportional values of the endometrium to the corpus uteri increased from 13.8% in the proliferative phase to 17.9% in the secretory phase and decreased to 8.0% in the menstrual phase. While that in the junctional zone decreased from 26.6% to 23.4% in secretory phase and increased to 35.0% in the menstrual phase. (author)

  8. Menstrual cyclic changes of human physiological uterus analized by MRI (magnetic resonance imaging)

    Energy Technology Data Exchange (ETDEWEB)

    Yasuzawa, Michio

    1989-05-01

    MRI (Magnetic Resonance Imaging) is useful facilitation to perform analysis of tissue structures with the gray scale. By use of super-conducting MRI with 0.5T resistive magnet, present study was designed to analyse characteristic features of the human uterus throughout menstrual cycle. Both T/sub 1/ and T/sub 2/ values of the endometrium, the junctional zone and the myometrium were estimated on total nine volunteers of nomal healthy women aged from 21 to 30 y.o. during menstrual cycle. MRI was taken in the mid /similar to/ late proliferative, the secretory, and the menstrual stage. Moreover, relative square ratio of the endometrium and the junctional zone to the corpus uteri were measured by computed image analyser (Lusex 500). Following results were obtained. (1) Both T/sub 1/ and T/sub 2/ values of the endometrium and the junctional zone were lowest in the menstrual phase. In the myometrium, T/sub 1/ values were shown as same tendency comparing with the above two layers but T/sub 2/ values were lowest in the proliferative phase and the menstrual one. (2) Proportional values of the endometrium to the corpus uteri increased from 13.8% in the proliferative phase to 17.9% in the secretory phase and decreased to 8.0% in the menstrual phase. While that in the junctional zone decreased from 26.6% to 23.4% in secretory phase and increased to 35.0% in the menstrual phase. (author).

  9. [Utilization of polymeric micelle magnetic resonance imaging (MRI) contrast agent for theranostic system].

    Science.gov (United States)

    Shiraishi, Kouichi

    2013-01-01

    We applied a polymeric micelle carrier system for the targeting of a magnetic resonance imaging (MRI) contrast agent. Prepared polymeric micelle MRI contrast agent exhibited a long circulation characteristic in blood, and considerable amount of the contrast agent was found to accumulate in colon 26 solid tumor by the EPR effect. The signal intensities of tumor area showed 2-folds increase in T1-weighted images at 24 h after i.v. injection. To observe enhancement of the EPR effect by Cderiv pretreatment on tumor targeting, we used the contrast agent for the evaluation by means of MRI. Cderiv pretreatment significantly enhanced tumor accumulation of the contrast agent. Interestingly, very high signal intensity in tumor region was found at 24 h after the contrast agent injection in Cderiv pretreated mice. The contrast agent visualized a microenvironmental change in tumor. These results indicate that the contrast agent exhibits potential use for tumor diagnostic agent. To combine with a polymeric micelle carrier system for therapeutic agent, the usage of the combination makes a new concept of "theranostic" for a better cancer treatment.

  10. Magnetic resonance imaging (MRI) evaluation of developmental delay in pediatric patients.

    Science.gov (United States)

    Ali, Althaf S; Syed, Naziya P; Murthy, G S N; Nori, Madhavi; Abkari, Anand; Pooja, B K; Venkateswarlu, J

    2015-01-01

    Developmental delay is defined as significant delay in one or more developmental domains. Magnetic Resonance Imaging (MRI) is the best modality to investigate such patients. Evaluation of a child with developmental delay is important not only because it allows early diagnosis and treatment but also helpful for parental counseling regarding the outcome of their child and to identify any possible risk of recurrence in the siblings. Thus this study was undertaken to evaluate the developmental delay in Indian children which will help the clinicians in providing an estimation of the child's ultimate developmental potential and organize specific treatment requirement and also relieve parental apprehension. To study the prevalence of normal and abnormal MRI in pediatric patients presenting with developmental delay and further categorize the abnormal MRI based on its morphological features. It is a prospective, observational & descriptive study of MRI Brain in 81 paediatric patients (46 Males and 35 Females), aged between three months to 12 years; presenting with developmental delay in Deccan College of Medical Sciences, Hyderabad; over a period of three years (Sept 2011 to Sept 2014). MRI brain was done on 1.5T Siemens Magnetom Essenza & 0.35T Magnetom C with appropriate sequences and planes after making the child sleep/sedated/ anesthetized. Various anatomical structures like Ventricles, Corpus callosum, etc were systematically assessed. The MRI findings were divided into various aetiological subgroups. Normal MRI findings were seen in 32% cases and 68% had abnormal findings of which the proportion of Traumatic/ Neurovascular Diseases, Congenital & Developmental, Metabolic and Degenerative, neoplastic and non specific were 31%, 17%, 10%, 2.5% and 7.5% respectively. The ventricles and white matter mainly the corpus callosum were the most commonly affected anatomical structures. The diagnostic yield was found to be 68% and higher yield was seen in patients presenting with

  11. Memory Deficits in Schizophrenia: A Selective Review of Functional Magnetic Resonance Imaging (fMRI Studies

    Directory of Open Access Journals (Sweden)

    Adrienne C. Lahti

    2013-06-01

    Full Text Available Schizophrenia is a complex chronic mental illness that is characterized by positive, negative and cognitive symptoms. Cognitive deficits are most predictive of long-term outcomes, with abnormalities in memory being the most robust finding. The advent of functional magnetic resonance imaging (fMRI has allowed exploring neural correlates of memory deficits in vivo. In this article, we will give a selective review of fMRI studies probing brain regions and functional networks that are thought to be related to abnormal memory performance in two memory systems prominently affected in schizophrenia; working memory and episodic memory. We revisit the classic “hypofrontality” hypothesis of working memory deficits and explore evidence for frontotemporal dysconnectivity underlying episodic memory abnormalities. We conclude that fMRI studies of memory deficits in schizophrenia are far from universal. However, the current literature does suggest that alterations are not isolated to a few brain regions, but are characterized by abnormalities within large-scale brain networks.

  12. Clinico-pathomorphological study on schizophrenia using magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Uematsu, Masayuki

    1990-01-01

    Forty two schizophrenic patients and 28 normal controls underwent magnetic resonance imaging (MRI) examination of the brain. All subjects were consenting males under 50 years old. The enlargement of the third ventricle, anterior one third of the corpus callosum, and the septum pellucidum significantly differentiated schizophrenics from controls by a discriminant analysis. These findings may not be changes that appeared in the process of illness, but might have existed before the onset of the disorder. MRI measurements which significantly differentiated familial patients from non-familial patients using a discriminant analysis included the enlargement of the third ventricle, the cerebellar vermis, and the septum pellucidum. Negative symptoms and anergia symptoms depended on the degree of atrophy of the frontal lobe and the enlargement of the septum pellucidum. Poor heterosexual relations and low levels of education depended on the enlargement of the anterior one third of the corpus callosum. The good therapeutic response to neuroleptics in schizophrenics was associated with a small cerebellar vermis. All these findings suggested that combining morphological changes in the brain as illustrated by MRI with clinical variables may provide a useful new approach to subclassifying of schizophrenia. (author) 77 refs

  13. FY1995 report on the novel methods for magnetic resonance imaging; 1995 nendo senshin MRI gazoka shuho no kiso kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The purpose of this project is to develop new 2-dimensional ultrafast MRI (Magnetic Resonance Imaging) methods for the Image Guided Cancer Therapy (IGT) and the non-invasive clinical diagnosis. We have developed two MRI methods. They can reconstruct a two dimensional image by only a RF excitation and slow changing of gradient fields. This paper describes theoretically how to apply the RF wave and the gradient in x, y and z direction, respectively. Echo signals are acquired under multi-frequency resonance. The frequency bandwidth of the RF wave adjusts the field of view (FOV) of the imaging plane. Biological effects of the applied RF wave was evaluated by the brain microdialysis. In animal experiments, these was not significant change of neurotransmitters subject to the RF wave. From these theoretical and experimental results, these MRI methods are applicable to IGT and the clinical diagnosis for the cancer and other diseases. (NEDO)

  14. Functional resonance magnetic imaging (fMRI) in adolescents with idiopathic musculoskeletal pain: a paradigm of experimental pain

    OpenAIRE

    Molina, Juliana; Amaro, Edson; da Rocha, Liana Guerra Sanches; Jorge, Liliana; Santos, Flavia Heloisa; Len, Claudio A.

    2017-01-01

    Background Studies on functional magnetic resonance imaging (fMRI) have shown that adults with musculoskeletal pain syndromes tolerate smaller amount of pressure (pain) as well as differences in brain activation patterns in areas related to pain.The objective of this study was to evaluate, through fMRI, the brain activation in adolescents with idiopathic musculoskeletal pain (IMP) while performing an experimental paradigm of pain. Methods The study included 10 consecutive adolescents with idi...

  15. Defining active sacroiliitis on magnetic resonance imaging (MRI) for classification of axial spondyloarthritis: a consensual approach by the ASAS/OMERACT MRI group

    DEFF Research Database (Denmark)

    Rudwaleit, M; Jurik, A G; Hermann, K-G A

    2009-01-01

    BACKGROUND: Magnetic resonance imaging (MRI) of sacroiliac joints has evolved as the most relevant imaging modality for diagnosis and classification of early axial spondyloarthritis (SpA) including early ankylosing spondylitis. OBJECTIVES: To identify and describe MRI findings in sacroiliitis and...... relevant for sacroiliitis have been defined by consensus by a group of rheumatologists and radiologists. These definitions should help in applying correctly the imaging feature "active sacroiliitis by MRI" in the new ASAS classification criteria for axial SpA.......BACKGROUND: Magnetic resonance imaging (MRI) of sacroiliac joints has evolved as the most relevant imaging modality for diagnosis and classification of early axial spondyloarthritis (SpA) including early ankylosing spondylitis. OBJECTIVES: To identify and describe MRI findings in sacroiliitis...... conditions which may mimic SpA. Descriptions of the pathological findings and technical requirements for the appropriate acquisition were formulated. In a consensual approach MRI findings considered to be essential for sacroiliitis were defined. RESULTS: Active inflammatory lesions such as bone marrow oedema...

  16. Heart MRI

    Science.gov (United States)

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  17. Edge-augmented Fourier partial sums with applications to Magnetic Resonance Imaging (MRI)

    Science.gov (United States)

    Larriva-Latt, Jade; Morrison, Angela; Radgowski, Alison; Tobin, Joseph; Iwen, Mark; Viswanathan, Aditya

    2017-08-01

    Certain applications such as Magnetic Resonance Imaging (MRI) require the reconstruction of functions from Fourier spectral data. When the underlying functions are piecewise-smooth, standard Fourier approximation methods suffer from the Gibbs phenomenon - with associated oscillatory artifacts in the vicinity of edges and an overall reduced order of convergence in the approximation. This paper proposes an edge-augmented Fourier reconstruction procedure which uses only the first few Fourier coefficients of an underlying piecewise-smooth function to accurately estimate jump information and then incorporate it into a Fourier partial sum approximation. We provide both theoretical and empirical results showing the improved accuracy of the proposed method, as well as comparisons demonstrating superior performance over existing state-of-the-art sparse optimization-based methods.

  18. Safety assessment of the magnetic resonance imaging (MRI) facility at the 37 Military Hospital

    International Nuclear Information System (INIS)

    Mintah, R.O

    2010-01-01

    Safety assessment of the operation of the Magnetic Resonance Imaging (MRI) system at 37 Military Hospital was done. Protocols were developed to assess the radiological health and safety impact of some selected MR imaging procedures on patients, staff and the general public. The parameters considered to be assessed were; specific absorption rate (SAR); temperature rise in the body, variation of the magnetic field gradients, RF energy used, sound pressure level and the potential for missile effects. The Smart brain and Routine lumbar Spine examination cards specific to brain and lumbar spine anatomy techniques were used. For brain examinations the T1 W-SE sagittal PH, and the T1 W-SE Tra-PH protocols gave the highest SAR values with a mean value 1.6 W/kg for 3 minutes. For the lumbar spine examinations, the T1 W-TSE axial protocols exposed patients to the highest consistent SAR value of 2.8 W /kg. The T2W-TSE axial protocol gave the highest SAR value of 3.8 W/kg with a mean value of 3.1 W/kg with the highest exposure time of 4 minutes with a mean of 2.5 minutes. These SAR values were within the limits recommended by the United States Food and Drug Administration (USFDA). To optimize patient, staff and public safety, local guidelines for safety assessment were developed which include: in house screening with a metal detector, filling in the screening form and ensuring that safety requirements are met before entering the MR room. The choice of protocols that minimize SAR values and strict compliance to safety protocols developed at the MRI facility therefore should be followed and continuously updated to achieve maximum safety for staff, patient and the general public in and around an MRI facility. (au)

  19. Magnetic resonance imaging (MRI to study striatal iron accumulation in a rat model of Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Ana Virel

    Full Text Available Abnormal accumulation of iron is observed in neurodegenerative disorders. In Parkinson's disease, an excess of iron has been demonstrated in different structures of the basal ganglia and is suggested to be involved in the pathogenesis of the disease. Using the 6-hydroxydopamine (6-OHDA rat model of Parkinson's disease, the edematous effect of 6-OHDA and its relation with striatal iron accumulation was examined utilizing in vivo magnetic resonance imaging (MRI. The results revealed that in comparison with control animals, injection of 6-OHDA into the rat striatum provoked an edematous process, visible in T2-weighted images that was accompanied by an accumulation of iron clearly detectable in T2*-weighted images. Furthermore, Prussian blue staining to detect iron in sectioned brains confirmed the existence of accumulated iron in the areas of T2* hypointensities. The presence of ED1-positive microglia in the lesioned striatum overlapped with this accumulation of iron, indicating areas of toxicity and loss of dopamine nerve fibers. Correlation analyses demonstrated a direct relation between the hyperintensities caused by the edema and the hypointensities caused by the accumulation of iron.

  20. Three dimensional gel dosimetry by use of nuclear magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    De Deene, Y.; De Wagter, C.; Van Duyse, B.; Achten, E.; De Neve, W.; De Poorter, J.

    1995-01-01

    As co-monomers are found to polymerize by radiation, they are eligible for constructing a three dimensional dosimeter. Another kind of three dimensional dosimeter, based on the radiation sensitivity of the ferrous ions in a Fricke solution, was tested in a previous study. However, a major problem that occurs in this kind of gel dosimeters is the diffusion of the ferric and ferrous ions. The co-monomer gels are more stable. The degree of polymerisation is visualized with a clinical MRI system. Acrylamide and N,N-methylene-bis-acrylamide are dissolved in a gel composed of gelatin and water. By irradiation the co-monomers are polymerized to polyacrylamide. The gel is casted in humanoid forms. As such, a simulation of the irradiation of the patient can be performed. Magnetic resonance relaxivity images of the irradiated gel display the irradiation dose. The images of the gel are fused with the radiological images of the patient. Quantitation of the dose response of the co-monomer gel is obtained through calibration by test tubes

  1. Three dimensional gel dosimetry by use of nuclear magnetic resonance imaging (MRI)

    Energy Technology Data Exchange (ETDEWEB)

    De Deene, Y; De Wagter, C; Van Duyse, B; Achten, E; De Neve, W [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; De Poorter, J [Ghent Univ. (Belgium). Dept. of Magnetic Resonance

    1995-12-01

    As co-monomers are found to polymerize by radiation, they are eligible for constructing a three dimensional dosimeter. Another kind of three dimensional dosimeter, based on the radiation sensitivity of the ferrous ions in a Fricke solution, was tested in a previous study. However, a major problem that occurs in this kind of gel dosimeters is the diffusion of the ferric and ferrous ions. The co-monomer gels are more stable. The degree of polymerisation is visualized with a clinical MRI system. Acrylamide and N,N-methylene-bis-acrylamide are dissolved in a gel composed of gelatin and water. By irradiation the co-monomers are polymerized to polyacrylamide. The gel is casted in humanoid forms. As such, a simulation of the irradiation of the patient can be performed. Magnetic resonance relaxivity images of the irradiated gel display the irradiation dose. The images of the gel are fused with the radiological images of the patient. Quantitation of the dose response of the co-monomer gel is obtained through calibration by test tubes.

  2. Vision 20/20: Magnetic resonance imaging-guided attenuation correction in PET/MRI: Challenges, solutions, and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Mehranian, Abolfazl; Arabi, Hossein [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva CH-1211 (Switzerland); Zaidi, Habib, E-mail: habib.zaidi@hcuge.ch [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva CH-1211 (Switzerland); Geneva Neuroscience Centre, University of Geneva, Geneva CH-1205 (Switzerland); Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Groningen 9700 RB (Netherlands)

    2016-03-15

    Attenuation correction is an essential component of the long chain of data correction techniques required to achieve the full potential of quantitative positron emission tomography (PET) imaging. The development of combined PET/magnetic resonance imaging (MRI) systems mandated the widespread interest in developing novel strategies for deriving accurate attenuation maps with the aim to improve the quantitative accuracy of these emerging hybrid imaging systems. The attenuation map in PET/MRI should ideally be derived from anatomical MR images; however, MRI intensities reflect proton density and relaxation time properties of biological tissues rather than their electron density and photon attenuation properties. Therefore, in contrast to PET/computed tomography, there is a lack of standardized global mapping between the intensities of MRI signal and linear attenuation coefficients at 511 keV. Moreover, in standard MRI sequences, bones and lung tissues do not produce measurable signals owing to their low proton density and short transverse relaxation times. MR images are also inevitably subject to artifacts that degrade their quality, thus compromising their applicability for the task of attenuation correction in PET/MRI. MRI-guided attenuation correction strategies can be classified in three broad categories: (i) segmentation-based approaches, (ii) atlas-registration and machine learning methods, and (iii) emission/transmission-based approaches. This paper summarizes past and current state-of-the-art developments and latest advances in PET/MRI attenuation correction. The advantages and drawbacks of each approach for addressing the challenges of MR-based attenuation correction are comprehensively described. The opportunities brought by both MRI and PET imaging modalities for deriving accurate attenuation maps and improving PET quantification will be elaborated. Future prospects and potential clinical applications of these techniques and their integration in commercial

  3. Prostate gland motion assessed with cine-magnetic resonance imaging (cine-MRI)

    International Nuclear Information System (INIS)

    Ghilezan, Michel J.; Jaffray, David A.; Siewerdsen, Jeffrey H.; Herk, Marcel van; Shetty, Anil; Sharpe, Michael B.; Zafar Jafri, Syed; Vicini, Frank A.; Matter, Richard C.; Brabbins, Donald S.; Martinez, Alvaro A.

    2005-01-01

    Purpose: To quantify prostate motion during a radiation therapy treatment using cine-magnetic resonance imaging (cine-MRI) for time frames comparable to that expected in an image-guided radiation therapy treatment session (20-30 min). Materials and Methods: Six patients undergoing radiation therapy for prostate cancer were imaged on 3 days, over the course of therapy (Weeks 1, 3, and 5). Four hundred images were acquired during the 1-h MRI session in 3 sagittal planes through the prostate at 6-s intervals. Eleven anatomic points of interest (POIs) have been used to characterize prostate/bony pelvis/abdominal wall displacement. Motion traces and standard deviation for each of the 11 POIs have been determined. The probability of displacement over time has also been calculated. Results: Patients were divided into 2 groups according to rectal filling status: full vs. empty rectum. The displacement of POIs (standard deviation) ranged from 0.98 to 1.72 mm for the full-rectum group and from 0.68 to 1.04 mm for the empty-rectum group. The low standard deviations in position (2 mm or less) would suggest that these excursions have a low frequency of occurrence. The most sensitive prostate POI to rectal wall motion was the midposterior with a standard deviation of 1.72 mm in the full-rectum group vs. 0.79 mm in the empty-rectum group (p 0.0001). This POI has a 10% probability of moving more than 3 mm in a time frame of ∼1 min if the rectum is full vs. ∼20 min if the rectum is empty. Conclusion: Motion of the prostate and seminal vesicles during a time frame similar to a standard treatment session is reduced compared to that reported in interfraction studies. The most significant predictor for intrafraction prostate motion is the status of rectal filling. A prostate displacement of <3 mm (90%) can be expected for the 20 min after the moment of initial imaging for patients with an empty rectum. This is not the case for patients presenting with full rectum. The determination

  4. Indications and value of bone scintigraphy in comparison to magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Haug, A.; Hacker, M.; Weiss, M.; Hahn, K.; Pfluger, T.

    2006-01-01

    With increasing use of cross-sectional imaging (CT/MRI) in radiology as well as PET and PET/CT in nuclear medicine, remaining indications for bone scintigraphy are in question. Recently introduced whole-body MRI represents an attractive alternative to bone scintigraphy, as MRI is additionally able to assess lesions that are limited to bone marrow and are located extraosseously. In this overview, indication-related strengths and limitations of MRI and bone scintigraphy are presented and discussed. Furthermore, complementary use of both modalities for special clinical questions is demonstrated. (orig.)

  5. A protocol for patients with cardiovascular implantable devices undergoing magnetic resonance imaging (MRI): should defibrillation threshold testing be performed post-(MRI).

    Science.gov (United States)

    Burke, Peter Thomas; Ghanbari, Hamid; Alexander, Patrick B; Shaw, Michael K; Daccarett, Marcos; Machado, Christian

    2010-06-01

    Magnetic resonance imaging (MRI) in patients with Cardiovascular Implantable Electronic Devices (CIED) has not been approved by the Food and Drug Administration. Recent data suggests MRI as a relative rather than absolute contraindication in CIED patients. Recently, the American Heart Association has recommended defibrillation threshold testing (DFTT) in implantable cardioverter defibrillator (ICD) patients undergoing MRI. We evaluated the feasibility and safety of a protocol for MRI in CIED patients, incorporating the new recommendations on DFTT. Consecutive patients with CIED undergoing MRI were included. The protocol consisted of continuous monitoring during imaging, device interrogation pre- and post-MRI, reprogramming of the pacemaker to an asynchronous mode in pacemaker-dependent (PMD) patients and a non-tracking/sensing mode for non-PMD patients. All tachyarrhythmia therapies were disabled. Devices were interrogated for lead impedance, battery life, pacing, and sensing thresholds. All patients with ICD underwent DFTT/defibrillator safety margin testing (DSMT) post-MRI. A total of 92 MRI's at 1.5 Tesla were performed in 38 patients. A total of 13 PMD patients, ten ICD patients, four cardiac resynchronization therapy with defibrillator (CRT-D) patients, and 11 non-PMD patients were scanned from four major manufacturers. No device circuitry damage, programming alterations, inappropriate shocks, failure to pace, or changes in sensing, pacing, or defibrillator thresholds were found on single or multiple MRI sessions. Our protocol for MRI in CIED patients appears safe, feasible, and reproducible. This is irrespective of the type of CIED, pacemaker dependancy or multiple 24-h scanning sessions. Our protocol addresses early detection of potential complications and establishes a response system for potential device-related complications. Our observation suggests that routine DFTT/DSMT post-MRI may not be necessary.

  6. A medical software system for volumetric analysis of cerebral pathologies in magnetic resonance imaging (MRI) data.

    Science.gov (United States)

    Egger, Jan; Kappus, Christoph; Freisleben, Bernd; Nimsky, Christopher

    2012-08-01

    In this contribution, a medical software system for volumetric analysis of different cerebral pathologies in magnetic resonance imaging (MRI) data is presented. The software system is based on a semi-automatic segmentation algorithm and helps to overcome the time-consuming process of volume determination during monitoring of a patient. After imaging, the parameter settings-including a seed point-are set up in the system and an automatic segmentation is performed by a novel graph-based approach. Manually reviewing the result leads to reseeding, adding seed points or an automatic surface mesh generation. The mesh is saved for monitoring the patient and for comparisons with follow-up scans. Based on the mesh, the system performs a voxelization and volume calculation, which leads to diagnosis and therefore further treatment decisions. The overall system has been tested with different cerebral pathologies-glioblastoma multiforme, pituitary adenomas and cerebral aneurysms- and evaluated against manual expert segmentations using the Dice Similarity Coefficient (DSC). Additionally, intra-physician segmentations have been performed to provide a quality measure for the presented system.

  7. Magnetic Resonance Imaging (MRI) Analysis of Fibroid Location in Women Achieving Pregnancy After Uterine Artery Embolization

    International Nuclear Information System (INIS)

    Walker, Woodruff J.; Bratby, Mark John

    2007-01-01

    The purpose of this study was to evaluate the fibroid morphology in a cohort of women achieving pregnancy following treatment with uterine artery embolization (UAE) for symptomatic uterine fibroids. A retrospective review of magnetic resonance imaging (MRI) of the uterus was performed to assess pre-embolization fibroid morphology. Data were collected on fibroid size, type, and number and included analysis of follow-up imaging to assess response. There have been 67 pregnancies in 51 women, with 40 live births. Intramural fibroids were seen in 62.7% of the women (32/48). Of these the fibroids were multiple in 16. A further 12 women had submucosal fibroids, with equal numbers of types 1 and 2. Two of these women had coexistent intramural fibroids. In six women the fibroids could not be individually delineated and formed a complex mass. All subtypes of fibroid were represented in those subgroups of women achieving a live birth versus those who did not. These results demonstrate that the location of uterine fibroids did not adversely affect subsequent pregnancy in the patient population investigated. Although this is only a small qualitative study, it does suggest that all types of fibroids treated with UAE have the potential for future fertility

  8. Advanced magnetic resonance imaging of the brain : MRI of the brain

    African Journals Online (AJOL)

    Since the development of magnetic resonance imaging by Paul. Lauterbur and ... Functional brain imaging refers to the family of techniques that aim to measure the .... left thumb, the fingers of their right hand against their right thumb, or rest.

  9. Fat Imaging via Magnetic Resonance Imaging (MRI) in Young Children (Ages 1-4 Years) without Sedation.

    Science.gov (United States)

    Shearrer, Grace E; House, Benjamin T; Gallas, Michelle C; Luci, Jeffrey J; Davis, Jaimie N

    2016-01-01

    This pilot study developed techniques to perform Magnetic Resonance Imaging (MRI) of specific fat deposition in 18 children (age 18 months to 4 years). The children engaged in a series of practice tests to become acclimated to the scanner noises, reduce claustrophobia, and rehearse holding still for a set time. The practice tests assessed if the child could remain still for two minutes while watching a video, first while lying on a blanket, second, on the blanket with headphones, and third, in the mock scanner. The children who passed the three practice tests were then scanned with a 3T Siemens Skyra magnet. Abdominal fat distribution (region of interest (ROI) from the top of the ileac crest to the bottom of the ribcage) volume was measured using 2-point DIXON technique. This region was chosen to give an indication of the body composition around the liver. Twelve out of eighteen participants successfully completed the actual MRI scan. Chi-squared test showed no significant difference between male and female pass-fail rates. The median age of completed scans was 36 months, whereas the median age for children unable to complete a scan was 28 months. The average total trunk fat was 240.9±85.2mL and the average total VAT was 37.7±25.9mLand liver fat was not quantifiable due to physiological motion. Several strategies (modeling, videos, and incentives) were identified to improve pediatric imaging in different age ranges. Using an age-specific and tailored protocol, we were able to successfully use MRI for fat imaging in a majority of young children. Development of such protocols enables researchers to better understand the etiology of fat deposition in young children, which can be used to aid in the prevention and treatment of adiposity.

  10. Fat Imaging via Magnetic Resonance Imaging (MRI in Young Children (Ages 1-4 Years without Sedation.

    Directory of Open Access Journals (Sweden)

    Grace E Shearrer

    Full Text Available This pilot study developed techniques to perform Magnetic Resonance Imaging (MRI of specific fat deposition in 18 children (age 18 months to 4 years.The children engaged in a series of practice tests to become acclimated to the scanner noises, reduce claustrophobia, and rehearse holding still for a set time. The practice tests assessed if the child could remain still for two minutes while watching a video, first while lying on a blanket, second, on the blanket with headphones, and third, in the mock scanner. The children who passed the three practice tests were then scanned with a 3T Siemens Skyra magnet. Abdominal fat distribution (region of interest (ROI from the top of the ileac crest to the bottom of the ribcage volume was measured using 2-point DIXON technique. This region was chosen to give an indication of the body composition around the liver.Twelve out of eighteen participants successfully completed the actual MRI scan. Chi-squared test showed no significant difference between male and female pass-fail rates. The median age of completed scans was 36 months, whereas the median age for children unable to complete a scan was 28 months. The average total trunk fat was 240.9±85.2mL and the average total VAT was 37.7±25.9mLand liver fat was not quantifiable due to physiological motion. Several strategies (modeling, videos, and incentives were identified to improve pediatric imaging in different age ranges.Using an age-specific and tailored protocol, we were able to successfully use MRI for fat imaging in a majority of young children. Development of such protocols enables researchers to better understand the etiology of fat deposition in young children, which can be used to aid in the prevention and treatment of adiposity.

  11. An availability of brain magnetic resonance imaging (MRI) in the early diagnosis of latent hepatic encephalopathy

    International Nuclear Information System (INIS)

    Kuwahara, Noaki; Tanabe, Masako; Fujiwara, Akiko; Minato, Takeshi; Sasaki, Hiromasa; Higashi, Toshihiro; Tsuji, Takao.

    1996-01-01

    Brain MRI was carried out in patients with chronic liver diseases. No abnormal findings were recognized in patients with chronic viral hepatitis, while 59.2% of cirrhotics showed a symmetrically strong signal in basal ganglia on T1 weighted image in MRI. This finding significantly related with lowered Fischer's ratio of serum amino acid, increased levels of serum phenylalanine, tyrosine and hyaluronic acid, prolonged prothrombin time and decreased platelet counts in the peripheral blood. Overt hepatic encephalopathy was observed in 6 of 34 patients with the strong signal in MRI during follow-up period, while none of patients without that finding developed hepatic encephalopathy. These results have indicated that the strong signal in basal ganglia on MRI appears in cirrhotic patients with severe liver dysfunction, and it is an useful index in the early diagnosis of latent hepatic encephalopathy. An improvement of this MRI finding was not observed by long-term oral administration of branched-chain amino acid. (author)

  12. Improving Brain Magnetic Resonance Image (MRI Segmentation via a Novel Algorithm based on Genetic and Regional Growth

    Directory of Open Access Journals (Sweden)

    Javadpour A.

    2016-06-01

    Full Text Available Background: Regarding the importance of right diagnosis in medical applications, various methods have been exploited for processing medical images solar. The method of segmentation is used to analyze anal to miscall structures in medical imaging. Objective: This study describes a new method for brain Magnetic Resonance Image (MRI segmentation via a novel algorithm based on genetic and regional growth. Methods: Among medical imaging methods, brains MRI segmentation is important due to high contrast of non-intrusive soft tissue and high spatial resolution. Size variations of brain tissues are often accompanied by various diseases such as Alzheimer’s disease. As our knowledge about the relation between various brain diseases and deviation of brain anatomy increases, MRI segmentation is exploited as the first step in early diagnosis. In this paper, regional growth method and auto-mate selection of initial points by genetic algorithm is used to introduce a new method for MRI segmentation. Primary pixels and similarity criterion are automatically by genetic algorithms to maximize the accuracy and validity in image segmentation. Results: By using genetic algorithms and defining the fixed function of image segmentation, the initial points for the algorithm were found. The proposed algorithms are applied to the images and results are manually selected by regional growth in which the initial points were compared. The results showed that the proposed algorithm could reduce segmentation error effectively. Conclusion: The study concluded that the proposed algorithm could reduce segmentation error effectively and help us to diagnose brain diseases.

  13. Diffusion-weighted magnetic resonance imaging (MRI) in acute brain stem infarction

    International Nuclear Information System (INIS)

    Narisawa, Aya; Shamoto, Hiroshi; Shimizu, Hiroaki; Tominaga, Teiji; Yoshimoto, Takashi

    2001-01-01

    Diffusion-weighted magnetic resonance imaging (DWI) provides one of the earliest demonstrations of ischemic lesions. However some lesions may be missed in the acute stage due to technical limitation of DWI. We therefore conducted the study to clarify the sensitivity of DWI to acute brain stem infarctions. Twenty-eight patients with the final diagnosis of brain stem infarction (midbrain 2, pons 9, medulla oblongata 17) who had been examined by DWI within 24 hours of onset were retrospectively analyzed for how sensitively the initial DWI demonstrated the final ischemic lesion. Only obvious (distinguishable with DWI alone without referring clinical symptoms and other informations) hyperintensity on DWI was regarded to show an ischemic lesion. Sixteen (57.1%) out of 28 patients had brain stem infarctions demonstrated by initial DWI. In the remaining 12 cases, no obvious ischemic lesion was evident on initial DWI. Subsequent MRI studies obtained 127 hours, on average after the onset showed infarction in the medulla oblongate in 11 cases and in the pons in one case. Negative findings of DWI in the acute stage does not exclude possibility of the brain stem infarction, in particularly medulla oblongata infarction. (author)

  14. Studies on improvement of diagnosis of neurosurgical lesions by magnetic resonance imaging (MRI), 3

    International Nuclear Information System (INIS)

    Shimizu, Kotoyuki

    1989-01-01

    Fourteen patients with spinocerebellar degeneration (SCD) and 97 healthy volunteers were examined by magnetic resonance imaging (MRI) using inversion recovery technique. According to clinical symptoms and disease course, SCD was divided into late cortical cerebellar atrophy (LCCA) and olivo-ponto-cerebellar atrophy (OPCA). To evaluate atrophic changes in the cerebellum and brain stem with aging, healthy volunteers were divided into four age groups. Parameters measured were: the cerebellar vermis, hemisphere, peduncle, pons and medulla, and the fourth ventricle. In the control group, atrophied vermis and peduncle of the cerebellum, and dilated fourth ventricle were observed with aging. A statistically significant atrophy in all of the parameters for the brain stem and cerebellum was observed in the group of SCD, as compared with the control group. The atrophy was restricted to the cerebellum for LCCA; and was observed in both the cerebellum and brain stem for OPCA. The size of the cerebellar hemisphere (H), as calculated as the product of the major and minor axes, was useful in the quantitative evaluation of atrophy of the cerebellar hemisphere. The ratio of H value to the anterior-posterior diameter of the pons was useful in the differentiation between LCCA and OPCA. (N.K.)

  15. Indications for fetal magnetic resonance imaging (MRI); Indikationen zur fetalen Magnetresonanztomographie

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, D. [Medizinische Universitaet Wien (Austria). Klinik fuer Radiodiagnostik; Brugger, P.C. [Zentrum fuer Anatomie und Zellbiologie der Medizinischen Universitaet Wien (Austria). Arbeitsgruppe Integrative Morphologie; Krampl, E. [Medizinische Universitaet Wien (Austria). Klinik fuer Gynaekologie und Geburtshilfe; Prayer, L. [Diagnosezentrum Urania, Wien (Austria)

    2006-02-15

    Indications to perform fetal magnetic resonance imaging (MRI) are composed of common ones related to methodological problems of ultrasound (US) assessment (such as for instance hydramnios) and special ones. The latter are related to MR capability of high-resolution soft tissue contrast and an extended field of view that allows visualization of the whole fetus, even in later stages of pregnancy. The most important indications include confirmation of US findings, work-up of malformations with respect to individual prognosis and genetic background, differentiation between acquired conditions and malformations, visualization of pathologies that have to be treated surgically immediately after birth, and morphological changes of the placenta. (orig.) [German] Indikationen zur Durchfuehrung einer fetalen Magnetresonanztomographie (MRT) setzen sich aus allgemeinen Fragestellungen zusammen, die auf methodischen Problemen von Ultraschalluntersuchungen (US) beruhen (wie beispielsweise Anhydramnion), und speziellen, bei denen die MR-Eigenschaften der hochaufloesenden Gewebedifferenzierung und eines Untersuchungsfensters, das eine Abbildung des gesamten Fetus auch im fortgeschrittenen Schwangerschaftsalter erlaubt, ausgenuetzt werden. Im Vordergrund stehen dabei die Absicherung von US-Befunden, die Abklaerung von Fehlbildungen in Hinblick auf individuelle Prognose und Vorliegen eines Syndroms mit genetisch determiniertem Hintergrund, und die Differenzierung erworbener Stoerungen von Fehlbildungen, die Abklaerung von Veraenderungen, die einer unmittelbar postnatalen operativen Therapie beduerfen, und morphologischer Veraenderungen der Plazenta. (orig.)

  16. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses ... identify and accurately characterize diseases than other imaging methods. This detail makes MRI an invaluable tool in ...

  17. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... work? Unlike conventional x-ray examinations and computed tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, ... Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children ...

  18. gr-MRI: A software package for magnetic resonance imaging using software defined radios

    Science.gov (United States)

    Hasselwander, Christopher J.; Cao, Zhipeng; Grissom, William A.

    2016-09-01

    The goal of this work is to develop software that enables the rapid implementation of custom MRI spectrometers using commercially-available software defined radios (SDRs). The developed gr-MRI software package comprises a set of Python scripts, flowgraphs, and signal generation and recording blocks for GNU Radio, an open-source SDR software package that is widely used in communications research. gr-MRI implements basic event sequencing functionality, and tools for system calibrations, multi-radio synchronization, and MR signal processing and image reconstruction. It includes four pulse sequences: a single-pulse sequence to record free induction signals, a gradient-recalled echo imaging sequence, a spin echo imaging sequence, and an inversion recovery spin echo imaging sequence. The sequences were used to perform phantom imaging scans with a 0.5 Tesla tabletop MRI scanner and two commercially-available SDRs. One SDR was used for RF excitation and reception, and the other for gradient pulse generation. The total SDR hardware cost was approximately 2000. The frequency of radio desynchronization events and the frequency with which the software recovered from those events was also measured, and the SDR's ability to generate frequency-swept RF waveforms was validated and compared to the scanner's commercial spectrometer. The spin echo images geometrically matched those acquired using the commercial spectrometer, with no unexpected distortions. Desynchronization events were more likely to occur at the very beginning of an imaging scan, but were nearly eliminated if the user invoked the sequence for a short period before beginning data recording. The SDR produced a 500 kHz bandwidth frequency-swept pulse with high fidelity, while the commercial spectrometer produced a waveform with large frequency spike errors. In conclusion, the developed gr-MRI software can be used to develop high-fidelity, low-cost custom MRI spectrometers using commercially-available SDRs.

  19. Study of human brain functions by functional magnetic resonance imaging (fMRI) and spectroscopy (fMRS)

    International Nuclear Information System (INIS)

    Jagannathan, N.R.

    1998-01-01

    Functional magnetic resonance imaging (fMRI) has become a powerful tool in the detection and assessment of cerebral pathophysiology and the regional mapping and characterization of cognitive processes such as motor skills, vision, language and memory. The results of the effect of motor cortex stimulation during repetitive hand squeezing task activation using in-vivo single voxel NMR spectroscopy carried out on normal volunteer subjects are presented

  20. Abnormal findings of magnetic resonance imaging (MRI) in patients with systemic lupus erythematosus involving the brain

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Akira; Okada, Jun; Kondo, Hirobumi (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine); Kashiwazaki, Sadao

    1992-06-01

    To elucidate the clinical significance of MRI on central nervous system systemic lupus erythematosus (CNS-SLE), MRI and CT scans were performed in 35 patients with SLE, of 18 patients who had CNS manifestations at the time of MRI examinations. The investigations were also carried out in 17 patients without CNS-SLE. The rate of detection of abnormal findings on MRI in patients with CNS-SLE was 77.2% (14/18), which was high, as compared with the rate of those on CT scans (50%: 9/18). Especially, all of 4 patients with seizure and 3 patients with encephalopathy showed abnormal MRI findings, although respectively 50% and 33.3% of them had abnormal CT scan findings. MRI findings were classified into 4 groups below: (1) Large focal are as increased signal intensity at T2 weighted image. These were observed in 2 of 4 patients with seizure and 1 of 3 patients with encephalopathy, which were completely resolved after treatment. (2) Patchy subcortical foci of increased signal intensity at T2 weighted image. These were observed in 11 of 18 CNS-SLE and 7 of 17 without CNS-SLE, which were not detected by CT scan. (3) All of six patients with cerebral infarctions showed high signal intensity areas at T2 weighted image and low signal intensity areas at T1 weighted image. (4) Normal findings were observed in 4 of 18 CNS-SLE (22.2%). We concluded that MRI is useful for the evaluation of CNS-SLE and provides more information than CT scan. (author).

  1. Abnormal findings of magnetic resonance imaging (MRI) in patients with systemic lupus erythematosus involving the brain

    International Nuclear Information System (INIS)

    Ishikawa, Akira; Okada, Jun; Kondo, Hirobumi; Kashiwazaki, Sadao.

    1992-01-01

    To elucidate the clinical significance of MRI on central nervous system systemic lupus erythematosus (CNS-SLE), MRI and CT scans were performed in 35 patients with SLE, of 18 patients who had CNS manifestations at the time of MRI examinations. The investigations were also carried out in 17 patients without CNS-SLE. The rate of detection of abnormal findings on MRI in patients with CNS-SLE was 77.2% (14/18), which was high, as compared with the rate of those on CT scans (50%: 9/18). Especially, all of 4 patients with seizure and 3 patients with encephalopathy showed abnormal MRI findings, although respectively 50% and 33.3% of them had abnormal CT scan findings. MRI findings were classified into 4 groups below: 1) Large focal are as increased signal intensity at T2 weighted image. These were observed in 2 of 4 patients with seizure and 1 of 3 patients with encephalopathy, which were completely resolved after treatment. 2) Patchy subcortical foci of increased signal intensity at T2 weighted image. These were observed in 11 of 18 CNS-SLE and 7 of 17 without CNS-SLE, which were not detected by CT scan. 3) All of six patients with cerebral infarctions showed high signal intensity areas at T2 weighted image and low signal intensity areas at T1 weighted image. 4) Normal findings were observed in 4 of 18 CNS-SLE (22.2%). We concluded that MRI is useful for the evaluation of CNS-SLE and provides more information than CT scan. (author)

  2. Quantification of synovistis by MRI: correlation between dynamic and static gadolinium-enhanced magnetic resonance imaging and microscopic and macroscopic signs of synovial inflammation

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Stoltenberg, M; Løvgreen-Nielsen, P

    1998-01-01

    Dynamic and static gadolinium-diethylenetriaminepentaacetic acid(Gd-DTPA)-enhanced magnetic resonance imaging (MRI) were evaluated as measures of joint inflammation in arthritis, by a comparison with macroscopic and microscopic signs of synovitis. Furthermore, the importance of the size...

  3. Preoperative axillary lymph node evaluation in breast cancer patients by breast magnetic resonance imaging (MRI): Can breast MRI exclude advanced nodal disease?

    International Nuclear Information System (INIS)

    Hyun, Su Jeong; Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Kim, Min Jung

    2016-01-01

    To evaluate the diagnostic performance of breast magnetic resonance imaging (MRI) in preoperative evaluation of axillary lymph node metastasis (ALNM) in breast cancer patients and to assess whether breast MRI can be used to exclude advanced nodal disease. A total of 425 patients were included in this study and breast MRI findings were retrospectively reviewed. The diagnostic performance of breast MRI for diagnosis of ALNM was evaluated in all patients, patients with neoadjuvant chemotherapy (NAC), and those without NAC (no-NAC). We evaluated whether negative MRI findings (cN0) can exclude advanced nodal disease (pN2-pN3) using the negative predictive value (NPV) in each group. The sensitivity and NPV of breast MRI in evaluation of ALNM was 51.3 % (60/117) and 83.3 % (284/341), respectively. For cN0 cases on MRI, pN2-pN3 manifested in 1.8 % (6/341) of the overall patients, 0.4 % (1/257) of the no-NAC group, and 6 % (5/84) of the NAC group. The NPV of negative MRI findings for exclusion of pN2-pN3 was higher for the no-NAC group than for the NAC group (99.6 % vs. 94.0 %, p = 0.039). Negative MRI findings (cN0) can exclude the presence of advanced nodal disease with an NPV of 99.6 % in the no-NAC group. (orig.)

  4. Preoperative axillary lymph node evaluation in breast cancer patients by breast magnetic resonance imaging (MRI): Can breast MRI exclude advanced nodal disease?

    Energy Technology Data Exchange (ETDEWEB)

    Hyun, Su Jeong [Yonsei University College of Medicine, Department of Radiology, Breast Cancer Clinic, Severance Hospital, Research Institute of Radiological Science, Seoul (Korea, Republic of); Hallym University Medical Center, Department of Radiology, Kangnam Sacred Heart Hospital, Seoul (Korea, Republic of); Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Kim, Min Jung [Yonsei University College of Medicine, Department of Radiology, Breast Cancer Clinic, Severance Hospital, Research Institute of Radiological Science, Seoul (Korea, Republic of)

    2016-11-15

    To evaluate the diagnostic performance of breast magnetic resonance imaging (MRI) in preoperative evaluation of axillary lymph node metastasis (ALNM) in breast cancer patients and to assess whether breast MRI can be used to exclude advanced nodal disease. A total of 425 patients were included in this study and breast MRI findings were retrospectively reviewed. The diagnostic performance of breast MRI for diagnosis of ALNM was evaluated in all patients, patients with neoadjuvant chemotherapy (NAC), and those without NAC (no-NAC). We evaluated whether negative MRI findings (cN0) can exclude advanced nodal disease (pN2-pN3) using the negative predictive value (NPV) in each group. The sensitivity and NPV of breast MRI in evaluation of ALNM was 51.3 % (60/117) and 83.3 % (284/341), respectively. For cN0 cases on MRI, pN2-pN3 manifested in 1.8 % (6/341) of the overall patients, 0.4 % (1/257) of the no-NAC group, and 6 % (5/84) of the NAC group. The NPV of negative MRI findings for exclusion of pN2-pN3 was higher for the no-NAC group than for the NAC group (99.6 % vs. 94.0 %, p = 0.039). Negative MRI findings (cN0) can exclude the presence of advanced nodal disease with an NPV of 99.6 % in the no-NAC group. (orig.)

  5. A study on the clinical significance of magnetic resonance imaging (MRI) findings in patients with cervical spondylotic myelopathy

    International Nuclear Information System (INIS)

    Toyooka, Satoshi

    1997-01-01

    This study was designed to evaluate magnetic resonance (MR) images of the cervical compressive myelopathy. It was also meant to serve as a review of clinical symptoms and an investigation of the usefulness of MRI. Comparative studies were carried out on 110 cases concerning the shape and signal intensity of the spinal cord, anterior epidural venous plexus MR images and clinical symptoms. The shape of the spinal cord and pre- and post-surgical conditions revealed by MRI correlated with clinical symptoms. As for the signal intensity of the spinal cord, in cases in which both high (T2-weighted image) and low (T1-weighted image) signals detected prior to surgery continued after surgery, as well as cases with high and low signals appearing after surgery, had the lower improvement than average. Low signal intensity on T1-weighted images are assumed to indicate irreversible changes of the spinal cord. High signal intensity on T2-weighted images is assumed to indicate both reversible and irreversible changes of the spinal cord. Epidural venous plexus can also be observed in healthy people and is not directly bound to clinical manifestations. Nevertheless, changes in the shape of the epidural venous plexus and signal intensity can reflect venous plexus compression and circulatory changes caused by compression. In the application of MRI to cervical compressive myelopathies, images of changes in the shape and signal intensity of the spinal cord and anterior epidural venous plexus images were considered important observations linked to clinical symptoms. MRI is an essential non-invasive imaging technique for the diagnosis of cervical compressive myelopathy, estimation of prognosis and postoperative follow-up. More investigations of compressive factors, circulatory dynamics of the spinal cord and high quality image are necessary. (author)

  6. The usefulness of magnetic resonance imaging (MRI) in cervical carcinoma assessment - a preliminary report

    International Nuclear Information System (INIS)

    Tacikowska, M.; Grzesiakowska, U.; Tacikowski, T.; Sobiczewski, P.

    2002-01-01

    The aim of diagnostic imaging is not so much the detection of cervical carcinoma, but the evaluation of its stage. In view of this the aim of this study included: 1) comparison of MR results with the results of histological examinations after operations with reference to the dimensions of cervical carcinoma; 2) assessment of the sensitivity and specificity of MRl in the evaluation of parametrium infiltration; 3) analysis of the sensitivity and specificity of MRI in the evaluation of infiltration of the vagina and uterus; 4) assessment of the usefulness of this method in the detection of metastases to lymph nodes.The material consisted of pelvic MRI, obtained with 2T Elscint unit in 15 patients with cervical carcinoma, aged 37 to 73 years. All patients underwent surgical treatment within 30 days after MR. During the MR examination the following sequences were performed: SE (spin echo) T1 (longitudinal relaxation time) in axial projection before administration of gadolinium (Gd-DTPA); SE T1 in axial, frontal and sagittal projections after contrast injection and FSE (fast spin echo) T2 (transversal relaxation time) in axial, frontal and sagittal projections.1) in the assessment of cervical carcinoma dimensions MRI results are highly concordant with the results of postoperative histological examination (p = 0. 9389); 2) in the assessment of parametrium infiltration sensitivity and specificity of MRI are 75% and 100%, respectively; 3) in the assessment of the infiltration of the vagina and uterine corpus the sensitivity and specificity of MRI imaging were respectively 100% and 85%; 100% and 100%; 4) in the detection of lymph node metastases MRI sensitivity was 67% and its specificity 100%. In patients with cervical carcinoma MRI is a valuable method for the assessment of tumour dimensions, parametrium infiltration, infiltration of the vagina and uterine corpus.(author)

  7. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful ... for an MRI exam contains a metal called gadolinium . Gadolinium can be used in patients with iodine ...

  8. Visualizing arthritic inflammation and therapeutic response by fluorine-19 magnetic resonance imaging (19F MRI

    Directory of Open Access Journals (Sweden)

    Balducci Anthony

    2012-06-01

    Full Text Available Abstract Background Non-invasive imaging of inflammation to measure the progression of autoimmune diseases, such as rheumatoid arthritis (RA, and to monitor responses to therapy is critically needed. V-Sense, a perfluorocarbon (PFC contrast agent that preferentially labels inflammatory cells, which are then recruited out of systemic circulation to sites of inflammation, enables detection by 19F MRI. With no 19F background in the host, detection is highly-specific and can act as a proxy biomarker of the degree of inflammation present. Methods Collagen-induced arthritis in rats, a model with many similarities to human RA, was used to study the ability of the PFC contrast agent to reveal the accumulation of inflammation over time using 19F MRI. Disease progression in the rat hind limbs was monitored by caliper measurements and 19F MRI on days 15, 22 and 29, including the height of clinically symptomatic disease. Naïve rats served as controls. The capacity of the PFC contrast agent and 19F MRI to assess the effectiveness of therapy was studied in a cohort of rats administered oral prednisolone on days 14 to 28. Results Quantification of 19F signal measured by MRI in affected limbs was linearly correlated with disease severity. In animals with progressive disease, increases in 19F signal reflected the ongoing recruitment of inflammatory cells to the site, while no increase in 19F signal was observed in animals receiving treatment which resulted in clinical resolution of disease. Conclusion These results indicate that 19F MRI may be used to quantitatively and qualitatively evaluate longitudinal responses to a therapeutic regimen, while additionally revealing the recruitment of monocytic cells involved in the inflammatory process to the anatomical site. This study may support the use of 19F MRI to clinically quantify and monitor the severity of inflammation, and to assess the effectiveness of treatments in RA and other diseases with an inflammatory

  9. An availability of brain magnetic resonance imaging (MRI) in the early diagnosis of latent hepatic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Kuwahara, Noaki; Tanabe, Masako; Fujiwara, Akiko; Minato, Takeshi; Sasaki, Hiromasa [Hiroshima Posts and Telecommunications Hospital (Japan); Higashi, Toshihiro; Tsuji, Takao

    1996-03-01

    Brain MRI was carried out in patients with chronic liver diseases. No abnormal findings were recognized in patients with chronic viral hepatitis, while 59.2% of cirrhotics showed a symmetrically strong signal in basal ganglia on T1 weighted image in MRI. This finding significantly related with lowered Fischer`s ratio of serum amino acid, increased levels of serum phenylalanine, tyrosine and hyaluronic acid, prolonged prothrombin time and decreased platelet counts in the peripheral blood. Overt hepatic encephalopathy was observed in 6 of 34 patients with the strong signal in MRI during follow-up period, while none of patients without that finding developed hepatic encephalopathy. These results have indicated that the strong signal in basal ganglia on MRI appears in cirrhotic patients with severe liver dysfunction, and it is an useful index in the early diagnosis of latent hepatic encephalopathy. An improvement of this MRI finding was not observed by long-term oral administration of branched-chain amino acid. (author).

  10. Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Voos, Avery; Pelphrey, Kevin

    2013-01-01

    Functional magnetic resonance imaging (fMRI), with its excellent spatial resolution and ability to visualize networks of neuroanatomical structures involved in complex information processing, has become the dominant technique for the study of brain function and its development. The accessibility of in-vivo pediatric brain-imaging techniques…

  11. Magnetic Resonance Fingerprinting - a promising new approach to obtain standardized imaging biomarkers from MRI

    OpenAIRE

    2015-01-01

    Current routine MRI examinations rely on the acquisition of qualitative images that have a contrast ?weighted? for a mixture of (magnetic) tissue properties. Recently, a novel approach was introduced, namely MR Fingerprinting (MRF) with a completely different approach to data acquisition, post-processing and visualization. Instead of using a repeated, serial acquisition of data for the characterization of individual parameters of interest, MRF uses a pseudo randomized acquisition that causes ...

  12. The OMERACT psoriatic arthritis magnetic resonance imaging scoring system (PsAMRIS): definitions of key pathologies, suggested MRI sequences, and preliminary scoring system for PsA Hands

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; McQueen, Fiona; Wiell, Charlotte

    2009-01-01

    This article describes a preliminary OMERACT psoriatic arthritis magnetic resonance image scoring system (PsAMRIS) for evaluation of inflammatory and destructive changes in PsA hands, which was developed by the international OMERACT MRI in inflammatory arthritis group. MRI definitions of important...... pathologies in peripheral PsA and suggestions concerning appropriate MRI sequences for use in PsA hands are also provided....

  13. Magnetic Resonance Fingerprinting - a promising new approach to obtain standardized imaging biomarkers from MRI.

    Science.gov (United States)

    2015-04-01

    Current routine MRI examinations rely on the acquisition of qualitative images that have a contrast "weighted" for a mixture of (magnetic) tissue properties. Recently, a novel approach was introduced, namely MR Fingerprinting (MRF) with a completely different approach to data acquisition, post-processing and visualization. Instead of using a repeated, serial acquisition of data for the characterization of individual parameters of interest, MRF uses a pseudo randomized acquisition that causes the signals from different tissues to have a unique signal evolution or 'fingerprint' that is simultaneously a function of the multiple material properties under investigation. The processing after acquisition involves a pattern recognition algorithm to match the fingerprints to a predefined dictionary of predicted signal evolutions. These can then be translated into quantitative maps of the magnetic parameters of interest. MR Fingerprinting (MRF) is a technique that could theoretically be applied to most traditional qualitative MRI methods and replaces them with acquisition of truly quantitative tissue measures. MRF is, thereby, expected to be much more accurate and reproducible than traditional MRI and should improve multi-center studies and significantly reduce reader bias when diagnostic imaging is performed. Key Points • MR fingerprinting (MRF) is a new approach to data acquisition, post-processing and visualization.• MRF provides highly accurate quantitative maps of T1, T2, proton density, diffusion.• MRF may offer multiparametric imaging with high reproducibility, and high potential for multicenter/ multivendor studies.

  14. Analysis of spatial and temporal dynamics of xylem refilling in Acer rubrum L. using magnetic resonance imaging (MRI.

    Directory of Open Access Journals (Sweden)

    Maciej Andrzej Zwieniecki

    2013-07-01

    Full Text Available We report results of an analysis of embolism formation and subsequent refilling observed in stems of Acer rubrum L. using magnetic resonance imaging (MRI. MRI is one of the very few techniques that can provide direct non-destructive observations of the water content within opaque biological materials at a micrometer resolution. Thus, it has been used to determine temporal dynamics and water distributions within xylem tissue. In this study, we found good agreement between MRI measures of pixel brightness to assess xylem liquid water content and the percent loss in hydraulic conductivity (PLC in response to water stress (P50 values of 2.51 and 2.70 for MRI and PLC, respectively. These data provide strong support that pixel brightness is well correlated to PLC and can be used as a proxy of PLC even when single vessels cannot be resolved on the image. Pressure induced embolism in moderately stressed plants resulted in initial drop of pixel brightness. This drop was followed by brightness gain over 100 minutes following pressure application suggesting that plants can restore water content in stem after induced embolism. This recovery was limited only to current year wood ring; older wood did not show signs of recovery within the length of experiment (16 hours. In vivo MRI observations of the xylem of moderately stressed (~-0.5 MPa A. rubrum stems revealed evidence of a spontaneous embolism formation followed by rapid refilling (~30 minutes. Spontaneous (not induced embolism formation was observed only once, despite over 60 hours of continuous MRI observations made on several plants. Thus this observation provide evidence for presence of naturally occurring embolism-refilling cycle in A. rubrum, but it is impossible to infer any conclusions in relation to its frequency in nature.

  15. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... it is useful to bring that to the attention of the technologist or scheduler before the exam. ... patient for magnetic resonance imaging (MRI) exam. View full size with caption Pediatric Content Some imaging tests ...

  16. Functional magnetic resonance imaging (fMRI) for fetal oxygenation during maternal hypoxia: initial results

    International Nuclear Information System (INIS)

    Wedegaertner, U.; Adam, G.; Tchirikov, M.; Schroeder, H.; Koch, M.

    2002-01-01

    Purpose: To investigate the potential of fMRI to measure changes in fetal tissue oxygenation during acute maternal hypoxia in fetal lambs. Material and Methods: Two ewes carrying singleton fetuses (gestational age 125 and 131 days) underwent MR imaging under inhalation anesthesia. BOLD imaging of the fetal brain, liver and myocardium was performed during acute maternal hypoxia (oxygen replaced by N 2 O). Maternal oxygen saturation and heart rate were monitored by a pulse-oxymeter attached to the maternal tongue. Results: Changes of fetal tissue oxygenation during maternal hypoxia were clearly visible with BOLD MRI. Signal intensity decreases were more distinct in liver and heart (∝40%) from control than in the fetal brain (∝10%). Conclusions: fMRI is a promising diagnostic tool to determine fetal tissue oxygenation and may open new opportunities in monitoring fetal well being in high risk pregnancies complicated by uteroplacentar insufficiency. Different signal changes in liver/heart and brain may reflect a centralization of the fetal blood flow. (orig.) [de

  17. Efficient solution methodology for calibrating the hemodynamic model using functional Magnetic Resonance Imaging (fMRI) measurements

    KAUST Repository

    Zambri, Brian

    2015-11-05

    Our aim is to propose a numerical strategy for retrieving accurately and efficiently the biophysiological parameters as well as the external stimulus characteristics corresponding to the hemodynamic mathematical model that describes changes in blood flow and blood oxygenation during brain activation. The proposed method employs the TNM-CKF method developed in [1], but in a prediction/correction framework. We present numerical results using both real and synthetic functional Magnetic Resonance Imaging (fMRI) measurements to highlight the performance characteristics of this computational methodology. © 2015 IEEE.

  18. Efficient solution methodology for calibrating the hemodynamic model using functional Magnetic Resonance Imaging (fMRI) measurements

    KAUST Repository

    Zambri, Brian; Djellouli, Rabia; Laleg-Kirati, Taous-Meriem

    2015-01-01

    Our aim is to propose a numerical strategy for retrieving accurately and efficiently the biophysiological parameters as well as the external stimulus characteristics corresponding to the hemodynamic mathematical model that describes changes in blood flow and blood oxygenation during brain activation. The proposed method employs the TNM-CKF method developed in [1], but in a prediction/correction framework. We present numerical results using both real and synthetic functional Magnetic Resonance Imaging (fMRI) measurements to highlight the performance characteristics of this computational methodology. © 2015 IEEE.

  19. Human developmental anatomy: microscopic magnetic resonance imagingMRI) of four human embryos (from Carnegie Stage 10 to 20).

    Science.gov (United States)

    Lhuaire, Martin; Martinez, Agathe; Kaplan, Hervé; Nuzillard, Jean-Marc; Renard, Yohann; Tonnelet, Romain; Braun, Marc; Avisse, Claude; Labrousse, Marc

    2014-12-01

    Technological advances in the field of biological imaging now allow multi-modal studies of human embryo anatomy. The aim of this study was to assess the high magnetic field μMRI feasibility in the study of small human embryos (less than 21mm crown-rump) as a new tool for the study of human descriptive embryology and to determine better sequence characteristics to obtain higher spatial resolution and higher signal/noise ratio. Morphological study of four human embryos belonging to the historical collection of the Department of Anatomy in the Faculty of Medicine of Reims was undertaken by μMRI. These embryos had, successively, crown-rump lengths of 3mm (Carnegie Stage, CS 10), 12mm (CS 16), 17mm (CS 18) and 21mm (CS 20). Acquisition of images was performed using a vertical nuclear magnetic resonance spectrometer, a Bruker Avance III, 500MHz, 11.7T equipped for imaging. All images were acquired using 2D (transverse, sagittal and coronal) and 3D sequences, either T1-weighted or T2-weighted. Spatial resolution between 24 and 70μm/pixel allowed clear visualization of all anatomical structures of the embryos. The study of human embryos μMRI has already been reported in the literature and a few atlases exist for educational purposes. However, to our knowledge, descriptive or morphological studies of human developmental anatomy based on data collected these few μMRI studies of human embryos are rare. This morphological noninvasive imaging method coupled with other techniques already reported seems to offer new perspectives to descriptive studies of human embryology.

  20. Breast density quantification using magnetic resonance imaging (MRI) with bias field correction: a postmortem study.

    Science.gov (United States)

    Ding, Huanjun; Johnson, Travis; Lin, Muqing; Le, Huy Q; Ducote, Justin L; Su, Min-Ying; Molloi, Sabee

    2013-12-01

    Quantification of breast density based on three-dimensional breast MRI may provide useful information for the early detection of breast cancer. However, the field inhomogeneity can severely challenge the computerized image segmentation process. In this work, the effect of the bias field in breast density quantification has been investigated with a postmortem study. T1-weighted images of 20 pairs of postmortem breasts were acquired on a 1.5 T breast MRI scanner. Two computer-assisted algorithms were used to quantify the volumetric breast density. First, standard fuzzy c-means (FCM) clustering was used on raw images with the bias field present. Then, the coherent local intensity clustering (CLIC) method estimated and corrected the bias field during the iterative tissue segmentation process. Finally, FCM clustering was performed on the bias-field-corrected images produced by CLIC method. The left-right correlation for breasts in the same pair was studied for both segmentation algorithms to evaluate the precision of the tissue classification. Finally, the breast densities measured with the three methods were compared to the gold standard tissue compositions obtained from chemical analysis. The linear correlation coefficient, Pearson's r, was used to evaluate the two image segmentation algorithms and the effect of bias field. The CLIC method successfully corrected the intensity inhomogeneity induced by the bias field. In left-right comparisons, the CLIC method significantly improved the slope and the correlation coefficient of the linear fitting for the glandular volume estimation. The left-right breast density correlation was also increased from 0.93 to 0.98. When compared with the percent fibroglandular volume (%FGV) from chemical analysis, results after bias field correction from both the CLIC the FCM algorithms showed improved linear correlation. As a result, the Pearson's r increased from 0.86 to 0.92 with the bias field correction. The investigated CLIC method

  1. Breast density quantification using magnetic resonance imaging (MRI) with bias field correction: A postmortem study

    International Nuclear Information System (INIS)

    Ding, Huanjun; Johnson, Travis; Lin, Muqing; Le, Huy Q.; Ducote, Justin L.; Su, Min-Ying; Molloi, Sabee

    2013-01-01

    Purpose: Quantification of breast density based on three-dimensional breast MRI may provide useful information for the early detection of breast cancer. However, the field inhomogeneity can severely challenge the computerized image segmentation process. In this work, the effect of the bias field in breast density quantification has been investigated with a postmortem study. Methods: T1-weighted images of 20 pairs of postmortem breasts were acquired on a 1.5 T breast MRI scanner. Two computer-assisted algorithms were used to quantify the volumetric breast density. First, standard fuzzy c-means (FCM) clustering was used on raw images with the bias field present. Then, the coherent local intensity clustering (CLIC) method estimated and corrected the bias field during the iterative tissue segmentation process. Finally, FCM clustering was performed on the bias-field-corrected images produced by CLIC method. The left–right correlation for breasts in the same pair was studied for both segmentation algorithms to evaluate the precision of the tissue classification. Finally, the breast densities measured with the three methods were compared to the gold standard tissue compositions obtained from chemical analysis. The linear correlation coefficient, Pearson'sr, was used to evaluate the two image segmentation algorithms and the effect of bias field. Results: The CLIC method successfully corrected the intensity inhomogeneity induced by the bias field. In left–right comparisons, the CLIC method significantly improved the slope and the correlation coefficient of the linear fitting for the glandular volume estimation. The left–right breast density correlation was also increased from 0.93 to 0.98. When compared with the percent fibroglandular volume (%FGV) from chemical analysis, results after bias field correction from both the CLIC the FCM algorithms showed improved linear correlation. As a result, the Pearson'sr increased from 0.86 to 0.92 with the bias field correction

  2. Optimization image of magnetic resonance imaging (MRI) T2 fast spin echo (FSE) with variation echo train length (ETL) on the rupture tendon achilles case

    International Nuclear Information System (INIS)

    Muzamil, Akhmad; Firmansyah, Achmad Haries

    2017-01-01

    The research was done the optimization image of Magnetic Resonance Imaging (MRI) T2 Fast Spin Echo (FSE) with variation Echo Train Length (ETL) on the Rupture Tendon Achilles case. This study aims to find the variations Echo Train Length (ETL) from the results of ankle’s MRI image and find out how the value of Echo Train Length (ETL) works on the MRI ankle to produce optimal image. In this research, the used ETL variations were 12 and 20 with the interval 2 on weighting T2 FSE sagittal. The study obtained the influence of Echo Train Length (ETL) on the quality of ankle MRI image sagittal using T2 FSE weighting and analyzed in 25 images of five patients. The data analysis has done quantitatively with the Region of Interest (ROI) directly on computer MRI image planes which conducted statistical tests Signal to Noise Ratio (SNR) and Contras to Noise Ratio (CNR). The Signal to Noise Ratio (SNR) was the highest finding on fat tissue, while the Contras to Noise Ratio (CNR) on the Tendon-Fat tissue with ETL 12 found in two patients. The statistics test showed the significant SNR value of the 0.007 (p<0.05) of Tendon tissue, 0.364 (p>0.05) of the Fat, 0.912 (p>0.05) of the Fibula, and 0.436 (p>0.05) of the Heel Bone. For the contrast to noise ratio (CNR) of the Tendon-FAT tissue was about 0.041 (p>0.05). The results of the study showed that ETL variation with T2 FSE sagittal weighting had difference at Tendon tissue and Tendon-Fat tissue for MRI imaging quality. SNR and CNR were an important aspect on imaging optimization process to give the diagnose information. (paper)

  3. The hidden-Markov brain: comparison and inference of white matter hyperintensities on magnetic resonance imaging (MRI)

    Science.gov (United States)

    Pham, Tuan D.; Salvetti, Federica; Wang, Bing; Diani, Marco; Heindel, Walter; Knecht, Stefan; Wersching, Heike; Baune, Bernhard T.; Berger, Klaus

    2011-02-01

    Rating and quantification of cerebral white matter hyperintensities on magnetic resonance imaging (MRI) are important tasks in various clinical and scientific settings. As manual evaluation is time consuming and imprecise, much effort has been made to automate the quantification of white matter hyperintensities. There is rarely any report that attempts to study the similarity/dissimilarity of white matter hyperintensity patterns that have different sizes, shapes and spatial localizations on the MRI. This paper proposes an original computational neuroscience framework for such a conceptual study with a standpoint that the prior knowledge about white matter hyperintensities can be accumulated and utilized to enable a reliable inference of the rating of a new white matter hyperintensity observation. This computational approach for rating inference of white matter hyperintensities, which appears to be the first study, can be utilized as a computerized rating-assisting tool and can be very economical for diagnostic evaluation of brain tissue lesions.

  4. Benchtop-magnetic resonance imaging (BT-MRI) characterization of push-pull osmotic controlled release systems.

    Science.gov (United States)

    Malaterre, Vincent; Metz, Hendrik; Ogorka, Joerg; Gurny, Robert; Loggia, Nicoletta; Mäder, Karsten

    2009-01-05

    The mechanism of drug release from push-pull osmotic systems (PPOS) has been investigated by Magnetic Resonance Imaging (MRI) using a new benchtop apparatus. The signal intensity profiles of both PPOS layers were monitored non-invasively over time to characterize the hydration and swelling kinetics. The drug release performance was well-correlated to the hydration kinetics. The results show that (i) hydration and swelling critically depend on the tablet core composition, (ii) high osmotic pressure developed by the push layer may lead to bypassing the drug layer and incomplete drug release and (iii) the hydration of both the drug and the push layers needs to be properly balanced to efficiently deliver the drug. MRI is therefore a powerful tool to get insights on the drug delivery mechanism of push-pull osmotic systems, which enable a more efficient optimization of such formulations.

  5. Magnetic resonance imaging (MRI) evaluation of residual breast tissue following mastectomy and reconstruction with silicone implants.

    Science.gov (United States)

    Zippel, Douglas; Tsehmaister-Abitbol, Vered; Rundstein, Arie; Shalmon, Anat; Zbar, Andrew; Nardini, Gil; Novikov, Ilya; Sklair-Levy, Miri

    2015-01-01

    We present our use of magnetic resonance (MR) measurement to determine the amount of residual breast tissue (RBT) following total mastectomy with reconstruction. Breast MR images of 45 women who underwent surgery between January and November 2011 were reviewed. The cohort included therapeutic and prophylactic mastectomies. RBT was evaluated at four points with a digital caliper assessing T2-weighted and T1-weighted images. Patients undergoing mastectomy for carcinoma tended to have less RBT than in prophylactic surgery. Greater age and recent surgery both correlated with larger RBT. Variable thickness of RBT is demonstrable following mastectomy and implant reconstruction using MR imaging. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Signal to noise ratio (SNR) and image uniformity: an estimate of performance of magnetic resonance imaging (MRI) system

    International Nuclear Information System (INIS)

    Narayan, P.; Suri, S.; Choudhary, S.R.

    2001-01-01

    In most general definition, noise in an image, is any variation that represents a deviation from truth. Noise sources in MRI can be systematic or random and statistical in nature. Data processing algorithms that smooth and enhance the edges by non-linear intensity assignments among other factors can affect the distribution of statistical noise. The SNR and image uniformity depends on the various parameters of NMR imaging system (viz. General system calibration, Gain coil tuning, AF shielding, coil loading, image processing and scan parameters like TE, TR, interslice distance, slice thickness, pixel size and matrix size). A study on SNR and image uniformity have been performed using standard head AF coil with different TR and the estimates of their variation are presented. A comparison between different techniques has also been evaluated using standard protocol of the Siemens Magnetom Vision Plus MRI system

  7. Magnetic resonance imaging (MRI)-based indication for neoadjuvant treatment of rectal carcinoma and the surrogate endpoint CRM status.

    Science.gov (United States)

    Strassburg, Joachim; Junginger, Theo; Trinh, Trong; Püttcher, Olaf; Oberholzer, Katja; Heald, Richard J; Hermanek, Paul

    2008-11-01

    Is it possible to reduce the frequency of neoadjuvant therapy for rectal carcinoma and nevertheless achieve a rate of more than 90% circumferential resection margin (CRM)-negative resection specimens by a novel concept of magnetic resonance imaging (MRI)-based therapy planning? One hundred eighty-one patients from Berlin and Mainz, Germany, with primary rectal carcinoma, without distant metastasis, underwent radical surgery with curative intention. Surgical procedures applied were anterior resection with total mesorectal excision (TME) or partial mesorectal excision (PME; PME for tumours of the upper rectum) or abdominoperineal excision with TME. With MRI selection of the highest-risk cases, neoadjuvant therapy was given to only 62 of 181 (34.3%). The rate of CRM-negative resection specimens on histology was 170 of 181 (93.9%) for all patients, and in Berlin, only 1 of 93 (1%) specimens was CRM-positive. Patients selected for primary surgery had CRM-negative specimens on histology in 114 of 119 (95.8%). Those selected for neoadjuvant therapy had a lower rate of clear margin: 56 of 62 (90%). By applying a MRI-based indication, the frequency of neoadjuvant treatment with its acute and late adverse effects can be reduced to 30-35% without reduction of pathologically CRM-negative resection specimens and, thus, without the danger of worsening the oncological long-term results. This concept should be confirmed in prospective multicentre observation studies with quality assurance of MRI, surgery and pathology.

  8. Merits of magnetic resonance imaging (MRI) for the diagnosis of myositis ossificans circumscripta

    International Nuclear Information System (INIS)

    Bouchardy, L.; Garcia, J.

    1994-01-01

    A retrospective study of 5 cases, 4 of myositis ossificans circumscripta (MOC) and 1 of non-ossificans myositis, is presented. The clinical presentation was a painful soft-tissues swelling, and the final diagnosis was established by biopsy in 3 cases and clinical evolution in 2 cases. Different types of imaging techniques were performed: 4 MRI, 2 arteriographies, 3 Tc 99m scintigraphies, 3 US, 3 CT and plain film radiographs for all patients. MOC is a benign process (as opposed to myositis ossificans progressiva, which is an hereditary pathology with a fatal prognosis) with 3 phases of evolution: an acute or pseudo-inflammatory phase, a sub-acute or pseudo-tumoral phase and a chronic phase with a spontaneous healing. The radiologic diagnostic findings are dependent of the phase of the disease. The calcifications are seen earlier with scintigraphy than plain films, with US being less helpful. A heterogenous mass and calcifications are seen with CT. MRI allows the characterization of oedema during the acute phase and sometimes can exclude a malignant process. MRI is the best method for an early diagnosis, the differential diagnosis and to follow the evolution. (authors). 26 refs., 8 figs

  9. Magnetic resonance imaging: project planning and management of a superconductive M.R.I. installation

    International Nuclear Information System (INIS)

    Condon, P.M.; Robertson, A.R.

    1989-01-01

    The planning and installation of a Superconductive Magnetic Resonance Imaging installation at the Royal Adelaide Hospital, Adelaide, South Australia is described. Tender specification, assessment of offers via criteria weighted analysis of technical and economic factors and the final recommendation for a 1.0 Tesla unit are discussed. Building and installation considerations are noted including fringe field effects, magnetic shielding, radiofrequency shielding, cryogens, metallic screening and specific considerations in the Magnet room. 9 refs., 7 figs

  10. Space-occupying, inflammatory and dyplastic lesions of the cranio-cervical junction seen in nuclear magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Friedburg, H.; Schumacher, M.; Hennig, J.

    1987-01-01

    Lesions of the cranio-cervical junction have acquired a special place amongst lesions of the posterior cranial fossa and the upper cervical region. This is due to the unusually long period between the appearance of the first symptoms and reaching a conclusive diagnosis. Frequently such lesions cannot be detected by either normal X-rays or conventional tomographic techniques. The introduction, however, of computer tomography (CT) and, in particular, magnetic resonance imaging (MRI) has made the examination of the critical zone of the cranio-cervical junction much easier and the diagnosis of thee lesions has now become largely dependent upon those techniques. Because soft tissue contrast is intrinsic to MRI this technique, in particular, has made possible substantial improvements in the quality of images of ligaments and soft tissue than those provided by standard CT. In this paper, the advantages which are provided by MRI in the context of the diagnosis of non-bony lesions in the cranio-cervical region are presented and discussed

  11. MRI imaging in pediatric appendicitis

    Directory of Open Access Journals (Sweden)

    Robin Riley

    2018-04-01

    Full Text Available An 8-year-old male presents with two days of abdominal pain and emesis. Computed tomography was concerning for obstruction or reactive ileus with an apparent transition point in the right lower quadrant, possibly due to Crohn's. Magnetic resonance imaging was concerning for perforated appendicitis. As demonstrated by this case MRI can be as sensitive as CT in detecting pediatric appendicitis [2]. We recommend using MRI instead of CT to diagnose appendicitis to avoid ionizing radiation and increased cancer risk in the pediatric population. Keywords: Computer tomography, Magnetic resonance imaging, Pediatric appendicitis

  12. Early myocardial dysfunction in streptozotocin-induced diabetic mice: a study using in vivo magnetic resonance imaging (MRI

    Directory of Open Access Journals (Sweden)

    Chandrasekaran Suresh

    2007-02-01

    Full Text Available Abstract Background Diabetes is associated with a cardiomyopathy that is independent of coronary artery disease or hypertension. In the present study we used in vivo magnetic resonance imaging (MRI and echocardiographic techniques to examine and characterize early changes in myocardial function in a mouse model of type 1 diabetes. Methods Diabetes was induced in 8-week old C57BL/6 mice with two intraperitoneal injections of streptozotocin. The blood glucose levels were maintained at 19–25 mmol/l using intermittent low dosages of long acting insulin glargine. MRI and echocardiography were performed at 4 weeks of diabetes (age of 12 weeks in diabetic mice and age-matched controls. Results After 4 weeks of hyperglycemia one marker of mitochondrial function, NADH oxidase activity, was decreased to 50% of control animals. MRI studies of diabetic mice at 4 weeks demonstrated significant deficits in myocardial morphology and functionality including: a decreased left ventricular (LV wall thickness, an increased LV end-systolic diameter and volume, a diminished LV ejection fraction and cardiac output, a decreased LV circumferential shortening, and decreased LV peak ejection and filling rates. M-mode echocardiographic and Doppler flow studies of diabetic mice at 4 weeks showed a decreased wall thickening and increased E/A ratio, supporting both systolic and diastolic dysfunction. Conclusion Our study demonstrates that MRI interrogation can identify the onset of diabetic cardiomyopathy in mice with its impaired functional capacity and altered morphology. The MRI technique will lend itself to repetitive study of early changes in cardiac function in small animal models of diabetic cardiomyopathy.

  13. Early myocardial dysfunction in streptozotocin-induced diabetic mice: a study using in vivo magnetic resonance imaging (MRI)

    Science.gov (United States)

    Yu, Xichun; Tesiram, Yasvir A; Towner, Rheal A; Abbott, Andrew; Patterson, Eugene; Huang, Shijun; Garrett, Marion W; Chandrasekaran, Suresh; Matsuzaki, Satoshi; Szweda, Luke I; Gordon, Brian E; Kem, David C

    2007-01-01

    Background Diabetes is associated with a cardiomyopathy that is independent of coronary artery disease or hypertension. In the present study we used in vivo magnetic resonance imaging (MRI) and echocardiographic techniques to examine and characterize early changes in myocardial function in a mouse model of type 1 diabetes. Methods Diabetes was induced in 8-week old C57BL/6 mice with two intraperitoneal injections of streptozotocin. The blood glucose levels were maintained at 19–25 mmol/l using intermittent low dosages of long acting insulin glargine. MRI and echocardiography were performed at 4 weeks of diabetes (age of 12 weeks) in diabetic mice and age-matched controls. Results After 4 weeks of hyperglycemia one marker of mitochondrial function, NADH oxidase activity, was decreased to 50% of control animals. MRI studies of diabetic mice at 4 weeks demonstrated significant deficits in myocardial morphology and functionality including: a decreased left ventricular (LV) wall thickness, an increased LV end-systolic diameter and volume, a diminished LV ejection fraction and cardiac output, a decreased LV circumferential shortening, and decreased LV peak ejection and filling rates. M-mode echocardiographic and Doppler flow studies of diabetic mice at 4 weeks showed a decreased wall thickening and increased E/A ratio, supporting both systolic and diastolic dysfunction. Conclusion Our study demonstrates that MRI interrogation can identify the onset of diabetic cardiomyopathy in mice with its impaired functional capacity and altered morphology. The MRI technique will lend itself to repetitive study of early changes in cardiac function in small animal models of diabetic cardiomyopathy. PMID:17309798

  14. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose medical conditions. MRI ...

  15. A Novel Magnetic Resonance Imaging (MRI) Approach for Measuring Weak Electric Currents Inside the Human Brain

    DEFF Research Database (Denmark)

    Göksu, Cihan

    of individual ohmic conductivity values may open up the possibility of creating more realistic and accurate head models, which may ameliorate the simulations and practical use of NIBS techniques. Magnetic resonance current density imaging (MRCDI) and magnetic resonance electrical impedance tomography (MREIT......Knowing the electrical conductivity and current density distribution inside the human brain will be useful in various biomedical applications, i.e. for improving the efficiency of non-invasive brain stimulation (NIBS) techniques, the accuracy of electroencephalography (EEG......) and magnetoencephalography (MEG) source localization, or localization of pathological tissues. For example, the accuracy of electric field simulations for NIBS techniques is currently reduced by assigning inaccurate ohmic conductivity values taken from literature to different brain tissues. Therefore, the knowledge...

  16. Should the orthodontic brackets always be removed prior to magnetic resonance imaging (MRI)?

    Science.gov (United States)

    Poorsattar-Bejeh Mir, Arash; Rahmati-Kamel, Manouchehr

    2015-01-01

    Request for temporary removal of orthodontic appliances due to medical conditions that require magnetic resonance (MR) imaging is not uncommon in daily practice in the field of orthodontics. This may be at the expense of time and cost. Metal Orthodontic appliances cause more signal loss and image distortion as compared to ceramic and titanium ones. Stainless steel and large brackets in addition to the oriented miniscrews in relation to the axis of magnetic field may cause severe signal loss and image distortion. Moreover, gradient echo and frequency-selective fat saturation MR protocols are more susceptible to metal artifacts. The spin echo and fat-suppression protocols, low magnetic field strength (e.g., 1.5 Tesla vs. 3 Tesla), small field of view, high-resolution matrix, thin slice, increased echo train length and increased receiver band width could be applied to lessen the metal artifacts in MR images. The larger the distance between an appliance and desired location to be imaged, the lower the distortion and signal loss. Decision to remove brackets should be made based on its composition and desired anatomic location. In this review, first the principles of MR imaging are introduced (Part-I) and then the interactions of orthodontic appliances and magnetic field are farther discussed (Part-II). PMID:27195213

  17. A study utility of gadolinium enhanced magnetic resonance imaging (Gd-MRI) in the preoperative diagnosis of lymph node metastasis of esophageal carcinoma

    International Nuclear Information System (INIS)

    Makino, Harufumi

    1997-01-01

    We evaluated the utility of gadolinium enhanced magnetic resonance imaging (Gd-MRI) in the diagnosis of lymph node metastasis of esophageal carcinoma. Gd-MRI was performed in 42 patients with esophageal carcinoma. The intensities of 50 lymph nodes in MR imaging were measured. No differences were observed in intensity between metastatic and non-metastatic nodes. However, intensity values did overlap. Thus, the author devised a new method allowing comparison of metastatic and non-metastatic nodes on Gd-MRI utilizing an enhancement ratio (ER). ER higher than 45% reflected metastatic nodes. (author)

  18. Preparation and Evaluation of Multiple Nanoemulsions Containing Gadolinium (III) Chelate as a Potential Magnetic Resonance Imaging (MRI) Contrast Agent.

    Science.gov (United States)

    Sigward, Estelle; Corvis, Yohann; Doan, Bich-Thuy; Kindsiko, Kadri; Seguin, Johanne; Scherman, Daniel; Brossard, Denis; Mignet, Nathalie; Espeau, Philippe; Crauste-Manciet, Sylvie

    2015-09-01

    The objective was to develop, characterize and assess the potentiality of W1/O/W2 self-emulsifying multiple nanoemulsions to enhance signal/noise ratio for Magnetic Resonance Imaging (MRI). For this purpose, a new formulation, was designed for encapsulation efficiency and stability. Various methods were used to characterize encapsulation efficiency ,in particular calorimetric methods (Differential Scanning Calorimetry (DSC), thermogravimetry analysis) and ultrafiltration. MRI in vitro relaxivities were assessed on loaded DTPA-Gd multiple nanoemulsions. Characterization of the formulation, in particular of encapsulation efficiency was a challenge due to interactions found with ultrafiltration method. Thanks to the specifically developed DSC protocol, we were able to confirm the formation of multiple nanoemulsions, differentiate loaded from unloaded nanoemulsions and measure the encapsulation efficiency which was found to be quite high with a 68% of drug loaded. Relaxivity studies showed that the self-emulsifying W/O/W nanoemulsions were positive contrast agents, exhibiting higher relaxivities than those of the DTPA-Gd solution taken as a reference. New self-emulsifying multiple nanoemulsions that were able to load satisfactory amounts of contrasting agent were successfully developed as potential MRI contrasting agents. A specific DSC protocol was needed to be developed to characterize these complex systems as it would be useful to develop these self-formation formulations.

  19. Magnetic resonance imaging-guided attenuation correction of positron emission tomography data in PET/MRI

    OpenAIRE

    Izquierdo-Garcia, David; Catana, Ciprian

    2016-01-01

    Attenuation correction (AC) is one of the most important challenges in the recently introduced combined positron emission tomography/magnetic resonance imaging (PET/MR) scanners. PET/MR AC (MR-AC) approaches aim to develop methods that allow accurate estimation of the linear attenuation coefficients (LACs) of the tissues and other components located in the PET field of view (FoV). MR-AC methods can be divided into three main categories: segmentation-, atlas- and PET-based. This review aims to...

  20. Functional magnetic resonance imaging (fMRI) for fetal oxygenation during maternal hypoxia: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Wedegaertner, U.; Adam, G. [Abt. fuer Diagnostische und Interventionelle Radiologie, Klinik und Poliklinik fuer Radiologie, UKE Hamburg (Germany); Tchirikov, M.; Schroeder, H. [Abt. fuer experimentelle Gynaekologie der Universitaetsfrauenklinik, Klinik und Poliklinik fuer Frauenheilkunde, UKE, Hamburg (Germany); Koch, M. [Klinik und Poliklinik fuer Neurologie, UKE Hamburg (Germany)

    2002-06-01

    Purpose: To investigate the potential of fMRI to measure changes in fetal tissue oxygenation during acute maternal hypoxia in fetal lambs. Material and Methods: Two ewes carrying singleton fetuses (gestational age 125 and 131 days) underwent MR imaging under inhalation anesthesia. BOLD imaging of the fetal brain, liver and myocardium was performed during acute maternal hypoxia (oxygen replaced by N{sub 2}O). Maternal oxygen saturation and heart rate were monitored by a pulse-oxymeter attached to the maternal tongue. Results: Changes of fetal tissue oxygenation during maternal hypoxia were clearly visible with BOLD MRI. Signal intensity decreases were more distinct in liver and heart ({proportional_to}40%) from control than in the fetal brain ({proportional_to}10%). Conclusions: fMRI is a promising diagnostic tool to determine fetal tissue oxygenation and may open new opportunities in monitoring fetal well being in high risk pregnancies complicated by uteroplacentar insufficiency. Different signal changes in liver/heart and brain may reflect a centralization of the fetal blood flow. (orig.) [German] Ziel: Untersuchung des Potentiales der funktionellen MRT (BOLD) in der Darstellung von Veraenderungen in der Sauerstoffsaettigung fetaler Gewebe waehrend akuter materner Hypoxie bei fetalen Laemmern. Material und Methoden: Die MR-Untersuchung wurde an zwei Mutterschafen mit 125 und 131 Tage alten Feten in Inhalationsnarkose durchgefuehrt. Die BOLD Messungen von fetaler Leber, Myokard und Gehirn erfolgten waehrend einer akuten Hypoxiephase des Muttertieres, in der Sauerstoff durch N{sub 2}O ersetzt wurde. Die materne Sauerstoffsaettigung und Herzfrequenz wurde durch ein Pulsoxymeter ueberwacht. Ergebnisse: Aenderungen der fetalen Gewebsoxygenierung waehrend einer akuten Hypoxiephase der Mutter waren mit der BOLD-MR-Bildgebung deutlich darstellbar. In der fetalen Leber und dem Myokard zeigte sich ein staerkerer Signalabfall um ca. 40% von den Kontrollwerten als im fetalen

  1. Magnetic resonance imaging

    International Nuclear Information System (INIS)

    Sigal, R.

    1988-01-01

    This book is an introduction to magnetic resonance imaging (MRI). The basic principles for the interpretation of MR images are developed. The book is divided into five chapters: introduction, tissue, parameters, acquisition parameters, contribution to diagnosis, and practical management of an MR examination. Eight exercises allow the reader to test the knowledge he has acquired. Signal localization and MR artefacts are reviewed in an appendix

  2. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed ... problems, medications, recent surgeries and allergies. The magnetic field is not harmful, but it may cause some ...

  3. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... MRI) exam. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Catheter Angiography Magnetic Resonance, ...

  4. The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas

    International Nuclear Information System (INIS)

    Krestan, C.; Czerny, C.; Gstoettner, W.; Franz, P.

    2003-01-01

    The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas will be described in this paper. The pre- and postoperative imaging of the temporal bone was performed with HRCT and MRI. HRCT and MRI were performed in the axial and coronal plane. MRI was done with T2 weighted and T1 weighted sequences both before and after the intravenous application of contrast material. All imaging findings were confirmed clinically or surgically. The preoperative cholesteatoma-caused complications depicted by HRCT included bony erosions of the ossicles, scutum, facial canal in the middle ear, tympanic walls including the tegmen tympani, and of the labyrinth. The preoperative cholesteatoma-caused complications depicted by MRI included signs indicative for labyrinthitis, and brain abscess. Postoperative HRCT depicted bony erosions caused by recurrent cholesteatoma, bony defects of the facial nerve and of the labyrinth, and a defect of the tegmen tympani with a soft tissue mass in the middle ear. Postoperative MRI delineated neuritis of the facial nerve, labyrinthitis, and a meningo-encephalocele protruding into the middle ear. HRCT and MRI are excellent imaging tools to depict either bony or soft tissue complications or both if caused by acquired cholesteatomas. According to our findings and to the literature HRCT and MRI are complementary imaging methods to depict pre- or postoperative complications of acquired cholesteatomas if these are suspected by clinical examination. (orig.) [de

  5. Synthesis and characterization of Gadolinium-Lectin conjugates as selective blood-vessel contrast agents for magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Pashkunova-Martic, I.

    2004-11-01

    Molecular imaging without use of ionizing radiation has recently been developed for both magnetic resonance and ultrasound imaging (MRI, US) and is expected to play a major future role in diagnosis and monitoring of tumours. In MRI, targeted nanoparticle contrast media (CM) with high relaxivities are required in order to obtain adequate signal-to-noise ratios, due to the low number of target sites. The size, charge and chemical constitution of the targeted nanoparticle CM are expected to influence nanoparticle interactions with cells and tissue elements significantly, and hence the targeting, the accumulation and dwell time at the targeted site, and the type and rate of clearance of the nanoparticles. The work reported here aims to characterise and optimise these parameters in mouse and human models, using nanoparticles targeted to a major carbohydrate determinant of the endothelial cell surface which is present in all blood vessels. Specific binding to the endothelium was demonstrated in both living and chemically fixed human vessels and in mice. Long-standing spin-echo and FLASH-3D images were obtained in the vasculature of living mice, in strong contrast to the rapid renal clearance of gadolinium-DTPA chelates which are widely used in the clinic. Nanoparticle size was found to be a major determinant of the biological response, and our data indicate that an optimal nanoparticle size lies between 50-100 nm diameter. We expect that hyperpermeable vessels present in tumours will permit targeting of optimised nanoparticles to the tumour cells, permitting MRI monitoring of the tumour. (author)

  6. Assessing the Accuracy and Reliability of Root Crack and Fracture Detection in Teeth Using Sweep Imaging with Fourier Transform (SWIFT) Magnetic Resonance Imaging (MRI)

    Science.gov (United States)

    Schuurmans, Tyler J.

    Introduction: Magnetic Resonance Imaging (MRI) has the potential to aid in determining the presence and extent of cracks/fractures in teeth due to more advantageous contrast, without ionizing radiation. An MRI technique called Sweep Imaging with Fourier Transform (SWIFT) has overcome many of the inherent difficulties of conventional MRI with detecting fast-relaxing signals from densely mineralized dental tissues. The objectives of this in vitro investigation were to develop MRI criteria for root crack/fracture identification in teeth and to establish intra- and inter-rater reliabilities and corresponding sensitivity and specificity values for the detection of tooth-root cracks/fractures in SWIFT MRI and limited field of view (FOV) CBCT. Materials and Methods: MRI-based criteria for crack/fracture appearance was developed by an MRI physicist and 6 dentists, including 3 endodontists and 1 Oral and Maxillofacial (OMF) radiologist. Twenty-nine human adult teeth previously extracted following clinical diagnosis by a board-certified endodontist of a root crack/fracture were frequency-matched to 29 non-cracked controls. Crack/fracture status confirmation was performed with magnified visual inspection, transillumination and vital staining. Samples were scanned with two 3D imaging modalities: 1) SWIFT MRI (10 teeth/scan) via a custom oral radiofrequency (RF) coil and a 90cm, 4-T magnet; 2) Limited FOV CBCT (1 tooth/scan) via a Carestream (CS) 9000 (Rochester, NY). Following a training period, a blinded 4-member panel (3 endodontists, 1 OMF radiologist) evaluated the images with a proportion randomly re-tested to establish intra-rater reliability. Overall observer agreement was measured using Cohen's kappa and levels of agreement judged using the criteria of Landis and Koch. Sensitivity and specificity were computed with 95% confidence interval (CI); statistical significance was set at alpha ≤ 0.05. Results: MRI-based crack/fracture criteria were defined as 1-2 sharply

  7. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging of bone marrow in healthy individuals

    Energy Technology Data Exchange (ETDEWEB)

    Hillengass, Jens (Dept. of Radiology, German Cancer Research Center, Heidelberg (Germany); Dept. of Hematology, Oncology and Rheumatology, Univ. of Heidelberg (Germany)), e-mail: j.hillengass@dkfz.de; Stieltjes, Bram (Dept. of Radiology, German Cancer Research Center, Heidelberg (Germany)); Baeuerle, Tobias (Dept. of Medical Physics in Radiology, German Cancer Research Center, Heidelberg (Germany)) (and others)

    2011-04-15

    Background: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) displays microcirculation and permeability by application of contrast-media and diffusion-weighted imaging (DWI) is a tool for quantification of cellularity in the investigated area. Recently published examples cover breast cancer, CNS tumors, head and neck cancer, gastrointestinal cancer, prostate cancer as well as hematologic malignancies. Purpose: To investigated the influence of age, sex, and localization of the investigated region on findings of DCE-MRI and DWI. Material and Methods: DCE-MRI-parameters amplitude A and exchange rate constant kep as well as the DWI-parameter ADC of the bone marrow of the lumbar vertebral column of 30 healthy individuals covering the typical range of age of tumor patients were evaluated. ADC was calculated using b=0 and a maximal b value of either 400 or 750 s/mm2. Results: Amplitude A of DCE-MRI decreased with age (P = 0.01) and amplitude A, exchange rate constant kep as well as ADC based on b = 400 s/mm2 and b = 750 s/mm2, respectively, decreased significantly from the first to the fifth lumbar vertebra with P = 0.02, P = 0.05, P = 0.003, and P = 0.002, respectively. Conclusion: Quantitative parameters of functional imaging techniques in bone marrow are influenced by the age of the examined individual and the anatomical location of the investigated region

  8. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging of bone marrow in healthy individuals

    International Nuclear Information System (INIS)

    Hillengass, Jens; Stieltjes, Bram; Baeuerle, Tobias

    2011-01-01

    Background: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) displays microcirculation and permeability by application of contrast-media and diffusion-weighted imaging (DWI) is a tool for quantification of cellularity in the investigated area. Recently published examples cover breast cancer, CNS tumors, head and neck cancer, gastrointestinal cancer, prostate cancer as well as hematologic malignancies. Purpose: To investigated the influence of age, sex, and localization of the investigated region on findings of DCE-MRI and DWI. Material and Methods: DCE-MRI-parameters amplitude A and exchange rate constant kep as well as the DWI-parameter ADC of the bone marrow of the lumbar vertebral column of 30 healthy individuals covering the typical range of age of tumor patients were evaluated. ADC was calculated using b=0 and a maximal b value of either 400 or 750 s/mm2. Results: Amplitude A of DCE-MRI decreased with age (P = 0.01) and amplitude A, exchange rate constant kep as well as ADC based on b = 400 s/mm 2 and b = 750 s/mm 2 , respectively, decreased significantly from the first to the fifth lumbar vertebra with P = 0.02, P = 0.05, P = 0.003, and P = 0.002, respectively. Conclusion: Quantitative parameters of functional imaging techniques in bone marrow are influenced by the age of the examined individual and the anatomical location of the investigated region

  9. Pancreatic gross tumor volume contouring on computed tomography (CT) compared with magnetic resonance imaging (MRI): Results of an international contouring conference.

    Science.gov (United States)

    Hall, William A; Heerkens, Hanne D; Paulson, Eric S; Meijer, Gert J; Kotte, Alexis N; Knechtges, Paul; Parikh, Parag J; Bassetti, Michael F; Lee, Percy; Aitken, Katharine L; Palta, Manisha; Myrehaug, Sten; Koay, Eugene J; Portelance, Lorraine; Ben-Josef, Edgar; Erickson, Beth A

    Accurate identification of the gross tumor volume (GTV) in pancreatic adenocarcinoma is challenging. We sought to understand differences in GTV delineation using pancreatic computed tomography (CT) compared with magnetic resonance imaging (MRI). Twelve attending radiation oncologists were convened for an international contouring symposium. All participants had a clinical and research interest in pancreatic adenocarcinoma. CT and MRI scans from 3 pancreatic cases were used for contouring. CT and MRI GTVs were analyzed and compared. Interobserver variability was compared using Dice's similarity coefficient (DSC), Hausdorff distances, and Jaccard indices. Mann-Whitney tests were used to check for significant differences. Consensus contours on CT and MRI scans and constructed count maps were used to visualize the agreement. Agreement regarding the optimal method to determine GTV definition using MRI was reached. Six contour sets (3 from CT and 3 from MRI) were obtained and compared for each observer, totaling 72 contour sets. The mean volume of contours on CT was significantly larger at 57.48 mL compared with a mean of 45.76 mL on MRI, P = .011. The standard deviation obtained from the CT contours was significantly larger than the standard deviation from the MRI contours (P = .027). The mean DSC was 0.73 for the CT and 0.72 for the MRI (P = .889). The conformity index measurement was similar for CT and MRI (P = .58). Count maps were created to highlight differences in the contours from CT and MRI. Using MRI as a primary image set to define a pancreatic adenocarcinoma GTV resulted in smaller contours compared with CT. No differences in DSC or the conformity index were seen between MRI and CT. A stepwise method is recommended as an approach to contour a pancreatic GTV using MRI. Copyright © 2017 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  10. Magnetic resonance imaging-guided attenuation correction of positron emission tomography data in PET/MRI

    Science.gov (United States)

    Izquierdo-Garcia, David; Catana, Ciprian

    2018-01-01

    Synopsis Attenuation correction (AC) is one of the most important challenges in the recently introduced combined positron emission tomography/magnetic resonance imaging (PET/MR) scanners. PET/MR AC (MR-AC) approaches aim to develop methods that allow accurate estimation of the linear attenuation coefficients (LACs) of the tissues and other components located in the PET field of view (FoV). MR-AC methods can be divided into three main categories: segmentation-, atlas- and PET-based. This review aims to provide a comprehensive list of the state of the art MR-AC approaches as well as their pros and cons. The main sources of artifacts such as body-truncation, metallic implants and hardware correction will be presented. Finally, this review will discuss the current status of MR-AC approaches for clinical applications. PMID:26952727

  11. Preoperative staging of rectal cancer by magnetic resonance imaging (MRI) and computed tomography (CT)

    International Nuclear Information System (INIS)

    Itabashi, Michiaki; Kameoka, Shingo; Nakajima, Kiyotaka; Izumi, Kiminari; Miyazaki, Kaname; Hamano, Kyoichi; Kouno, Atsushi

    1991-01-01

    To clarify the usefulness and limitations of CT and MRI in preoperative assessment of the wall invasion of rectal cancer, we compared the results of CT and MRI with the histopathological findings, classifying tumors by the region and site in 34 patients with rectal cancer. Subjects were patients preoperatively examined by MRI and CT. Overall, the percent of cases with the extent of invasion accurately assessed by MRI was 88.2%, and that by CT was 64.7%. In all instances of wrong assessment, the extent of invasion was overestimated. The accurate assessment rate was significantly higher for MRI than for CT. After classification by the region, the accurate assessment rate at Rs was low as 50% for both MRI and CT because slices were not perpendicular to the tumor. The accurate assessment rate was 100% for MRI and 82% for CT at Ra, and respectively 94% and 59% at Rb. The majority of tumors at Ra or Rb centering on the lateral wall of the rectum were accurately assessed either by MRI or CT. With tumors at Ra or Rb (particularly Rb) centering on the anterior or posterior wall, CT frequently failed to identify the extent of invasion accurately, so that MRI seemed more suitable for these tumors. (author)

  12. Whole body sodium MRI at 3T using an asymmetric birdcage resonator and short echo time sequence: first images of a male volunteer

    Science.gov (United States)

    Wetterling, Friedrich; Corteville, Dominique M.; Kalayciyan, Raffi; Rennings, Andreas; Konstandin, Simon; Nagel, Armin M.; Stark, Helmut; Schad, Lothar R.

    2012-07-01

    Sodium magnetic resonance imaging (23Na MRI) is a non-invasive technique which allows spatial resolution of the tissue sodium concentration (TSC) in the human body. TSC measurements could potentially serve to monitor early treatment success of chemotherapy on patients who suffer from whole body metastases. Yet, the acquisition of whole body sodium (23Na) images has been hampered so far by the lack of large resonators and the extremely low signal-to-noise ratio (SNR) achieved with existing resonator systems. In this study, a 23Na resonator was constructed for whole body 23Na MRI at 3T comprising of a 16-leg, asymmetrical birdcage structure with 34 cm height, 47.5 cm width and 50 cm length. The resonator was driven in quadrature mode and could be used either as a transceiver resonator or, since active decoupling was included, as a transmit-only resonator in conjunction with a receive-only (RO) surface resonator. The relative B1-field profile was simulated and measured on phantoms, and 3D whole body 23Na MRI data of a healthy male volunteer were acquired in five segments with a nominal isotropic resolution of (6 × 6 × 6) mm3 and a 10 min acquisition time per scan. The measured SNR values in the 23Na-MR images varied from 9 ± 2 in calf muscle, 15 ± 2 in brain tissue, 23 ± 2 in the prostate and up to 42 ± 5 in the vertebral discs. Arms, legs, knees and hands could also be resolved with applied resonator and short time-to-echo (TE) (0.5 ms) radial sequence. Up to fivefold SNR improvement was achieved through combining the birdcage with local RO surface coil. In conclusion, 23Na MRI of the entire human body provides sub-cm spatial resolution, which allows resolution of all major human body parts with a scan time of less than 60 min.

  13. Magnetic resonance imaging

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    Magnetic resonance imaging (MRI) is a new and innovative technique that affords anatomic images in multiple planes and that may provide information about tissue characterization. The magnetic resonance images are obtained by placing the patient or the area of interest within a powerful, highly uniform, static magnetic field. Magnetized protons (hydrogen nuclei) within the patient align like small magnets in this field. Radiofrequency pulses are then used to create an oscillating magnetic field perpendicular to the main field. Magnetic resonance images differ from those produced by x-rays: the latter are associated with absorption of x-ray energy while magnetic resonance images are based on proton density and proton relaxation dynamics. Proton characteristics vary according to the tissue under examination and reflect its physical and chemical properties. To resolve issues regarding safety and efficacy, the Warren Grant Magnuson Clinical Center and the Office of Medical Applications of Research of the National Institutes of Health (NIH) convened a consensus conference about MRI Oct 26 through 28, 1987. At the NIH, the Consensus Development Conference brings together investigators in the biomedical sciences, clinical investigators, practicing physicians, and consumer and special interest groups to make a scientific assessment of technologies, including drugs, devices, and procedures, and to seek agreement on their safety and effectiveness

  14. Symptomatic laterality and magnetic resonance imaging (MRI) of the putamen in striatonigral degeneration (SND)

    Energy Technology Data Exchange (ETDEWEB)

    Yanagihara, Chie; Ichikawa, Keiji; Kageyama, Yasufumi; Satou, Mutsumi; Hoshino, Masataka (Hyogo Prefectural Amagasaki Hospital (Japan))

    1994-04-01

    The relationship between sympatomatic laterality and lesions of the putamen was investigated by magnetic resonance (MR) imaging in 6 patients with striatonigral degeneration (SND). According to Yahr's classification, one patient had I, III, and V each, and 3 had IV. All patients had asymmetric onset of parkinsonism. They developed variable cerebellar ataxia and/or autonomic failure. T1-weighted imaging was most superior in delineating atrophy of the putamen and laterality. The atrophy and lateral difference of the putamen were associated with progression of symptoms. Both the area and the maximum transverse diameter of the putamen were significantly decreased. Atophied putamen extended from the dorsal to the abdominal sides with symptom progression. Attention should be paid to the dorsal side of the putamen in delineating the atrophy and bilateral difference. The measurement of the maximum transverse diameter of the dorsal atrophy of the putamen was a simple, useful means for assessing the atrophy of the putamen. The diameter 7.4 mm or less of the putamen suggested the presence of atrophy. (N.K.).

  15. Positron emission tomography/magnetic resonance imaging (PET/MRI: An update and initial experience at HC-FMUSP

    Directory of Open Access Journals (Sweden)

    Marcelo A. Queiroz

    Full Text Available Summary The new technology of PET/MRI is a prototype of hybrid imaging, allowing for the combination of molecular data from PET scanning and morphofunctional information derived from MRI scanning. Recent advances regarding the technical aspects of this device, especially after the development of MRI-compatible silicon photomultipliers of PET, permitted an increase in the diagnostic performance of PET/MRI translated into dose reduction and higher imaging quality. Among several clinical applications, PET/MRI gains ground initially in oncology, where MRI per se plays an essential role in the assessment of primary tumors (which is limited in the case of PET/CT, including prostate, rectal and gynecological tumors. On the other hand, the evaluation of the lungs remains an enigma although new MRI sequences are being designed to overcome this. More clinical indications of PET/MRI are seen in the fields of neurology, cardiology and inflammatory processes, and the use of PET/MRI also opens perspectives for pediatric populations as it involves very low radiation exposure. Our review aimed to highlight the current indications of PET/MRI and discuss the challenges and perspectives of PET/MRI at HC-FMUSP.

  16. Temporomandibular joint (TMJ) pain revisited with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)

    International Nuclear Information System (INIS)

    Tasali, N.; Cubuk, R.; Aricak, M.; Ozarar, M.; Saydam, B.; Nur, H.; Tuncbilek, N.

    2012-01-01

    Purpose: We aimed to assess the contrast enhancement patterns of the retrodiscal tissue with dynamic contrast-enhanced MR imaging (DCE-MRI) with respect to different temporomandibular joint disc pathologies. Additionally, we questioned the relationship between the temporomandibular joint (TMJ) pain and the contrast enhancement pattern of the retrodiscal tissue regardless of the TMJ disc position. Materials and methods: 52 joints of 26 patients (4 males and 22 females) who have pain in at least at one of their TMJ were included in this study. For the qualitative analysis, the joints were divided into four groups in terms of their disc positions: normal (1), partially displaced with or without reduction (2), totally dislocated with reduction (3) and totally dislocated without reduction (4). Besides, two different joint groups were constituted, namely the painful group and painless group according to the clinical findings without taking the TMJ disc positions into account. Quantitative analyses were made by means of measuring signal intensity ratios (SI) ratio at the retrodiscal tissue (from internal side and external side of the each joint) using DCE-MRI and these measurements were analyzed with paired samples t test to define the difference between the measurements. At the second stage, the time-dependent arithmetical mean values of the SI ratios were calculated for each joint group and significant differences between the groups were questioned using analysis of variance (ANOVA) test. Besides, painful and painless groups which were classified on the basis of the clinical data were compared according to the mean SI ratios found for each joint and the significant differences between these two groups were assessed by means of Student's T test. The results were assessed in 95% confidence interval where the significance level was p < 0.05. Results: A significant difference was observed between the internal and external contrast enhancement of the joints with partial

  17. Magnetic Resonance Imaging. Chapter 15

    Energy Technology Data Exchange (ETDEWEB)

    Leach, M. O. [The Institute of Cancer Research and The Royal Marsden Hospital, London (United Kingdom)

    2014-09-15

    In Chapter 14, the principles of nuclear magnetic resonance were presented, along with an introduction to image forming processes. In this chapter, magnetic resonance imaging (MRI) will be reviewed, beginning with the hardware needed and its impact on image quality. The acquisition processes and image reconstruction will be discussed, as well as the artefacts that are possible, with discussion of the important area of safety and bioeffects completing the chapter.

  18. Porencephaly in dogs and cats: relationships between magnetic resonance imaging (MRI) features and hippocampal atrophy.

    Science.gov (United States)

    Hori, Ai; Hanazono, Kiwamu; Miyoshi, Kenjirou; Nakade, Tetsuya

    2015-07-01

    Porencephaly is the congenital cerebral defect and a rare malformation and described few MRI reports in veterinary medicine. MRI features of porencephaly are recognized the coexistence with the unilateral/bilateral hippocampal atrophy, caused by the seizure symptoms in human medicine. We studied 2 dogs and 1 cat with congenital porencephaly to characterize the clinical signs and MRI, and to discuss the associated MRI with hippocampal atrophy. The main clinical sign was the seizure symptoms, and all had hippocampal atrophy at the lesion side or the larger defect side. There is association between hippocampal atrophy or the cyst volume and the severe of clinical signs, and it is suggested that porencephaly coexists with hippocampal atrophy as well as humans in this study.

  19. Clinical Utility of Magnetic Resonance Imaging (MRI) and Ultrasonography (US) for Diagnosis of Polycystic Ovary Syndrome (PCOS) in Adolescent Girls

    Science.gov (United States)

    Kenigsberg, Lisa E; Agarwal, Chhavi; Sin, Sanghun; Shifteh, Keivan; Isasi, Carmen R; Crespi, Rebecca; Ivanova, Janeta; Coupey, Susan M; Heptulla, Rubina A; Arens, Raanan

    2015-01-01

    Objectives Evaluate ovarian morphology using 3-dimensional MRI in adolescent girls with and without PCOS. Compare the utility of MRI versus ultrasonography (US) for diagnosis of PCOS Design Cross-sectional Setting Urban academic tertiary-care children’s hospital Patients Thirty-nine adolescent girls with untreated PCOS and 22 age/BMI-matched controls. Intervention MRI and/or transvaginal/transabdominal US Main Outcome Measure Ovarian volume (OV); follicle number per section (FNPS); correlation between OV on MRI and US; proportion of subjects with features of polycystic ovaries on MRI and US. Results MRI demonstrated larger OV and higher FNPS in subjects with PCOS compared to controls. Within the PCOS group, median OV was 11.9 (7.7) cm3 by MRI, compared with 8.8 (7.8) cm3 by US. Correlation coefficient between OV by MRI and US was 0.701. Due to poor resolution, FNPS could not be determined by US or compared with MRI. ROC curve analysis for MRI demonstrated that increasing volume cut-offs for polycystic ovaries from 10cm3 to 14cm3, increased specificity from 77% to 95%. For FNPS on MRI, specificity increased from 82% to 98% by increasing cut-offs from ≥12 to ≥17. Using Rotterdam cut-offs, 91% of subjects with PCOS met polycystic ovary criteria on MRI, while only 52% met criteria by US. Conclusions US measures smaller OV than MRI, cannot accurately detect follicle number, and is a poor imaging modality for characterizing polycystic ovaries in adolescents with suspected PCOS. For adolescents in whom diagnosis of PCOS remains uncertain after clinical and laboratory evaluation, MRI should be considered as a diagnostic imaging modality. PMID:26354095

  20. Assessment of language lateralization with functional magnetic resonance imaging (fMRI)

    International Nuclear Information System (INIS)

    Salagierska-Barwinska, A.; Goraj, B.

    2004-01-01

    fMRI offers powerful methods to delineate which brain regions are engaged in language processing in the intact brain. Until now hemisphere dominance for language has been usually assessed by means of the intraoperative methods: the Wada test or electrocortical stimulation mapping. Recently functional MRI becomes the valuable method in determining hemisphere dominance for language. fMRI study was proved to be concordant with invasive measures. fMRI was carried out in 30 healthy selected participants (15 females: 10 strongly right-handed and 5 strongly left-handed; 15 males: 10 strongly right-handed and 5 strongly left-handed). The subject's handedness was assessed by standardized psychological tests inter alia the 'lateralization inventory'. Two different language tasks were used: a verb generation task and a phonological task. Subjects were scanned,while performing experimental block. The block contained alternately 8 active (language task) and 8 control conditions. Statistical analysis of evoked blood oxygenation level-dependent BOLD) responses, measured with echo planar imagining (1.5 T) were used. During a verb generation task in strongly right or left handed subjects the inferior frontal region was activated on the side opposite to the subject's handedness determined by the psychological test. Our fMRI studies demonstrated no gender effects on brain during these language tasks. Our study suggests that fMRI is a good device for the study of the language organization. The advantage of fMRI is its capacity for exact localization of activated areas. fMRI together with adequate neurolinguistic test could be promising routine preoperative tool in identification hemisphere dominance for language. These results encourage to further investigation for evaluating correlation in patients with brain injuries. (author)

  1. Magnetic resonance imaging the basics

    CERN Document Server

    Constantinides, Christakis

    2014-01-01

    Magnetic resonance imaging (MRI) is a rapidly developing field in basic applied science and clinical practice. Research efforts in this area have already been recognized with five Nobel prizes awarded to seven Nobel laureates in the past 70 years. Based on courses taught at The Johns Hopkins University, Magnetic Resonance Imaging: The Basics provides a solid introduction to this powerful technology. The book begins with a general description of the phenomenon of magnetic resonance and a brief summary of Fourier transformations in two dimensions. It examines the fundamental principles of physics for nuclear magnetic resonance (NMR) signal formation and image construction and provides a detailed explanation of the mathematical formulation of MRI. Numerous image quantitative indices are discussed, including (among others) signal, noise, signal-to-noise, contrast, and resolution. The second part of the book examines the hardware and electronics of an MRI scanner and the typical measurements and simulations of m...

  2. Clinically relevant magnetic resonance imaging (MRI findings in elite swimmers’ shoulders

    Directory of Open Access Journals (Sweden)

    Arno Celliers

    2017-01-01

    Objective: To assess clinically relevant MRI findings in the shoulders of symptomatic and asymptomatic elite swimmers. Method: Twenty (aged 16–23 years elite swimmers completed questionnaires on their swimming training, pain and shoulder function. MRI of both shoulders (n = 40 were performed and all swimmers were given a standardised clinical shoulder examination. Results: Both shoulders of 11 male and 9 female elite swimmers (n = 40 were examined. Eleven of the 40 shoulders were clinically symptomatic and 29 were asymptomatic. The most common clinical finding in both the symptomatic and asymptomatic shoulders was impingement during internal rotation, with impingement in 54.5% of the symptomatic shoulders and in 31.0% of the asymptomatic shoulders. The most common MRI findings in the symptomatic and asymptomatic shoulders were supraspinatus tendinosis (45.5% vs. 20.7%, subacromial subdeltoid fluid (45.5% vs. 34.5%, increased signal in the AC Joint (45.5% vs. 37.9% and AC joint arthrosis (36.4% vs. 34.5%. Thirty-nine (97.5% of the shoulders showed abnormal MRI features. Conclusion: MRI findings in the symptomatic and asymptomatic shoulders of young elite swimmers are similar and care should be taken when reporting shoulder MRIs in these athletes. Asymptomatic shoulders demonstrate manifold MRI abnormalities that may be radiologically significant but appear not to be clinically significant.

  3. Pancreatic iron stores assessed by magnetic resonance imaging (MRI) in beta thalassemic patients

    International Nuclear Information System (INIS)

    Feitosa de Assis, Reijâne Alves; Ribeiro, Andreza Alice; Kay, Fernando Uliana; Rosemberg, Laércio Alberto; Nomura, Cesar Higa; Loggetto, Sandra Regina; Araujo, Aderson S.; Fabron Junior, Antonio; Pinheiro de Almeida Veríssimo, Mônica; Baldanzi, Giorgio Roberto; Espósito, Breno Pannia; Baroni, Ronaldo Hueb; Wood, John C.; Hamerschlak, Nelson

    2012-01-01

    Purpose: To assess the correlation between MRI findings of the pancreas with those of the heart and liver in patients with beta thalassemia; to compare the pancreas T2* MRI results with glucose and ferritin levels and labile plasma iron (LPI). Materials and methods: We retrospectively evaluated chronically transfused patients, testing glucose with enzymatic tests, serum ferritin with chemiluminescence, LPI with cellular fluorescence, and T2* MRI to assess iron content in the heart, liver, and pancreas. MRI results were compared with one another and with serum glucose, ferritin, and LPI. Liver iron concentration (LIC) was determined in 11 patients’ liver biopsies by atomic absorption spectrometry. Results: 289 MRI studies were available from 115 patients during the period studied. 9.4% of patients had overt diabetes and an additional 16% of patients had impaired fasting glucose. Both pancreatic and cardiac R2* had predictive power (p 2 = 0.20, p 2 = 0.09, p 2 = 0.14, p 2 = 0.03, p 2 of 0.91. Conclusions: Pancreatic iron overload can be assessed by MRI, but siderosis in other organs did not correlate significantly with pancreatic hemosiderosis.

  4. Dental magnetic resonance imaging

    International Nuclear Information System (INIS)

    Hilgenfeld, Tim; Bendszus, Martin; Haehnel, Stefan

    2016-01-01

    Growing distribution and utilization of digital volume tomography (DVT) extend the spectrum of clinical dental imaging. Additional diagnostic value, however, comes along with an increasing amount of radiation. In contrast, magnetic resonance imaging is a radiation free imaging technique. Furthermore, it offers a high soft tissue contrast. Morphological and numerical dental anomalies, differentiation of periapical lesions and exclusion of complications of dental diseases are field of applications for dental MRI. In addition, detection of caries and periodontal lesions and injury of inferior alveolar nerve are promising application areas in the future.

  5. Functional magnetic resonance imaging (fMRI) of motor deficits in schizophrenia

    International Nuclear Information System (INIS)

    Wenz, F.; Floemer, F.; Kaick, G. van

    1995-01-01

    The purpose of this study was to investigate differences in the cerebral activation pattern in ten schizophrenic patients and ten healthy volunteers using functional MRI. fMRI was performed using a modified FLASH sequence (TR/TE/α=100/60/40 ) and a conventional 1.5 T MR scanner. Colorcoded statistical parametric maps based on Student's t-test were calculated. Activation strength was quantified using a 5x6 grid overlay. The volunteers showed a higher activation strength during left hand movement compared to right hand movement. This lateralization effect was reversed in patients who showed overall reduced activation strength. Disturbed interhemispheric balance in schizophrenic patients during motor task performance can be demonstrated using fMRI. (orig.) [de

  6. A novel passive paradigm for functional magnetic resonance imaging (fMRI) to localize brain functions

    International Nuclear Information System (INIS)

    Gasser, T.; Sandalcioglu, I.E.; Skwarek, V.; Gizewski, E.; Stolke, D.; Hans, V.

    2003-01-01

    The design of a shielded stimulation-device for electrical stimulation of peripheral nerves in the MRI-environment as passive fMRI-paradigm is content of this study. Especially the technical aspects and selection criteria of the stimulation-parameters are discussed. The clinical value for neurosurgical patients is outlined by supplying data from clinical studies, evaluating this novel paradigm. Thus neurosurgeons are supplied with superior information about functional anatomy, therefore being able to preserve functionally relevant brain-structures. (orig.) [de

  7. Non-invasive in vivo evaluation of in situ forming PLGA implants by benchtop magnetic resonance imaging (BT-MRI) and EPR spectroscopy.

    Science.gov (United States)

    Kempe, Sabine; Metz, Hendrik; Pereira, Priscila G C; Mäder, Karsten

    2010-01-01

    In the present study, we used benchtop magnetic resonance imaging (BT-MRI) for non-invasive and continuous in vivo studies of in situ forming poly(lactide-co-glycolide) (PLGA) implants without the use of contrast agents. Polyethylene glycol (PEG) 400 was used as an alternative solvent to the clinically used NMP. In addition to BT-MRI, we applied electron paramagnetic resonance (EPR) spectroscopy to characterize implant formation and drug delivery processes in vitro and in vivo. We were able to follow key processes of implant formation by EPR and MRI. Because EPR spectra are sensitive to polarity and mobility, we were able to follow the kinetics of the solvent/non-solvent exchange and the PLGA precipitation. Due to the high water affinity of PEG 400, we observed a transient accumulation of water in the implant neighbourhood. Furthermore, we detected the encapsulation by BT-MRI of the implant as a response of the biological system to the polymer, followed by degradation over a period of two months. We could show that MRI in general has the potential to get new insights in the in vivo fate of in situ forming implants. The study also clearly shows that BT-MRI is a new viable and much less expensive alternative for superconducting MRI machines to monitor drug delivery processes in vivo in small mammals. Copyright 2009 Elsevier B.V. All rights reserved.

  8. Measurement of human advanced brain function in calculation processing using functional magnetic resonance imaging (fMRI)

    International Nuclear Information System (INIS)

    Hashida, Masahiro; Yamauchi, Syuichi; Wu, Jing-Long

    2001-01-01

    Using functional magnetic resonance imaging (fMRI), we investigated the activated areas of the human brain related with calculation processing as an advanced function of the human brain. Furthermore, we investigated differences in activation between visual and auditory calculation processing. The eight subjects (all healthy men) were examined on a clinical MR unit (1.5 tesla) with a gradient echo-type EPI sequence. SPM99 software was used for data processing. Arithmetic problems were used for the visual stimulus (visual image) as well as for the auditory stimulus (audible voice). The stimuli were presented to the subjects as follows: no stimulation, presentation of random figures, and presentation of arithmetic problems. Activated areas of the human brain related with calculation processing were the inferior parietal lobule, middle frontal gyrus, and inferior frontal gyrus. Comparing the arithmetic problems with the presentation of random figures, we found that the activated areas of the human brain were not differently affected by visual and auditory systems. The areas activated in the visual and auditory experiments were observed at nearly the same place in the brain. It is possible to study advanced functions of the human brain such as calculation processing in a general clinical hospital when adequate tasks and methods of presentation are used. (author)

  9. Imaging prostate cancer: an update on positron emission tomography and magnetic resonance imaging

    DEFF Research Database (Denmark)

    Bouchelouche, Kirsten; Turkbey, Baris; Choyke, Peter

    2010-01-01

    , and molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI...

  10. Clinical evaluation of cardiovascular disease by gated-MRI (magnetic resonance imaging) in the operating field of 0.35 and 1.5 Tesla

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko; Naito, Hiroaki; Yamada, Yukinori; Kozuka, Takahiro

    1985-01-01

    To evaluate the clinical usefulness of magnetic resonance imaging (MRI) in the cardiovascular disease, 21 patients were examined using 0.35 and 1.5 Tesla superconductive type (Magnetom, Siemens). In our study, all patients were performed using ECG-gated MRI. Therefore, the cardiac chambers were discriminated clearly from the myocardial wall compared to non-gated MRI. Gated-MRI was performed in 6 normal persons in the operating field at 0.35 and 1.5 Tesla. The image of the latter showed superior than that of the former because of high S/N ratio. In myocardial infarction, infarct area was demonstrated as the wall thinning in 4 of 5 patients. Hypertrophic cardiomyopathy showed thickened left ventricle associated with its narrowed cavity in 7 patients. In the remaining such as congenital and valvular heart disease, global and regional cardiac morphology were assessed noninvasively by gated MRI. In addition, gated MRI was also applied to the diagnosis of peripheral vascular diseases. In dissecting aneurysm, double channels with an intimal flap in the aorta were clearly visualized. And in the aortitis syndrome, aortic dilatation and stenosis were also assessed noninvasively. In conclusion, gated MRI in diagnosing various abnormalities of cardiovascular disease was confirmed. (author)

  11. Optimal gadolinium dose level for magnetic resonance imaging (MRI) contrast enhancement of U87-derived tumors in athymic nude rats for the assessment of photodynamic therapy

    Science.gov (United States)

    Cross, Nathan; Varghai, Davood; Flask, Chris A.; Feyes, Denise K.; Oleinick, Nancy L.; Dean, David

    2009-02-01

    This study aims to determine the effect of varying gadopentetate dimeglumine (Gd-DTPA) dose on Dynamic Contrast Enhanced-Magnetic Resonance Imaging (DCE-MRI) tracking of brain tumor photodynamic therapy (PDT) outcome. Methods: We injected 2.5 x 105 U87 cells (derived from human malignant glioma) into the brains of six athymic nude rats. After 9, 12, and 13 days DCE-MRI images were acquired on a 9.4 T micro-MRI scanner before and after administration of 100, 150, or 200 μL of Gd-DTPA. Results: Tumor region normalized DCE-MRI scan enhancement at peak was: 1.217 over baseline (0.018 Standard Error [SE]) at the 100 μL dose, 1.339 (0.013 SE) at the 150 μL dose, and 1.287 (0.014 SE) at the 200 μL dose. DCE-MRI peak tumor enhancement at the 150 μL dose was significantly greater than both the 100 μL dose (p DTPA dose provided the greatest T1 weighted contrast enhancement, while minimizing negative T2* effects, in DCE-MRI scans of U87-derived tumors. Maximizing Gd-DTPA enhancement in DCE-MRI scans may assist development of a clinically robust (i.e., unambiguous) technique for PDT outcome assessment.

  12. The clinical value of routine whole-body magnetic resonance imaging (MRI) in palliative care

    Energy Technology Data Exchange (ETDEWEB)

    Geitung, Jonn Terje (Department of Radiology, Haraldspass Deaconess (University) Hospital (Norway); Department of Surgical Sciences, University of Bergen (Norway)), Email: jtgeit@online.no; Eikeland, Joakim (Department of Public Health and Primary Health Care, University of Bergen (Norway)); Rosland, Jan Henrik (Department of Public Health and Primary Health Care, University of Bergen (Norway); Sunniva Clinic for Palliative Care, Haraldsplass Deaconess (University) Hospital (Norway))

    2012-03-15

    Background. Whole-body MRI (WBMRI) has become an accessible method for detecting different types of pathologies both in the skeleton and the viscera, which may explain painful conditions, for example tumors and inflammation. Purpose. To assess a possible value of using WBMRI in order to improve palliative care. Material and Methods. Twenty patients (all eligible patients) admitted to the Department for Palliative Care were consecutively included in this study. They underwent a modified WBMRI, with fewer and shorter pulse sequences than in a standard WBMRI, to reduce patient stress. However, the patients' physicians were to exclude patients where little might be obtained and discomfort, distress, and pain could be induced. The treating physicians registered clinical utility directly after receiving the MRI report in a questionnaire. The registration was repeated after ended treatment. Results. Eighty percent had new findings detected, and 40% of the patients had a change in treatment due to the MRI result, mainly changes in analgesics and/or radiation therapy. Conclusion. The WBMRI helped the clinicians to improve treatment and a majority of the patients benefited from this. In eight patients the treatment was changed due to the results. The clinical value (utility) was indicated to be high

  13. High-resolution magnetic resonance imaging (HR-MRI) of the pleura and chest wall: Normal findings and pathological changes

    International Nuclear Information System (INIS)

    Bittner, R.C.; Schnoy, N.; Schoenfeld, N.; Grassot, A.; Loddenkemper, R.; Lode, H.; Kaiser, D.; Krumhaar, D.; Felix, R.

    1995-01-01

    To determine the value of high-resolution MRI in pleural and chest wall diseases, the normal and pathologic costal pleura and adjacent chest wall between paravertebral and the axillar region were examined with contrast enhanced high-resolution T 1 -weighted MRI images using a surface coil. Normal anatomy was evaluated in 5 healthy volunteers and a normal specimen of the thoracic wall, and correlation was made with corresponding HR-CT and histologic sections. CT-proved focal and diffuse changes of the pleura and the chest wall in 36 patients underwent HR-MRI, and visual comparison of MRI and CT was done retrospectively. Especially sagittal T 1 -weighted HR-MRI images allowed accurate delineation of the peripleural fat layer (PFL) and the innermost intercostal muscle (IIM), which served as landmarks of the intact inner chest wall. PFL and IIM were well delineated in 3/4 patients with tuberculous pleuritis, and in all 7 patients with non-specific pleuritis, as opposed to impairment of the PFL and/or the IIM, which was detected in 15/18 malignancies as a pattern of malignant chest wall involvement. In one case of tuberculous pleural empyema with edema of the inner chest wall HR-MRI produced false positive diagnosis of malignant disease. HR-MRI images improved non-invasive evaluation of pleural and chest wall diseases, and allowed for differentiation of bengin and malignant changes. (orig./MG) [de

  14. Measuring and manipulating brain connectivity with resting state functional connectivity magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS).

    Science.gov (United States)

    Fox, Michael D; Halko, Mark A; Eldaief, Mark C; Pascual-Leone, Alvaro

    2012-10-01

    Both resting state functional magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS) are increasingly popular techniques that can be used to non-invasively measure brain connectivity in human subjects. TMS shows additional promise as a method to manipulate brain connectivity. In this review we discuss how these two complimentary tools can be combined to optimally study brain connectivity and manipulate distributed brain networks. Important clinical applications include using resting state fcMRI to guide target selection for TMS and using TMS to modulate pathological network interactions identified with resting state fcMRI. The combination of TMS and resting state fcMRI has the potential to accelerate the translation of both techniques into the clinical realm and promises a new approach to the diagnosis and treatment of neurological and psychiatric diseases that demonstrate network pathology. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Comparison between target magnetic resonance imaging (MRI) in-gantry and cognitively directed transperineal or transrectal-guided prostate biopsies for Prostate Imaging-Reporting and Data System (PI-RADS) 3-5 MRI lesions.

    Science.gov (United States)

    Yaxley, Anna J; Yaxley, John W; Thangasamy, Isaac A; Ballard, Emma; Pokorny, Morgan R

    2017-11-01

    To compare the detection rates of prostate cancer (PCa) in men with Prostate Imaging-Reporting and Data System (PI-RADS) 3-5 abnormalities on 3-Tesla multiparametric (mp) magnetic resonance imaging (MRI) using in-bore MRI-guided biopsy compared with cognitively directed transperineal (cTP) biopsy and transrectal ultrasonography (cTRUS) biopsy. This was a retrospective single-centre study of consecutive men attending the private practice clinic of an experienced urologist performing MRI-guided biopsy and an experienced urologist performing cTP and cTRUS biopsy techniques for PI-RADS 3-5 lesions identified on 3-Tesla mpMRI. There were 595 target mpMRI lesions from 482 men with PI-RADS 3-5 regions of interest during 483 episodes of biopsy. The abnormal mpMRI target lesion was biopsied using the MRI-guided method for 298 biopsies, the cTP method for 248 biopsies and the cTRUS method for 49 biopsies. There were no significant differences in PCa detection among the three biopsy methods in PI-RADS 3 (48.9%, 40.0% and 44.4%, respectively), PI-RADS 4 (73.2%, 81.0% and 85.0%, respectively) or PI-RADS 5 (95.2, 92.0% and 95.0%, respectively) lesions, and there was no significant difference in detection of significant PCa among the biopsy methods in PI-RADS 3 (42.2%, 30.0% and 33.3%, respectively), PI-RADS 4 (66.8%, 66.0% and 80.0%, respectively) or PI-RADS 5 (90.5%, 89.8% and 90.0%, respectively) lesions. There were also no differences in PCa or significant PCa detection based on lesion location or size among the methods. We found no significant difference in the ability to detect PCa or significant PCa using targeted MRI-guided, cTP or cTRUS biopsy methods. Identification of an abnormal area on mpMRI appears to be more important in increasing the detection of PCa than the technique used to biopsy an MRI abnormality. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

  16. Magnetic resonance imaging. 1

    International Nuclear Information System (INIS)

    Wall, E.E. van der; Roos, A.A. de; Doornbos, J.; Dijkman, P.R.M. van; Matheijssen, N.A.A.; Laarse, A. van der; Krauss, X.H.; Blokland, J.A.k.; Manger Cats, V.; Voorthuisen, A.E. van; Bruschke, A.V.G.

    1991-01-01

    The cardiovascular applications of MRI in coronary artery disease have considerably increased in recent years. Although many applications overlap those of other more cost-effective techniques, such as echocardiography, radionuclide angiography, and CT, MRI offers unique features not shared by the conventional techniques. Technical advantages are the excellent spatial resolution, the characterization of myocardial tissue, and the potential for three-dimensional imaging. This allows the accurate assessment of left ventricular mass and volume, the differentiation of infarcted tissue from normal myocardial tissue, and the determination of systolic wall thickening and regional wall motion abnormalities. Also inducible myocardial ischemia using pharmacological stress (dipyramidole or dobutamine) may be assessed by magnetic resonance imaging. Future technical developments include real-time imaging and noninvasive visualization of the coronary arteries. These advantages will have a major impact on the application of MRI in coronary artery disease, potentially unsurpassed by other techniques and certainly justifying the expenses. Consequently, the clinical use of MRI for the detection of coronary artery disease largely depends on the progress of technical developments. (author). 134 refs.; 10 figs.; 2 tabs

  17. Providing and optimizing functional MR (Magnetic Resonance) of motor cortex of human brain by MRI ( Magnetic Resonance Imaging) facilities of Imam Khomeinie Hospital

    International Nuclear Information System (INIS)

    Khosravie, H.R.

    2000-01-01

    Display of human brain cortical activity is accomplished using various techniques, by them different spatial and temporal resolution may be obtained. F MRI technique with proper spatial and temporal resolution due to its noninvasivity is one of the promising techniques for detection of brain activities. This can be used as an important tool by neurologists, since a great development has been achieved for display different brain function. This thesis report the results of simulation effects of thumb motor cortex of normal volunteer by using conventional standard 1.5 T imager and optimized gradient echo techniques. Activating sensory and motor stimulations can be led to, respective cortical area of that stimulation by which oxygenated blood flow is increased in that area (Bold contrast). By designing of a T 2* sensitized gradient echo protocol, thumb's sensory and motor cortex activation is evaluated. A protocol known as F AST i n picker system with the following specifications was used for F MRI: Band Width:24 Hz/Pixel, Tr=101 m Sec , T E=49 m Sec , Flip Angle= 10 deg., N E X=1 ,Slice thickness=5-7 mm F O V=250 mm ,Matrix=128*128 and total scan time= 14 Sec. Stimulation of the motor cortex was performed by periodic movement of dominant thumb in up-down and right-left direction within a Ls hape trajectory of plastic sheet with a frequency about 2 Hz. Then, acquired images in rest and stimulation period were evaluated by S P M 97, S P M 99 b software. During the stimulation, an observable increased signal (%2-%5)in respective sensory-motor cortex was obtained after correcting for partial volume effects, optimizing S/N,and incorporating small vowels. The 2 D F A S T functional image obtained by this method, showed an anatomical association of the increased signal with gray matter of sensory-motor cortex(in T 1 weighted image). The resultant data showed the feasibility of functional magnetic resonance imaging using optimized gradient echo sequences on a standard 1.5 T

  18. Automatic Substitute Computed Tomography Generation and Contouring for Magnetic Resonance Imaging (MRI)-Alone External Beam Radiation Therapy From Standard MRI Sequences

    Energy Technology Data Exchange (ETDEWEB)

    Dowling, Jason A., E-mail: jason.dowling@csiro.au [CSIRO Australian e-Health Research Centre, Herston, Queensland (Australia); University of Newcastle, Callaghan, New South Wales (Australia); Sun, Jidi [University of Newcastle, Callaghan, New South Wales (Australia); Pichler, Peter [Calvary Mater Newcastle Hospital, Waratah, New South Wales (Australia); Rivest-Hénault, David; Ghose, Soumya [CSIRO Australian e-Health Research Centre, Herston, Queensland (Australia); Richardson, Haylea [Calvary Mater Newcastle Hospital, Waratah, New South Wales (Australia); Wratten, Chris; Martin, Jarad [University of Newcastle, Callaghan, New South Wales (Australia); Calvary Mater Newcastle Hospital, Waratah, New South Wales (Australia); Arm, Jameen [Calvary Mater Newcastle Hospital, Waratah, New South Wales (Australia); Best, Leah [Department of Radiology, Hunter New England Health, New Lambton, New South Wales (Australia); Chandra, Shekhar S. [School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, Queensland (Australia); Fripp, Jurgen [CSIRO Australian e-Health Research Centre, Herston, Queensland (Australia); Menk, Frederick W. [University of Newcastle, Callaghan, New South Wales (Australia); Greer, Peter B. [University of Newcastle, Callaghan, New South Wales (Australia); Calvary Mater Newcastle Hospital, Waratah, New South Wales (Australia)

    2015-12-01

    Purpose: To validate automatic substitute computed tomography CT (sCT) scans generated from standard T2-weighted (T2w) magnetic resonance (MR) pelvic scans for MR-Sim prostate treatment planning. Patients and Methods: A Siemens Skyra 3T MR imaging (MRI) scanner with laser bridge, flat couch, and pelvic coil mounts was used to scan 39 patients scheduled for external beam radiation therapy for localized prostate cancer. For sCT generation a whole-pelvis MRI scan (1.6 mm 3-dimensional isotropic T2w SPACE [Sampling Perfection with Application optimized Contrasts using different flip angle Evolution] sequence) was acquired. Three additional small field of view scans were acquired: T2w, T2*w, and T1w flip angle 80° for gold fiducials. Patients received a routine planning CT scan. Manual contouring of the prostate, rectum, bladder, and bones was performed independently on the CT and MR scans. Three experienced observers contoured each organ on MRI, allowing interobserver quantification. To generate a training database, each patient CT scan was coregistered to their whole-pelvis T2w using symmetric rigid registration and structure-guided deformable registration. A new multi-atlas local weighted voting method was used to generate automatic contours and sCT results. Results: The mean error in Hounsfield units between the sCT and corresponding patient CT (within the body contour) was 0.6 ± 14.7 (mean ± 1 SD), with a mean absolute error of 40.5 ± 8.2 Hounsfield units. Automatic contouring results were very close to the expert interobserver level (Dice similarity coefficient): prostate 0.80 ± 0.08, bladder 0.86 ± 0.12, rectum 0.84 ± 0.06, bones 0.91 ± 0.03, and body 1.00 ± 0.003. The change in monitor units between the sCT-based plans relative to the gold standard CT plan for the same dose prescription was found to be 0.3% ± 0.8%. The 3-dimensional γ pass rate was 1.00 ± 0.00 (2 mm/2%). Conclusions: The MR-Sim setup and automatic s

  19. Automatic Substitute Computed Tomography Generation and Contouring for Magnetic Resonance Imaging (MRI)-Alone External Beam Radiation Therapy From Standard MRI Sequences

    International Nuclear Information System (INIS)

    Dowling, Jason A.; Sun, Jidi; Pichler, Peter; Rivest-Hénault, David; Ghose, Soumya; Richardson, Haylea; Wratten, Chris; Martin, Jarad; Arm, Jameen; Best, Leah; Chandra, Shekhar S.; Fripp, Jurgen; Menk, Frederick W.; Greer, Peter B.

    2015-01-01

    Purpose: To validate automatic substitute computed tomography CT (sCT) scans generated from standard T2-weighted (T2w) magnetic resonance (MR) pelvic scans for MR-Sim prostate treatment planning. Patients and Methods: A Siemens Skyra 3T MR imaging (MRI) scanner with laser bridge, flat couch, and pelvic coil mounts was used to scan 39 patients scheduled for external beam radiation therapy for localized prostate cancer. For sCT generation a whole-pelvis MRI scan (1.6 mm 3-dimensional isotropic T2w SPACE [Sampling Perfection with Application optimized Contrasts using different flip angle Evolution] sequence) was acquired. Three additional small field of view scans were acquired: T2w, T2*w, and T1w flip angle 80° for gold fiducials. Patients received a routine planning CT scan. Manual contouring of the prostate, rectum, bladder, and bones was performed independently on the CT and MR scans. Three experienced observers contoured each organ on MRI, allowing interobserver quantification. To generate a training database, each patient CT scan was coregistered to their whole-pelvis T2w using symmetric rigid registration and structure-guided deformable registration. A new multi-atlas local weighted voting method was used to generate automatic contours and sCT results. Results: The mean error in Hounsfield units between the sCT and corresponding patient CT (within the body contour) was 0.6 ± 14.7 (mean ± 1 SD), with a mean absolute error of 40.5 ± 8.2 Hounsfield units. Automatic contouring results were very close to the expert interobserver level (Dice similarity coefficient): prostate 0.80 ± 0.08, bladder 0.86 ± 0.12, rectum 0.84 ± 0.06, bones 0.91 ± 0.03, and body 1.00 ± 0.003. The change in monitor units between the sCT-based plans relative to the gold standard CT plan for the same dose prescription was found to be 0.3% ± 0.8%. The 3-dimensional γ pass rate was 1.00 ± 0.00 (2 mm/2%). Conclusions: The MR-Sim setup and automatic s

  20. The functional magnetic resonance imaging (fMRI) procedure as experienced by healthy participants and stroke patients – A pilot study

    International Nuclear Information System (INIS)

    Szameitat, André J; Shen, Shan; Sterr, Annette

    2009-01-01

    An important aspect in functional imaging research employing magnetic resonance imaging (MRI) is how participants perceive the MRI scanning itself. For instance, the knowledge of how (un)comfortable MRI scanning is perceived may help institutional review boards (IRBs) or ethics committees to decide on the approval of a study, or researchers to design their experiments. We provide empirical data from our lab gained from 70 neurologically healthy mainly student subjects and from 22 mainly elderly patients suffering from motor deficits after brain damage. All participants took part in various basic research fMRI studies using a 3T MRI scanner. Directly after the scanning, all participants completed a questionnaire assessing their experience with the fMRI procedure. 87.2% of the healthy subjects and 77.3% of the patients rated the MRI procedure as acceptable to comfortable. In healthy subjects, males found the procedure more comfortable, while the opposite was true for patients. 12.1% of healthy subjects considered scanning durations between 30 and 60 min as too long, while no patient considered their 30 min scanning interval as too long. 93.4% of the healthy subjects would like to participate in an fMRI study again, with a significantly lower rate for the subjects who considered the scanning as too long. Further factors, such as inclusion of a diffusion tensor imaging (DTI) scan, age, and study duration had no effect on the questionnaire responses. Of the few negative comments, the main issues were noise, the restriction to keep still for the whole time, and occasional feelings of dizziness. MRI scanning in the basic research setting is an acceptable procedure for elderly and patient participants as well as young healthy subjects

  1. SIMS imaging of gadolinium isotopes in tissue from Nephrogenic Systemic Fibrosis patients: Release of free Gd from magnetic resonance imaging (MRI) contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Jerrold L. [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Chandra, Subhash [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)], E-mail: sc40@cornell.edu; Thakral, Charu [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Abraham, Joshua M. [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)

    2008-12-15

    Recently, Gd-based magnetic resonance imaging (MRI) contrast agents (GBMCA) have been linked to a new disease, Nephrogenic Systemic Fibrosis (NSF), with skin and systemic toxicity and death in certain patients with renal failure. Due to widespread use of GBMCA in diagnostic MRI, it is essential to study their excretion, metabolism, and target sites in cells and tissues. A CAMECA IMS-3f SIMS ion microscope and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) were used for imaging Gd isotopes in relation to calcium distributions in histologic sections of human tissues. SIMS imaging revealed two types of Gd localization in skin biopsies of patients who received GBMCA. The Gd was present in micrometer size deposits in association with calcium, and in detectable amounts in a more diffuse cellular distribution. Only the Gd-containing deposits associated with Ca and P were detectable using SEM/EDS. As only insoluble deposits remain in the biopsy tissues after aqueous and organic solvent processing of the tissue, our observations support release of free Gd from the GBMCA and selective localization of insoluble Gd in the target tissue from patients with NSF. This study opens new novel applications of SIMS for characterization of the safety of GBMCA.

  2. Neural Correlates of Consumer Buying Motivations: A 7T functional Magnetic Resonance Imaging (fMRI Study

    Directory of Open Access Journals (Sweden)

    Adam M. Goodman

    2017-09-01

    Full Text Available Consumer buying motivations can be distinguished into three categories: functional, experiential, or symbolic motivations (Keller, 1993. Although prior neuroimaging studies have examined the neural substrates which enable these motivations, direct comparisons between these three types of consumer motivations have yet to be made. In the current study, we used 7 Tesla (7T functional magnetic resonance imaging (fMRI to assess the neural correlates of each motivation by instructing participants to view common consumer goods while emphasizing either functional, experiential, or symbolic values of these products. The results demonstrated mostly consistent activations between symbolic and experiential motivations. Although, these motivations differed in that symbolic motivation was associated with medial frontal gyrus (MFG activation, whereas experiential motivation was associated with posterior cingulate cortex (PCC activation. Functional motivation was associated with dorsolateral prefrontal cortex (DLPFC activation, as compared to other motivations. These findings provide a neural basis for how symbolic and experiential motivations may be similar, yet different in subtle ways. Furthermore, the dissociation of functional motivation within the DLPFC supports the notion that this motivation relies on executive function processes relatively more than hedonic motivation. These findings provide a better understanding of the underlying neural functioning which may contribute to poor self-control choices.

  3. Preoperative mapping of speech-eloquent areas with functional magnetic resonance imaging (fMRI): comparison of different task designs

    International Nuclear Information System (INIS)

    Prothmann, S.; Zimmer, C.; Puccini, S.; Dalitz, B.; Kuehn, A.; Kahn, T.; Roedel, L.

    2005-01-01

    Purpose: Functional magnetic resonance imaging (fMRI) is a well-established, non-invasive method for pre-operative mapping of speech-eloquent areas. This investigation tests three simple paradigms to evaluate speech lateralisation and visualisation of speech-eloquent areas. Materials and Methods: 14 healthy volunteers and 16 brain tumour patients were given three tasks: to enumerate months in the correct order (EM), to generate verbs fitting to a given noun (GV) and to generate words fitting to a given alphabetic character (GW). We used a blocked design with 80 measurements which consisted of 4 intervals of speech activation alternating with relaxation periods. The data were analysed on the basis of the general linear model using Brainvoyager registered . The activated clusters in the inferior frontal (Broca) and the posterior temporal (Wernicke) cortex were analysed and the laterality indices calculated. Results: In both groups the paradigms GV and GW activated the Broca's area very robustly. Visualisation of the Wernicke's area was best achieved by the paradigm GV. The paradigm EM did not reliably stimulate either the frontal or the temporal cortex. Frontal lateralisation was best determined by GW and GV, temporal lateralisation by GV. Conclusion: The paradigms GV and GW visualise two essential aspects of speech processing: semantic word processing and word production. In a clinical setting with brain tumour patients, both, GV and GW can be used to visualise frontal and temporal speech areas, and to determine speech dominance. (orig.)

  4. Functional resonance magnetic imaging (fMRI) in adolescents with idiopathic musculoskeletal pain: a paradigm of experimental pain.

    Science.gov (United States)

    Molina, Juliana; Amaro, Edson; da Rocha, Liana Guerra Sanches; Jorge, Liliana; Santos, Flavia Heloisa; Len, Claudio A

    2017-11-14

    Studies on functional magnetic resonance imaging (fMRI) have shown that adults with musculoskeletal pain syndromes tolerate smaller amount of pressure (pain) as well as differences in brain activation patterns in areas related to pain.The objective of this study was to evaluate, through fMRI, the brain activation in adolescents with idiopathic musculoskeletal pain (IMP) while performing an experimental paradigm of pain. The study included 10 consecutive adolescents with idiopathic musculoskeletal pain (average age 16.3±1.0) and 10 healthy adolescents age-matched. fMRI exams were performed in a 3 T scanner (Magnetom Trio, Siemens) using an event-related design paradigm. Pressure stimuli were performed in the nondominant hand thumb, divided into two stages, fixed pain and variable pain. The two local Research Ethics Committees (Ethics Committee from Universidade Federal de São Paulo- Brazil, process number 0688/11, on July 1st, 2011 and Ethics Committee from Hospital Israelita Albert Einsten - Brazil, process number 1673, on October 19th, 2011) approved the study. The idiopathic musculoskeletal pain (IMP) group showed a reduced threshold for pain (3.7 kg/cm 2 versus 4.45 kg/cm 2 , p = 0.005). Control group presented increased bain activation when compared to IMP group in the following areas: thalamus (p = 0.00001), precentral gyrus (p = 0.0004) and middle frontal gyrus (p = 0.03). In intragroup analysis, IMP group showed greater brain activation during the unpredictable stimuli of the variable pain stage, especially in the lingual gyrus (p = 0.0001), frontal lobe (p = 0.0001), temporal gyrus (p = 0.0001) and precentral gyrus (p = 0.03), when compared to predictable stimulus of fixed pain. The same intragroup analysis with the control group showed greater activation during the unpredictable stimuli in regions of the precentral gyrus (p = 0.0001), subcallosal area (p = 0.0001), right and left occipital fusiform gyrus (p

  5. Nuclear magnetic resonance in cardiology: cardiac MRI

    International Nuclear Information System (INIS)

    Fernandez, Claudio C.

    2003-01-01

    As a new gold standard for mass, volume and flow, the magnetic resonance imaging (MRI) is probably the most rapidly evolving technique in the cardiovascular diagnosis. An integrated cardiac MRI examination allows the evaluation of morphology, global and regional function, coronary anatomy, perfusion, viability and myocardial metabolism, all of them in only one diagnostic test and in a totally noninvasive manner. The surgeons can obtain relevant information on all aspects of diseases of the heart and great vessels, which include anatomical details and relationships with the greatest field of view, and may help to reduce the number of invasive procedures required in pre and postoperative evaluation. However, despite these excellent advantages the present clinical utilization of MRI is still too often restricted to few pathologies or case studies in which other techniques fail to identify the cardiac or cardiovascular abnormalities. If magnetic resonance is an excellent method for diagnosing so many different cardiac conditions, why is so little it used in routine cardiac practice? Cardiologists are still not very familiar with the huge possibilities or cardiovascular MRI utilities. Our intention is to give a comprehensive survey of many of the clinical applications of this challenger technique in the study of the heart and great vessels. Those who continue to ignore this important and mature imaging technique will rightly fail to benefit. (author) [es

  6. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... of which shows a thin slice of the body. The images can then be studied from different angles by ... about radiology? Share your patient story here Images ... Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's ( ...

  7. Magnetic resonance vascular imaging

    International Nuclear Information System (INIS)

    Axel, L

    1989-01-01

    The basis principles of MRI are reviewed in order to understand how blood flow effects arise in conventional imaging. Then some of the ways these effects have ben used in MRI techniques specifically designed for vascular imaging, are considered. (author)

  8. High-resolution small field-of-view magnetic resonance image acquisition system using a small planar coil and a pneumatic manipulator in an open MRI scanner.

    Science.gov (United States)

    Miki, Kohei; Masamune, Ken

    2015-10-01

    Low-field open magnetic resonance imaging (MRI) is frequently used for performing image-guided neurosurgical procedures. Intraoperative magnetic resonance (MR) images are useful for tracking brain shifts and verifying residual tumors. However, it is difficult to precisely determine the boundary of the brain tumors and normal brain tissues because the MR image resolution is low, especially when using a low-field open MRI scanner. To overcome this problem, a high-resolution MR image acquisition system was developed and tested. An MR-compatible manipulator with pneumatic actuators containing an MR signal receiver with a small radiofrequency (RF) coil was developed. The manipulator had five degrees of freedom for position and orientation control of the RF coil. An 8-mm planar RF coil with resistance and inductance of 2.04 [Formula: see text] and 1.00 [Formula: see text] was attached to the MR signal receiver at the distal end of the probe. MR images of phantom test devices were acquired using the MR signal receiver and normal head coil for signal-to-noise ratio (SNR) testing. The SNR of MR images acquired using the MR signal receiver was 8.0 times greater than that of MR images acquired using the normal head coil. The RF coil was moved by the manipulator, and local MR images of a phantom with a 2-mm grid were acquired using the MR signal receiver. A wide field-of-view MR image was generated from a montage of local MR images. A small field-of-view RF system with a pneumatic manipulator was integrated in a low-field MRI scanner to allow acquisition of both wide field-of-view and high-resolution MR images. This system is promising for image-guided neurosurgery as it may allow brain tumors to be observed more clearly and removed precisely.

  9. The Standardized Histogram Shift of T2 Magnetic Resonance Image (MRI) Signal Intensities of Nephroblastoma Does Not Predict Histopathological Diagnostic Information

    OpenAIRE

    M?ller, Sabine; David, Ruslan; Marias, Kostas; Graf, Norbert

    2015-01-01

    The objective of this study is to assess standardized histograms of signal intensities of T2-weighted magnetic resonance image (MRI) modality before and after preoperative chemotherapy for nephroblastoma (Wilms? tumor). All analyzed patients are enrolled in the International Society of Paediatric Oncology (SIOP) 2001/GPOH trial.1 The question to be answered is whether the comparison of the histograms can add new knowledge by comparing them with the histology of the tumor after preoperative ch...

  10. Note: Progress on the use of MgB2 superconducting joint technique for the development of MgB2 magnets for magnetic resonance imaging (MRI).

    Science.gov (United States)

    Kim, Y G; Song, J B; Kim, J C; Kim, J M; Yoo, B H; Yun, S B; Hwang, D Y; Lee, H G

    2017-08-01

    This note presents a superconducting joint technique for the development of MgB 2 magnetic resonance imaging (MRI) magnets. The MgB 2 superconducting joint was fabricated by a powder processing method using Mg and B powders to establish a wire-bulk-wire connection. The joint resistance measured using a field-decay method was magnets operating in the persistent current mode.

  11. Measuring and manipulating brain connectivity with resting state functional connectivity magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS)

    OpenAIRE

    Fox, Michael D.; Halko, Mark A.; Eldaief, Mark C.; Pascual-Leone, Alvaro

    2012-01-01

    Both resting state functional magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS) are increasingly popular techniques that can be used to non-invasively measure brain connectivity in human subjects. TMS shows additional promise as a method to manipulate brain connectivity. In this review we discuss how these two complimentary tools can be combined to optimally study brain connectivity and manipulate distributed brain networks. Important clinical applications include...

  12. Enhanced control of dorsolateral prefrontal cortex neurophysiology with real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback training and working memory practice.

    Science.gov (United States)

    Sherwood, Matthew S; Kane, Jessica H; Weisend, Michael P; Parker, Jason G

    2016-01-01

    Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback can be used to train localized, conscious regulation of blood oxygen level-dependent (BOLD) signals. As a therapeutic technique, rt-fMRI neurofeedback reduces the symptoms of a variety of neurologic disorders. To date, few studies have investigated the use of self-regulation training using rt-fMRI neurofeedback to enhance cognitive performance. This work investigates the utility of rt-fMRI neurofeedback as a tool to enhance human cognition by training healthy individuals to consciously control activity in the left dorsolateral prefrontal cortex (DLPFC). A cohort of 18 healthy participants in the experimental group underwent rt-fMRI neurofeedback from the left DLPFC in five training sessions across two weeks while 7 participants in the control group underwent similar training outside the MRI and without rt-fMRI neurofeedback. Working memory (WM) performance was evaluated on two testing days separated by the five rt-fMRI neurofeedback sessions using two computerized tests. We investigated the ability to control the BOLD signal across training sessions and WM performance across the two testing days. The group with rt-fMRI neurofeedback demonstrated a significant increase in the ability to self-regulate the BOLD signal in the left DLPFC across sessions. WM performance showed differential improvement between testing days one and two across the groups with the highest increases observed in the rt-fMRI neurofeedback group. These results provide evidence that individuals can quickly gain the ability to consciously control the left DLPFC, and this training results in improvements of WM performance beyond that of training alone. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Analysis of Pseudohomophone Orthographic Errors through Functional Magnetic Resonance Imaging (fMRI).

    Science.gov (United States)

    Guardia-Olmos, Joan; Zarabozo-Hurtado, Daniel; Peró-Cebollero, Maribe; Gudayol-Farré, Esteban; Gómez-Velázquez, Fabiola R; González-Garrido, Andrés

    2017-12-04

    The study of orthographic errors in a transparent language such as Spanish is an important topic in relation to writing acquisition because in Spanish it is common to write pseudohomophones as valid words. The main objective of the present study was to explore the possible differences in activation patterns in brain areas while processing pseudohomophone orthographic errors between participants with high (High Spelling Skills (HSS)) and low (Low Spelling Skills (LSS)) spelling orthographic abilities. We hypothesize that (a) the detection of orthographic errors will activate bilateral inferior frontal gyri, and that (b) this effect will be greater in the HSS group. Two groups of 12 Mexican participants, each matched by age, were formed based on their results in a group of spelling-related ad hoc tests: HSS and LSS groups. During the fMRI session, two experimental tasks were applied involving correct and pseudohomophone substitution of Spanish words. First, a spelling recognition task and second a letter searching task. The LSS group showed, as expected, a lower number of correct responses (F(1, 21) = 52.72, p right inferior frontal gyrus in HSS group during the spelling task. However, temporal, frontal, and subcortical brain regions of the LSS group were activated during the same task.

  14. Intracerebral lesions associated with systemic lupos erythematosus in magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Poniatowska, R.; Krawczyk, R.; Boguslawska, R.; Palasik, W.; Kuczynska, A.

    2002-01-01

    The purpose of our study was to assess the involvement of central nervous system in brain magnetic resonance studies in patients with SLE. The MR study of the brain was carried out on 47 patients with these neurological symptoms: hemiparesis (15 cases), seizures (2), headache and vertigo (5), balance disorders (3), nausea (2), vision disorders (6). The MR findings were: in 15 cases single and in 5 multiple small focuses, coexistence of small and large focuses in 4 cases, subtentorial focuses in 3 (2 in cerebellum, 1 in pons), lesions in deep structures in 3 cases. In 1 case occlusion of internal carotid artery siphon with large ischemic focus, in 1 bleeding to choroid plexus occurred. The dominant were disseminated white matter lesions in subcortical and periventricular regions. In 16 case MR examinations showed cortical-subcortical atrophy. MR study allows us to assess severity of CNS involvement in course of SLE and helps to start a correct treatment. (author)

  15. The role of magnetic resonance imaging (MRI) and MRI-guided surgery in the evaluation of patients with early stage breast cancer for breast conserving therapy

    International Nuclear Information System (INIS)

    Tan, Jacqueline E.; Orel, Susan G.; Schnall, Mitchell D.; Solin, Lawrence J.

    1997-01-01

    Purpose: Mammography is the primary imaging modality for the detection of breast cancer and the evaluation of patients with early stage breast cancer for breast conserving therapy (BCT). MRI may be more sensitive than mammography for detecting breast cancer and may have an adjunctive role in assessing patients with early stage disease for BCT. Our experience with 83 patients undergoing breast MRI during consideration for breast conserving therapy is analyzed. Materials and Methods: We reviewed 83 consecutive cases of patients undergoing breast MRI during standard work-up and evaluation for BCT from 1993 to 1996. Analysis of cases was limited to women who were AJCC clinical Stage 0, I, or II and who received definitive therapy at our institution. All patients signed informed consent. MRI of the breast was performed at 1.5 Tesla. Sagittal T1 and T2 and 3-D gradient pre- and post-contrast images were obtained. All MRI studies were reviewed by two radiologists. All patients were evaluated by one radiation oncologist. The records of these 83 patients were reviewed for patient age, tumor size, AJCC stage, histology, physical examination findings, mammographic findings, ultrasound findings, MRI findings, timing of first MRI study with respect to excisional surgery, findings from MRI-guided surgery (when done), and whether the patient underwent BCT. Results: The median age at the time of presentation was 51.5 years (range 26-77 years). Of the 83 patients, 16% were AJCC clinical stage 0, 65% were stage I, and 19% were stage II. No patient presented with synchronous bilateral carcinoma. Two patients had a history of prior contralateral breast carcinoma; both received BCT for their initial disease. Sixteen percent of patients had intraductal carcinoma, 39% had intraductal and infiltrating carcinoma, 28% had infiltrating ductal carcinoma, 7% had infiltrating lobular carcinoma, 4% had tubular carcinoma, 2% had adenoid cystic carcinoma, 2% had medullary carcinoma, 1% had colloid

  16. Endometrial cancer: magnetic resonance imaging.

    Science.gov (United States)

    Manfredi, R; Gui, B; Maresca, G; Fanfani, F; Bonomo, L

    2005-01-01

    Carcinoma of the endometrium is the most common invasive gynecologic malignancy of the female genital tract. Clinically, patients with endometrial carcinoma present with abnormal uterine bleeding. The role of magnetic resonance imaging (MRI) in endometrial carcinoma is disease staging and treatment planning. MRI has been shown to be the most valuable imaging mod-ality in this task, compared with endovaginal ultrasound and computed tomography, because of its intrinsic contrast resolution and multiplanar capability. MRI protocol includes axial T1-weighted images; axial, sagittal, and coronal T2-weighted images; and dynamic gadolinium-enhanced T1-weighted imaging. MR examination is usually performed in the supine position with a phased array multicoil using a four-coil configuration. Endometrial carcinoma is isointense with the normal endometrium and myometrium on noncontrast T1-weighted images and has a variable appearance on T2-weighted images demonstrating heterogeneous signal intensity. The appearance of noninvasive endometrial carcinoma on MRI is characterized by a normal or thickened endometrium, with an intact junctional zone and a sharp tumor-myometrium interface. Invasive endometrial carcinoma is characterized disruption or irregularity of the junctional zone by intermediate signal intensity mass on T2-weighted images. Invasion of the cervical stroma is diagnosed when the low signal intensity cervical stroma is disrupted by the higher signal intensity endometrial carcinoma. MRI in endometrial carcinoma performs better than other imaging modalities in disease staging and treatment planning. Further, the accuracy and the cost of MRI are equivalent to those of surgical staging.

  17. Multi-frequency bioelectrical impedance analysis (BIA) compared to magnetic resonance imaging (MRI) for estimation of fat-free mass in colorectal cancer patients treated with chemotherapy

    DEFF Research Database (Denmark)

    Palle, Stine Skov; Tang Møllehave, Line; Kadkhoda, Zahra Taheri

    2016-01-01

    during the course of their treatments. Objective: To examine relationships between single cross-sectional thighs magnetic resonance imaging (MRI), skeletal muscle mass (SM) as reference and multi-frequency bioelectrical impedance analysis (BIA) fat free mass (FFM) in patients with colorectal cancer...... undergoing chemotherapy. Design: In an observational, prospective study we examine the relationships between single cross-sectional thighs MRI (T1-weighted (1.5 T) SM compared to FFM BIA (8-electrodes multi-frequency Tanita MC780MA)) and FFM skin-fold thickness (ST) (4-points (Harpenden, Skinfold Caliper......)) and SM equation for non-obese persons from Lee et al. 2000 (L2000) (based on age, height, weight, sex and race). FFM and SM (kg) were calculated based on either area (MRI) or weight. Results: 18 CRC patients (10 males and 8 females) with mean (SD) age 67 yr (6) were measured at baseline, and 13 were...

  18. Functional magnetic resonance imaging (fMRI of attention processes in presumed obligate carriers of schizophrenia: preliminary findings

    Directory of Open Access Journals (Sweden)

    Morris Robin G

    2008-10-01

    Full Text Available Abstract Background Presumed obligate carriers (POCs are the first-degree relatives of people with schizophrenia who, although do not exhibit the disorder, are in direct lineage of it. Thus, this subpopulation of first-degree relatives could provide very important information with regard to the investigation of endophenotypes for schizophrenia that could clarify the often contradictory findings in schizophrenia high-risk populations. To date, despite the extant literature on schizophrenia endophenotypes, we are only aware of one other study that examined the neural mechanisms that underlie cognitive abnormalities in this group. The aim of this study was to investigate whether a more homogeneous group of relatives, such as POCs, have neural abnormalities that may be related to schizophrenia. Methods We used functional magnetic resonance imaging (fMRI to collect blood oxygenated level dependent (BOLD response data in six POCs and eight unrelated healthy controls while performing under conditions of sustained, selective and divided attention. Results The POCs indicated alterations in a widely distributed network of regions involved in attention processes, such as the prefrontal and temporal (including the parahippocampal gyrus cortices, in addition to the anterior cingulate gyrus. More specifically, a general reduction in BOLD response was found in these areas compared to the healthy participants during attention processes. Conclusion These preliminary findings of decreased activity in POCs indicate that this more homogeneous population of unaffected relatives share similar neural abnormalities with people with schizophrenia, suggesting that reduced BOLD activity in the attention network may be an intermediate marker for schizophrenia.

  19. Contrast-enhanced spectral mammography (CESM) versus breast magnetic resonance imaging (MRI): A retrospective comparison in 66 breast lesions.

    Science.gov (United States)

    Li, L; Roth, R; Germaine, P; Ren, S; Lee, M; Hunter, K; Tinney, E; Liao, L

    2017-02-01

    The purpose of this study was to retrospectively compare the diagnostic performance of contrast-enhanced spectral mammography (CESM) with that of breast magnetic resonance imaging (BMRI) in breast cancer detection using parameters, including sensitivity, positive predictive value (PPV), lesion size, morphology, lesion and background enhancement, and examination time. A total of 48 women (mean age, 56years±10.6 [SD]) with breast lesions detected between October 2012 and March 2014 were included. Both CESM and BMRI were performed for each patient within 30 days. The enhancement intensity of lesions and breast background parenchyma was subjectively assessed for both modalities and was quantified for comparison. Statistical significance was analyzed using paired t-test for mean size of index lesions in all malignant breasts (an index lesion defined as the largest lesion in each breast), and a mean score of enhancement intensity for index lesions and breast background. PPV, sensitivity, and accuracy were calculated for both CESM and BMRI. The average duration time of CESM and MRI examinations was also compared. A total of 66 lesions were identified, including 62 malignant and 4 benign lesions. Both CESM and BMRI demonstrated a sensitivity of 100% for detection of breast cancer. There was no statistically significant difference between the mean size of index lesions (P=0.108). The enhancement intensity of breast background was significantly lower for CESM than for BMRI (P0.05). The average examination time for CESM was significantly shorter than that of BMRI (P<0.01). CESM has similar sensitivity than BMRI in breast cancer detection, with higher PPV and less background enhancement. CESM is associate with significantly shorter exam time thus a more accessible alternative to BMRI, and has the potential to play an important tool in breast cancer detection and staging. Copyright © 2016 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights

  20. MRI: Imaging of stomach

    International Nuclear Information System (INIS)

    Lam, W. W. M; Lee, J. S. W.; Ho, G.

    2007-01-01

    Full text: The study is to determine the optimal MRI bowel preparation regime for visualization of the stomach anatomy, Eight healthy volunteers were asked to take water, 75% barium and blueberry juice. The image quality and tolerance of different stomach distension regime were evaluated. Blueberry juice gave the best distension, but the signal intensity was not very homogeneous. Taking into account the image quality, tolerability and adverse effects, it is concluded that water is the most desirable oral contrast for MR stomach imaging

  1. Role of magnetic resonance imaging (MRI) establishing the indication for, planning, and following up uterine artery embolization (UAE) for treating symptomatic leiomyomas of the uterus

    International Nuclear Information System (INIS)

    Kroencke, T.J.; Hamm, B.

    2003-01-01

    To describe the role of magnetic resonance imaging (MRI) in establishing the indication for, planning, and following up uterine artery embolization (UAE) for treating symptomatic leiomyomas of the uterus on the basis of the current literature and our results. Retrospective analysis of the MRI findings obtained in 130 patients before and after UAE. Presentation of characteristic MRI features and their relevance in establishing the indication for, performing, and following up of UAE. Discussion of the results in conjunction with published data. The intermediate results of UAE reported in the literature show a successful improvement of leiomyoma-related symptoms in 82-94% of cases and an average reduction of leiomyoma size by 36-64%. The typical MRI appearance of degenerating leiomyomas is presented together with that of relevant differential diagnoses. MRI findings allow for establishing the indication for UAE by providing reliable information on the location, size, and number of uterine leiomyomas. Analysis of 60 patients of our study population showed solitary leiomyoma in 16% of cases, 2-10 leiomyomas in 47%, and over 10 in 37%. Subserosal, pedunculated leiomyomas cannot be treated by UAE; these were present in 5% of the patients. MR angiography is useful in assessing pelvic vascular anatomy before the intervention and identifies collateral vascular supply to the uterus. Contrast-enhanced imaging is suitable for monitoring successful devascularization following embolization and evaluating complications. (orig.) [de

  2. Studies on improvement of diagnosis of neurosurgical lesions by magnetic resonance imaging (MRI), 2; Advantages of MRI on diagnosis of parasellar lesions and comparison with X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Kotoyuki (Kagoshima Univ. (Japan). Faculty of Medicine)

    1989-05-01

    Findings of magnetic resonance (MRI) imaging in 46 patients with sellar or parasellar mass were reviewed and compared with those of concurrently available X-ray CT. Intrasellar contents, the hypothalamic pituitary region, adjacent brain stem, optic nerves, and the surrounding cerebrospinal fluid were clearly depicted on T1-weighted images. The cavernous sinus and blood vessels, including the Willis circle, were visualized on T2-weighted images. In detecting pituitary macroadenoma, MRI seemed to be the most userful modality, because it was superior to CT in identifying abnormal changes of the infundibulum, diaphragma sellae, cavernous sinus and optic chiasm. Macroadenoma of the pituitary gland was usually isointense to the normal cerebral cortex on T1- and T2-weighted images. T1- and T2-weighted relaxation times for pituitary adenoma were slightly prolonged. The normal pituitary gland was distinguishable from adenomatous tissues. For microadenoma, MRI failed to show lesions or erosion of the sellar floor. Craniopharyngioma, meningioma of the tuberculum sellae, hypothalamic tumor, such as glioma and germinoma, and the other parasellar masses were clearly visualized on MRI. MRI was superior to CT in detecting tumor and its involvement, but inferior in detecting presence of calcification. T1-weighted imaging was useful in identifing the presence of intratumoral hemorrhage. Cysts of craniopharyngioma had various appearances on T1-weighted images. High signal cyst intensity corresponded to a high cholesterol content or the presence of methemoglobin. MRI depicted empty sella. The intrasellar content had the same appearance as that of the cerebrospinal fluid space, and the flattened pituitary gland and pituitary stalk were detected on T1-weighted images. (N.K.).

  3. Multidimensionally encoded magnetic resonance imaging.

    Science.gov (United States)

    Lin, Fa-Hsuan

    2013-07-01

    Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here, we propose the multidimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel radiofrequency coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled. Copyright © 2012 Wiley Periodicals, Inc.

  4. Parallel magnetic resonance imaging

    International Nuclear Information System (INIS)

    Larkman, David J; Nunes, Rita G

    2007-01-01

    Parallel imaging has been the single biggest innovation in magnetic resonance imaging in the last decade. The use of multiple receiver coils to augment the time consuming Fourier encoding has reduced acquisition times significantly. This increase in speed comes at a time when other approaches to acquisition time reduction were reaching engineering and human limits. A brief summary of spatial encoding in MRI is followed by an introduction to the problem parallel imaging is designed to solve. There are a large number of parallel reconstruction algorithms; this article reviews a cross-section, SENSE, SMASH, g-SMASH and GRAPPA, selected to demonstrate the different approaches. Theoretical (the g-factor) and practical (coil design) limits to acquisition speed are reviewed. The practical implementation of parallel imaging is also discussed, in particular coil calibration. How to recognize potential failure modes and their associated artefacts are shown. Well-established applications including angiography, cardiac imaging and applications using echo planar imaging are reviewed and we discuss what makes a good application for parallel imaging. Finally, active research areas where parallel imaging is being used to improve data quality by repairing artefacted images are also reviewed. (invited topical review)

  5. Pediatric magnetic resonance imaging

    International Nuclear Information System (INIS)

    Cohen, M.D.

    1986-01-01

    This book defines the current clinical potential of magnetic resonance imaging and focuses on direct clinical work with pediatric patients. A section dealing with the physics of magnetic resonance imaging provides an introduction to enable clinicians to utilize the machine and interpret the images. Magnetic resonance imaging is presented as an appropriate imaging modality for pediatric patients utilizing no radiation

  6. Minimum joint space width (mJSW) of patellofemoral joint on standing ''skyline'' radiographs: test-retest reproducibility and comparison with quantitative magnetic resonance imaging (qMRI)

    International Nuclear Information System (INIS)

    Simoni, Paolo; Jamali, Sanaa; Alvarez Miezentseva, Victoria; Albert, Adelin; Totterman, Saara; Schreyer, Edward; Tamez-Pena, Jose G.; Zobel, Bruno Beomonte; Gillet, Philippe

    2013-01-01

    To assess the intraobserver, interobserver, and test-retest reproducibility of minimum joint space width (mJSW) measurement of medial and lateral patellofemoral joints on standing ''skyline'' radiographs and to compare the mJSW of the patellofemoral joint to the mean cartilage thickness calculated by quantitative magnetic resonance imaging (qMRI). A couple of standing ''skyline'' radiographs of the patellofemoral joints and MRI of 55 knees of 28 volunteers (18 females, ten males, mean age, 48.5 ± 16.2 years) were obtained on the same day. The mJSW of the patellofemoral joint was manually measured and Kellgren and Lawrence grade (KLG) was independently assessed by two observers. The mJSW was compared to the mean cartilage thickness of patellofemoral joint calculated by qMRI. mJSW of the medial and lateral patellofemoral joint showed an excellent intraobserver agreement (interclass correlation (ICC) = 0.94 and 0.96), interobserver agreement (ICC = 0.90 and 0.95) and test-retest agreement (ICC = 0.92 and 0.96). The mJSW measured on radiographs was correlated to mean cartilage thickness calculated by qMRI (r = 0.71, p < 0.0001 for the medial PFJ and r = 0.81, p < 0.0001 for the lateral PFJ). However, there was a lack of concordance between radiographs and qMRI for extreme values of joint width and KLG. Radiographs yielded higher joint space measures than qMRI in knees with a normal joint space, while qMRI yielded higher joint space measures than radiographs in knees with joint space narrowing and higher KLG. Standing ''skyline'' radiographs are a reproducible tool for measuring the mJSW of the patellofemoral joint. The mJSW of the patellofemoral joint on radiographs are correlated with, but not concordant with, qMRI measurements. (orig.)

  7. Imaging tools to study pharmacology: functional MRI on small rodents

    OpenAIRE

    Elisabeth eJonckers; Disha eShah; Julie eHamaide; Marleen eVerhoye; Annemie eVan Der Linden

    2015-01-01

    Functional Magnetic Resonance Imaging (fMRI) is an excellent tool to study the effect of pharmacological modulations on brain function in a non-invasive and longitudinal manner. We introduce several blood oxygenation level dependent (BOLD) fMRI techniques, including resting state (rsfMRI), stimulus-evoked (st-fMRI), and pharmacological MRI (phMRI). Respectively, these techniques permit the assessment of functional connectivity during rest as well as brain activation triggered by sensory stimu...

  8. Clinical magnetic resonance: imaging and spectroscopy

    International Nuclear Information System (INIS)

    Andrew, E.R.; Bydder, Graeme; Griffiths, John; Iles, Richard; Styles, Peter

    1990-01-01

    This book begins with a readable, comprehensive but non-mathematical introduction to the basic underlying principles of magnetic resonance. Further chapters include information on the theory and principles of MRI and MRS, the interpretation of MR images, the clinical applications and scope of MRI and MRS, practical aspects of spectroscopy and magnetic resonance, and also the practical problems associated with the siting, safety and operation of large MRI and MRS equipment. (author)

  9. Magnetic resonance imaging- physical principles and clinical application

    International Nuclear Information System (INIS)

    Tavri, O.J.

    1996-01-01

    The advances in imaging techniques for better and efficient diagnosis have become possible with the advent of Magnetic Resonance Imaging (MRI). The modalities of MRI technique for indication and diagnosis are mentioned in with typical examples. (author)

  10. Quantitative perfusion imaging in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Zoellner, F.G.; Gaa, T.; Zimmer, F.; Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M.

    2016-01-01

    Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [de

  11. Functional magnetic resonance imaging of the primary motor cortex ...

    Indian Academy of Sciences (India)

    Unknown

    Abbreviations used: BOLD, Blood oxygenation level dependent; CBF, cerebral blood flow; fMRI, functional magnetic resonance imaging; EPI, eco-planar imaging; FOV, field of view; MRI, Magnetic resonance imaging; MRS, magnetic resonance spectroscopy;. PET, position emission tomography; rCBF, regional cerebral ...

  12. Simultaneous PET/MRI with 13C magnetic resonance spectroscopic imaging (hyperPET): phantom-based evaluation of PET quantification

    DEFF Research Database (Denmark)

    Hansen, Adam E.; Andersen, Flemming L.; Henriksen, Sarah T.

    2016-01-01

    Background: Integrated PET/MRI with hyperpolarized 13C magnetic resonance spectroscopic imaging (13C-MRSI) offers simultaneous, dual-modality metabolic imaging. A prerequisite for the use of simultaneous imaging is the absence of interference between the two modalities. This has been documented...... for a clinical whole-body system using simultaneous 1 H-MRI and PET but never for 13C-MRSI and PET. Here, the feasibility of simultaneous PET and 13C-MRSI as well as hyperpolarized 13C-MRSI in an integrated whole-body PET/MRI hybrid scanner is evaluated using phantom experiments. Methods: Combined PET and 13C......-MRSI phantoms including a NEMA [18F]-FDG phantom, 13C-acetate and 13C-urea sources, and hyperpolarized 13C-pyruvate were imaged repeatedly with PET and/or 13C-MRSI. Measurements evaluated for interference effects included PET activity values in the largest sphere and a background region; total number of PET...

  13. Combining Magnetic Resonance Imaging (MRI) and Medical Infrared Thermography (MIT) in the pre- and per-operating management of severe Hidradenitis Suppurativa (HS).

    Science.gov (United States)

    Derruau, Stéphane; Renard, Yohann; Pron, Hervé; Taiar, Redha; Abdi, Ellie; Polidori, Guillaume; Lorimier, Sandrine

    2018-05-12

    Hidradenitis suppurativa (HS) is a chronic, inflammatory, and recurrent skin disease. Surgical excision of wounds appears to be the only curative treatment for the prevention of recurrence of moderate to severe stages. Magnetic resonance imaging (MRI) is a standard reference examination for the detection of HS peri-anal inflammatory fistula. In this case study, the use of real-time medical infrared thermography, in combination with MRI as appropriate imaging, is proposed. The aim is to assist surgeons in the pre- and peri-surgical management of severe perianal hidradenitis suppurativa with the intent to ensure that all diseased lesions were removed during surgery and therefore to limit recurrence. The results show that medical infrared thermography (MIT), coupled with MRI, could be highly effective strategy to address thermally distinguished health tissues and inflammatory sites during excision, as characterised by differential increases in temperature. Medical infrared thermography could be used to check the total excision of inflammatory lesions as a noninvasive method that is not painful, not radiant, and is easily transportable during surgery. Ultimately, this method could be complementary with MRI in providing clinicians with objective data on the status of tissues below the perianal skin surface in the pre- and per-operating management of severe hidradenitis suppurativa. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Magnetic resonance imaging in radiotherapy treatment planning

    NARCIS (Netherlands)

    Moerland, Marinus Adriaan

    1996-01-01

    From its inception in the early 1970's up to the present, magnetic resonance imaging (MRI) has evolved into a sophisticated technique, which has aroused considerable interest in var- ious subelds of medicine including radiotherapy. MRI is capable of imaging in any plane and does not use ionizing

  15. Fetal abdominal magnetic resonance imaging

    International Nuclear Information System (INIS)

    Brugger, Peter C.; Prayer, Daniela

    2006-01-01

    This review deals with the in vivo magnetic resonance imaging (MRI) appearance of the human fetal abdomen. Imaging findings are correlated with current knowledge of human fetal anatomy and physiology, which are crucial to understand and interpret fetal abdominal MRI scans. As fetal MRI covers a period of more than 20 weeks, which is characterized not only by organ growth, but also by changes and maturation of organ function, a different MR appearance of the fetal abdomen results. This not only applies to the fetal intestines, but also to the fetal liver, spleen, and adrenal glands. Choosing the appropriate sequences, various aspects of age-related and organ-specific function can be visualized with fetal MRI, as these are mirrored by changes in signal intensities. Knowledge of normal development is essential to delineate normal from pathological findings in the respective developmental stages

  16. Fetal abdominal magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Brugger, Peter C. [Center of Anatomy and Cell Biology, Integrative Morphology Group, Medical University of Vienna, Waehringerstrasse 13, 1090 Vienna (Austria)]. E-mail: peter.brugger@meduniwien.ac.at; Prayer, Daniela [Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria)

    2006-02-15

    This review deals with the in vivo magnetic resonance imaging (MRI) appearance of the human fetal abdomen. Imaging findings are correlated with current knowledge of human fetal anatomy and physiology, which are crucial to understand and interpret fetal abdominal MRI scans. As fetal MRI covers a period of more than 20 weeks, which is characterized not only by organ growth, but also by changes and maturation of organ function, a different MR appearance of the fetal abdomen results. This not only applies to the fetal intestines, but also to the fetal liver, spleen, and adrenal glands. Choosing the appropriate sequences, various aspects of age-related and organ-specific function can be visualized with fetal MRI, as these are mirrored by changes in signal intensities. Knowledge of normal development is essential to delineate normal from pathological findings in the respective developmental stages.

  17. Comparative magnetic resonance imaging of renal space-occupying lesions with a high and a low field MRI system

    International Nuclear Information System (INIS)

    Gehl, H.B.; Lorch, H.; Amblank, O.B.M.; Engerhoff, B.; Weiss, H.D.

    1998-01-01

    Purpose: A prospective study of the diagnostic accuracy and image quality of two MRI systems in the detection of renal tumors was investigated. Materials and Methods: 34 patients with the clinical suspicion of a space-occupying renal lesion were examined by MRI with a low field (0.2 Tesla magnet) and a high field (1.5 Tesla magnet) for comparison. An 'informed' and a 'blind' observer evaluated all of the MR images. In addition, the signal-to-noise and contrast-to-noise ratios were evaluated as second quality parameters. Results: In 29 cases the results could be compared with a confirmed release diagnosis. Diagnostic accuracy was comparable with both systems (Sensitivity for both observer on LF apparatus: 83%, HF apparatus: 81%) although the signal-to-noise and contrast-to-noise ratios were significantly poorer at low field. Conclusions: The low field system in comparable to the high field MRI for detection and differentiation of renal space-occupying lesions. (orig.) [de

  18. MRI Reporter Genes for Noninvasive Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Caixia Yang

    2016-05-01

    Full Text Available Magnetic resonance imaging (MRI is one of the most important imaging technologies used in clinical diagnosis. Reporter genes for MRI can be applied to accurately track the delivery of cell in cell therapy, evaluate the therapy effect of gene delivery, and monitor tissue/cell-specific microenvironments. Commonly used reporter genes for MRI usually include genes encoding the enzyme (e.g., tyrosinase and β-galactosidase, the receptor on the cells (e.g., transferrin receptor, and endogenous reporter genes (e.g., ferritin reporter gene. However, low sensitivity limits the application of MRI and reporter gene-based multimodal imaging strategies are common including optical imaging and radionuclide imaging. These can significantly improve diagnostic efficiency and accelerate the development of new therapies.

  19. Large field-of-view transmission line resonator for high field MRI

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Johannesson, Kristjan Sundgaard; Boer, Vincent

    2016-01-01

    Transmission line resonators is often a preferable choice for coils in high field magnetic resonance imaging (MRI), because they provide a number of advantages over traditional loop coils. The size of such resonators, however, is limited to shorter than half a wavelength due to high standing wave....... Achieved magnetic field distribution is compared to the conventional transmission line resonator. Imaging experiments are performed using 7 Tesla MRI system. The developed resonator is useful for building coils with large field-of-view....

  20. Presurgical functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Stippich, C.

    2010-01-01

    Functional magnetic resonance imaging (fMRI) is an important and novel neuroimaging modality for patients with brain tumors. By non-invasive measurement, localization and lateralization of brain activiation, most importantly of motor and speech function, fMRI facilitates the selection of the most appropriate and sparing treatment and function-preserving surgery. Prerequisites for the diagnostic use of fMRI are the application of dedicated clinical imaging protocols and standardization of the respective imaging procedures. The combination with diffusion tensor imaging (DTI) also enables tracking and visualization of important fiber bundles such as the pyramidal tract and the arcuate fascicle. These multimodal MR data can be implemented in computer systems for functional neuronavigation or radiation treatment. The practicability, accuracy and reliability of presurgical fMRI have been validated by large numbers of published data. However, fMRI cannot be considered as a fully established modality of diagnostic neuroimaging due to the lack of guidelines of the responsible medical associations as well as the lack of medical certification of important hardware and software components. This article reviews the current research in the field and provides practical information relevant for presurgical fMRI. (orig.) [de

  1. Magnetic resonance imaging (MRI) findings among children with fetal alcohol syndrome (FAS), partial fetal alcohol syndrome (pFAS) and alcohol related neurodevelopmental disorders (ARND).

    Science.gov (United States)

    Anna Dyląg, Katarzyna; Sikora-Sporek, Aleksanda; Bańdo, Bożena; Boroń-Zyss, Joanna; Drożdż, Dorota; Dumnicka, Paulina; Przybyszewska, Katarzyna; Sporek, Mateusz; Walocha, Jerzy W; Wojciechowski, Wadim; Urbanik, Andrzej

    The aim of the study was to analyze the findings in MRI (magnetic resonance imaging) of the brain amongst children diagnosed with fetal alcohol syndrome (FAS), partial fetal alcohol syndrome (pFAS) or alcohol related neurodevelopmental disorders (ARND). The issue has been studied in several researches previously but the experts agree that there is still few data on the MRI results in the group of younger children. MRI results of 121 patients with either FAS or pFAS or ARND diagnosed with Canadian criteria were analyzed regarding the presence of abnormalities. The group consisted of 71 patients diagnosed with FAS, 33 diagnosed with pFAS and 17 diagnosed with ARND. The mean age of the patients was 8.03 years (standard deviation 4.07). In the total group of FASD patients 61.98% of the patients’ MRI results were abnormal. The most common abnormality in MRI of the patients were demyelination plaques (incidence 23.1%) and corpus callosum narrowing (20.7%) as well as ventricular asymmetry (18.8%).The demyelination plaques and corpus callosum narrowing were more frequent among children ≤4 years old (41.7% vs 18.6%; p=0.016 and 50.0% vs.13.4%; ppFAS and ARND. Both age ≤4 years and FAS diagnosis were independent predictors for multiple anomalies in multiple logistic regression. In structural brain MRI of younger children, multiple anomalies were found more frequently than among older children. Demyelination plaques and corpus callosum narrowing were more common in younger FASD patients than in older ones.

  2. Magnetic resonance imaging of pelvic endometriosis

    International Nuclear Information System (INIS)

    Vieira, G.P.; Martin, B.; Tubiana, J.M.

    1994-01-01

    Twenty-five magnetic resonance imaging (MRI) studies were performed in 18 patients with proven endometriosis. MRI findings were analyzed and compared with laparoscopic or surgical findings; MRI accurately demonstrated ovarian endometrial cysts as well as ectopic foci of endometriosis. Adhesions may be also suggested. Contrary to laparoscopy, MRI easily depicts both deep lesions and endometrial implants under the peritoneum. Consequently, MRI appears as an useful adjunct to laparoscopy for initial diagnosis before starting a medical treatment and above all as the imaging modality of choice for evaluation of the answer to treatment, avoiding iterative and often adhesions limited laparoscopies. (author). 7 refs.; 9 figs

  3. Correlation between liver histology and novel magnetic resonance imaging in adult patients with non-alcoholic fatty liver disease - MRI accurately quantifies hepatic steatosis in NAFLD.

    Science.gov (United States)

    Permutt, Z; Le, T-A; Peterson, M R; Seki, E; Brenner, D A; Sirlin, C; Loomba, R

    2012-07-01

    Conventional magnetic resonance imaging (MRI) techniques that measure hepatic steatosis are limited by T1 bias, T(2)* decay and multi-frequency signal-interference effects of protons in fat. Newer MR techniques such as the proton density-fat fraction (PDFF) that correct for these factors have not been specifically compared to liver biopsy in adult patients with non-alcoholic fatty liver disease (NAFLD). To examine the association between MRI-determined PDFF and histology-determined steatosis grade, and their association with fibrosis. A total of 51 adult patients with biopsy-confirmed NAFLD underwent metabolic-biochemical profiling, MRI-determined PDFF measurement of hepatic steatosis and liver biopsy assessment according to NASH-CRN histological scoring system. The average MRI-determined PDFF increased significantly with increasing histology-determined steatosis grade: 8.9% at grade-1, 16.3% at grade-2, and 25.0% at grade-3 with P ≤ 0.0001 (correlation: r(2) = 0.56, P hepatic steatosis by both MRI-determined PDFF (7.6% vs. 17.8%, P steatosis grade (1.4 vs. 2.2, P steatosis were more likely to have characteristics of advanced liver disease including higher average AST:ALT (0.87 vs. 0.60, P steatosis grade in adults with NAFLD. Steatosis is non-linearly related to fibrosis progression. In patients with NAFLD, a low amount of hepatic steatosis on imaging does not necessarily indicate mild disease. © 2012 Blackwell Publishing Ltd.

  4. Assessment of atherosclerotic plaque activity in patients with sleep apnea using hybrid positron emission tomography/magnetic resonance imaging (PET/MRI): a feasibility study.

    Science.gov (United States)

    Kundel, Vaishnavi; Trivieri, Maria Giovanna; Karakatsanis, Nicolas A; Robson, Phillip M; Mani, Venkatesh; Kizer, Jorge R; Kaplan, Robert; Fayad, Zahi; Shah, Neomi

    2018-03-05

    Evidence suggests that the inflammatory state of an atherosclerotic plaque is important in predicting future risk of plaque rupture. This study aims to investigate the feasibility of measuring plaque inflammation in patients with obstructive sleep apnea (OSA) utilizing advanced vascular imaging - hybrid positron-emission tomography/magnetic resonance imaging (PET/MRI) with fluorodeoxyglucose (FDG) tracer-before and after continuous positive airway pressure (CPAP). Patients with newly diagnosed moderate to severe OSA underwent baseline PET/MRI for assessment of vascular inflammation of the carotid arteries and thoracic aorta prior to initiation of CPAP. Those adherent to CPAP returned for repeat imaging after 3-6 months of CPAP use. Atherosclerotic plaque activity, as measured by arterial wall FDG uptake, was calculated using target-to-background ratios (TBR) before and after CPAP. Five patients were recruited as part of a focused project. Mean age was 52 years (80% male), and mean apnea-hypopnea index (AHI) was 33. Three patients were objectively adherent with CPAP. In the pre-CPAP phase, all patients had focal FDG uptake in the carotid arteries and aorta. After CPAP, there was an average reduction in TBR of 5.5% (TBR mean ) and 6.2% (TBR max ) in carotid and aortic plaque inflammation, similar in magnitude to the reduction observed with statin therapy alone in non-OSA patients (previously reported by others). We demonstrate the feasibility of using hybrid PET/MRI to assess atherosclerotic plaque inflammation in patients with OSA before and after CPAP. Use of the vascular PET/MRI platform in patients with OSA may provide better insight into the role of OSA and its treatment in reducing atherosclerotic inflammation.

  5. Magnetic resonance imaging in neuroradiology

    International Nuclear Information System (INIS)

    Voigt, K.; Lotx, J.W.

    1990-01-01

    Magnetic resonance imaging (MRI) is now accepted as an effective method of investigating a wide range of disorders, especially of the brain and spine. A short introduction on image contrast in MRI is given and the advantages and disadvantages for the different diseases of the brain is discussed. Excellent soft-tissue contrast, multiplanar imaging capabilities and lack of ionising radiation are conspicuous advantages, and it is now established as the investigation of choice in a large number of clinical conditions, especially when the central nervous system is involved. However, it remains only one of a series of imaging modalities. A confident provisional clinical diagnosis is essential for establishing an imaging protocol and the intention should always be to reach a definitive diagnosis in the least invasive and most cost-effective way. 7 figs., 19 refs

  6. Magnetic resonance imaging in psychiatry

    International Nuclear Information System (INIS)

    Mann, K.

    1993-01-01

    Diagnosis and research in psychiatry are increasingly availing themselves of magnetic resonance imaging (MRI). In comparison to computed tomography (CT), this offers the combined benefits of no exposure to radiation, high resolution, artefact-free display of structures near bone, and a sharp contrast between the grey and white brain matter, with freedom to select the section. With the exception of very anxious patients, MRI will gradually replace CT scans for a wide range of differential diagnostic investigations. Its superiority in systematic studies of psychiatric patients with discrete cerebral parenchyma lesions is already considered proven. This is illustrated on the basis of research into schizophrenia and alcoholism. (orig.) [de

  7. Contemporary imaging: Magnetic resonance imaging, computed tomography, and interventional radiology

    International Nuclear Information System (INIS)

    Goldberg, H.I.; Higgins, C.; Ring, E.J.

    1985-01-01

    In addition to discussing the most recent advances in magnetic resonance imaging (MRI), computerized tomography (CT), and the vast array of interventional procedures, this book explores the appropriate clinical applications of each of these important modalities

  8. Longitudinal Magnetic Resonance Imaging (MRI) Analysis of the Developmental Changes of Tourette Syndrome Reveal Reduced Diffusion in the Cortico-Striato-Thalamo-Cortical Pathways

    DEFF Research Database (Denmark)

    Debes, Nanette; Jeppesen, Signe; Raghava, Jayachandra Mitta

    2015-01-01

    There is evidence that cortico-striato-thalamo-cortical pathways are involved in Tourette syndrome. We performed a longitudinal imaging study in 22 patients and 21 healthy controls in order to examine the development of tics and its correlation with magnetic resonance imaging (MRI) findings....... Patients were divided in a group with persisting and a group with remission of tics. We found a decrease in volume of left putamen in controls, but not in patients. We found changes in mean diffusivity between patients and controls in right caudate nucleus, thalamus, and frontal lobe. In contrast...... to controls, parallel and perpendicular diffusivity decreased in patients and were most pronounced in the patients with persisting tics compared to those with remission. The findings suggest that the development of the brain in patients with remission resembles the normal development more than in patients...

  9. Magnetic Resonance Imaging of Liver Metastasis.

    Science.gov (United States)

    Karaosmanoglu, Ali Devrim; Onur, Mehmet Ruhi; Ozmen, Mustafa Nasuh; Akata, Deniz; Karcaaltincaba, Musturay

    2016-12-01

    Liver magnetic resonance imaging (MRI) is becoming the gold standard in liver metastasis detection and treatment response assessment. The most sensitive magnetic resonance sequences are diffusion-weighted images and hepatobiliary phase images after Gd-EOB-DTPA. Peripheral ring enhancement, diffusion restriction, and hypointensity on hepatobiliary phase images are hallmarks of liver metastases. In patients with normal ultrasonography, computed tomography (CT), and positron emission tomography (PET)-CT findings and high clinical suspicion of metastasis, MRI should be performed for diagnosis of unseen metastasis. In melanoma, colon cancer, and neuroendocrine tumor metastases, MRI allows confident diagnosis of treatment-related changes in liver and enables differential diagnosis from primary liver tumors. Focal nodular hyperplasia-like nodules in patients who received platinum-based chemotherapy, hypersteatosis, and focal fat can mimic metastasis. In cancer patients with fatty liver, MRI should be preferred to CT. Although the first-line imaging for metastases is CT, MRI can be used as a problem-solving method. MRI may be used as the first-line method in patients who would undergo curative surgery or metastatectomy. Current limitation of MRI is low sensitivity for metastasis smaller than 3mm. MRI fingerprinting, glucoCEST MRI, and PET-MRI may allow simpler and more sensitive diagnosis of liver metastasis. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Cryogenic Preamplifiers for Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Johansen, Daniel H.; Sanchez-Heredia, Juan D.; Petersen, Jan R.

    2018-01-01

    Pursuing the ultimate limit of detection in magnetic resonance imaging (MRI) requires cryogenics to decrease the thermal noise of the electronic circuits. As cryogenic coils for MRI are slowly emerging cryogenic preamplifiers are required to fully exploit their potential. A cryogenic preamplifier...

  11. Magnetic resonance imaging in pediatric neurological disease

    International Nuclear Information System (INIS)

    Tsukiyama, Takashi; Nishimoto, Hiroshi; Fujioka, Mutsuhisa; Aihara, Toshinori; Tanaka, Osamu.

    1986-01-01

    In this paper, we summarize our initial experience with Magnetic Resonance Imaging(MRI) in the evaluation of pediatric neurological disease. 17 children between the ages of 2 month and 8.5 year have been examined with MRI. All subjects tolerated the MRI procedure well, although sedation was necessary for young children. Result as follows : (1) MRI does not utilize ionising radiation to produce an image. (2) MRI images more clearly demonstrate cerebral gray and white matter than X-ray CT. (3) Compared with X-ray CT, MRI proved to be advantageous in detection and characterization of the pathology, especially when the abnormality was located along the posterior fossa and spinal canal. It is suggested that these nature of MRI makes it the ideal diagnostic method for children. (author)

  12. Enhancing contrast of magnetic resonance imaging in patients with ...

    African Journals Online (AJOL)

    DTPA), a recent magnetic resonance imaging (MRI) contrast agent, in hepatobiliary system of patients with liver cirrhosis. Methods: Liver cirrhosis patients that underwent contrast MRI examination at Renai Hospital, Taipei City, Taiwan were ...

  13. Categorization of aortic aneurysm thrombus morphology by magnetic resonance imaging

    DEFF Research Database (Denmark)

    de la Motte, Louise; Pedersen, Mads Møller; Thomsen, Carsten

    2013-01-01

    Magnetic resonance imaging (MRI) has been proposed for qualitative categorization of intraluminal thrombus morphology. We aimed to correlate the qualitative MRI categorization previously described to quantitative measurements of signal intensity and to compare morphological characteristics...

  14. Positron emission tomography (PET) and magnetic resonance imaging (MRI) for the assessment of axillary lymph node metastases in early breast cancer: systematic review and economic evaluation.

    Science.gov (United States)

    Cooper, K L; Meng, Y; Harnan, S; Ward, S E; Fitzgerald, P; Papaioannou, D; Wyld, L; Ingram, C; Wilkinson, I D; Lorenz, E

    2011-01-01

    Breast cancer is the most common type of cancer in women. Evaluation of axillary lymph node metastases is important for breast cancer staging and treatment planning. To evaluate the diagnostic accuracy, cost-effectiveness and effect on patient outcomes of positron emission tomography (PET), with or without computed tomography (CT), and magnetic resonance imaging (MRI) in the evaluation of axillary lymph node metastases in patients with newly diagnosed early-stage breast cancer. A systematic review of literature and an economic evaluation were carried out. Key databases (including MEDLINE, EMBASE and nine others) plus research registers and conference proceedings were searched for relevant studies up to April 2009. A decision-analytical model was developed to determine cost-effectiveness in the UK. One reviewer assessed titles and abstracts of studies identified by the search strategy, obtained the full text of relevant papers and screened them against inclusion criteria. Data from included studies were extracted by one reviewer using a standardised data extraction form and checked by a second reviewer. Discrepancies were resolved by discussion. Quality of included studies was assessed using the quality assessment of diagnostic accuracy studies (QUADAS) checklist, applied by one reviewer and checked by a second. Forty-five citations relating to 35 studies were included in the clinical effectiveness review: 26 studies of PET and nine studies of MRI. Two studies were included in the cost-effectiveness review: one of PET and one of MRI. Of the seven studies evaluating PET/CT (n = 862), the mean sensitivity was 56% [95% confidence interval (CI) 44% to 67%] and mean specificity 96% (95% CI 90% to 99%). Of the 19 studies evaluating PET only (n = 1729), the mean sensitivity was 66% (95% CI 50% to 79%) and mean specificity 93% (95% CI 89% to 96%). PET performed less well for small metastases; the mean sensitivity was 11% (95% CI 5% to 22%) for micrometastases (≤ 2 mm

  15. Feasibility of diffusion-weighted magnetic resonance imaging in patients with juvenile idiopathic arthritis on 1.0-T open-bore MRI

    Energy Technology Data Exchange (ETDEWEB)

    Barendregt, Anouk M.; Nusman, Charlotte M. [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Hemke, Robert; Lavini, Cristina; Maas, Mario [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Amiras, Dimitri [Imperial College Healthcare NHS Trust, Radiology Department, St. Mary' s Hospital, Paddington, London (United Kingdom); Kuijpers, Taco W. [University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands)

    2015-12-15

    To evaluate the feasibility of non-invasive diffusion-weighted imaging (DWI) of the knee of children with juvenile idiopathic arthritis (JIA) and, further, to analyze the apparent diffusion coefficient (ADC) levels to distinguish synovium from effusion. Standard magnetic resonance imaging of the knee including post-contrast imaging was obtained in eight patients (mean age, 12 years 8 months, five females) using an open-bore magnetic resonance imaging system (1.0 T). In addition, axially acquired echo-planar DWI datasets (b-values 0, 50, and 600) were prospectively obtained and the diffusion images were post-processed into ADC{sub 50-600} maps. Two independent observers selected a region of interest (ROI) for both synovium and effusion using aligned post-contrast images as landmarks. Mann-Whitney U test was performed to compare ADC synovium and ADC effusion. DWI was successfully obtained in all patients. When data of both observers was combined, ADC synovium was lower than ADC effusion in the ROI in seven out of eight patients (median, 1.92 x 10{sup -3} mm{sup 2}/s vs. 2.40 x 10{sup -3} mm{sup 2}/s, p = 0.006, respectively). Similar results were obtained when the two observers were analyzed separately (observer 1: p = 0.006, observer 2: p = 0.04). In this pilot study, on a patient-friendly 1.0-T open-bore MRI, we demonstrated that DWI may potentially be a feasible non-invasive imaging technique in children with JIA. We could differentiate synovium from effusion in seven out of eight patients based on the ADC of synovium and effusion. However, to select synovium and effusion on DWI, post-contrast images were still a necessity. (orig.)

  16. Assessment of Myocardial Remodeling Using an Elastin/Tropoelastin Specific Agent with High Field Magnetic Resonance Imaging (MRI).

    Science.gov (United States)

    Protti, Andrea; Lavin, Begoña; Dong, Xuebin; Lorrio, Silvia; Robinson, Simon; Onthank, David; Shah, Ajay M; Botnar, Rene M

    2015-08-13

    Well-defined inflammation, proliferation, and maturation phases orchestrate the remodeling of the injured myocardium after myocardial infarction (MI) by controlling the formation of new extracellular matrix. The extracellular matrix consists mainly of collagen but also fractions of elastin. It is thought that elastin is responsible for maintaining elastic properties of the myocardium, thus reducing the risk of premature rupture. An elastin/tropoelastin-specific contrast agent (Gd-ESMA) was used to image tropoelastin and mature elastin fibers for in vivo assessment of extracellular matrix remodeling post-MI. Gd-ESMA enhancement was studied in a mouse model of myocardial infarction using a 7 T MRI scanner and results were compared to those achieved after injection of a nonspecific control contrast agent, gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). In the infarcted tissue, Gd-ESMA uptake (measured as R1 relaxation rate) steadily increased from day 3 to day 21 as a result of the synthesis of elastin/tropoelastin. R1 values were in good agreement with histological findings. A similar R1 behavior was observed in the remote myocardium. No mature cross-linked elastin was found at any time point. In contrast, Gd-DTPA uptake was only observed in the infarct with no changes in R1 values between 3 and 21 days post-MI. We demonstrate the feasibility of in vivo imaging of extracellular matrix remodeling post-MI using a tropoelastin/elastin binding MR contrast agent, Gd-ESMA. We found that tropoelastin is the main contributor to the increased MRI signal at late stages of MI where its augmentation in areas of infarction was in good agreement with the R1 increase. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  17. Simultaneous PET/MRI with (13)C magnetic resonance spectroscopic imaging (hyperPET): phantom-based evaluation of PET quantification.

    Science.gov (United States)

    Hansen, Adam E; Andersen, Flemming L; Henriksen, Sarah T; Vignaud, Alexandre; Ardenkjaer-Larsen, Jan H; Højgaard, Liselotte; Kjaer, Andreas; Klausen, Thomas L

    2016-12-01

    Integrated PET/MRI with hyperpolarized (13)C magnetic resonance spectroscopic imaging ((13)C-MRSI) offers simultaneous, dual-modality metabolic imaging. A prerequisite for the use of simultaneous imaging is the absence of interference between the two modalities. This has been documented for a clinical whole-body system using simultaneous (1)H-MRI and PET but never for (13)C-MRSI and PET. Here, the feasibility of simultaneous PET and (13)C-MRSI as well as hyperpolarized (13)C-MRSI in an integrated whole-body PET/MRI hybrid scanner is evaluated using phantom experiments. Combined PET and (13)C-MRSI phantoms including a NEMA [(18)F]-FDG phantom, (13)C-acetate and (13)C-urea sources, and hyperpolarized (13)C-pyruvate were imaged repeatedly with PET and/or (13)C-MRSI. Measurements evaluated for interference effects included PET activity values in the largest sphere and a background region; total number of PET trues; and (13)C-MRSI signal-to-noise ratio (SNR) for urea and acetate phantoms. Differences between measurement conditions were evaluated using t tests. PET and (13)C-MRSI data acquisition could be performed simultaneously without any discernible artifacts. The average difference in PET activity between acquisitions with and without simultaneous (13)C-MRSI was 0.83 (largest sphere) and -0.76 % (background). The average difference in net trues was -0.01 %. The average difference in (13)C-MRSI SNR between acquisitions with and without simultaneous PET ranged from -2.28 to 1.21 % for all phantoms and measurement conditions. No differences were significant. The system was capable of (13)C-MRSI of hyperpolarized (13)C-pyruvate. Simultaneous PET and (13)C-MRSI in an integrated whole-body PET/MRI hybrid scanner is feasible. Phantom experiments showed that possible interference effects introduced by acquiring data from the two modalities simultaneously are small and non-significant. Further experiments can now investigate the benefits of simultaneous PET and

  18. Cardiac magnetic resonance imaging

    African Journals Online (AJOL)

    2011-03-06

    Mar 6, 2011 ... Cardiac magnetic resonance imaging. Cardiovascular magnetic resonance imaging is becoming a routine diagnostic technique. BRUCE s sPOTTiswOOdE, PhD. MRC/UCT Medical Imaging Research Unit, University of Cape Town, and Division of Radiology, Stellenbosch University. Bruce Spottiswoode ...

  19. Magnetic resonance imaging of spinal diseases

    International Nuclear Information System (INIS)

    Nakatani, Mariko; Sekiya, Toru; Harada, Junta; Kawakami, Kenji; Tada, Shimpei

    1985-01-01

    Twenty-two patients were examined to determine the clinical value of magnetic resonance imaging (MRI) in the spinal disease. Using different pulse sequences T 1 value was obtained from 38 spines; the result showed that increased T 1 value indicated spinal marrow abnormalities. A comparative study of MRI and bone scintigraphy was performed in 18 patients. Although it was not feasible to evaluate effect of therapy in metastatic disease by MRI, diffuse bone marrow disease, such as diffuse bone marrow metastases and blood dyscrasia could be detected by MRI. This limited study will suggest applicability of MRI in the spinal disease. (author)

  20. Sensorineural hearing loss after magnetic resonance imaging

    DEFF Research Database (Denmark)

    Mollasadeghi, Abolfazl; Mehrparvar, Amir Houshang; Atighechi, Saeid

    2013-01-01

    Magnetic resonance imaging (MRI) devices produce noise, which may affect patient's or operators' hearing. Some cases of hearing impairment after MRI procedure have been reported with different patterns (temporary or permanent, unilateral or bilateral, with or without other symptoms like tinnitus......). In this report, a case of bilateral sensorineural hearing loss in an otherwise healthy patient underwent brain MRI was described. The patient's hearing loss was accompanied with tinnitus and was not improved after 3 months of followup....

  1. Endovascular interventional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Bartels, L W; Bakker, C J G

    2003-01-01

    Minimally invasive interventional radiological procedures, such as balloon angioplasty, stent placement or coiling of aneurysms, play an increasingly important role in the treatment of patients suffering from vascular disease. The non-destructive nature of magnetic resonance imaging (MRI), its ability to combine the acquisition of high quality anatomical images and functional information, such as blood flow velocities, perfusion and diffusion, together with its inherent three dimensionality and tomographic imaging capacities, have been advocated as advantages of using the MRI technique for guidance of endovascular radiological interventions. Within this light, endovascular interventional MRI has emerged as an interesting and promising new branch of interventional radiology. In this review article, the authors will give an overview of the most important issues related to this field. In this context, we will focus on the prerequisites for endovascular interventional MRI to come to maturity. In particular, the various approaches for device tracking that were proposed will be discussed and categorized. Furthermore, dedicated MRI systems, safety and compatibility issues and promising applications that could become clinical practice in the future will be discussed. (topical review)

  2. Magnetic resonance imaging in complex partial seizures

    International Nuclear Information System (INIS)

    Furune, Sunao; Negoro, Tamiko; Maehara, Mitsuo; Nomura, Kazushi; Miura, Kiyokuni; Takahashi, Izumi; Watanabe, Kazuyoshi

    1989-01-01

    Magnetic resonance imaging (MRI) and computed tomography (CT) were performed on 45 patients with intractable complex partial seizures. MRI was performed with a superconducting whole-body scanner operating at 0.5 tesla (T) and 1.5 T. In patients with temporal lobe epilepsy, 8 of 24 patients had abnormal CT, but 16 or 24 patients showed abnormal MRI. 1.5 T MRI detected more abnormality than 0.5 T MRI when CT was normal. In patients with frontal lobe epilepsy, 5 of 7 patients had normal CT and MRI. In 2 other patients, MRI demonstrated an arachnoid cyst and increased signal intensity area on the T2-weighted images which were not detected by CT. In patients with occipital lobe epilepsy, 5 of 6 patients show abnormal CT and MRI. In patients with tuberous sclerosis, MRI revealed some increased signal intensity areas on the T2-weighted images in the occipital and temporal lobe, which were not detected by CT. Most surface EEG foci corresponded with the side of MRI abnormality. These data indicate that MRI is more informative than CT in complex partial seizures. MRI is the imaging technique of choice in the diagnosis of complex partial seizures. (author)

  3. Magnetic resonance imaging apparatus

    International Nuclear Information System (INIS)

    Ehnholm, G.J.

    1991-01-01

    This patent describes an electron spin resonance enhanced magnetic resonance (MR) imaging (ESREMRI) apparatus able to generate a primary magnetic field during periods of nuclear spin transition excitation and magnetic resonance signal detection. This allows the generation of ESREMRI images of a subject. A primary magnetic field of a second and higher value generated during periods of nuclear spin transition excitation and magnetic resonance signal detection can be used to generate conventional MR images of a subject. The ESREMRI and native MR images so generated may be combined, (or superimposed). (author)

  4. Functional magnetic resonance imaging (fMRI) in patients with gliomas adjacent to classical language areas. Lateralization of activated prefrontal cortex is important in determining the dominant hemisphere

    International Nuclear Information System (INIS)

    Karibe, Hiroshi; Kumabe, Toshihiro; Shirane, Reizo; Yoshimoto, Takashi

    2003-01-01

    In patients with gliomas adjacent to classical language areas, lateralized activation of prefrontal cortex was assessed to determine language dominant hemisphere using functional magnetic resonance imaging (fMRI). Twelve patients presented with aphasias were studied. In all patients, either the left frontal operculum or left superior temporal gyri were adjacent to gliomas, suggesting all patients had left lateralization in hemispheric language dominance. Functional MRI was performed with a 1.5T scanner, with the sequence of gradient-echo type echo-planar imaging. As specific language tasks, verb, word, and capping generations were used. Using a cross-correlation analysis method, primary activation maps were generated using pixels with a correlation coefficient of >0.7. The lateralized activation of frontal operculum, superior temporal gyrus, and prefrontal cortex were assessed by calculating laterality index. Successful activation of frontal operculum was imaged in 11 of 12, in the superior temporal gyrus or prefrontal cortex. Three out of 11 cases had apparent activation lateralized in the right frontal operculum on fMRI, while 3 out of 12 cases showed activation in the superior temporal gyrus. On the other hand, all cases had apparent activation lateralized to the left prefrontal cortex. Significant activation of true language area may not be obtained in some cases with gliomas adjacent to classical language areas. In such cases, lateralization of apparent activation of prefrontal cortex may reflect lateralization in the dominant hemisphere. These result suggest that the assessment of apparent activation of prefrontal cortex lateralization is useful to determine the language dominant hemisphere. (author)

  5. Usefulness of magnetic resonance imaging in diagnosis of varicocele

    International Nuclear Information System (INIS)

    Akiyama, Hironobu; Nagai, Atsushi; Ichikawa, Takaharu; Oeda, Tadashi; Nasu, Yasutomo; Ohmori, Hiroyuki; Togami, Izumi; Katoh, Katsuya; Hiraki, Yoshio

    1996-01-01

    Magnetic resonance imaging (MRI) was applied for diagnosis of varicocele testis. Twelve of fourteen patients with varicocele had positive findings on MRI. In addition, four of seven patients with clinically undetectable varicocele had positive findings on MRI. We think MRI is one of the useful means for detection of varicocele including subclinical form. (author)

  6. Improving the spatial accuracy in functional magnetic resonance imaging (fMRI) based on the blood oxygenation level dependent (BOLD) effect: benefits from parallel imaging and a 32-channel head array coil at 1.5 Tesla.

    Science.gov (United States)

    Fellner, C; Doenitz, C; Finkenzeller, T; Jung, E M; Rennert, J; Schlaier, J

    2009-01-01

    Geometric distortions and low spatial resolution are current limitations in functional magnetic resonance imaging (fMRI). The aim of this study was to evaluate if application of parallel imaging or significant reduction of voxel size in combination with a new 32-channel head array coil can reduce those drawbacks at 1.5 T for a simple hand motor task. Therefore, maximum t-values (tmax) in different regions of activation, time-dependent signal-to-noise ratios (SNR(t)) as well as distortions within the precentral gyrus were evaluated. Comparing fMRI with and without parallel imaging in 17 healthy subjects revealed significantly reduced geometric distortions in anterior-posterior direction. Using parallel imaging, tmax only showed a mild reduction (7-11%) although SNR(t) was significantly diminished (25%). In 7 healthy subjects high-resolution (2 x 2 x 2 mm3) fMRI was compared with standard fMRI (3 x 3 x 3 mm3) in a 32-channel coil and with high-resolution fMRI in a 12-channel coil. The new coil yielded a clear improvement for tmax (21-32%) and SNR(t) (51%) in comparison with the 12-channel coil. Geometric distortions were smaller due to the smaller voxel size. Therefore, the reduction in tmax (8-16%) and SNR(t) (52%) in the high-resolution experiment seems to be tolerable with this coil. In conclusion, parallel imaging is an alternative to reduce geometric distortions in fMRI at 1.5 T. Using a 32-channel coil, reduction of the voxel size might be the preferable way to improve spatial accuracy.

  7. Magnetic Resonance Imaging (MRI of Intratumoral Voxel Heterogeneity as a Potential Response Biomarker: Assessment in a HER2+ Esophageal Adenocarcinoma Xenograft Following Trastuzumab and/or Cisplatin Therapy

    Directory of Open Access Journals (Sweden)

    Connie Yip

    2017-06-01

    Full Text Available We evaluated magnetic resonance imaging (MRI voxel heterogeneity following trastuzumab and/or cisplatin in a HER2+ esophageal xenograft (OE19 as a potential response biomarker. OE19 xenografts treated with saline (controls, monotherapy, or combined cisplatin and trastuzumab underwent 9.4-T MRI. Tumor MRI parametric maps of T1 relaxation time (pre/post contrast, T2 relaxation time, T2* relaxation rate (R2*, and apparent diffusion coefficient obtained before (TIME0, after 24 hours (TIME1, and after 2 weeks of treatment (TIME2 were analyzed. Voxel histogram and fractal parameters (from the whole tumor, rim and center, and as a ratio of rim‐to‐center were derived. Tumors were stained for immunohistochemical markers of hypoxia (CA-IX, angiogenesis (CD34, and proliferation (Ki-67. Combination therapy reduced xenograft growth rate (relative change, ∆ +0.58 ± 0.43 versus controls, ∆ +4.1 ± 1.0; P = 0.008. More spatially homogeneous voxel distribution between the rim to center was noted after treatment for combination therapy versus controls, respectively, for contrast-enhanced T1 relaxation time (90th percentile: ratio 1.00 versus 0.88, P = 0.009, T2 relaxation time (mean: 1.00 versus 0.92, P = 0.006; median: 0.98 versus 0.91, P = 0.006; 75th percentile: 1.02 versus 0.94, P = 0.007, and R2* (10th percentile: 0.99 versus 1.26, P = 0.003. We found that combination and trastuzumab monotherapy reduced MRI spatial heterogeneity and growth rate compared to the control or cisplatin groups, the former providing adjunctive tumor response information.

  8. Reducing Field Distortion in Magnetic Resonance Imaging

    Science.gov (United States)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

    2010-01-01

    A concept for a magnetic resonance imaging (MRI) system that would utilize a relatively weak magnetic field provides for several design features that differ significantly from the corresponding features of conventional MRI systems. Notable among these features are a magnetic-field configuration that reduces (relative to the conventional configuration) distortion and blurring of the image, the use of a superconducting quantum interference device (SQUID) magnetometer as the detector, and an imaging procedure suited for the unconventional field configuration and sensor. In a typical application of MRI, a radio-frequency pulse is used to excite precession of the magnetic moments of protons in an applied magnetic field, and the decaying precession is detected for a short time following the pulse. The precession occurs at a resonance frequency proportional to the strengths of the magnetic field and the proton magnetic moment. The magnetic field is configured to vary with position in a known way; hence, by virtue of the aforesaid proportionality, the resonance frequency varies with position in a known way. In other words, position is encoded as resonance frequency. MRI using magnetic fields weaker than those of conventional MRI offers several advantages, including cheaper and smaller equipment, greater compatibility with metallic objects, and higher image quality because of low susceptibility distortion and enhanced spin-lattice-relaxation- time contrast. SQUID MRI is being developed into a practical MRI method for applied magnetic flux densities of the order of only 100 T

  9. Magnetic resonance imaging of the genitourinary tract

    International Nuclear Information System (INIS)

    Strake, L. te; Persijn van Meerten, E.L. van; Trimbos, J.B.M.Z.; Paul, L.C.; Langeveld, J.W.; Bloem, J.L.; Bluemm, R.G.; Doornbos, J.

    1986-01-01

    This is an overview of the current applications of magnetic resonance imaging (MRI) in the genitourinary tract based on the experience with the 0.5-Tesla MR scanner (Gyroscan, Philips) at the Leiden University Hospital and on reports in the literature. MRI appears to share some of the limitations of CT. MRI cannot reliably differentiate between a malignant and a benign tumor. In the staging of ovarian malignancies by means of MRI, bowel preparation would be desirable. On the other hand, the soft-tissue contrast resolution of MRI is superior to that of CT and images can be obtained in any plane. Thus MRI promises to be an accurate method for staging malignancies. The results in the examination of transplant kidneys are encouraging. It is expected that there will be a place for MRI as a complementary technique to ultrasonography in the diagnosis of scrotal disease. (Auth.)

  10. Olfactometer for functional resonance imaging

    International Nuclear Information System (INIS)

    Andrieu, Patrice

    2013-01-01

    The Magnetic Resonance Imaging (fMRI) has been developing for twenty years. Indeed, the marketing of high-resolution MRI (5 Tesla and 7 Tesla recently) allowed the study of brain mechanisms. The research work of this PHD was to develop instrumentation for objective studies of brain behavior during a sensory stimulation. We are interested in the study of olfaction. We have designed and built a six-channel olfactometer, synchronized with breathing and controlled by computer. The originality of our work lies in the modularity of our device, which makes it adaptable to a wide range of studies. We also propose a new method to change the intensity of stimulation delivered: the Pulse Width Modulation (PWM). This device has been used in several studies in fMRI. The effectiveness of the PWM is highlighted in a psychophysical study described in this manuscript. (author)

  11. Fully automatic, multiorgan segmentation in normal whole body magnetic resonance imaging (MRI), using classification forests (CFs), convolutional neural networks (CNNs), and a multi-atlas (MA) approach.

    Science.gov (United States)

    Lavdas, Ioannis; Glocker, Ben; Kamnitsas, Konstantinos; Rueckert, Daniel; Mair, Henrietta; Sandhu, Amandeep; Taylor, Stuart A; Aboagye, Eric O; Rockall, Andrea G

    2017-10-01

    As part of a program to implement automatic lesion detection methods for whole body magnetic resonance imaging (MRI) in oncology, we have developed, evaluated, and compared three algorithms for fully automatic, multiorgan segmentation in healthy volunteers. The first algorithm is based on classification forests (CFs), the second is based on 3D convolutional neural networks (CNNs) and the third algorithm is based on a multi-atlas (MA) approach. We examined data from 51 healthy volunteers, scanned prospectively with a standardized, multiparametric whole body MRI protocol at 1.5 T. The study was approved by the local ethics committee and written consent was obtained from the participants. MRI data were used as input data to the algorithms, while training was based on manual annotation of the anatomies of interest by clinical MRI experts. Fivefold cross-validation experiments were run on 34 artifact-free subjects. We report three overlap and three surface distance metrics to evaluate the agreement between the automatic and manual segmentations, namely the dice similarity coefficient (DSC), recall (RE), precision (PR), average surface distance (ASD), root-mean-square surface distance (RMSSD), and Hausdorff distance (HD). Analysis of variances was used to compare pooled label metrics between the three algorithms and the DSC on a 'per-organ' basis. A Mann-Whitney U test was used to compare the pooled metrics between CFs and CNNs and the DSC on a 'per-organ' basis, when using different imaging combinations as input for training. All three algorithms resulted in robust segmenters that were effectively trained using a relatively small number of datasets, an important consideration in the clinical setting. Mean overlap metrics for all the segmented structures were: CFs: DSC = 0.70 ± 0.18, RE = 0.73 ± 0.18, PR = 0.71 ± 0.14, CNNs: DSC = 0.81 ± 0.13, RE = 0.83 ± 0.14, PR = 0.82 ± 0.10, MA: DSC = 0.71 ± 0.22, RE = 0.70 ± 0.34, PR = 0.77 ± 0.15. Mean surface distance

  12. Magnetic resonance imaging and neurolupus

    International Nuclear Information System (INIS)

    Schott, A.M.; Colson, F.; Tebib, J.; Noel, E.; Bouvier, M.

    1990-01-01

    Magnetic resonance imaging (MRI) was assessed in the management of neuropsychiatric manifestations occurring in 6 SLE patients. The MRI scans were normal in 3 cases and was associated with remission of the symptoms except for a patient who experienced a chorea at the time of the examination. Abnormal MRI scans always revealed more lesions than CT scan. 2 different patterns of abnormalities seem to correspond to 2 specific disorders. In 2 patients with clinical presentation suggesting a cortical ischemia by vascular thrombosis, both MRI scans showed areas of abnormal high signal intensities located in the subcortical white matter. In one last patient, MRI scan revealed multiple focal areas of high signal intensities (on T 1 weighter scans) disseminated not only in the deep white matter but also in the gray one. These lesions could be depend upon demyelinisation which may occur by a local vascular process. This serie confirms the interest of MRI in the management of SLE brain involvement as well as it points out some problem of interpretation. This suggest further comparative studies especially at the real onset and during the course of neuro-psychiatric manifestations. At last, the coronal sections may be more informative for the diagnosis and patholophysiology than the horizontal ones [fr

  13. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... or patients with claustrophobia. Other MRI machines are open on the sides (open MRI). Open units are especially helpful for examining larger patients or those with claustrophobia. Newer open MRI units provide very high quality images for ...

  14. Magnetic resonance imaging (MRI) of liver and brain in haematologic-organic patients with fever of unknown origin

    International Nuclear Information System (INIS)

    Heussel, C.P.; Kauczor, H.U.; Poguntke, M.; Schadmand-Fischer, S.; Mildenberger, P.; Thelen, M.; Heussel, G.

    1998-01-01

    To examine the advantage of liver and brain MRI in clinically anomalous haematological patients with fever of unknown origin. Material and Methods: Twenty liver MRI (T 2 -TSE, T 2 -HASTE, T 1 -FLASH±Gd dynamic) and 16 brain MRI (T 2 -TSE, FLAIR, T 1 -TSE±Gd) were performed searching for a focus of fever with a suspected organ system. Comparison with clinical follow-up. Results: suspected organ system. Comparison with clinical follow-up. Results: A focus was detected in 11/20 liver MRI. Candidiasis (n=3), mycobacteriosis (n=2), relapse of haematological disease (n=3), graft versus host disease (n=1), non-clarified (n=2). The remaining 9 cases with normal MRI were not suspicious of infectious hepatic disease during follo-wup. In brain MRI, 3/16 showed a focus (toxoplasmosis, aspergillosis, mastoiditis). Clinical indication for an infectious involvement of the brain was found in 4/16 cases 2--5 months after initially normal brain MRI. No suspicion of an infectious involvement of brain was present in the remaining 9/16 cases. Conclusion: In case of fever of unknown origin and suspicion of liver involvement, MRI of the liver should be performed due to data given in literature and its sensitivity of 100%. Because of the delayed detectability of cerebral manifestations, in cases of persisting suspicion even a previously normal MRI of the brain should be repeated. (orig.) [de

  15. Discrepancy between morphological findings in juvenile osteochondritis dissecans (OCD): a comparison of magnetic resonance imaging (MRI) and arthroscopy.

    Science.gov (United States)

    Roßbach, Björn Peter; Paulus, Alexander Christoph; Niethammer, Thomas Richard; Wegener, Veronika; Gülecyüz, Mehmet Fatih; Jansson, Volkmar; Müller, Peter Ernst; Utzschneider, Sandra

    2016-04-01

    The aim of this study was to assess the reliability of preoperative MRI for the staging of osteochondritis dissecans (OCD) lesions of the knee and the talus in juvenile patients, using arthroscopy as the gold standard of diagnosis. Sixty-three juvenile patients (range 8-16 years) with an OCD of the knee or the talus underwent arthroscopy after MRI. In 54/9 out of 63 cases, 1.5/3 T MR scanners were used. The OCD stage was classified according the staging criteria of Dipaola et al. Arthroscopic findings were compared with MRI reports in each patient. From the 63 juvenile patients, MRI/arthroscopy revealed a stage I OCD in 4/19 patients, stage II in 31/22 patients, stage III in 22/9 patients and stage IV in 6/6 patients. No osteochondral pathology was evident in arthroscopy in seven out of 63 patients. The overall accuracy of preoperative MRI in staging an OCD lesion of the knee or the talus was 41.3%. In 33 out of 63 patients (52.4%), arthroscopy revealed a lower OCD stage than in the preoperative MRI grading, and in four out of 63 cases (6.4%), the intraoperative arthroscopic grading was worse than in preoperative MRI prior to surgery. The utilization of the 3 T MRI provided a correct diagnosis with 44.4%. Even with today's modern MRI scanners, it is not possible to predict an accurate OCD stage in children. The children's orthopaedist should not solely rely on the MRI when it comes to the decision to further conservative or surgical treatment of a juvenile OCD, but rather should take surgical therapy in consideration within persisting symptoms despite a low OCD stage provided by MRI. III.

  16. Magnetic resonance imaging of chemistry.

    Science.gov (United States)

    Britton, Melanie M

    2010-11-01

    Magnetic resonance imaging (MRI) has long been recognized as one of the most important tools in medical diagnosis and research. However, MRI is also well placed to image chemical reactions and processes, determine the concentration of chemical species, and look at how chemistry couples with environmental factors, such as flow and heterogeneous media. This tutorial review will explain how magnetic resonance imaging works, reviewing its application in chemistry and its ability to directly visualise chemical processes. It will give information on what resolution and contrast are possible, and what chemical and physical parameters can be measured. It will provide examples of the use of MRI to study chemical systems, its application in chemical engineering and the identification of contrast agents for non-clinical applications. A number of studies are presented including investigation of chemical conversion and selectivity in fixed-bed reactors, temperature probes for catalyst pellets, ion mobility during tablet dissolution, solvent dynamics and ion transport in Nafion polymers and the formation of chemical waves and patterns.

  17. Sensorineural hearing loss after magnetic resonance imaging

    DEFF Research Database (Denmark)

    Mollasadeghi, Abolfazl; Mehrparvar, Amir Houshang; Atighechi, Saeid

    2013-01-01

    Magnetic resonance imaging (MRI) devices produce noise, which may affect patient's or operators' hearing. Some cases of hearing impairment after MRI procedure have been reported with different patterns (temporary or permanent, unilateral or bilateral, with or without other symptoms like tinnitus)......). In this report, a case of bilateral sensorineural hearing loss in an otherwise healthy patient underwent brain MRI was described. The patient's hearing loss was accompanied with tinnitus and was not improved after 3 months of followup.......Magnetic resonance imaging (MRI) devices produce noise, which may affect patient's or operators' hearing. Some cases of hearing impairment after MRI procedure have been reported with different patterns (temporary or permanent, unilateral or bilateral, with or without other symptoms like tinnitus...

  18. Magnetic resonance imaging (MRI) as a tool for the assessment of disease activity in multiple sclerosis (MS)

    International Nuclear Information System (INIS)

    Paty, D.W.; Willoughby, E.W.; Koopmans, R.A.; Oger, J.F.J.; Li, D.K.B.

    1990-01-01

    The results are discussed of systematic serial MRI examinations in selected patients. A computer assisted method of quantitation of MS lesions with MRI, based upon pathological correlation studies (performed earlier by one of the authors), was used ion assessment the (total) burden of desease. (H.W.) 14 refs.; 1 tab

  19. Evaluation of an image-based tracking workflow using a passive marker and resonant micro-coil fiducials for automatic image plane alignment in interventional MRI.

    Science.gov (United States)

    Neumann, M; Breton, E; Cuvillon, L; Pan, L; Lorenz, C H; de Mathelin, M

    2012-01-01

    In this paper, an original workflow is presented for MR image plane alignment based on tracking in real-time MR images. A test device consisting of two resonant micro-coils and a passive marker is proposed for detection using image-based algorithms. Micro-coils allow for automated initialization of the object detection in dedicated low flip angle projection images; then the passive marker is tracked in clinical real-time MR images, with alternation between two oblique orthogonal image planes along the test device axis; in case the passive marker is lost in real-time images, the workflow is reinitialized. The proposed workflow was designed to minimize dedicated acquisition time to a single dedicated acquisition in the ideal case (no reinitialization required). First experiments have shown promising results for test-device tracking precision, with a mean position error of 0.79 mm and a mean orientation error of 0.24°.

  20. The value of magnetic resonance imaging and ultrasonography (MRI/US)-fusion biopsy platforms in prostate cancer detection: a systematic review.

    Science.gov (United States)

    Gayet, Maudy; van der Aa, Anouk; Beerlage, Harrie P; Schrier, Bart Ph; Mulders, Peter F A; Wijkstra, Hessel

    2016-03-01

    Despite limitations considering the presence, staging and aggressiveness of prostate cancer, ultrasonography (US)-guided systematic biopsies (SBs) are still the 'gold standard' for the diagnosis of prostate cancer. Recently, promising results have been published for targeted prostate biopsies (TBs) using magnetic resonance imaging (MRI) and ultrasonography (MRI/US)-fusion platforms. Different platforms are USA Food and Drug Administration registered and have, mostly subjective, strengths and weaknesses. To our knowledge, no systematic review exists that objectively compares prostate cancer detection rates between the different platforms available. To assess the value of the different MRI/US-fusion platforms in prostate cancer detection, we compared platform-guided TB with SB, and other ways of MRI TB (cognitive fusion or in-bore MR fusion). We performed a systematic review of well-designed prospective randomised and non-randomised trials in the English language published between 1 January 2004 and 17 February 2015, using PubMed, Embase and Cochrane Library databases. Search terms included: 'prostate cancer', 'MR/ultrasound(US) fusion' and 'targeted biopsies'. Extraction of articles was performed by two authors (M.G. and A.A.) and were evaluated by the other authors. Randomised and non-randomised prospective clinical trials comparing TB using MRI/US-fusion platforms and SB, or other ways of TB (cognitive fusion or MR in-bore fusion) were included. In all, 11 of 1865 studies met the inclusion criteria, involving seven different fusion platforms and 2626 patients: 1119 biopsy naïve, 1433 with prior negative biopsy, 50 not mentioned (either biopsy naïve or with prior negative biopsy) and 24 on active surveillance (who were disregarded). The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool was used to assess the quality of included articles. No clear advantage of MRI/US fusion-guided TBs was seen for cancer detection rates (CDRs) of all prostate

  1. Chest magnetic resonance imaging: a protocol suggestion

    Directory of Open Access Journals (Sweden)

    Bruno Hochhegger

    2015-12-01

    Full Text Available Abstract In the recent years, with the development of ultrafast sequences, magnetic resonance imaging (MRI has been established as a valuable diagnostic modality in body imaging. Because of improvements in speed and image quality, MRI is now ready for routine clinical use also in the study of pulmonary diseases. The main advantage of MRI of the lungs is its unique combination of morphological and functional assessment in a single imaging session. In this article, the authors review most technical aspects and suggest a protocol for performing chest MRI. The authors also describe the three major clinical indications for MRI of the lungs: staging of lung tumors; evaluation of pulmonary vascular diseases; and investigation of pulmonary abnormalities in patients who should not be exposed to radiation.

  2. Multiparametric and molecular imaging of breast tumors with MRI and PET/MRI

    International Nuclear Information System (INIS)

    Pinker, K.; Marino, M.A.; Meyer-Baese, A.; Helbich, T.H.

    2016-01-01

    Magnetic resonance imaging (MRI) of the breast is an indispensable tool in breast imaging for many indications. Several functional parameters with MRI and positron emission tomography (PET) have been assessed for imaging of breast tumors and their combined application is defined as multiparametric imaging. Available data suggest that multiparametric imaging using different functional MRI and PET parameters can provide detailed information about the hallmarks of cancer and may provide additional specificity. Multiparametric and molecular imaging of the breast comprises established MRI parameters, such as dynamic contrast-enhanced MRI, diffusion-weighted imaging (DWI), MR proton spectroscopy ( 1 H-MRSI) as well as combinations of radiological and MRI techniques (e.g. PET/CT and PET/MRI) using radiotracers, such as fluorodeoxyglucose (FDG). Multiparametric and molecular imaging of the breast can be performed at different field-strengths (range 1.5-7 T). Emerging parameters comprise novel promising techniques, such as sodium imaging ( 23 Na MRI), phosphorus spectroscopy ( 31 P-MRSI), chemical exchange saturation transfer (CEST) imaging, blood oxygen level-dependent (BOLD) and hyperpolarized MRI as well as various specific radiotracers. Multiparametric and molecular imaging has multiple applications in breast imaging. Multiparametric and molecular imaging of the breast is an evolving field that will enable improved detection, characterization, staging and monitoring for personalized medicine in breast cancer. (orig.) [de

  3. 76 FR 58281 - Magnetic Resonance Imaging Safety; Public Workshop

    Science.gov (United States)

    2011-09-20

    ...] Magnetic Resonance Imaging Safety; Public Workshop AGENCY: Food and Drug Administration, HHS. ACTION... announcing a public workshop entitled: ``Magnetic Resonance Imaging (MRI) Safety Public Workshop.'' The purpose of the public workshop is to discuss factors affecting the safe use of magnetic resonance imaging...

  4. On the characterization of single-event related brain activity from functional Magnetic Resonance Imaging (fMRI) measurements

    KAUST Repository

    Khoram, Nafiseh; Zayane, Chadia; Laleg-Kirati, Taous-Meriem; Djellouli, Rabia

    2014-01-01

    We propose an efficient numerical technique for calibrating the mathematical model that describes the singleevent related brain response when fMRI measurements are given. This method employs a regularized Newton technique in conjunction with a

  5. [Dobutamine stress magnetic resonance imaging (DS-MRI), a valuable tool for the diagnosis of ischemic heart disease].

    Science.gov (United States)

    van Dijkman, P R M; Kuijpers, Th J A; Blom, B M; van Herpen, G

    2002-07-13

    Assessment of the clinical applicability of DS-MRI for the detection of myocardial ischemia and myocardial viability. Prospective. In the period from 1 November 1999 to 31 October 2000, patients with suspected coronary artery disease who could not be studied by means of conventional bicycle ergometry underwent breath-hold DS-MRI (1 Tesla) 4 days after cessation of anti-ischemic medication. Three left ventricular short-axis planes were examined for the occurrence of disorders in wall movement during infusion of increasing doses of dobutamine (10, 20, 30 and 40 micrograms/kg/min). Temporary recovery of wall thickening in a previously diminished or non-contracting segment under 5 micrograms/kg/min of dobutamine was considered proof of viability. Development of hypo-, a- or dyskinesia at higher doses of dobutamine was taken to indicate ischemia. If the DS-MRI test was positive for ischemia, coronary angiography was performed. If indicated, this was followed by revascularisation. If DS-MRI did not reveal ischemia, the patient was seen at the outpatient department. Of the 100 patients (62 men and 38 women with an average age of 62 years, SD = 12) subjected to DS-MRI, 95 yielded results that were suitable for diagnosis. Of the 42 patients with DS-MRI scans that were considered positive for ischemia and in whom coronary angiography was subsequently performed, 41 had such coronary abnormalities that revascularisation was indicated. One patient was false-positive. All 53 patients with non-ischemic DS-MRI scans were followed-up for 11-23 months (mean 17 months). One patient died suddenly 2 weeks after the MRI-test. The other 52 patients did not experience any coronary events nor sudden cardiac death. The predictive value of a positive DS-MRI scan for ischemia was 98% and the predictive value of a negative DS-MRI scan was also 98%. DS-MRI is a safe diagnostic method for the detection or exclusion of myocardial ischemia and viability in patients with suspected coronary artery

  6. Magnetic resonance imaging in cardiovascular disease

    International Nuclear Information System (INIS)

    Eckel, C.G.; Mettler, F.A. Jr.; Wicks, J.D.; Stevens, G.F.

    1986-01-01

    How does magnetic resonance imaging (MRI) currently contribute in the evaluation of patients with suspected heart disease? What role will MRI play in the future in evaluation of cardiovascular disease? To understand better where MRI fits into the diagnostic algorithm of cardiovascular disease the authors first consider the characteristics that they would like to see in the ideal diagnostic test and then survey the available cardiac diagnostic tests to note the characteristics that limit or recommend a test. In the final analysis, the justification for expensive diagnostic tests such as MRI must be an overall improvement in survival or quality of life in those patients treated after diagnosis

  7. Fetal magnetic resonance imaging and human genetics

    International Nuclear Information System (INIS)

    Hengstschlaeger, Markus

    2006-01-01

    The use of fetal magnetic resonance imaging (MRI), in addition to prenatal genetic testing and sonography, has the potential to improve prenatal diagnosis of genetic disorders. MRI plays an important role in the evaluation of fetal abnormalities and malformations. Fetal MRI often enables a differential diagnosis, a determination of the extent of the disorder, the prognosis, and an improvement in therapeutic management. For counseling of parents, as well as to basically understand how genetic aberrations affect fetal development, it is of great importance to correlate different genotypes with fetal MRI data

  8. Fetal magnetic resonance imaging and human genetics

    Energy Technology Data Exchange (ETDEWEB)

    Hengstschlaeger, Markus [Medical Genetics, Obstetrics and Gynecology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria)]. E-mail: markus.hengstschlaeger@meduniwien.ac.at

    2006-02-15

    The use of fetal magnetic resonance imaging (MRI), in addition to prenatal genetic testing and sonography, has the potential to improve prenatal diagnosis of genetic disorders. MRI plays an important role in the evaluation of fetal abnormalities and malformations. Fetal MRI often enables a differential diagnosis, a determination of the extent of the disorder, the prognosis, and an improvement in therapeutic management. For counseling of parents, as well as to basically understand how genetic aberrations affect fetal development, it is of great importance to correlate different genotypes with fetal MRI data.

  9. Magnetic resonance imaging of unicornuate uterus

    Energy Technology Data Exchange (ETDEWEB)

    Fedele, L.; Dorta, M.; Brioschi, D.; Giudici, M.N.; Villa, L. (1st Dept. of Obstetrics and Gynecology, Univ. of Milan (Italy))

    1990-01-01

    Five patient with a hysterosalpingographic diagnosis of unicornuate uterus underwent resonance imaging (MRI) and subsequently laparoscopy/laparotomy to evaluate the ability of MRI to identify the various subclasses of this malformation. The method was demonstrated to be valid, since in all 5 cases (one subclass A1b, two subclass B) were correctly diagnosed. Compared with laparoscopy, MRI is less expensive, less invasive, and can be performed in women in whom laparoscopic examination is risky. However, unlike laparoscopy, MRI can not detect the presence of minimal and mild endometriosis and does not allow assessment of the tubal conditions. (au).

  10. On the characterization of single-event related brain activity from functional Magnetic Resonance Imaging (fMRI) measurements

    KAUST Repository

    Khoram, Nafiseh

    2014-08-01

    We propose an efficient numerical technique for calibrating the mathematical model that describes the singleevent related brain response when fMRI measurements are given. This method employs a regularized Newton technique in conjunction with a Kalman filtering procedure. We have applied this method to estimate the biophysiological parameters of the Balloon model that describes the hemodynamic brain responses. Illustrative results obtained with both synthetic and real fMRI measurements are presented. © 2014 IEEE.

  11. Predictive values of BI-RADS® magnetic resonance imaging (MRI) in the detection of breast ductal carcinoma in situ (DCIS)

    International Nuclear Information System (INIS)

    Badan, Gustavo Machado; Piato, Sebastião; Roveda, Décio; Faria Castro Fleury, Eduardo de

    2016-01-01

    Purpose: The purpose of this study was to evaluate BI-RADS indicators in the detection of DCIS by MRI. Materials and methods: Prospective observational study that started in 2014 and lasted 24 months. A total of 110 consecutive patients were evaluated, who presented with suspicious or highly suspicious microcalcifications on screening mammography (BI-RADS categories 4 and 5) and underwent stereotactic-guided breast biopsy, having had an MRI scan performed prior to biopsy. Results: Altogether, 38 cases were characterized as positive for malignancy, of which 25 were DCIS and 13 were invasive ductal carcinoma cases. MRI had a sensitivity of 96%; specificity of 75.67%; positive predictive value (PPV) for DCIS detection of 57.14%; negative predictive value (NPV) in the detection of DCIS of 98.24%; and an accuracy of 80.80%. Conclusion: BI-RADS as a tool for the detection of DCIS by MRI is a powerful instrument whose sensitivity was higher when compared to that observed for mammography in the literature. Likewise, the PPV obtained by MRI was higher than that observed in the present study for mammography, and the high NPV obtained on MRI scans can provide early evidence to discourage breast biopsy in selected cases.

  12. Automated Segmentation of Cardiac Magnetic Resonance Images

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Nilsson, Jens Chr.; Grønning, Bjørn A.

    2001-01-01

    Magnetic resonance imaging (MRI) has been shown to be an accurate and precise technique to assess cardiac volumes and function in a non-invasive manner and is generally considered to be the current gold-standard for cardiac imaging [1]. Measurement of ventricular volumes, muscle mass and function...

  13. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... identify and accurately characterize diseases than other imaging methods. This detail makes MRI an invaluable tool in ... might be obscured by bone with other imaging methods. The contrast material used in MRI exams is ...

  14. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... claustrophobia. Newer open MRI units provide very high quality images for many types of exams; however, older ... MRI units may not provide this same image quality. Certain types of exams cannot be performed using ...

  15. Remote viewing with the artist Ingo Swann: neuropsychological profile, electroencephalographic correlates, magnetic resonance imaging (MRI), and possible mechanisms.

    Science.gov (United States)

    Persinger, M A; Roll, W G; Tiller, S G; Koren, S A; Cook, C M

    2002-06-01

    In the present study, the artist Ingo Swann, who helped develop the process of remote viewing (awareness of distant objects or places without employing normal senses), was exposed during a single setting of 30 min. to specific patterns of circumcerebral magnetic fields that significantly altered his subjective experiences. Several times during subsequent days, he was asked to sit in a quiet chamber and to sketch and to describe verbally distant stimuli (pictures or places) beyond his normal senses. The proportions of unusual 7-Hz spike and slow wave activity over the occipital lobes per trial were moderately correlated (rho=.50) with the ratings of accuracy between these distal, hidden stimuli and his responses. A neuropsychological assessment and Magnetic Resonance Imaging indicated a different structural and functional organization within the parieto-occipital region of the subject's right hemisphere from organizations typically noted. The results suggest that this type of paranormal phenomenon, often dismissed as methodological artifact or accepted as proofs of spiritual existence, is correlated with neurophysiological processes and physical events. Remote viewing may be enhanced by complex experimentally generated magnetic fields designed to interact with the neuromagnetic "binding factor" of consciousness.

  16. Structural magnetic resonance imaging in epilepsy

    International Nuclear Information System (INIS)

    Deblaere, Karel; Achten, Eric

    2008-01-01

    Because of its sensitivity and high tissue contrast, magnetic resonance imaging (MRI) is the technique of choice for structural imaging in epilepsy. In this review the effect of using optimised scanning protocols and the use of high field MR systems on detection sensitivity is discussed. Also, the clinical relevance of adequate imaging in patients with focal epilepsy is highlighted. The most frequently encountered MRI findings in epilepsy are reported and their imaging characteristics depicted. Imaging focus will be on the diagnosis of hippocampal sclerosis and malformations of cortical development, two major causes of medically intractable focal epilepsy. (orig.)

  17. Structural magnetic resonance imaging in epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Deblaere, Karel [Ghent University Hospital, Department of Neuroradiology, Ghent (Belgium); Ghent University Hospital, MR Department - 1K12, Ghent (Belgium); Achten, Eric [Ghent University Hospital, Department of Neuroradiology, Ghent (Belgium)

    2008-01-15

    Because of its sensitivity and high tissue contrast, magnetic resonance imaging (MRI) is the technique of choice for structural imaging in epilepsy. In this review the effect of using optimised scanning protocols and the use of high field MR systems on detection sensitivity is discussed. Also, the clinical relevance of adequate imaging in patients with focal epilepsy is highlighted. The most frequently encountered MRI findings in epilepsy are reported and their imaging characteristics depicted. Imaging focus will be on the diagnosis of hippocampal sclerosis and malformations of cortical development, two major causes of medically intractable focal epilepsy. (orig.)

  18. Interventional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Debatin, J.F.; Adam, G.

    1998-01-01

    With the advent of open configuration MR imaging systems, the vision of MRI-based guidance, control, and monitoring of minimally invasive interventions has evolved from a hypothetical concept to a practical possibility. This book provides a comprehensive overview of the very exciting emerging field of interventional MRI. The international authorship provides firsthand experience of all relevant topics. This book will familiarize the reader with the basic principles underlying currently available hardware and software configurations. In addition, technical aspects of thermosensitive imaging, techniques for instrument visualization, and safety aspects are covered. Finally, the book emphasizes both existing and future clinical applications. (orig.)

  19. FDG-PET in the diagnosis of neuropsychiatric Lupus erythematosus and comparison with computed tomography and magnetic resonance imaging. Einsatz der FDG-PET bei der Diagnostik des zentralnervoesen Lupus erythematodes und Vergleich mit CT und MRI

    Energy Technology Data Exchange (ETDEWEB)

    Stoppe, G [Medizinische Hochschule Hannover (Germany, F.R.). Neurologische Klinik mit Klinischer Neurophysiologie; Wildhagen, K [Medizinische Hochschule Hannover (Germany, F.R.). Abt. Immunologie und Transfusionsmedizin; Meyer, G J [Medizinische Hochschule Hannover (Germany, F.R.). Abt. Nuklearmedizin und Spezielle Biophysik; Schober, O [Muenster Univ. (Germany, F.R.). Klinik und Poliklinik fuer Nuklearmedizin

    1989-10-01

    Central nervous system involvement has been found in 30-75% of all cases of systemic lupus erythematosus (SLE). Up to now, clinical diagnosis is difficult and there are no markers for disease activity. We have compared cranial computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) using fluorodesoxyglucose (FDG) in two cases. FDG-PET is shown to be the most sensitive method demonstrating even reversible deficits and a better correlation with other neurological findings. MRI seems to be more sensitive than CT. A survey of the literature concerning imaging methods in neuropsychiatric SLE is given. The special problem of neuronal desactivation by antineuronal activity is discussed. (orig.).

  20. N-Terminal pro-Brain Natriuretic Peptide and Associations With Brain Magnetic Resonance Imaging (MRI Features in Middle Age: The CARDIA Brain MRI Study

    Directory of Open Access Journals (Sweden)

    Ian T. Ferguson

    2018-05-01

    Full Text Available ObjectiveAs part of research on the heart–brain axis, we investigated the association of N-terminal pro-brain natriuretic peptide (NT-proBNP with brain structure and function in a community-based cohort of middle-aged adults from the Brain Magnetic Resonance Imaging sub-study of the Coronary Artery Risk Development in Young Adults (CARDIA Study.Approach and resultsIn a cohort of 634 community-dwelling adults with a mean (range age of 50.4 (46–52 years, we examined the cross-sectional association of NT-proBNP to total, gray (GM and white matter (WM volumes, abnormal WM load and WM integrity, and to cognitive function tests [the Digit Symbol Substitution Test (DSST, the Stroop test, and the Rey Auditory–Verbal Learning Test]. These associations were examined using linear regression models adjusted for demographic and cardiovascular risk factors and cardiac output. Higher NT-proBNP concentration was significantly associated with smaller GM volume (β = −3.44; 95% CI = −5.32, −0.53; p = 0.003, even after additionally adjusting for cardiac output (β = −2.93; 95% CI = −5.32, −0.53; p = 0.017. Higher NT-proBNP levels were also associated with lower DSST scores. NT-proBNP was not related to WM volume, WM integrity, or abnormal WM load.ConclusionIn this middle-aged cohort, subclinical levels of NT-proBNP were related to brain function and specifically to GM and not WM measures, extending similar findings in older cohorts. Further research is warranted into biomarkers of cardiac dysfunction as a target for early markers of a brain at risk.

  1. Magnetic resonance imaging

    International Nuclear Information System (INIS)

    Robertson, Angus

    1990-01-01

    An assessment is made of the clinical benefits of expensive diagnostic technology, such as the magnetic resonance imaging. It is concluded that to most radiologists, magnetic resonance imaging has a definite place in the diagnostic scenario, especially for demonstrating central nervous system lesions in multiple sclerosis. While it is recognized that medical and financial resources are limited, it is emphasised that the cost to society must be balanced against the patient benefit. 17 refs

  2. New magnetic resonance imaging methods in nephrology

    Science.gov (United States)

    Zhang, Jeff L.; Morrell, Glen; Rusinek, Henry; Sigmund, Eric; Chandarana, Hersh; Lerman, Lilach O.; Prasad, Pottumarthi Vara; Niles, David; Artz, Nathan; Fain, Sean; Vivier, Pierre H.; Cheung, Alfred K.; Lee, Vivian S.

    2013-01-01

    Established as a method to study anatomic changes, such as renal tumors or atherosclerotic vascular disease, magnetic resonance imaging (MRI) to interrogate renal function has only recently begun to come of age. In this review, we briefly introduce some of the most important MRI techniques for renal functional imaging, and then review current findings on their use for diagnosis and monitoring of major kidney diseases. Specific applications include renovascular disease, diabetic nephropathy, renal transplants, renal masses, acute kidney injury and pediatric anomalies. With this review, we hope to encourage more collaboration between nephrologists and radiologists to accelerate the development and application of modern MRI tools in nephrology clinics. PMID:24067433

  3. Magnetic resonance imaging of popliteal artery pathologies

    International Nuclear Information System (INIS)

    Holden, Andrew; Merrilees, Stephen; Mitchell, Nicola; Hill, Andrew

    2008-01-01

    This paper illustrates examples of popliteal artery pathologies imaged with contrast enhanced magnetic resonance angiography (CE-MRA) and magnetic resonance imaging (MRI) at a single tertiary referral centre. Popliteal artery pathologies were identified in 1710 patients referred over a 6-year period with symptoms suggesting lower limb arterial occlusive disease. Common pathologies such as atherosclerotic occlusive disease, thromboemboli and aneurysm disease are discussed as well as unusual pathologies such as cystic adventitial disease, mycotic aneurysm and arterial entrapment. The combination of CE-MRA and the excellent soft tissue resolution of MRI allow detailed evaluation of arterial and peri-arterial pathologies, and facilitate appropriate management decisions

  4. Magnetic resonance imaging of popliteal artery pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Holden, Andrew [Department of Radiology, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: andrewh@adhb.govt.nz; Merrilees, Stephen [Department of Radiology, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: smerrilees@adhb.govt.nz; Mitchell, Nicola [Department of Radiology, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: nmit010@ec.auckland.ac.nz; Hill, Andrew [Department of Vascular Surgery, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: ahill@adhb.govt.nz

    2008-07-15

    This paper illustrates examples of popliteal artery pathologies imaged with contrast enhanced magnetic resonance angiography (CE-MRA) and magnetic resonance imaging (MRI) at a single tertiary referral centre. Popliteal artery pathologies were identified in 1710 patients referred over a 6-year period with symptoms suggesting lower limb arterial occlusive disease. Common pathologies such as atherosclerotic occlusive disease, thromboemboli and aneurysm disease are discussed as well as unusual pathologies such as cystic adventitial disease, mycotic aneurysm and arterial entrapment. The combination of CE-MRA and the excellent soft tissue resolution of MRI allow detailed evaluation of arterial and peri-arterial pathologies, and facilitate appropriate management decisions.

  5. MRI of the Chest

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Chest Magnetic resonance imaging (MRI) ... clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in ...

  6. Investigation of water mobility and diffusivity in hydrating micronized low-substituted hydroxypropyl cellulose, hydroxypropylmethyl cellulose, and hydroxypropyl cellulose matrix tablets by magnetic resonance imaging (MRI).

    Science.gov (United States)

    Kojima, Masazumi; Nakagami, Hiroaki

    2002-12-01

    The water mobility and diffusivity in the gel-layer of hydrating low-substituted hydroxypropyl cellulose (LH41) tablets with or without a drug were investigated by magnetic resonance imaging (MRI) and compared with those properties in the gel-layer of hydroxypropylmethyl cellulose (HPMC) and hydroxypropyl cellulose (HPC) tablets. For this purpose, a localized image-analysis method was newly developed, and the spin-spin relaxation time (T(2)) and apparent self-diffusion coefficient (ADC) of water in the gel-layer were visualized in one-dimensional maps. Those maps showed that the extent of gel-layer growth in the tablets was in the order of HPC>HPMC>LH41, and there was a water mobility gradient across the gel-layers of all three tablet formulations. The T(2) and ADC in the outer parts of the gel-layers were close to those of free water. In contrast, these values in the inner parts of the gel-layer decreased progressively; suggesting that the water mobility and diffusivity around the core interface were highly restricted. Furthermore, the correlation between the T(2) of (1)H proton in the gel-layer of the tablets and the drug release rate from the tablets was observed.

  7. Investigation of water mobility and diffusivity in hydrating micronized low-substituted hydroxypropyl cellulose, hydroxypropylmethyl cellulose, and hydroxypropyl cellulose matrix tablets by magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Kojima, Masazumi; Nakagami, Hiroaki

    2002-01-01

    The water mobility and diffusivity in the gel-layer of hydrating low-substituted hydroxypropyl cellulose (LH41) tablets with or without a drug were investigated by magnetic resonance imaging (MRI) and compared with those properties in the gel-layer of hydroxypropylmethyl cellulose (HPMC) and hydroxypropyl cellulose (HPC) tablets. For this purpose, a localized image-analysis method was newly developed, and the spin-spin relaxation time (T 2 ) and apparent self-diffusion coefficient (ADC) of water in the gel-layer were visualized in one-dimensional maps. Those maps showed that the extent of gel-layer growth in the tablets was in the order of HPC>HPMC>>LH41, and there was a water mobility gradient across the gel-layers of all three tablet formulations. The T 2 and ADC in the outer parts of the gel-layers were close to those of free water. In contrast, these values in the inner parts of the gel-layer decreased progressively; suggesting that the water mobility and diffusivity around the core interface were highly restricted. Furthermore, the correlation between the T 2 of 1 H proton in the gel-layer of the tablets and the drug release rate from the tablets was observed. (author)

  8. A novel approach to calibrate the Hemodynamic Model using functional Magnetic Resonance Imaging (fMRI) measurements

    KAUST Repository

    Khoram, Nafiseh; Zayane, Chadia; Djellouli, Rabia; Laleg-Kirati, Taous-Meriem

    2016-01-01

    We have designed an iterative numerical technique, called the TNM-CKF algorithm, for calibrating the mathematical model that describes the single-event related brain response when fMRI measurements are given. The method appears to be highly accurate and effective in reconstructing the BOLD signal even when the measurements are tainted with high noise level (as high as 30%).

  9. Magnetic resonance imaging for clinical management of rectal cancer

    DEFF Research Database (Denmark)

    Beets-Tan, Regina G H; Lambregts, Doenja M J; Maas, Monique

    2018-01-01

    OBJECTIVES: To update the 2012 ESGAR consensus guidelines on the acquisition, interpretation and reporting of magnetic resonance imaging (MRI) for clinical staging and restaging of rectal cancer. METHODS: Fourteen abdominal imaging experts from the European Society of Gastrointestinal and Abdomin...

  10. Lateralization of functional magnetic resonance imaging (fMRI) activation in the auditory pathway of patients with lateralized tinnitus

    Energy Technology Data Exchange (ETDEWEB)

    Smits, Marion [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, Hs 224, Rotterdam (Netherlands); Kovacs, Silvia; Peeters, Ronald R; Hecke, Paul van; Sunaert, Stefan [University Hospitals of the Catholic University Leuven, Department of Radiology, Leuven (Belgium); Ridder, Dirk de [University of Antwerp, Department of Neurosurgery, Edegem (Belgium)

    2007-08-15

    Tinnitus is hypothesized to be an auditory phantom phenomenon resulting from spontaneous neuronal activity somewhere along the auditory pathway. We performed fMRI of the entire auditory pathway, including the inferior colliculus (IC), the medial geniculate body (MGB) and the auditory cortex (AC), in 42 patients with tinnitus and 10 healthy volunteers to assess lateralization of fMRI activation. Subjects were scanned on a 3T MRI scanner. A T2*-weighted EPI silent gap sequence was used during the stimulation paradigm, which consisted of a blocked design of 12 epochs in which music presented binaurally through headphones, which was switched on and off for periods of 50 s. Using SPM2 software, single subject and group statistical parametric maps were calculated. Lateralization of activation was assessed qualitatively and quantitatively. Tinnitus was lateralized in 35 patients (83%, 13 right-sided and 22 left-sided). Significant signal change (P{sub corrected} < 0.05) was found bilaterally in the primary and secondary AC, the IC and the MGB. Signal change was symmetrical in patients with bilateral tinnitus. In patients with lateralized tinnitus, fMRI activation was lateralized towards the side of perceived tinnitus in the primary AC and IC in patients with right-sided tinnitus, and in the MGB in patients with left-sided tinnitus. In healthy volunteers, activation in the primary AC was left-lateralized. Our paradigm adequately visualized the auditory pathways in tinnitus patients. In lateralized tinnitus fMRI activation was also lateralized, supporting the hypothesis that tinnitus is an auditory phantom phenomenon. (orig.)

  11. Lateralization of functional magnetic resonance imaging (fMRI) activation in the auditory pathway of patients with lateralized tinnitus

    International Nuclear Information System (INIS)

    Smits, Marion; Kovacs, Silvia; Peeters, Ronald R.; Hecke, Paul van; Sunaert, Stefan; Ridder, Dirk de

    2007-01-01

    Tinnitus is hypothesized to be an auditory phantom phenomenon resulting from spontaneous neuronal activity somewhere along the auditory pathway. We performed fMRI of the entire auditory pathway, including the inferior colliculus (IC), the medial geniculate body (MGB) and the auditory cortex (AC), in 42 patients with tinnitus and 10 healthy volunteers to assess lateralization of fMRI activation. Subjects were scanned on a 3T MRI scanner. A T2*-weighted EPI silent gap sequence was used during the stimulation paradigm, which consisted of a blocked design of 12 epochs in which music presented binaurally through headphones, which was switched on and off for periods of 50 s. Using SPM2 software, single subject and group statistical parametric maps were calculated. Lateralization of activation was assessed qualitatively and quantitatively. Tinnitus was lateralized in 35 patients (83%, 13 right-sided and 22 left-sided). Significant signal change (P corrected < 0.05) was found bilaterally in the primary and secondary AC, the IC and the MGB. Signal change was symmetrical in patients with bilateral tinnitus. In patients with lateralized tinnitus, fMRI activation was lateralized towards the side of perceived tinnitus in the primary AC and IC in patients with right-sided tinnitus, and in the MGB in patients with left-sided tinnitus. In healthy volunteers, activation in the primary AC was left-lateralized. Our paradigm adequately visualized the auditory pathways in tinnitus patients. In lateralized tinnitus fMRI activation was also lateralized, supporting the hypothesis that tinnitus is an auditory phantom phenomenon. (orig.)

  12. Contrast Agent in Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Vu-Quang, Hieu

    2015-01-01

    Nanoparticles have been employed as contrast agent in magnetic resonance imaging (MRI) in order to improve sensitivity and accuracy in diagnosis. In addition, these contrast agents are potentially combined with other therapeutic compounds or near infrared bio-imaging (NIR) fluorophores to obtain...... theranostic or dual imaging purposes, respectively. There were two main types of MRI contrast agent that were synthesized during this PhD project including fluorine containing nanoparticles and magnetic nanoparticles. In regard of fluorine containing nanoparticles, there were two types contrast agent...... cancer cells for cancer diagnosis in MRI. F127-Folate coated SPION were stable in various types of suspension medium for over six months. They could specifically target folate receptor of cancer cells in vitro and in vivo thus enhancing the contrast in MRI T2/T2* weighted images. These are preliminary...

  13. Shimadzu magnetic resonance imaging system, SMT-50

    International Nuclear Information System (INIS)

    Oikawa, Shiro; Nishida, Takayuki; Fujio, Yasuo

    1986-01-01

    The magnetic resonance imaging (MRI) system, as a new modality of medical imaging, has already been put to practical applications on many clinical sites, through which a lot of clinical data has been accumulated. It can offer a powerful new probe of internal anatomy of the human body and its functions. Now that the MRI has established its effectiveness in diagnosis, a really practical MRI system which features high efficiency and economical design with high patient throughput is strongly called for. Introduced in this article is a superconductive magnet MRI system, SMT-50, operating at 5000 Gauss. It has realized an excellent diagnostic capability with such functions as multi-slice multi-echo imaging, high sensitive, surface coil technique and so on. High resolution image display (1024 x 1024 pixcel) unit and separate console system (viewing console and scanning console) will assist high patient throughput. The outline of the SMT-50 and its clinical data are reported here. (author)

  14. Magnetic resonance imaging in hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Ichida, Fukiko; Hamamichi, Yuuji; Hashimoto, Ikuo; Tsubata, Shinichi; Miyazaki, Ayumi; Okada, Toshio; Futatsuya, Ryuusuke; Okada, Eikichi

    1994-01-01

    To evaluate the capability of magnetic resonance imaging (MRI) in the anatomical diagnosis and tissue characterization, 8 children with hypertrophic cardiomyopathy were studied comparing with echocardiography and 201 Tl myocardial imaging. The severity and distribution of hypertrophy were comparable on echocardiography and MRI. MRI was superior to echocardiography to demonstrate the apical hypertrophy. In 4 patients with severe hypertrophy, heterogenous high signal intensity was demonstrated in the site of hypertrophy, which was enhanced by T 2 weighted imaging. In the patient with decreased cardiac performance and progressed cardiac failure, the heterogeneity and high signal intensity progressed in one year interval. Simultaneously performed 201 Tl myocardial imaging showed patchy perfusion defect. Histological findings of the left ventricle demonstrated hypertrophy, degeneration and marked dysarray of the myocytes and fibrosis. MRI has the potential ability for the evaluation and sequential monitoring of myocardial tissue characterization as well as cardiac anatomy in childhood hypertrophic cardiomyopathy. (author)

  15. Magnetic resonance imaging in hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Ichida, Fukiko; Hamamichi, Yuuji; Hashimoto, Ikuo; Tsubata, Shinichi; Miyazaki, Ayumi; Okada, Toshio; Futatsuya, Ryuusuke; Okada, Eikichi [Toyama Medical and Pharmaceutical Univ. (Japan)

    1994-02-01

    To evaluate the capability of magnetic resonance imaging (MRI) in the anatomical diagnosis and tissue characterization, 8 children with hypertrophic cardiomyopathy were studied comparing with echocardiography and [sup 201]Tl myocardial imaging. The severity and distribution of hypertrophy were comparable on echocardiography and MRI. MRI was superior to echocardiography to demonstrate the apical hypertrophy. In 4 patients with severe hypertrophy, heterogenous high signal intensity was demonstrated in the site of hypertrophy, which was enhanced by T[sub 2] weighted imaging. In the patient with decreased cardiac performance and progressed cardiac failure, the heterogeneity and high signal intensity progressed in one year interval. Simultaneously performed [sup 201]Tl myocardial imaging showed patchy perfusion defect. Histological findings of the left ventricle demonstrated hypertrophy, degeneration and marked dysarray of the myocytes and fibrosis. MRI has the potential ability for the evaluation and sequential monitoring of myocardial tissue characterization as well as cardiac anatomy in childhood hypertrophic cardiomyopathy. (author).

  16. SU-E-J-226: Efficient Use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for Cervical-Cancer Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Damato, A; Bhagwat, M; Buzurovic, I; Cormack, R; Lee, L; Viswanathan, A [Harvard Medical School, Boston, MA (United States)

    2015-06-15

    Purpose: To investigate image modality selection in an environment with limited access to interventional MRI for image-guided high-dose-rate cervical-cancer brachytherapy. Methods: Records of all cervical-cancer patients treated with brachytherapy between 1/2013 and 8/2014 were analyzed. Insertions were performed under CT guidance (CT group) or with >1 fraction under 3T MR guidance (MRI group; subMRI includes only patients who also had a CT-guided insertion). Differences between groups in clinical target volume (CTV), disease stage (I/II or III/IV), number of patients with or without interstitial needles, and CTV D90 were investigated. Statistical significance was evaluated with the Student T test and Fisher test (p <0.05). Results: 46 cervical-cancer patients were included (16 MRI [3 subMRI], 30 CT). CTV: overall, 55±53 cm3; MRI, 81±61 cm3; CT, 42±44 cm3 (p = 0.017). Stage: overall, 24 I/II and 22 III/IV; MRI, 3 I/II and 13 III/IV; CT, 21 I/II and 9 III/IV (p = 0.002). Use of needles: overall, 26 without and 20 with; MRI, 5 without and 11 with; CT, 21 without and 9 with (p = 0.015). CTV D90: overall, 82±5 Gy; MRI, 81±6 Gy; CT, 82±5 Gy (p = 0.78). SubMRI: CTV and D90 (as % of nominal fraction dose) were 23±6 cm3 and 124±3% for MRI-guided insertions and 21±5 cm3 (p = 0.83) and 106±12% (p = 0.15) for CT-guided insertions. Conclusion: Statistically significant differences in patient population indicate preferential use of MRI for patients with high-stage disease and large residual CTVs requiring the use of interstitial needles. CTV D90 was similar between groups, despite the difference in patient selection. For patients who underwent both CT and MRI insertions, a larger MR CTV D90 and similar CTVs between insertions were observed. While MRI is generally preferable to CT, MRI selection can be optimized in environments without a dedicated MRI brachytherapy suite. This work was partially funded by the NIH R21 CA167800 (PI: Viswanathan; aviswanathan@partners.org)

  17. SU-E-J-226: Efficient Use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for Cervical-Cancer Brachytherapy

    International Nuclear Information System (INIS)

    Damato, A; Bhagwat, M; Buzurovic, I; Cormack, R; Lee, L; Viswanathan, A

    2015-01-01

    Purpose: To investigate image modality selection in an environment with limited access to interventional MRI for image-guided high-dose-rate cervical-cancer brachytherapy. Methods: Records of all cervical-cancer patients treated with brachytherapy between 1/2013 and 8/2014 were analyzed. Insertions were performed under CT guidance (CT group) or with >1 fraction under 3T MR guidance (MRI group; subMRI includes only patients who also had a CT-guided insertion). Differences between groups in clinical target volume (CTV), disease stage (I/II or III/IV), number of patients with or without interstitial needles, and CTV D90 were investigated. Statistical significance was evaluated with the Student T test and Fisher test (p <0.05). Results: 46 cervical-cancer patients were included (16 MRI [3 subMRI], 30 CT). CTV: overall, 55±53 cm3; MRI, 81±61 cm3; CT, 42±44 cm3 (p = 0.017). Stage: overall, 24 I/II and 22 III/IV; MRI, 3 I/II and 13 III/IV; CT, 21 I/II and 9 III/IV (p = 0.002). Use of needles: overall, 26 without and 20 with; MRI, 5 without and 11 with; CT, 21 without and 9 with (p = 0.015). CTV D90: overall, 82±5 Gy; MRI, 81±6 Gy; CT, 82±5 Gy (p = 0.78). SubMRI: CTV and D90 (as % of nominal fraction dose) were 23±6 cm3 and 124±3% for MRI-guided insertions and 21±5 cm3 (p = 0.83) and 106±12% (p = 0.15) for CT-guided insertions. Conclusion: Statistically significant differences in patient population indicate preferential use of MRI for patients with high-stage disease and large residual CTVs requiring the use of interstitial needles. CTV D90 was similar between groups, despite the difference in patient selection. For patients who underwent both CT and MRI insertions, a larger MR CTV D90 and similar CTVs between insertions were observed. While MRI is generally preferable to CT, MRI selection can be optimized in environments without a dedicated MRI brachytherapy suite. This work was partially funded by the NIH R21 CA167800 (PI: Viswanathan; aviswanathan@partners.org)

  18. Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) Combined with Positron Emission Tomography-Computed Tomography (PET-CT) and Video-Electroencephalography (VEEG) Have Excellent Diagnostic Value in Preoperative Localization of Epileptic Foci in Children with Epilepsy.

    Science.gov (United States)

    Wang, Gui-Bin; Long, Wei; Li, Xiao-Dong; Xu, Guang-Yin; Lu, Ji-Xiang

    2017-01-01

    BACKGROUND To investigate the effect that dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has on surgical decision making relative to video-electroencephalography (VEEG) and positron emission tomography-computed tomography (PET-CT), and if the differences in these variables translates to differences in surgical outcomes. MATERIAL AND METHODS A total of 166 children with epilepsy undergoing preoperative DCE-MRI, VEEG, and PET-CT examinations, surgical resection of epileptic foci, and intraoperative electrocorticography (ECoG) monitoring were enrolled. All children were followed up for 12 months and grouped by Engles prognostic classification for epilepsy. Based on intraoperative ECoG as gold standard, the diagnostic values of DCE-MRI, VEEG, PET-CT, DCE-MRI combined with VEEG, DCE-MRI combined with PET-CT, and combined application of DCE-MRI, VEEG, and PET-CT in preoperative localization for epileptic foci were evaluated. RESULTS The sensitivity of DCE-MRI, VEEG, and PET-CT was 59.64%, 76.51%, and 93.98%, respectively; the accuracy of DCE-MRI, VEEG, PET-CT, DCE-MRI combined with VEEG, and DCE-MRI combined with PET-CT was 57.58%, 67.72%, 91.03%, 91.23%, and 96.49%, respectively. Localization accuracy rate of the combination of DCE-MRI, VEEG, and PET-CT was 98.25% (56/57), which was higher than that of DCE-MRI combined with VEEG and of DCE-MRI combined with PET-CT. No statistical difference was found in the accuracy rate of localization between these three combined techniques. During the 12-month follow-up, children were grouped into Engles grade I (n=106), II (n=31), III (n=21), and IV (n=8) according to postoperative conditions. CONCLUSIONS All DCE-MRI combined with VEEG, DCE-MRI combined with PET-CT, and DCE-MRI combined with VEEG and PET-CT examinations have excellent accuracy in preoperative localization of epileptic foci and present excellent postoperative efficiency, suggesting that these combined imaging methods are suitable for serving as the

  19. Imaging by magnetic resonance

    International Nuclear Information System (INIS)

    Duroure, J.F.; Serpolay, H.; Vallens, D.

    1995-01-01

    Here are described the advanced technology for nuclear magnetic resonance imaging: reduction of acquisition times, and rebuilding times, images quality improvement. The tendency is to open the machines at low and middle field, on a market being at 10% of NMR I sales, with economical, scientifical and ergonomic reasons broadly developed by constructors

  20. Application of magnetic resonance imaging (MRI) to determine the influence of fluid dynamics on desulfurization in Bench scale reactors

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, N.L.; Reimert, R. [Engler-Bunte-Institut, Bereich Gas, Erdoel und Kohle, Universitaet Karlsruhe (T.H.) (Germany); Hardy, E.H. [Institut fuer Mechanische Verfahrenstechnik und Mechanik, Universitaet Karlsruhe (T.H.) (Germany)

    2006-07-15

    The influence of fluid dynamics on the hydrodesulfurization (HDS) reactions of a diesel oil in bench-scale reactors was evaluated. The porosities and liquid saturations of catalyst beds were quantified by using the MRI technique. The gas-liquid systems used in the experiments were nitrogen diesel and hydrogen diesel. An apparatus was especially constructed, allowing in situ measurements of gas and liquid distributions in packed beds at elevated pressure and temperature up to 20 bar and 200 C, respectively. The reactor itself had a length of 500 mm and an internal diameter of 19 mm. The packed beds used in this MRI study consisted of: (1) 2 mm diameter nonporous spherical glass beads and (2) 1.3 mm diameter porous Al{sub 2}O{sub 3} trilobes having the same size as the original trilobe catalyst used in HDS bench-scale experiments. The superficial gas and liquid velocities were set within the range of trickle flow, e.g., u{sub 0G} = 20-500 mm/s and u{sub 0L} = 0.1-6 mm/s. In parallel with the MRI experiments, the hydrodesulfurization of a gas oil was investigated in a bench-scale plant. Its reactor had the same dimensions of the trickle-bed column used in the MRI experiments and was filled with original trilobe catalyst. These catalytic experiments were carried out at a wide range of operating conditions (p = 30-80 bar, T = 300-380 C, LHSV = 1-4 h{sup -1}). The results of both fluid dynamic and catalytic reaction experiments were then combined for developing a simulation model to predict the HDS performance by accounting for fluid dynamic nonidealities. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  1. Animal MRI Core

    Data.gov (United States)

    Federal Laboratory Consortium — The Animal Magnetic Resonance Imaging (MRI) Core develops and optimizes MRI methods for cardiovascular imaging of mice and rats. The Core provides imaging expertise,...

  2. A novel approach to calibrate the Hemodynamic Model using functional Magnetic Resonance Imaging (fMRI) measurements

    KAUST Repository

    Khoram, Nafiseh

    2016-01-21

    Background The calibration of the hemodynamic model that describes changes in blood flow and blood oxygenation during brain activation is a crucial step for successfully monitoring and possibly predicting brain activity. This in turn has the potential to provide diagnosis and treatment of brain diseases in early stages. New Method We propose an efficient numerical procedure for calibrating the hemodynamic model using some fMRI measurements. The proposed solution methodology is a regularized iterative method equipped with a Kalman filtering-type procedure. The Newton component of the proposed method addresses the nonlinear aspect of the problem. The regularization feature is used to ensure the stability of the algorithm. The Kalman filter procedure is incorporated here to address the noise in the data. Results Numerical results obtained with synthetic data as well as with real fMRI measurements are presented to illustrate the accuracy, robustness to the noise, and the cost-effectiveness of the proposed method. Comparison with Existing Method(s) We present numerical results that clearly demonstrate that the proposed method outperforms the Cubature Kalman Filter (CKF), one of the most prominent existing numerical methods. Conclusion We have designed an iterative numerical technique, called the TNM-CKF algorithm, for calibrating the mathematical model that describes the single-event related brain response when fMRI measurements are given. The method appears to be highly accurate and effective in reconstructing the BOLD signal even when the measurements are tainted with high noise level (as high as 30%).

  3. Magnetic resonance imaging for cardiac tumors

    International Nuclear Information System (INIS)

    Niwa, Koichiro; Tashima, Kazuyuki; Okajima, Yoshitomo; Nakajima, Hiromichi; Terai, Masaru; Nakajima, Hironori; Harada, Tsutomu; Ishida, Yoshikazu.

    1988-01-01

    We performed magnetic resonance imaging (MRI) in 4 patients with cardiac tumor (1 with rhabdomyoma, 1 with left atrial myxoma, and 2 with tumor of the left ventricular wall) for morphological evaluation of the tumor. ECG-gated MRI was performed by the spin echo imaging technique using a superconducting MRI system operating at 0.5 tesla. Spatial extension of the tumor was clearly demonstrated in all the patients. Gadolinium-DTPA (Gd-DTPA), was used in the 2 patients with tumor of the left ventricular myocardium to enhance the contrast, and allowed clear visualization of the tumor. These findings show the usefulness of MRI and MRI with Gd-DTPA for morphological evaluation of cardiac tumor. (author)

  4. Magnetic resonance imaging of placenta accreta

    Science.gov (United States)

    Varghese, Binoj; Singh, Navdeep; George, Regi A.N; Gilvaz, Sareena

    2013-01-01

    Placenta accreta (PA) is a severe pregnancy complication which occurs when the chorionic villi (CV) invade the myometrium abnormally. Optimal management requires accurate prenatal diagnosis. Ultrasonography (USG) and magnetic resonance imaging (MRI) are the modalities for prenatal diagnosis of PA, although USG remains the primary investigation of choice. MRI is a complementary technique and reserved for further characterization when USG is inconclusive or incomplete. Breath-hold T2-weighted half-Fourier rapid acquisition with relaxation enhancement (RARE) and balanced steady-state free precession imaging in the three orthogonal planes is the key MRI technique. Markedly heterogeneous placenta, thick intraplacental dark bands on half-Fourier acquisition single-shot turbo spin-echo (HASTE), and disorganized abnormal intraplacental vascularity are the cardinal MRI features of PA. MRI is less reliable in differentiating between different degrees of placental invasion, especially between accreta vera and increta. PMID:24604945

  5. Magnetic resonance imaging of placenta accreta

    Directory of Open Access Journals (Sweden)

    Binoj Varghese

    2013-01-01

    Full Text Available Placenta accreta (PA is a severe pregnancy complication which occurs when the chorionic villi (CV invade the myometrium abnormally. Optimal management requires accurate prenatal diagnosis. Ultrasonography (USG and magnetic resonance imaging (MRI are the modalities for prenatal diagnosis of PA, although USG remains the primary investigation of choice. MRI is a complementary technique and reserved for further characterization when USG is inconclusive or incomplete. Breath-hold T2-weighted half-Fourier rapid acquisition with relaxation enhancement (RARE and balanced steady-state free precession imaging in the three orthogonal planes is the key MRI technique. Markedly heterogeneous placenta, thick intraplacental dark bands on half-Fourier acquisition single-shot turbo spin-echo (HASTE, and disorganized abnormal intraplacental vascularity are the cardinal MRI features of PA. MRI is less reliable in differentiating between different degrees of placental invasion, especially between accreta vera and increta.

  6. Magnetic resonance imaging of placenta accreta

    International Nuclear Information System (INIS)

    Varghese, Binoj; Singh, Navdeep; George, Regi A.N; Gilvaz, Sareena

    2013-01-01

    Placenta accreta (PA) is a severe pregnancy complication which occurs when the chorionic villi (CV) invade the myometrium abnormally. Optimal management requires accurate prenatal diagnosis. Ultrasonography (USG) and magnetic resonance imaging (MRI) are the modalities for prenatal diagnosis of PA, although USG remains the primary investigation of choice. MRI is a complementary technique and reserved for further characterization when USG is inconclusive or incomplete. Breath-hold T2-weighted half-Fourier rapid acquisition with relaxation enhancement (RARE) and balanced steady-state free precession imaging in the three orthogonal planes is the key MRI technique. Markedly heterogeneous placenta, thick intraplacental dark bands on half-Fourier acquisition single-shot turbo spin-echo (HASTE), and disorganized abnormal intraplacental vascularity are the cardinal MRI features of PA. MRI is less reliable in differentiating between different degrees of placental invasion, especially between accreta vera and increta

  7. Does magnetic resonance imaging predict future low back pain?

    DEFF Research Database (Denmark)

    Steffens, D; Hancock, M J; Maher, C G

    2014-01-01

    Magnetic resonance imaging (MRI) has the potential to identify pathology responsible for low back pain (LBP). However, the importance of findings on MRI remains controversial. We aimed to systematically review whether MRI findings of the lumbar spine predict future LBP in different samples...

  8. Magnetic Resonance Imaging (MRI) of TMJ. Inter-observer influence on diagnosis or therapy and difference of interpretation regarding abnormal signs

    International Nuclear Information System (INIS)

    Iinuma, Hideto; Minowa, Kazuyuki; Kobayashi, Ichizou; Matsuda, Akemi; Kaneko, Masayuki

    2006-01-01

    The purpose of study was to evaluate the influence of a head and neck radiologist after MRI examinations of the temporomandibular joint on the therapeutic strategy in patients with temporomandibular disorders and, furthermore, to analyze interobserver agreement for defined MRI criteria. Eighteen patients including 36 TMJ (10 males and 8 females; age 15-53 years) were enrolled. All were clinically evaluated, diagnosed ''TMD'' and MRI examinations were performed. The medical and MRI records of 18 patients were retrospectively reviewed. Four MR images (proton density, T1, T2-weighted and Gd-DTPA enhanced sagittal images at the open and closed mouth) were obtained. Therapeutic strategies before and after performance of the MRI were compared. One radiologist and main dentist independently analyzed the sagittal MR images for position of the disk, position of the condyle, signal intensity of the disk and bilaminar zone, bone changes and several additional findings. Additionally, the agreement between one radiologist and main dentist with respect to the diagnoses was evaluated. There were 13 cases that the modification of diagnosis was needed after MRI examinations. In 10 of the 18 subjective symptom-free subjects, there were abnormal signs anatomically. Also in 1 subjective and objective symptom-free subjects, abnormal signs were seen on MRI. In 1 individual, MRI revealed larger abnormal signs in clinically asymptomatic TMJ as compared with symptomatic TMJ. Whereas as for 1 symptomatic subject, Abnormal signs could not be identified in any of the TMJs. There were no cases that the change of treatment methods was needed after MRI examinations, but as for 13 cases, the correction of treatment contents was needed, such as the changes of the therapeutic regimen and the form of the sprint were registered after MRI. The disagreement between one radiologist and main dentist was seen in: the bone change of condyle; 30 TMJs, the change of temporal bone ;6 TMJs, the relationship

  9. Magnetic resonance imaging of the bone marrow

    International Nuclear Information System (INIS)

    Baur-Melnyk, Andrea

    2013-01-01

    The first book devoted to MRI of the bone marrow. Describes the MRI appearances of normal bone marrows and the full range of bone marrow disorders. Discusses the role of advanced MRI techniques and contrast enhancement. On account of its unrivalled imaging capabilities and sensitivity, magnetic resonance imaging (MRI) is considered the modality of choice for the investigation of physiologic and pathologic processes affecting the bone marrow. This book describes the MRI appearances of both the normal bone marrow, including variants, and the full range of bone marrow disorders. Detailed discussion is devoted to malignancies, including multiple myeloma, lymphoma, chronic myeloproliferative disorders, leukemia, and bone metastases. Among the other conditions covered are benign and malignant compression fractures, osteonecrosis, hemolytic anemia, Gaucher's disease, bone marrow edema syndrome, trauma, and infective and non-infective inflammatory disease. Further chapters address the role of MRI in assessing treatment response, the use of contrast media, and advanced MRI techniques. Magnetic Resonance Imaging of the Bone Marrow represents an ideal reference for both novice and experienced practitioners.

  10. Magnetic resonance imaging of the bone marrow

    Energy Technology Data Exchange (ETDEWEB)

    Baur-Melnyk, Andrea (ed.) [Klinikum der Univ. Muenchen (Germany). Inst. fuer Klinische Radiologie

    2013-08-01

    The first book devoted to MRI of the bone marrow. Describes the MRI appearances of normal bone marrows and the full range of bone marrow disorders. Discusses the role of advanced MRI techniques and contrast enhancement. On account of its unrivalled imaging capabilities and sensitivity, magnetic resonance imaging (MRI) is considered the modality of choice for the investigation of physiologic and pathologic processes affecting the bone marrow. This book describes the MRI appearances of both the normal bone marrow, including variants, and the full range of bone marrow disorders. Detailed discussion is devoted to malignancies, including multiple myeloma, lymphoma, chronic myeloproliferative disorders, leukemia, and bone metastases. Among the other conditions covered are benign and malignant compression fractures, osteonecrosis, hemolytic anemia, Gaucher's disease, bone marrow edema syndrome, trauma, and infective and non-infective inflammatory disease. Further chapters address the role of MRI in assessing treatment response, the use of contrast media, and advanced MRI techniques. Magnetic Resonance Imaging of the Bone Marrow represents an ideal reference for both novice and experienced practitioners.

  11. Nuclear magnetic resonance imaging

    International Nuclear Information System (INIS)

    Young, I.R.

    1984-01-01

    In a method of imaging a body in which nuclear magnetic resonance is excited in a region including part of the body, and the free induction decay signal is measured, a known quantity of a material of known nuclear magnetic resonance properties, for example a bag of water, is included in the region so as to enhance the measured free induction decay signal. This then reduces the generation of noise during subsequent processing of the signal. (author)

  12. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... six weeks) before being safe for MRI examinations. Examples include but are not limited to: artificial heart ... electrocardiography (ECG). MRI typically costs more and may take more time to perform than other imaging modalities. ...

  13. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings In most cases, an MRI exam is safe for patients with metal implants, except for a few types. ...

  14. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings In most cases, an MRI exam is safe for patients with metal implants, except for a ...

  15. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... to cancer treatment MRI is often the best choice for imaging the joints and bones, where it ... regular daily routine and have him/her take food and medications as usual. Some MRI examinations may ...

  16. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings ... tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that ...

  17. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... and pelvic region, MRI is used to: diagnose causes of pain evaluate for injury after trauma diagnose and monitor infectious or inflammatory disorders monitor response to cancer treatment MRI is often the best choice for imaging ...

  18. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging technique that ... used for conventional x-rays and CT scanning. Risks The MRI examination poses almost no risk to ...

  19. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... other internal body structures. MRI does not use ionizing radiation (x-rays). Detailed MR images allow physicians ... computed tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms ...

  20. Ultra-fast speech comprehension in blind subjects engages primary visual cortex, fusiform gyrus, and pulvinar – a functional magnetic resonance imaging (fMRI) study

    Science.gov (United States)

    2013-01-01

    Background Individuals suffering from vision loss of a peripheral origin may learn to understand spoken language at a rate of up to about 22 syllables (syl) per second - exceeding by far the maximum performance level of normal-sighted listeners (ca. 8 syl/s). To further elucidate the brain mechanisms underlying this extraordinary skill, functional magnetic resonance imaging (fMRI) was performed in blind subjects of varying ultra-fast speech comprehension capabilities and sighted individuals while listening to sentence utterances of a moderately fast (8 syl/s) or ultra-fast (16 syl/s) syllabic rate. Results Besides left inferior frontal gyrus (IFG), bilateral posterior superior temporal sulcus (pSTS) and left supplementary motor area (SMA), blind people highly proficient in ultra-fast speech perception showed significant hemodynamic activation of right-hemispheric primary visual cortex (V1), contralateral fusiform gyrus (FG), and bilateral pulvinar (Pv). Conclusions Presumably, FG supports the left-hemispheric perisylvian “language network”, i.e., IFG and superior temporal lobe, during the (segmental) sequencing of verbal utterances whereas the collaboration of bilateral pulvinar, right auditory cortex, and ipsilateral V1 implements a signal-driven timing mechanism related to syllabic (suprasegmental) modulation of the speech signal. These data structures, conveyed via left SMA to the perisylvian “language zones”, might facilitate – under time-critical conditions – the consolidation of linguistic information at the level of verbal working memory. PMID:23879896