First Measurement of Signal Changes Induced by Ionizing Radiation in Magnetic Resonance Imaging

2013 ◽  
Vol 80 (11) ◽  
Author(s):  
Markus Rausch ◽  
Felix Schyboll ◽  
Heiko Neeb
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Ionizing Radiation ◽  
Resonance Imaging ◽  
Signal Changes

scholarly journals The Pathophysiology of Primary Hip Osteoarthritis may Originate from Bone Alterations

2013 ◽  
Vol 7 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Mikio Kamimura ◽  
Yukio Nakamura ◽  
Shota Ikegami ◽  
Keijiro Mukaiyama ◽  
Shigeharu Uchiyama ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Proximal Femur ◽  
Hip Osteoarthritis ◽  
Pain Scale ◽  
Resonance Imaging ◽  
Mineral Density ◽  
Plain Radiographs ◽  
Signal Changes ◽  
Magnetic Resonance Imaging Mri

Objectives: The aim of this study was to investigate whether bone alterations detected by hip magnetic resonance imaging (MRI) were associated with subsequent primary hip OA. Methods: We enrolled 7 patients with hip joint pain from their first visit, at which hip joints were classified as grade 0 or I on the Kellgren-Lawrence grading scale. Plain radiographs and magnetic resonance imaging (MRI) were performed on all cases, and pain was assessed with the Denis pain scale. Average age, height, weight, body mass index, bone mineral density (L1-4), central edge angle, Sharp’s angle, and acetabular hip index were calculated. Results: Within two months of the onset of pain, 4 of the 7 cases showed broad bone signal changes, while 3 cases showed local signal changes in the proximal femur on hip MRI. Three to 6 months after the onset of pain, in all patients whose pain was much improved, plain radiographs showed progression to further-stage OA. Conclusion: Our findings suggest that bone abnormalities in the proximal femur might be involved in the pathogenesis of primary hip OA.

Abstract 107: Early Change in Ferumoxytol-Enhanced Magnetic Resonance Imaging Signal Suggests Unstable Human Cerebral Aneurysm. A Pilot Study

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
David M Hasan ◽  
donald hesitad
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Cerebral Aneurysm ◽  
Cerebral Aneurysms ◽  
Resonance Imaging ◽  
Unruptured Aneurysms ◽  
Ruptured Aneurysms ◽  
Cyclooxygenase 1 ◽  
Signal Changes ◽  
Cox 2

Background: Imaging with magnetic resonance imaging (MRI) 72 hours after infusion of ferumoxytol demonstrated maximal uptake by macrophages in the wall of human cerebral aneurysms. The clinical significance of early (i.e. within the first 24 hours) uptake of ferumoxytol by macrophages in the wall of human cerebral aneurysms is not clear. The purpose of this study was to determine whether early uptake of ferumoxytol which may indicate inflammation, suggests unstable cerebral aneurysm. Methods: 30 unruptured aneurysms in 22 patients were imaged with MRI 24 hours after infusion of ferumoxytol. Eighteen aneurysms were also imaged 72 hours after infusion of ferumoxytol. Aneurysm dome tissue was collected from four patients with early MRI signal changes, five patients with late signal changes, and five other patients with ruptured aneurysms. The tissue was immunostained for expression of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), microsomal-prostaglandin-E2 synthase-1 (mPGES-1) and macrophages. Findings: In 23% (7/30) of aneurysms, there was pronounced early uptake of ferumoxytol. Four aneurysms were clipped. The remaining three aneurysms which were managed conservatively with observation, all ruptured within six months. In 89% (16/18) of aneurysms, there was pronounced uptake of ferumoxytol at 72 hours. Nine aneurysms were surgically clipped and nine were managed conservatively; none ruptured or increased in size in six months. With immunostaining, expression of COX-2, mPGES-1, and macrophages was similar in unruptured aneurysms with early uptake of ferumoxytol and ruptured aneurysms. Expression of these inflammatory molecules was significantly higher in aneurysms with early uptake of ferumoxytol than in aneurysms with late uptake. Interpretation: Uptake of ferumoxytol in aneurysm walls within the first 24 hours strongly suggests aneurysm instability and probability of rupture within six months, and may warrant intervention. Larger clinical studies are indicated to validate this preliminary observation.

Magnetic Resonance Imaging Signal Changes in Denervated Muscles after Peripheral Nerve Injury

Neurosurgery ◽  
1994 ◽  
Vol 35 (6) ◽  
pp. 1077???1086 ◽  
Author(s):  
G. Alexander West ◽  
David R. Haynor ◽  
Robert Goodkin ◽  
Jay S. Tsuruda ◽  
Andrew D. Bronstein ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Signal ◽  
Signal Changes ◽  
Denervated Muscles

Magnetic Resonance Imaging of Congenital Midline Nasal Masses

1986 ◽  
Vol 95 (3_part_1) ◽  
pp. 303-306 ◽  
Author(s):  
Rodney P. Lusk ◽  
Phillip C. Lee
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissue ◽  
Ionizing Radiation ◽  
Preoperative Evaluation ◽  
Ct Scanning ◽  
Tissue Imaging ◽  
Intracranial Extension ◽  
Resonance Imaging ◽  
Cross Sectional

Congenital midline nasal masses are rare lesions with potential intracranial extensions. Thus, thoughtful preoperative evaluation Is essential in planning the appropriate surgical approach, to prevent such complications as cerebral spinal fluid leaks and meningitis. Preoperative computerized tomographic (CT) scans are useful in visualizing bony defects, but are not well suited for soft tissue imaging. Magnetic resonance imaging (MRI) Is the latest advance in cross-sectional imaging technology. It offers superior soft tissue contrast, is noninvasive, and does not use ionizing radiation. It is particularly useful in imaging encephaloceles. Three cases of congenital midline masses are presented as illustrations. Two dermoid cysts demonstrate the usefulness of MRI in ruling out intracranial extension. A large encephalocele dramatically demonstrates the superiority of MRI in imaging the brain herniating into the nose. Since MRI is noninvasive and does not use ionizing radiation, it should be considered before CT scanning, to rule out intracranial extension.

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