scholarly journals Magnetic Resonance Conditional Microinjector

2018 ◽  
Vol 5 (1) ◽  
pp. 4 ◽  
Author(s):  
Adam Wineland ◽  
Yue Chen ◽  
Brian Boland ◽  
Kevin Chan ◽  
Zion Tse
Keyword(s):  
Intraocular Pressure ◽  
Magnetic Resonance ◽  
Intact Animal ◽  
Target Volume ◽  
Resonance Imaging ◽  
Mri Scan ◽  
Mr Conditional ◽  
Specialized Equipment ◽  
Target Pressure ◽  
Magnetic Resonance Imaging Mri

Glaucoma, one of the leading causes of blindness, has been linked to increases in intraocular pressure. In order to observe and study this effect, proposed is a specialized microinjector and driver that can be used to inject small amounts of liquid into a target volume. Magnetic resonance imaging (MRI) guided remotely activated devices require specialized equipment that is compatible with the MR environment. This paper presents an MR Conditional microinjector system with a pressure sensor for investigating the effects of intraocular pressure (IOP) in near-real-time. The system uses pressurized air and a linear actuation device to push a syringe in a controlled, stepwise manner. The feasibility and utility of the proposed investigative medical research tool were tested and validated by measuring the pressure inside an intact animal donor eyeball while precise, small volumes of water were injected into the specimen. Observable increases in the volume of the specimen at measured, specific target pressure increases show that the system is technically feasible for studying IOP effects, while the changes in shape were depicted in MRI scan images themselves. In addition, it was verified that the presence and operation of the system did not interfere with the MRI machine, confirming its conditional compatibility with the 3T MRI.

Transdermal Patch Administration and Magnetic Resonance Imaging (MRI)—2020

2021 ◽  
pp. 001857872098713
Author(s):  
Janna Afanasjeva ◽  
Michael Gabay ◽  
Thomas Poznanski ◽  
Stefanie Kerns
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Drug Administration ◽  
Hospital Pharmacy ◽  
Transdermal Patch ◽  
Resonance Imaging ◽  
Mri Scan ◽  
Transdermal Patches ◽  
Magnetic Resonance Imaging Mri ◽  
Prescribing Information

This is an update to the 2010 article published in Hospital Pharmacy on safety concerns involving transdermal patches and magnetic resonance imaging (MRI). Since publication of the original article, new brand and generic transdermal medications have become available and notable changes regarding the presence or absence of metallic content among existing transdermal formulations occurred. To update the tables within the article, Food and Drug Administration (FDA)-approved transdermal medications through October 2020 were researched in order to determine metallic content and procedures for reapplication after MRI, if applicable. Readers should consult the prescribing information or manufacturer for the most current information on use of transdermal medications in the MRI setting. Of note, manufacturers have not evaluated the use of transdermal products while patients undergo a MRI scan.

scholarly journals Kernohan-Woltman Notch Phenomenon—Case Report

2016 ◽  
Vol 38 (01) ◽  
pp. 056-059
Author(s):  
Carlos Pereira
Keyword(s):  
Magnetic Resonance Imaging ◽  
Case Report ◽  
Magnetic Resonance ◽  
Chronic Subdural Hematoma ◽  
Motor Deficit ◽  
Imaging Findings ◽  
Resonance Imaging ◽  
Mri Scan ◽  
Present Case Report ◽  
Magnetic Resonance Imaging Mri

AbstractThe Kernohan-Woltman notch phenomenon is a paradoxical neurological manifestation consisting of a motor deficit ipsilateral to a primary brain injury. It has been observed in patients with brain tumors and with supratentorial hematomas. It is considered a false localizing neurological sign. Magnetic resonance imaging (MRI) scan has been the test of choice. The recognition of this phenomenon is important to prevent a surgical procedure on the opposite side of the lesion. The present case report describes a case of chronic subdural hematoma with a probable finding of the Kernohan-Woltman phenomenon, and it discusses its pathophysiology, imaging findings, treatment, and prognosis.

scholarly journals Postpartum Regression of a Presumed Cavernous Meningioma

2016 ◽  
Vol 2016 ◽  
pp. 1-3
Author(s):  
See Yung Phang ◽  
Peter Whitfield
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Caucasian Woman ◽  
Complete Regression ◽  
Resonance Imaging ◽  
Third Trimester ◽  
Mri Scan ◽  
The Third ◽  
Cavernous Sinus Meningioma ◽  
Magnetic Resonance Imaging Mri

Meningiomas are known to be more common in females than males. They are also known in rare cases to grow in size during pregnancy, which can complicate its management. We describe a 31-year-old Caucasian woman who presented with blurring of her vision and diplopia during the third trimester of her pregnancy. Magnetic resonance imaging (MRI) showed a small left cavernous sinus meningioma. The patient was treated conservatively until her uncomplicated delivery. A postpartum MRI scan showed complete regression of the suspected meningioma. Currently the patient is contemplating a further pregnancy.

Subacute Pituitary Apoplexy: Clinical and Magnetic Resonance Imaging Characteristics

Neurosurgery ◽  
1990 ◽  
Vol 27 (2) ◽  
pp. 214-219 ◽  
Author(s):  
Roberta P. Glick ◽  
James A. Tiesi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Pituitary Apoplexy ◽  
Clinical Symptoms ◽  
Resonance Imaging ◽  
Mri Scan ◽  
Imaging Characteristics ◽  
Invaluable Tool ◽  
Magnetic Resonance Imaging Mri

Abstract Between 1987 and 1988, we utilized magnetic resonance imaging (MRI) in the diagnosis of seven cases of “subacute” pituitary apoplexy. that is, intra-adenomatous pituitary hemorrhage associated with clinical symptoms atypical of acute pituitary apoplexy. These symptoms lasted longer than 24 hours and included visual changes in four patients, headache in five, and seizures, endocrine dysfunction, and oculomotor palsy in one each. Estimates of the ages of the hemorrhages were also possible based on characteristics on the MRI scan and ranged from 48 hours to more than 14 days. Four of our seven patients underwent transsphenoidal decompression at which time the presence of intratumoral hemorrhage was confirmed. The remaining three patients have been followed as outpatients with serial MRI examinations and have shown improvement in clinical symptoms and stabilization of the radiological picture. From our series of patients, it is now apparent that the MRI scan is an invaluable tool in identifying this subacute form of intra-adenomatous pituitary hemorrhage and has proven especially useful as a means of therapeutic planning and follow-up care in patients presenting with symptoms not typical of classic pituitary apoplexy.

scholarly journals B0-Shimming Methodology for Affordable and Compact Low-Field Magnetic Resonance Imaging Magnets

2021 ◽  
Vol 9 ◽  
Author(s):  
Konstantin Wenzel ◽  
Hazem Alhamwey ◽  
Tom O’Reilly ◽  
Layla Tabea Riemann ◽  
Berk Silemek ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Field ◽  
Magnetic Resonance ◽  
Point Of Care ◽  
Low Cost ◽  
Field Measurements ◽  
Target Volume ◽  
Resonance Imaging ◽  
Low Field ◽  
Magnetic Resonance Imaging Mri

Low-field (B0 < 0.2 T) magnetic resonance imaging (MRI) is emerging as a low cost, point-of-care alternative to provide access to diagnostic imaging technology even in resource scarce environments. MRI magnets can be constructed based on permanent neodymium-iron-boron (NdFeB) magnets in discretized arrangements, leading to substantially lower mass and costs. A challenge with these designs is, however, a good B0 field homogeneity, which is needed to produce high quality images free of distortions. In this work, we describe an iterative approach to build a low-field MR magnet based on a B0-shimming methodology using genetic algorithms. The methodology is tested by constructing a small bore (inner bore diameter = 130 mm) desktop MR magnet (<15 kg) at a field strength of B0 = 0.1 T and a target volume of 4 cm in diameter. The configuration consists of a base magnet and shim inserts, which can be placed iteratively without modifying the base magnet assembly and without changing the inner dimensions of the bore or the outer dimensions of the MR magnet. Applying the shims, B0 field inhomogeneity could be reduced by a factor 8 from 5,448 to 682 ppm in the target central slice of the magnet. Further improvements of these results can be achieved in a second or third iteration, using more sensitive magnetic field probes (e.g., nuclear magnetic resonance based magnetic field measurements). The presented methodology is scalable to bigger magnet designs. The MR magnet can be reproduced with off-the-shelf components and a 3D printer and no special tools are needed for construction. All design files and code to reproduce the results will be made available as open source hardware.

Synchronous cystic teratomas of the craniofacial region

2003 ◽  
Vol 117 (10) ◽  
pp. 824-826
Author(s):  
Neena Chaudhary ◽  
Krishna Pal Singh Malik ◽  
Alok Gupta ◽  
Anil Kumar Rai ◽  
Pankaj Gupta ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Pathological Examination ◽  
Resonance Imaging ◽  
Mri Scan ◽  
Temporal Fossa ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Slow Growing

A case of synchronous cystic teratomas presented with the complaints of a slow-growing facial mass and forward protrusion of the right eye since birth. The patient was examined thoroughly and subjected to magnetic resonance imaging (MRI) scan. The MRI scan revealed the presence of two separate cysts in the right orbit and right temporal fossa. The patient was operated by a combined effort of ophthalmologists and otorhinolaryngologists. The cysts were excised and subjected to pathological examination. The histopathological survey revealed both the cysts to be mature cystic teratomas similar to each other. This coexistence of a primary temporal fossa teratoma with an orbital teratoma is the first of its kind and to the best of our knowledge has not been reported before.

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