scholarly journals A Passive Parallel Master–Slave Mechanism for Magnetic Resonance Imaging-Guided Interventions

2015 ◽  
Vol 9 (1) ◽  
Author(s):  
Santhi Elayaperumal ◽  
Mark R. Cutkosky ◽  
Pierre Renaud ◽  
Bruce L. Daniel
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Degrees Of Freedom ◽  
Isosceles Triangle ◽  
Parallel Mechanisms ◽  
Force Transmission ◽  
Resonance Imaging ◽  
Robot Architecture ◽  
Prismatic Joints ◽  
Magnetic Resonance Imaging Mri

A passive, parallel master–slave mechanism is presented for magnetic resonance imaging (MRI)-guided interventions in the pelvis. The mechanism allows a physician to stand outside the MRI scanner while manipulating a needle inside the bore and, unlike a powered robot, does not place actuators in proximity to the patient. The manipulator combines two parallel mechanisms based on the Delta robot architecture. The mechanism also includes a two-axis gimbal to allow for tool angulation, giving a total of five degrees of freedom so that the physician can insert and steer a needle using continuous natural arm and wrist movements, unlike simple needle guides. The need for access between the patient’s legs and within the MRI scanner leads to an unusual asymmetric design in which the sliding prismatic joints form the vertices of an isosceles triangle. Kinematic analysis shows that the dexterity index of this design is improved over the desired workspace, as compared to an equilateral design. The analysis is extended to estimate the effect of friction and model the input:output force transmission. Prototypes, with final dimensions selected for transperineal prostate interventions, showed force transmission behavior as predicted by simulation, and easily withstood maximum forces required for tool insertion.

Top-Ten Tips for Imaging the Brachial Plexus with Ultrasound and MRI

2019 ◽  
Vol 23 (04) ◽  
pp. 405-418 ◽  
Author(s):  
James F. Griffith ◽  
Radhesh Krishna Lalam
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Brachial Plexus ◽  
Muscle Denervation ◽  
Resonance Imaging ◽  
Neural Injury ◽  
Clinical Indications ◽  
Magnetic Resonance Imaging Mri ◽  
High Level ◽  
Extensive Involvement

AbstractWhen it comes to examining the brachial plexus, ultrasound (US) and magnetic resonance imaging (MRI) are complementary investigations. US is well placed for screening most extraforaminal pathologies, whereas MRI is more sensitive and accurate for specific clinical indications. For example, MRI is probably the preferred technique for assessment of trauma because it enables a thorough evaluation of both the intraspinal and extraspinal elements, although US can depict extraforaminal neural injury with a high level of accuracy. Conversely, US is probably the preferred technique for examination of neurologic amyotrophy because a more extensive involvement beyond the brachial plexus is the norm, although MRI is more sensitive than US for evaluating muscle denervation associated with this entity. With this synergy in mind, this review highlights the tips for examining the brachial plexus with US and MRI.

Use of Magnetic Resonance Imaging (MRI) to Determine the 3D Geometry in the Human Rectum

Endoscopy ◽  
2004 ◽  
Vol 36 (10) ◽  
Author(s):  
BP McMahon ◽  
JB Frøkjær ◽  
A Bergmann ◽  
DH Liao ◽  
E Steffensen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
3D Geometry ◽  
Human Rectum ◽  
Magnetic Resonance Imaging Mri

Magnetic resonance imaging in study of lungs

2019 ◽  
pp. 10-23
Author(s):  
T. A. Akhadov ◽  
S. Yu. Guryakov ◽  
M. V. Ublinsky
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Medical Society ◽  
Resonance Imaging ◽  
Iodinated Contrast ◽  
Long Time ◽  
Women And Children ◽  
Magnetic Resonance Imaging Mri ◽  
A Current ◽  
Lung Mri

For a long time, there was a need to apply magnetic resonance imaging (MRI) technique for lung visualization in clinical practice. The development of this method is stimulated by necessity of the emergence of an alternative to computed tomography, especially when radiation and injection of iodine-containing contrast agents are contraindicated or undesirable, for example, in pregnant women and children, people with intolerance to iodinated contrast. One of the reasons why lung MRI is still rarely used is lack of elaborated standardized protocols that would be adapted to clinical needs of medical society. This publication is a current literature review on the use of MRI in lung studies.

26. Nothing but the truth, so help me God: The history of magnetic resonance imaging

2007 ◽  
Vol 30 (4) ◽  
pp. 41
Author(s):  
A. Dechant
Keyword(s):  
Magnetic Resonance Imaging ◽  
New York ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nobel Prize ◽  
Resonance Imaging ◽  
Solid State Physics ◽  
Magnetic Resonance Imaging Mri ◽  
The Times ◽  
Nuclear Magnetic

On the morning of October 10, 2003, the residents of New York awoke to find that an entire page of their beloved paper, The Times, had been usurped for the sole purpose of flagrant self-promotion and protestation. On his own behalf, Dr. Raymand Damadian had purchased a one page spread bemoaning his exclusion in the Nobel Prize for Medicine that year which had previously been awarded to Paul Laterbur and Peter Mansfield for their contributions to the development of Magnetic Resonance Imaging (MRI). Over the course of the next few months, the public was to witness a series of such articles proclaiming that a shameful wrong had been committed, and that the truth would eventually prove Dr. Damadian’s accusations. That truth lay in the early theoretical and technical foundations that led to the discovery of MRI. Described just after the Second World War, nuclear magnetic resonance (NMR) was hailed as a breakthrough in physical chemistry for which Felix Bloch and Edward Purcell were awarded the Nobel Prize in Physics in 1952. Two decades later, in 1971, Dr. Damadian discovered that differences between the NMR signals of cancerous and normal tissue might provide a rapid means of cancer detection. However, Laterbur and Mansfield were the first to actually demonstrate images of live tissue using the application of magnetic gradients – the key to modern MRI. Though speculation exists that Dr. Damadian may have been excluded from the prize due to his religious beliefs or political rivalry, only time will reveal the whole truth when the Nobel files are opened 50 years hence. Bradley W. The Nobel Prize: Three Investigators Allowed but Two Were Chosen. Journal of Magnetic Resonance Imaging 2004; 19:520. Laterbur P. Image formation by induced local interactions: examples of employing nuclear magnetic resonance. Nature 1973; 242:190-191. Mansfield P, Grannell P. “NMR diffraction in solids?” Journal of Physics C: Solid State Physics 1973; 63:L433-L426.

Magnetic Resonance Imaging of Pseudo-impingement of Rotator Cuff with Strength Training

2019 ◽  
Vol 1 ◽  
pp. 2-6
Author(s):  
Asad Naqvi ◽  
Timothy Ariyanayagam ◽  
Mir Akber Ali ◽  
Akhila Rachakonda ◽  
Hema N. Choudur
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Rotator Cuff ◽  
Strength Training ◽  
Radiology Department ◽  
Resonance Imaging ◽  
Subacromial Space ◽  
History Of ◽  
Magnetic Resonance Imaging Mri ◽  
Training Exercises

Objective: The objective of this study was to outline a novel unique concept of secondary impingement of the muscles, myotendons, and tendons of the rotator cuff from hypertrophy as a result of strength training exercises. Methods: In this retrospective observational study, 58 patients were referred for an magnetic resonance imaging (MRI) by the orthopedic surgeon to the radiology department over a period of 1½ years. All patients gave a history of strength training exercises and presented with clinical features of rotator cuff impingement. Results: We identified features of hypertrophy of rotator cuff muscles, myotendons, and tendons in 12 of these 58 patients. This was the only abnormality on MRI. The hypertrophy of rotator cuff muscles and tendon bulk completely filling the subacromial space to the point of overfilling and resulting in secondary compressive features. Conclusion: Rotator cuff impingement is a common phenomenon that can occur with various inlet and outlet pathological conditions. However, rotator cuff impingement may also result from muscle and tendon hypertrophy from strength training regimens. Hypertrophy of the rotator cuff can result in overfilling of the subacromial space, leading to secondary impingement, which we have termed as “pseudo-impingement.”

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