MRI devices

T. Miyamoto, H. Sakurai, H. Takabaya-shi, M. Aoki 1989, (A development of a permanent magnet assembly for MRI devices using Nd-Fe-B material), IEEE Trans. Magn. 25, 3907-3909. 

There is some work indicating that NMR can become a more portable modality. For example, in the oil industry the NMR system is attached directly to the exploration drill to mine for petroleum sources. A generalization of this portability of NMR could lead to applications in a range of environmental studies as well as in medical contexts, where a handheld MRI device might be available to... 

List at least three safety concerns involving the use of MRI devices. 

The definition of system is quite varied, but a common element is that it focuses on the whole entity, for example A system is a construct or collection of different elements that together produce results not obtainable by the elements alone. The elements, or parts, can include people, hardware, software, facihties, poHcies, and documents that is, all things required to produce systems-level results. The results include system-level qualities, properties, characteristics, functions, behavior and performance. The value added by the system as a whole, beyond that contributed independently by the parts, is primarily created by the relationship among the parts that is, how they are interconnected. Using this definition, one can identify a variety of systems within the clinical setting. For example, an MRI device is... 

MRI devices are able to produce pictures that cannot be obtained with other techniques. The following MRI image shows a ruptured disc pressing on a patient s spinal cord. 

One of the most important features of MRI devices is the low risk to the patient. The magnetic field does not cause any known health concerns, and rf radiation is completely harmless. 

Vogan, J., Wingert, A., Hafez, M., et al. (2004) Manipulation in MRI Devices Using Electrostrictive Polymer Actuators with an Application to Reconfigurable Imaging Coils, Proceedings of the 2004 IEEE International Conference on Robotics and Automation, New Orleans, LA, 23 April-2 May, 2498-504. 

Fig. 2.6.10 Specialized experimental set-up for microfluidic flow dispersion measurements. Fluid is supplied from the top, flows via a capillary through the microfluidic device to be profiled and exits at the bottom. The whole apparatus is inserted into the bore of a superconducting magnet. Spatial information is encoded by MRI techniques, using rf and imaging gradient coils that surround the microfluidic device. They are symbolized by the hollow cylinder in the figure. After the fluid has exited the device, it is led through a capillary to a microcoil, which is used to read the encoded information in a time-resolved manner. The flow rate is controlled by a laboratory-built flow controller at the outlet [59, 60].

Fig. 14. Targeting of microparticles (e.g., bubbles and emulsion droplets) destined for molecular imaging and drug delivery Schematic simultaneous binding to a microparticle of a targeting device (antigen-specific ligands), of stealth-providing elements (e.g., PEG strands), and of drugs and markers (e.g., a Gd + chelate for MRI contrast enhancement).

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