1,745 research outputs found
An active learning approach to education in MRI technology for the biomedical engineering curriculum
It is challenging to give students an intuitive understanding of the basic magnetic resonance phenomenon and a sample of the many MRI techniques. Whereas compact mathematical descriptions of MRI techniques can be made, students are typically left with no intuitive understanding unless the common sense expressed in the math is in focus. Unfortunately, the nuclear dynamics happen in four dimensions, and are therefore not well suited for illustration on blackboard. 3D movies are more appropriate, but they do not encourage active learning. The typical solution employed by educators is hand waving (literally), since arm motions can to a limited extent be used to illustrate nuclear dynamics. Many students find this confusing, however, and students who do not grasp the meaning during lectures, are left in a bad position. For this reason, educational software was developed over the last decade (the Bloch Simulator). It is freely available and can be run directly from the software homepage that also links to YouTube software presentations aimed at educators and students who have already gotten a first introduction to MRI concepts. The software is mainly aimed at educators for interactive demonstration of MRI techniques but can also be used for student exercises which may significantly improve the understanding of MRI concepts. The presentation demonstrates software made for the first few minutes of MRI education but focuses mostly on the educational value of the more advanced Bloch Simulator. It is explored how, and to what extent, active learning based on the software may improve student understanding. An interactive teaching session on advanced topics (pulse types, the Fourier relationship, selectivity) was evaluated using pre- and post-lecture anonymous questionnaires. These are challenging and significant subjects, and it was hypothesized that the approach may improve student understanding considerably. Though rigorous testing of the benefit over traditional teaching was not within the scope of the project, indications of improved skills were found, and the student satisfaction was excellent
The Bloch Simulator and Viewer - Free, interactive MRI visualisation
The Bloch Simulator is 3D graphical
software for visualising spin physics
and MRI techniques. It provides
demonstrations and exploration of
otherwise abstract concepts involved
in MRI. It is useful for students and
teachers alike and is available online
at no cost.
Phenomena such as precession, resonance,
excitation, inhomogeneity and
relaxation can be demonstrated. Likewise,
rotating frames, weightings,
spoilers, spin-echoes, simulated
echoes and more can be explored.
Finally, MR imaging concepts can be
demonstrated, e.g., how the similarity
between induced phase roll patterns
and the structures of the imaged
object is reflected in the MR signal
Is Quantum Mechanics necessary for understanding Magnetic Resonance?
Educational material introducing magnetic resonance typically contains sections on the underlying principles. Unfortunately the explanations given are often unnecessarily complicated or even wrong. Magnetic resonance is often presented as a phenomenon that necessitates a quantum mechanical explanation whereas it really is a classical effect, i.e. a consequence of the common sense expressed in classical mechanics. This insight is not new, but there have been few attempts to challenge common misleading explanations, so authors and educators are inadvertently keeping myths alive. As a result, new students' first encounters with magnetic resonance are often obscured by explanations that make the subject difficult to understand. Typical problems are addressed and alternative intuitive
explanations are provided
MRI safety in practice: The EU directive on work in electromagnetic fields – practical and clinical aspects
The current paper addresses the practical consequences of the EU directive 2004/40/EC
passed in 2004 concerning protection of workers from electromagnetic fields (EMF). These
consequences were evaluated in detail only after the directive was passed, and they were
found to be severe. Consequently, the directive has not yet been implemented fully in the EU
member state's legislation, and a revision is expected before this happens in October 2013,
the latest. The revised directive is expected to be based on revised recommendations of
the International Commission on Non-Ionizing Radiation Protection (ICNIRP), and may in
other ways limit the detrimental consequences for MRI, but this is uncertain. Hence the
presented summary of consequences is based mainly on the current directive, representing a
realistic worst-case scenario, except for a static field limit that will likely be introduced in a
revised directive. An estimated 5-8% of current examinations will be severely affected. The
inadvertent effects include reduced access to interventional MRI, and to procedures involving
personnel in the scanner rooms during scanning, e.g paediatric examinations, and scanning
conducted under anaesthesia. Other consequences are increased use of alternative imaging
modalities including X-ray based techniques, hindered development of improved MRI
techniques, and general consequences of increased complexity and cost
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