Totally Accessible MRI

This practical guide offers an accessible introduction to the principles of MRI physics. Each chapter explains the why and how behind MRI physics. Includes a wealth of high quality MRI illustrations.

BS"D All magnetic resonance technologists and all radiologists who work with magnetic resonance (MR) technology can be divided into two subgroups: (1) those who understand the underlying physics principles and how to apply them; and (2) those who do not. For so many patients and for so many diagnostic considerations, the difference between membership in these two groups is minimal. One can easily diagnose a vestibular schwannoma and accurately differentiate it from a cerebellopontine angle meningioma without being that well versed with many of the concepts underlying the creation of the MR images on which these tumors are depicted. One by rote can generate images of the pelvis that are quite diagnostic and aesthetically pleasing without really understanding the intricate interrelationships between the varying imaging parameters used in the generation of the obtained image contrast. There are certain situations, however, for which a more in depth und- standing isrequired. For example: Seeing tissue signaldisappear on a short T1 inversion recovery sequence yet recognizing that it does not have to originate from fat but may come from methemoglobin or some other short T1 tissue may prove clinicallyvital for arriving at the correct diagnosis. For suchcircumstances, understanding the underlying principles that govern the creation of the image and the contrast contained therein is critical and sets one apart and distinctlyahead of the competition, whocannot make this claim.

In the Beginning: Generating, Detecting, and Manipulating the MR (NMR) Signal. - Laying the Foundation: Nuclear Magnetism, Spin, and the NMR Phenomenon. - Rocking the Boat: Resonance, Excitation, and Relaxation. - Relaxation: What Happens Next? . - Image Contrast: T1, T2, T2*, and Proton Density. - Hardware, Especially Gradient Magnetic Fields. - User Friendly: Localizing and Optimizing the MRI Signal for Imaging. - Spatial Localization: Creating an Image. - Defining Image Size and Spatial Resolution. - Putting It All Together: An Introduction to Pulse Sequences. - Understanding, Assessing, and Maximizing Image Quality. - Artifacts: When Things Go Wrong, It s Not Necessarily All Bad. - Safety: First, Do No Harm. - To the Limit: Advanced MRI Applications. - Preparatory Modules: Saturation Techniques. - Readout Modules: Fast Imaging. - Volumetric Imaging: The Three-dimensional Fourier Transform. - Parallel Imaging: Acceleration with SENSE and SMASH. - Flow and Angiography: Artifacts and Imaging of Coherent Motion. - Diffusion: Detection of Microscopic Motion. - Understanding and Exploiting Magnetic Susceptibility. - Spectroscopy and Spectroscopic Imaging: In Vivo Chemical Assays by Exploiting the Chemical Shift.