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Weekend Course
ORGANIZERS: Herbert Köstler, Dipl.-Phys. & N. Jon Shah, Ph.D.
Saturday, 22 April 2017
| Room 313BC |
08:15 - 12:15 |
Moderators: Adrienne Campbell-Washburn, Armin Nagel |
Skill Level: Intermediate to Advanced
Slack Channel: #e_phys_eng
Session Number: WE01
Overview
This course will describe commonly used imaging pulse sequences and their building blocks, data acquisition and artifact suppression strategies and basic and advanced image reconstruction techniques.
Target Audience
MR physicists and engineers, pulse sequence developers and clinicians who want to deepen their understanding of MRI acquisition and reconstruction methods. Individuals who will likely benefit most from the course are those who have recently completed or will complete a graduate educational program in MR physics, chemistry, applied mathematics or engineering and those practitioners of MR with extensive practical experience but seek to obtain a more systematic physics foundation.
Objectives
Upon completion of this course, participants should be able to:
-Discuss pulse sequence building blocks and components;
-Compare advanced data acquisition strategies, and their potential and limitations;
-Describe common approaches to address motion;
-Recall state-of-the-art fast imaging techniques;
-Recognize advanced image reconstruction algorithms; and
-Identify common artifacts and relate how to reduce them.
08:15
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MRI: the Classical Description 
Gareth Barker
The NMR (Nuclear Magnetic Resonance) signal can be described classically by considering the motion of the net magnetisation (the vector sum of magnetic moments of individual nuclei). By considering individual isochromats – i.e. subsets of the spins that are behaving identically– we can visualise how the received signal will decay away due to T1, T2 and T2* relaxation. By additionally considering the effects of magnetic field gradients, we can determine the spatial location of the signal, producing images. All these effects can be described by the Bloch equations, which give complete classical description of the behaviour of magnetisation.
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08:45
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Signal & Noise in MRI
Claudia Hillenbrand
The signal-to-noise ratio (SNR) is a fundamental measure of quality and performance in MRI, most frequently used as a metric for comparing and optimizing imaging sequences, MR hardware (e.g., RF coils), or to assess and process new imaging and reconstruction techniques. Clinically, signal and noise considerations are important for image assessment such as in reliable lesion characterization, or in the context of accurate parameter fitting (relaxometry). This presentation will review the basic principles relevant to SNR, sources of noise, basic noise statistics, multi-channel noise, measurement of SNR and contrast-to-noise ratio, and factors influencing SNR.
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09:15
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Spatial Encoding (k-Space, MRI as a Linear & Shift-Invariant System, PSF, MTF)
Michael Steckner
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09:45
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Break & Meet the Teachers |
10:15
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MRI: a Systems Overview
Lawrence Wald
The “big three” sections of an MR scanner are well known; Magnet, Gradient system, and RF system, and probably should have a fourth: Patient comfort and user experience components. We start with a review of these components, current limitations, and directions under investigation and continue to interaction between them needed to harmonize operation.
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10:45
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Bloch Equations & Typical MRI Contrast
Tobias Wech
This presentation will provide an overview of the typical forms of the Bloch Equations, the physical mechanisms of relaxation phenomena as well as the basis of typical MRI contrasts.
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11:15
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Pulse Sequence Check: Reality vs. Ideal
Oliver Speck
The effect of any pulse sequence on the magnetization in an object can be predicted very accurately using the Bloch equation. A general algebraic inversion of the Bloch equation is not possible and thus, the full set of object and system properties and parameters cannot be derived from measurement data directly. Using a few assumptions and neglecting possible deviations, the results of a given pulse sequence can be calculated and the spatial encoding can be inverted to reconstruct an image. But what if these assumptions are wrong?
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11:45
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Basic MR Safety (Magnetic Fields, Peripheral Nerve Stimulation, etc)
Harald Kugel
Magnetic resonance techniques are considered to be not harmful. The three electromagnetic fields used for MR - static magnetic field, switched gradient fields, and radio frequency field - interact with human tissue, but also with other materials exposed to these fields. The physical interactions with human tissue do not cause irreversible physiological effects, as long as certain limits are not exceeded. Concerning foreign material (e.g. implants), the physical effects of the applied fields may cause severe hazards for patients, staff, and material, if MR examinations are not performed properly.
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12:15
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Lunch & Meet the Teachers |
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Physics for Physicists
Weekend Course
ORGANIZERS: Herbert Köstler, Dipl.-Phys. & N. Jon Shah, Ph.D.
Saturday, 22 April 2017
| Room 313BC |
13:15 - 16:45 |
Moderators: |
Ana-Maria Oros-Peusquens, Michael Steckner |
Skill Level: Intermediate to Advanced
Slack Channel: #e_phys_eng
Session Number: WE01
Overview
This course will describe commonly used imaging pulse sequences and their building blocks, data acquisition and artifact suppression strategies and basic and advanced image reconstruction techniques.
Target Audience
MR physicists and engineers, pulse sequence developers and clinicians who want to deepen their understanding of MRI acquisition and reconstruction methods. Individuals who will likely benefit most from the course are those who have recently completed or will complete a graduate educational program in MR physics, chemistry, applied mathematics or engineering and those practitioners of MR with extensive practical experience but seek to obtain a more systematic physics foundation.
Objectives
Upon completion of this course, participants should be able to:
-Discuss pulse sequence building blocks and components;
-Compare advanced data acquisition strategies, and their potential and limitations;
-Describe common approaches to address motion;
-Recall state-of-the-art fast imaging techniques;
-Recognize advanced image reconstruction algorithms; and
-Identify common artifacts and relate how to reduce them.
13:15
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Sequences & Simulations
Martin Graves
This presentation will provide an overview of the main gradient echo based (gradient spoiled, RF spoiled and balanced steady state free precession) and conventional/fast spin echo based pulse sequences and will illustrate some methods by which their behaviour can be simulated.
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13:45
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EPI Acquisition Strategies
Walter Block
The presentation provides a summary of echo planar imaging (EPI) acquisition techniques with descriptions of methods used to shorten the acquisition interval to improve imaging performance ( resolution, SNR, distortion, and/or coverage)
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14:15
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EPI Artifacts & Correction Methods
Maxim Zaitsev
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14:45
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Break & Meet the Teachers |
15:15
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Diffusion Weighted Imaging & Applications
Rita Nunes
Diffusion-weighted imaging (DWI) makes use of molecular water motion to probe tissue microstructure. This lecture will focus on the basic principles of DWI acquisition. After introducing the most commonly used diffusion modules, the main acquisition challenges will be discussed. Typical acquisition approaches will be presented, including single-shot and multi-shot sequences. Examples of frequent DWI image artefacts will be shown, and some of the approaches available for minimizing or correcting for their effect will be presented. The main applications of DWI to brain and body imaging will also be presented, focusing on stroke and lesion characterization.
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15:45
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Diffusion Tensor Imaging & Applications
Ana-Maria Oros-Peusquens
This presentation will touch upon the following aspects: general properties of diffusion, acquisition methods, the diffusion tensor model and diffusion indices, correlations of these indices with other MRI parameters and histology-derived quantities, data sampling strategies, validation strategies, limitations of DTI and applications
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16:15
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q-Space: What is it?
Qiuyun Fan
Diffusion MRI can provide useful information on microstructures that are much smaller than the imaging voxel sizes. This presentation will start from the original idea by Callaghan and Cory and Garroway showing that the diffusion NMR signal is the Fourier transformation of the displacement probability function, followed by examples of MRI experiments to infer microstructural properties of biological tissues. The basic concepts of q-space and propagator based methods will be discussed.
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16:45
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Adjournment |
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