|
Weekend Course
ORGANIZERS: Daniel C. Alexander, Ph.D., Fernando Calamante, Ph.D., Benedikt A. Poser, Ph.D., Joshua S. Shimony, M.D., Ph.D. & Steven P. Sourbron, Ph.D.
Sunday, 23 April 2017
| Room 311 |
13:15 - 16:45 |
Moderators: |
Joshua Shimony, Steven Sourbron |
Skill Level: Advanced
Slack Channel: #e_diff_perf_fmri
Session Number: WE18
Overview
The session will cover recent advances in acquisition and analysis methods in the areas of diffusion, perfusion, and fMRI imaging. The aim is to highlight some promising recent developments to experienced researchers that are not necessarily subspecialists in any of the three fields.
Target Audience
The course is tailored to an audience of physicists and engineers with a working knowledge of MRI and interested to find out about recent developments of advanced MRI methods. Specific expertise in either diffusion, perfusion or fMRI is not assumed.
Educational Objectives
Upon completion of this course, participants should be able to:
-Identify new imaging techniques for diffusion, perfusion and fMRI and describe what new information and possible biomarkers can be obtained from these methods; and
-Describe the advantages and disadvantages of these methods over traditional methods and how they could be used for clinical benefit.
13:15
|
DCE/DSC with Multiple Echoes: Blurring the Boundaries 
Ashley Stokes
Contrast-enhanced MRI methods follow the dynamic passage of exogenous paramagnetic contrast agents to provide perfusion-related parameters, such as cerebral blood volume and cerebral blood flow, or permeability-related parameters, such as the volume transfer constant or extravascular extracellular volume. Perfusion- and permeability-related biomarkers can inform on different, but complementary, aspects related to vascular proliferation and angiogenic processes. Separate acquisitions and contrast injections are typically used to acquire both perfusion (DSC) and permeability (DCE) in patients. More advanced acquisitions involving multiple echoes permit simultaneous assessment of both perfusion and permeability information and may provide new insight into tumor-induced hemodynamic changes.
|
13:45
|
ASL with Multiple Inversion & Echo Times
David Thomas
This presentation will describe extensions of the standard ASL method which enable quantification of extra haemodynamic parameters, additional to tissue perfusion. These parameters include arterial and tissue arrival times, water exchange times between the intra- and extra-vascular compartments, and estimation of partial volume effects. Changes to the acquisition scheme required to achieve these extra measurements, using multiple inflow times and echo times, will be described, and examples of uses of the techniques in vivo will be shown.
|
14:15
|
Break & Meet the Teachers |
14:30
|
Multi-Echo, Multi-Band Acquisitions for BOLD
Keith Jamison
|
15:00
|
Multi Echo ICA (MICA)
Prantik Kundu
This talk covers the applications of multi-echo (ME)-fMRI in combination with independent components analysis (ICA), called ME-ICA (Kundu et al., 2011). The ME-ICA approach to fMRI acquisition and analysis greatly increases the fidelity of BOLD fMRI while reducing the burden of artifacts across fMRI applications. Thus, the target audience of this talk includes all users of fMRI. Examples include users of resting state fMRI, task-based fMRI, pharmaco-fMRI, clinical fMRI of patients with lesions, and preclinical fMRI. The evidence presented indicates that the ME-fMRI approach expands the range of experiments that is practicable using fMRI.
|
15:30
|
Break & Meet the Teachers |
15:45
|
Acquisition: Novel Gradient Waveforms
Markus Nilsson
Most diffusion MRI is today performed with the so-called pulsed gradient spin echo (PGSE) method, which encodes for diffusion using two gradient pulses. This method is sensitive to cellularity of tumours, orientation of white matter tracts, and microstructure features such as axon density and cell sizes. However, the PGSE method is fundamentally limited in several ways. This talk will pinpoint these limitations and show how novel gradient waveforms can overcome them.
|
16:15
|
Analysis: Tissue & Signal Models
Ileana Jelescu
The diffusion signal provides unique, but indirect information about tissue microstructure. In this course, we will examine two main avenues for diffusion analysis: signal representations and tissue models. The former render the signal behavior without any assumptions about the tissue structure and thus produce sensitive but unspecific metrics (e.g. fractional anisotropy from DTI). For models, a theoretical expression of the diffusion signal in a given geometry (assumed to describe the tissue well) is fit to the data and characteristic parameters of the geometry are extracted. This approach should yield more specific metrics but is also more challenging to implement correctly.
|
16:45
|
Adjournment |
|