Emily KochCIS II- Critical SummaryMRI Image Validation using MRI SimulationApril 10, 2001This presentation discussed the creation of an MRI simulator to test the validityand accuracy of post-imaging calculations. The information reviewed in this presentationwas obtained from the works of R. K-S. Kwan while he was a graduate student workingat McGill University, Montreal, Canada. Two different works were used. The first, MRISimulation for Quantitative Evaluation of Image-Processing Methods1, was an overviewof the problem that the simulator was designed to address, the potential solution for thisproblem, and examples obtained by using the MRI Simulator Program. The second, AnExtensible MRI Simulator for Post-Processing Evaluation2, gave an overview of theactual simulator structure and the design of the program. Although very interesting, these papers were extremely difficult to obtaininformation from. It was not an overabundance of information or extreme technicalwriting that made these papers difficult to read. In fact it was the opposite: the papersgenerally seemed to lack information about the computations involved and thealgorithms implemented. The overview paper was very informative, but offered no analysis of the project.This paper was broken up into three distinct parts: The Problem, The Solution and SomeExamples. Each section was concise and fairly easy to understand. The final sectionprovided some links to some actual clinical results obtained with the simulator. Thispaper provided good background to the purpose and direction of the MRI simulationproject. However, it did not analyze the potential pros and cons of using the simulator inrelation to some of the other solutions suggested. This would have been helpful indetermining the potential uses for the MRI simulator. The second paper spent a large amount of time breaking down the complexsimulator program into a series of smaller models. These models were split into twodifferent groups; one dealing with Signal Production and the other dealing with Image 1 R. K.-S. Kwan. MRI Simulation for Quantitative Evaluation of Image Processing Methods. www.bic.mcgill.ca/users/rkwan. June 18, 1997.2 R. K.-S. Kwan, A. C. Evans, G. Bruce Pike. An Extensible MRI Simulator for Post Processing Evaluation. Visualization in Biomedical Computing (VBC’96) Proceedings. Lecture Notes in Computer Science, vol. 1131. Springer-Verlag, 1996. 135-140Production. However, once again the paper seems to suffer from a lack of detail. Thesectional break down of the program was interesting, but it seemed to gloss over somepotentially useful information. While the complex mathematics used would not havebeen necessary, the combinational algorithms and some logic would have beeninteresting to know. As this paper was presented at a conference, there would have beenan accompanying presentation. I am sure attending this presentation would have clearedup some of the ambiguity about why the program was structured the way it was as wellas highlighting some of the other issues above. The results illustrated by the simulator are impressive visually. There seems to bea large deal of correlation between the actual MRI images and the simulated MRIimages. However, there were no statistics to illustrate the degree of correlation. I do notknow if such a calculation had been performed on these data sets. Overall, these papers really sparked interest in MRI simulation. However, they Ifeel that they did not adequately address some of the technical issues that theprogrammer would need to have addressed. A MRI simulator could be very useful in Cogitative Testing Program. A simulationprogram would not only allow for the correction of movement that could occur during thescan, it would allow for a standardization of the data obtained from multiple patients.This would become extremely useful in the creation of a brain atlas. Because theprogram aims to model both cognitively proficient and deficient brains, to work effectivelythe images should be normalized for movement, noise and slice