PowerPoint Presentation

Functional MRI 101The vasculature in the rest condition. Normal oxygen distribution.Blood flowchangesBlood oxygen level dependent signal:BOLD

StimulusElectricalActivityNow a stimulus is applied which causes electrical activity followed by increased blood flow delivering more oxygenated blood.

By altering the order of stimulus and control conditions, it is possible to predict and model the blood flow response. This depicts a block deign experiment.One can model the experiment and examine the MR data for voxels that have a time course that follows the model using a statistical test. The result is a map of regions that are statistically significant.

1Discuss resting blood flowPresence of stimulus increases flow in brain regions doing workThis is the BOLD response used to monitor differences in conditionsExplain fMRI design to detect these differencesUse a statistical model to determine regions that are statistically different and color code according to significance. This is the functional map. In this case simple movement of the fingers.

Functional MRIStimulusNeuralActivityBloodFlowOxygenMetabol.BloodVolumeBOLDResponseBOLD is comprised of a multitude of parameters mostly dominated by metabolism, flow and blood volume.A ping pong ball has been instrumented with a catheter. The ball (dotted circle) represents a capillary in cross section. The yellow box represents a voxel. When air is in the ball (Deoxygenated state) there is signal loss outside the vessel. When saline (oxygenated blood) is injected the signal outside the vessel is recovered because there is less of magnetic field inhomogeneity.Phantom of BOLD effect

Functional MRIHypothesis or QuestionNeuroscience, Clinical or PhysiologicParadigm designDriven by Question and assumptionsExperimental setupImaging protocolProcessing and Results

Motor & VisualLanguageSpatial AttentionMemoryEmotionMotivationLearningAging effectsTaste & SmellAuditory

ClinicalAssessmentandPre surgical planningFunctional MRI

Important QuestionsWhat do the colors mean?What if I dont see a blob?How do I know what the patient was doing?How does this patients map compare to a normal?