PSYC 441 Lecture Notes - Lecture 9: Radioactive Tracer, Paramagnetism, Hemoglobin
28 Oct 2017
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Similar to ct scans with xenon 133: pros & cons: Poor temporal resolution: functional scans, fmri, how does it work: Measures blood flow to different parts of the brain by measuring changes in blood oxygen (o2) levels: O2 is carried on hemoglobin, which is paramagnetic (i. e. susceptible to a magnetic field): The parametric properties of hemoglobin are different when going to cells (oxygenated) than when flowing away from cells (deoxygenated): The most active parts of the brain will have greatest changes in o2 level (i. e. greatest contrast between deoxy- and oxy- hemoglobin): essentially, fmri measures bold (blood oxygen-level. Made up of voxels (i. e. voxels create a standard space to overlap structural and functional scans and allow for a clearer image): (pet or fmri) + (structural mri) = combined image: fmri and contrasts (no there there): Look at brain activity in both conditions:
