“…The imaging studies reveal several important pieces of information about the brain which are otherwise not visible to human sensory mechanisms. The most commonly used image modalities to study the brain include CT [47,15,16,17,18,135,186,293,294,142,259], MRI [47,15,16,17,85,181,105,135,48,52,186,124,20,136,137,126,49,208,295,54,139,55,210,93,294,141,142,144,296], DSA [47], PET [47,135,48,208,259], SPECT [47,135,…”