Upper Left image shows rCBF distribution in a  group (n=92) of
Normal controls during rest. . Note the normal hyperfrontal flow pattern.

Upper Right image shows rCBF distribution in a group (n=133) of AD
patients. Alzheimer's patients show bilateral rCBF reductions in the
posterior association areas, and this is manifest even in the early stages
of the disease. Both the magnitude and the rate of blood flow decline are
related to the severity of intellectual impairment.

Lower Left image A statistical analysis (Student) of the difference
between the group of Normal subjects and the group of patients suffering
from Alzheimer's Disease.

Image courtesy: Siegbert Warkentin, Ass.Prof., Director of
CBF-laboratory, Neuropsychiatric Clinic and Dept.of Clinical
Physiology, University hospital MAS, Malmö, Sweden