Hypoperfusion in the limbic system and prefrontal cortex in depression: SPECT with anatomic standardization technique.
Depression is a common psychiatric illness, and several reports have described cerebral blood flow (CBF) abnormalities on SPECT studies in affected patients. However, because region of interest analyses were used to determine significant CBF changes in these studies, there were methodological limitations. Therefore, we investigated CBF distribution abnormalities in depression on a pixel-by-pixel basis using SPECT and an anatomic standardization technique that has been commonly used for PET activation studies.


METHODS
Eleven patients with unipolar depression, six patients with bipolar depression and nine age-matched normal control subjects underwent HMPAO brain SPECT studies. The radioactivities of SPECT images for each subject were globally normalized to 100 counts/pixel. Then, each SPECT image was transformed for standard brain anatomy using a computerized Human Brain Atlas system. For each group, the mean and variance images were calculated from the standardized anatomic SPECT images, and group comparisons were performed on a pixel-by-pixel basis.


RESULTS
Significant decreases in CBF in the prefrontal cortices, limbic systems and paralimbic areas were observed in both depression groups compared with the normal control group.


CONCLUSIONS
Decreases in CBF in these regions may be related to impaired attention as well as cognitive and emotional responses, which have been recognized as usual symptoms in depression. The anatomic standardization technique promises to be useful for group comparison analysis of brain SPECT on a pixel-by-pixel basis for individual neurological and psychiatric diseases.
Ito
H
H
Department of Nuclear Medicine and Radiology, Tohoku University, Sendai, Japan.
Kawashima
R
R
Awata
S
S
Ono
S
S
Sato
K
K
Goto
R
R
Koyama
M
M
Sato
M
M
Fukuda
H
H
D000368:Aged; D001714:Bipolar Disorder / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001921:Brain / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003866:Depressive Disorder / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008032:Limbic System / Q000098:blood supply* / Q000000981:diagnostic imaging; D008297:Male; D015609:Organotechnetium Compounds; D010091:Oximes; D017397:Prefrontal Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime