From anatomic standardization analysis of perfusion SPECT data to perfusion pattern modeling: evidence of functional networks in healthy subjects and temporal lobe epilepsy patients.
OBJECTIVE
In the general context of perfusion pattern modeling from single-photon emission computed tomographic (SPECT) data, the purpose of this study is to characterize interindividual functional variability and functional connectivity between anatomic structures in a set of SPECT data acquired from a homogeneous population of subjects.


METHODS
From volume of interest (VOI)-perfusion measurements performed on anatomically standardized SPECT data, we proposed to use correspondence analysis (CA) and hierarchical clustering (HC) to explore the structure of statistical dependencies among these measurements. The method was applied to study the perfusion pattern in two populations of subjects; namely, SPECT data from 27 healthy subjects and ictal SPECT data from 10 patients with mesio-temporal lobe epilepsy (MTLE).


RESULTS
For healthy subjects, anatomic structures showing statistically dependent perfusion patterns were classified into four groups; namely, temporomesial structures, internal structures, posterior structures, and remaining cortex. For patients with MTLE, they were classified as temporomesial structures, surrounding temporal structures, internal structures, and remaining cortex. Anatomic structures of each group showed similar perfusion behavior so that they may be functionally connected and may belong to the same network. Our main result is that the temporal pole and lenticular nucleus seemed to be highly relevant to characterize ictal perfusion in patients with MTLE. This exploratory analysis suggests that a network involving temporal structures, lenticular nucleus, brainstem, and cerebellum seems to be involved during MTLE seizures.


CONCLUSIONS
CA followed by HC is a promising approach to explore brain perfusion patterns from SPECT VOI measurements.
Grova
Christophe
C
Laboratoire IDM Medical School, University of Rennes 1, 35043 Rennes Cedex, France.
Jannin
Pierre
P
Buvat
Irène
I
Benali
Habib
H
Bansard
Jean-Yves
JY
Biraben
Arnaud
A
Gibaud
Bernard
B
D000328:Adult; D002560:Cerebrovascular Circulation / Q000502:physiology; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D013702:Temporal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon