From Anatomic Standardization Analysis of Perfusion SPECT Data to Perfusion Pattern Modeling

Christophe Grova, Pierre Jannin, Irène Buvat, Habib Benali, Jean-Yves Bansard, Arnaud Biraben, Bernard Gibaud
2005 Academic Radiology  
Rationale and Objectives. 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. Materials and Methods. From volume of interest (VOI)-perfusion measurements performed on anatomically standardized SPECT data, we proposed to
more » ... se 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 mesiotemporal 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. Conclusion. CA followed by HC is a promising approach to explore brain perfusion patterns from SPECT VOI measurements. Key Words. Functional variability; single-photon emission computed tomography (SPECT); correspondence analysis (CA); hierarchical clustering (HC); mesio-temporal lobe epilepsy; ictal perfusion. © AUR, 2005 Single-photon emission computed tomography (SPECT) using technetium 99m ( 99m Tc)-hexylmethyl-propyleneamine oxime (HMPAO) or 99m Tc-ethylcysteinatedimer (ECD) as a radiotracer is the most widely applied technique to study cerebral blood flow (1). Ictal SPECT is a high-sensitive technique for imaging extreme perfusion changes occurring during an epileptic seizure (2). It provides valuable information for the presurgical investigation of epilepsy. A perfusion pattern is defined as a typical spatial organization of brain perfusion in a homogeneous set of SPECT data. Perfusion patterns may be used to characterize subtypes of a pathological state, for example, in temporal lobe epilepsy Acad Radiol 2005; 12:554 -565
doi:10.1016/j.acra.2004.08.014 pmid:15866127 pmcid:PMC1978216 fatcat:o3mzzis53jfvjmf7duhibjjaiy