Evaluation of size of brain lesion by SPM program

Abstract

Objective : To test the ability of SPM program for detection of brain lesion size and to determine the effect of site on size detection. Research Design : Observational study, cross sectional study design. Site : Nuclear Medicine Division, Department of Radiology, King Chulalongkorn Memorial Hospital, Thai Red Cross Society. Method : Three cylindrical artificial lesions of diameters and length of (14x7mm, 9x5mm, 4x5mm) were positioned in 3 different regions [anterior cingulate cortex, posterior cingulate cortex, deep gray matter (basal ganglia)] in the brain phantom. Triple-headed SPECT acquisitions of simulated ictal and interictal states were carried out. Data were transferred to SPM2 program. SPM2 detected cluster volumes for each size and site were compared to actual lesion volumes. Result : SPM could detect 14 mm lesion sizes at all sites. The 9 mm lesions were detected at anterior and basal ganglia sites. The 4 mm lesion was only detected at basal ganglia site. The volume detected by SPM is larger than true volume. Conclusion : SPM is a tool assist detecting large lesion size. Sites of lesions may affect on size detection.