99 M TC-ETHHYLCISTEINATE (ECD) BRAIN SPECT IN CENTRAL NERVOUS SYSTEM INVOLVEMENT OF SYSTEMIC LUPUS ERYTHEMATOSUS

Simone Appenzeller, Barbara J. Amorim , Celso D. Ramos , A.O. Santos , E.C.S. Etchebehere , M.L. Lima , E.E. Camargo , Lilian T.L. Costallat , Fernando Cendes Internal Medicine, Radiology, Neurology, UNICAMP, Campinas, BrazilObjectives: To evaluate brain perfusion with 99 m Tc-ethhylcisteinate (ECD) SPECT in SLE patients with central nervous system involvement (CNS)with voxel-based morphometry (VBM).Methods: Forty patients (mean age 32 years) and 30 volunteers were selected and after written agreement submitted to cerebral SPECT scans. SLE patients were screened for the presence of CNS involvement following the ACR case definition. Standardized psychiatric and clinical research methods were used to assess cognitive impairment, anxiety and depression. Systemic disease activity was measured by defined SLEDAI. Patients with severe anxiety or mood disorders, CNS infections, uremia, diabetes and previous isquemic or hemorragic brain disease were excluded. MRI scans were obtained in a 2T scanner (Ellscint Prestige) with T1 - and T2-WI, as well as FLAIR, T1 Inversion Recovery and Proton Density axial scans. Cerebral SPECT were performed after injection the of 1100MBq ECD 99mTC. Reconstruction SPECT images were obtained thirty minutes later in the coronal, sagital and trans axial planes. SPECT images were analysed using the statistical parametric mapping (SPM 99) package (www fil.ion.ucl.ac.uk). After normalisation, segmentation, smoothing and modulation, the statistical differences among all SLE patients and volunteers and among SLE patients with and without SNC manifestations were compared using voxel based morphometry (VBM). Post-processed images were compared voxel-by-voxel using t-test, to determine differences in pixel intensity between groups. This analysis included grand mean scaling and proportional threshold masking (set to 0.4) and implicit masking. A p value of 0.1%, and cluster size of 32 was taken into consideration.Results: No difference between brains SPECTs was observed when all SLE patients were compared to controls. But when brains SPECTs of SLE patients with CNS involvement were compared to SLE patients without SNC involvement and to volunteers a global hypoperfusion, more intense in the frontal, dorsolateral and medial temporal lobe was observed.Conclusion: VBM of brain SPECT is a useful and objective method for detecting perfusion abnormalities in SLE patients. Brain perfusion abnormalities detected by ECD brain SPECT may be sensitive for the diagnosis of CNS involvement in SLE patients. If thes perfusion abnormalities are transient or permant has still to be determined.Citation: , volume , supplement , year 2004, page Session: SLE – Clinical aspects