TECHNETIUM-99M-HMPAO BRAIN SPECT IN BEHCETS-DISEASE

Behcet's disease (BD) is an idiopathic multisystem disorder. Involveme nt of the central nervous system (CNS) occurs in 4%-48% of cases. The aim of this study was to evaluate Tc-99m-hexamethyl propyleneamine oxi me (HMPAO) SPECT findings in BD patients and eventually to detect CNS involvement by depicting cerebral blood flow disturbances. Methods: Te chnetium-99m-HMPAO brain SPECT was performed on 33 consecutive BD pati ents. Qualitative and quantitative evaluation of the cortical uptake w as done using an automatic program that generated 32 regions of intere st (ROIs). An uptake index for each ROI was obtained. Reference values were obtained from a healthy control group (n = 20). Twenty-five pati ents also had an MRI study. Results: Twelve of 32 patients (36%) prese nted with a clinical neurological disorder. SPECT and visual evaluatio n revealed that 17 patients (51.5%) had abnormalities; 9 of 25 MRI stu dies (36%) were abnormal. Using the quantitative approach for SPECT, 2 3 patients (69.7%) had abnormally low values. Six of 12 patients with neurological symptoms had a visually abnormal SPECT scan, whereas quan titative analysis showed abnormalities in 11 patients. Of the 21 patie nts with no neurological findings, 9 had abnormal SPECT results, and 1 2 had low uptake indexes. Conclusion: HMPAO brain SPECT shows high rat es of cerebral blood flow abnormalities in BD patients presenting with neuropsychiatric symptoms, and it also is frequently abnormal in asym ptomatic BD patients who have no abnormalities on MR scans. Compared w ith visual analysis, quantitative analysis detects an even higher rate of SPECT changes in BD patients.