Abnormal regional cerebral blood flow found by technetium-99m ethyl cysteinate dimer brain single photon emission computed tomography in systemic lupus erythematosus patients with normal brain MRI findings

In this study, technetium-(99m) ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect regional cerebral blood flow (rCBF) of the brain in SLE patients with normal brain magnetic resonance imaging (MRI) findings. Twenty female SLE patients were enrolled in this study, divided into two groups. Group 1 consisted of 10 patients with neuropsychiatric manifestations. Group 2 consisted of 10 patients without neuropsychiatric manifestations. All patients had normal brain MRI findings. Another 10 SLE patients with abnormal MRI findings were included as group 3 for comparison. Meanwhile, 10 healthy female volunteers also underwent brain MRI and Tc-99m ECD brain SPECT for comparison. The scans revealed hypoperfusion lesions in 9/20 (45%) SLE patients, including 7/10 (70%) cases in group 1 and 2/10 (20%) cases in group 2. In contrast all 10 patients (100%) in group 3 had abnormal Tc-99m ECD brain SPECT findings. The parietal lobes were the most commonly involved areas. We conclude that Tc-99m ECD brain SPECT is more sensitive for detecting rCBF changes than is brain MRI in detecting the brain anatomic changes, and may have a diagnostic value in lupus cerebral involvement. However, 99mTc ECD brain SPECT may not be indicated for SLE patients with normal MRI and mild neuropsychiatric symptoms/signs, such headaches and dizziness.