Brain Perfusion Alterations on 3D Pseudocontinuous Arterial Spin-Labeling MR Imaging in Patients with Autoimmune Encephalitis: A Case Series and Literature Review

MR imaging of case 3. Findings on axial T2WI (A) and axial T1WI (B) are unremarkable. C, Coronal T2 FLAIR demonstrates hyperintensity in the right hippocampus (white arrow), whereas there are normal findings in the left hippocampus (white arrowhead). D, 3D pCASL depicts hyperperfusion in the corresponding regions on the FLAIR image, more obvious on the right side (black arrows).

MR imaging of case 5. Findings on axial T2WI (A) and axial T1WI (B) are unremarkable. C, Coronal T2 FLAIR shows subtle hyperintensity with mild swelling in the left hippocampus (white arrow), whereas it shows normal findings in the right hippocampus (white arrowhead). D, Increased CBF in the bilateral hippocampi could be detected on 3D pCASL, the left (black arrow) greater than the right (black arrowhead).

Serial MR imaging of case 7. On hospital day 3, the first conventional MR imaging examination findings were normal (not shown). On the second MR imaging check (26 days after admission), MR imaging shows swelling and hyperintensities on axial T2WI (A) and hypointensities on axial T1WI (B) in the bilateral hippocampi. C, Coronal T2 FLAIR shows hyperintensities in the bilateral hippocampi (white arrows). D, 3D pCASL reveals marked hyperperfusion in the bilateral medial temporal lobes (black arrows), the left greater than the right. On the third MR imaging check (96 days after admission), including axial T2WI (E), axial T1WI (F), and coronal T2 FLAIR (G), complete resolution of the inflammation in the bilateral medial temporal areas is seen, with enlargement of the bilateral temporal horns (white arrows), and 3D pCASL (H) shows decreased perfusion in the bilateral hippocampi (black arrows). The patient’s condition markedly improved with the administration of high-dose glucocorticoids, intravenous immunoglobulin, and plasma exchange (3 times).