We are attending to the Congress of Neurological Surgeons Annual Meeting in San Diego. I reached there together with Prof. Yoshimura and Dr. Yamada from Kobe. In this meeting, Prof. Kuroda presents clinical results of repeat bypass surgery for moyamoya disease. Dr. Emiko Hori presents the usefulness of computational flow dynamics (CFD) to determine the wall thickness of non-ruptured cerebral aneurysms. Dr. Yamamoto, our resident, presents the usefulness of 3D-CISS imaging to evaluate the pathophysiology of quasi-moyamoya disease (moyamoya syndrome). We will fly back to Fukuoka, Japan soon.