Our hospital, located on the mainland, serves as a hub hospital for eight hospitals on the islands of Nagasaki Prefecture, Kyushu, Japan (Fig 1 ). The SYNAPSE Teleradiology system (Fujifilm) connects our hospital with hospitals on the islands via Ajisai-net, which is the Japanese Health Information Exchange in Nagasaki [8 (link)]. In addition, a new information and communication technology (SYNAPSE ZERO; Fujifilm) using smart devices was introduced into the teleradiology system [9 (link)]. In the Islands group, a physician conducted a neurological assessment based on the NIHSS score at admission to an island hospital. Non-enhanced head CT and MRI data of all patients with AIS on the islands were then transmitted via the teleradiology system. The patients were transferred to our hub hospital using the SR method (Fig 2 , Islands group). Most patients with AIS who had LVO on the remote islands, without rt-PA and/or MT treatment, were managed at hospitals on the islands; these cases were not included in this study. The teleradiology system was not used in the Mainland group.
Our hospital uses three types of helicopter: helicopter emergency medical services (HEMS), a Maritime Self-Defense Force (MSDF) helicopter, and a firefighting disaster prevention (FDP) helicopter. Characteristics of each helicopter have been detailed in a previous report [8 (link)].
Our hospital uses three types of helicopter: helicopter emergency medical services (HEMS), a Maritime Self-Defense Force (MSDF) helicopter, and a firefighting disaster prevention (FDP) helicopter. Characteristics of each helicopter have been detailed in a previous report [8 (link)].