Automated Blood Perfusion Mapping

Blood perfusion maps were automatically obtained using the default process by the dedicated workstation (IntelliSpace Portal Release v.7.0.4.20175, Philips), and the data were derived from the blood perfusion maps. The regions of interest (ROIs) derived from the retinal-choroidal complex, the intraorbital segments of the optic nerve, the tractus opticus, and the visual center (Figure 2) were drawn by a neurologist (10 years of experience) and an ophthalmologist (10 years of experience), respectively, and clinical information was reviewed in a blinded fashion. The specific location of the retina-choroid complex, the orbital segment of the optic nerve, the optic tract, and the visual center were based on T1 and T2 weighted images. The unified criteria for drawing ROIs were as follows: The ROIs were all subrounded. The area of ROI of the retinal-choroidal complex, the intraorbital segments of the optic nerve, and the tractus opticus were 0.3 cm²; the area of ROI of the gyrus lingual, the cuneus, and the occipital lobe was 2 cm², and the average BF value was taken as the BF of the visual center. The relative BF (rBF) value was defined as rBF = affected BF/healthy BF (Muir and Duong, 2011 (link)). The results of the measurements were retrieved from the two observers and calculated as the average value.