Composite Images of Dual-Energy CT Aiming at Visualization of Acute Cerebral Stroke in Emergency

Abstract

Traditionally, it has been difficult to visualize acute cerebral stroke from images produced by X-ray computed tomography（ CT）. We have recently developed a phantom that simulates acute cerebral stroke. We attempted to visualize an acute-stage cerebral infarction by using Dual-Energy CT（ DECT） to obtain composite imaging of this phantom. Composite images were created by using DECT voltages combination at 80 kV/Sn 140 kV, 100 kV/Sn 140 kV, 140 kV/80 kV, were obtained in such a way that the sum of the assigned weight coefficients became 1.0. Calculation of the CNR values allowed us to evaluate the visualization of acute-stage cerebral infarction. The CNR value of composite images were the highest at low energy side 0.5, high energy side 0.5, under 80 kV/Sn 140 kV and 140 kV/80 kV, and at low energy side 0.6, high energy side 0.4, under 100 kV/Sn 140 kV. The CNR values of composite images at weight coefficients between 0.4 and 0.6 were significantly higher than those obtained for all other created coefficients images. Therefore, the optimal conditions for visualizing acute cerebral stroke were achievable.