超高速電圧切り替え方式デュアルエネルギーCTを用いた脳血管内治療後の画像評価

The efficacy and safety of neuroendovascular therapy is globally recognized due to the positive results of recent randomised control trials on mechanical thrombectomy for acute embolic stroke, on carotid arterial stenting for carotid artery stenosis, on coil embolization for intracranial aneurysm, and on embolization for arteriovenous malformation or dural arteriovenous fistula. In parallel, neuroradiologists frequently encounter difficulties in the interpretation of postinterventional non-contrast enhanced CT images, as they often have high attenuated areas derived from residual iodinated contrast media and metal artifacts caused by metallic devices such as platinum-coils, surgical clips, metallic stents, and liquid embolic agents such as Onyx®. Meanwhile, fast kV switching dual energy CT （gemstone spectral imaging: GSI） is one of the advanced imaging techniques that can overcome these obstacles. For instance, material decomposition using virtual monochromatic imaging （VMI） can generate an iodine map and water （virtual non-contrast） map, which enables residual iodinated contrast media and acute hemorrhage to be distinguished. Furthermore, the use of VMI with metal artifact reduction software, MARS, can suppress severe metal artifacts, resulting in improved image quality of surrounding vessels. In this review article, we demonstrate the utility of GSI after neuroendovascular therapy using representative clinical cases.