Application of spectral CT in the diagnosis of contrast encephalopathy following carotid artery stenting: a case report.

BACKGROUND Contrast encephalopathy is a rare complication of carotid artery stenting (CAS). Contrast encephalopathy is a diagnosis of exclusion that often needs to be distinguished from high perfusion syndrome, cerebral haemorrhage, subarachnoid haemorrhage (SAH), cerebral infarction and so on. CASE PRESENTATION In this study, we report on a 70-year-old man who was admitted to the hospital with transient ischaemic attacks presenting paroxysmal weakness of limbs in the previous 2 years. He had severe stenosis of the left internal carotid artery diagnosed by digital subtraction angiography (DSA) and underwent CAS. Two hours after the operation, the patient developed paralysis of the right upper limb, unclear speech, fever and restlessness. Emergency skull computed tomography (CT) showed swelling and a linear high-density area in the left cerebral hemisphere. To clarify the components of this high-density area in the traditional CT, the patient had spectral CT, which made the diagnosis of the leakage of contrast clear. After 1 week of supportive treatment, the patient improved. CONCLUSIONS Spectral CT can easily distinguish the components of high-density areas on traditional CT, which is haemorrhage, calcification or iodine contrast leakage. Therefore, spectral CT is worth consideration for the differential diagnosis of complications of vascular intervention.