In a clinical trial, efficacy and safety of intranasal midazolam and oral chloral hydrate in induction of sedation of 60 children 1-18 years old referred to Ct scan unit of Shahid Sadoughi Hospital , will be evaluated. The patients will randomly be assigned to receive either 75 mg/kg/dose of chloral hydrate or 0.2mg/kg intranasal midazolam until Ramsay score of four is attained. Vital signs and adverse effect will be evaluated in children for two hours after drug use. Efficacy of drugs in sedation induction, time to induction of sedation, total stay time in CT unit, serious adverse events (hypotension, hypoxia and cyanosis, severe vomiting, irritability, apnea, laryngospasm, and bradycardia), and caregiver’s satisfaction are also compared between groups.