At King Khalid University hospital approximately 1200-1500 MRI are done yearly on pediatric and neonatal patients. The investigating hospital is one of the pioneers in providing this service in the Kingdom (which was established about 10 years ago) to the patients of this age group. Only a small percentage of pediatric patients with age above 8 years accept the procedure to be done without anesthesia; and majority of MRI procedures are done under general anesthesia. The airway management of these patients is commonly accomplished with laryngeal mask airways (LMA).

LMA are in practice of anesthesia since early 1980s. Pediatric and neonatal patients (including ex-premature) have also been benefited by the use of LMA. There are many advantages of LMA over endotracheal tube (ETT) in pediatric patients like ease of insertion, securing airway rapidly, avoidance of muscle relaxants, reduced incidence of sore throat, post-operative hoarseness and coughing at the time of extubation, greater hemodynamic and intra ocular pressure (IOP) stability.

There are different types of pediatric LMAs available e.g. I-gel, ProSeal, LMA supreme, LMA classic, LMA unique, LarySeal and Ambu. These devices differ morphologically from each other (silicone, polyvinyl chloride or soft gel). Out of all this variety of LMAs only few are MRI compatible (do not produce any artifact in the MRI image), for example Ambu LMA and I-gel LMA and in King Khalid University Hospital (the investigating hospital) these two types are being used.

On search of literature the investigators found only one study in adults in which such comparison has been made and there was no study comparing different LMAs on the basis of their spatial effects on anatomical structures of the neck and airway in pediatric patients with age 12 years or below.

In this prospective randomized study, the investigators will compare the spatial relationship of I-gel Trademark (TM) and Ambu® AuraOnce (AO)TM on pediatric airway in pediatric patients undergoing 3-D MRI under general anesthesia (GA).

Inclusion Criteria:

• After getting informed voluntary consent from the parents.
• American society of anesthesiologists (ASA) physical status I and II
• Age up to 12 years,
• Scheduled to undergo elective Magnetic resonance imaging (MRI) under General anesthesia (GA) for some medical or surgical disease of the -area (not involving oral cavity, larynx, pharynx and neck)
• Not likely to require use of muscle relaxants as MRI prerequisite (e.g breath holding).

Exclusion Criteria:

• Co-operative patients who will accept to undergo the procedure without anaesthesia
• Patients with upper respiratory tract infection, fever
• Known to be suffering from deformity of the face, larynx, pharynx or neck,
• Potentially difficult intubation,
• Full stomach patient,
• Contraindication to supraglottic device placement or GA,
• Failed supraglottic insertion or requiring emergency endotracheal intubation during the procedure -Patients whose trachea will already be intubated or will be having tracheostomy.-