After obtaining due consent the patients are shifted into MRI suite, ASA standard monitors will be applied. Baseline Lung and  diaphragm sonography will be performed by an experienced investigator who are blinded to the group allocation, using ultrasound system  and baseline C score, totql lung score and diaphragm excursion noted.

The primary MRI anesthesia senior resident will open the sealed envelope and prepare the study drug as per the group allocation, who otherwise will have any involvement in this study. and the patients will receive either of the following sedative regimes:

Group A patients that is  Propofol group participants will receive  propofol and saline  followed by a continuous infusion of propofol 

Group B patients that is Propofol ketamine group Participants will receive  propofol and ketamine followed by a continuous infusion of propofol .

The above MRI sedation protocol will be carried out by Anaesthesia consultant posted in MRI as per the group allocation and will not be a further part of the study. The ultrasonography will be performed by one of the investigators blinded to the study group in question. The video clip and images of the performed USG scan will be stored for review.

After MRI scan, all patients will be shifted to PACU and a repeat USG lungs and diaphragm will be performed and data on C score, Total lung score and Diaphragm excursion noted. Patients will be kept for monitoring in PACU for a minimum of 6 hours and then followed up from the day of MRI to 72 hours after MRI sedation by telephonic interview of parents at 24 hours,48 hours and 72 hours from the MRI scan. A pre established structured questionnaire designed to screen patients for any features of postoperative pulmonary complications will be used for the purpose. The parents would have been informed about the proposed telephonic interview and the questionnaire on the day of the Pre-anaesthetic assessment.