Prospective Observational Study To Assess The Temperature Changes In Children Undergoing Magnetic Resonance Imaging (MRI) Under Sedation

Magnetic Resonance Imaging (MRI) is a vital diagnostic modality that offers detailed visualization of internal body structures without exposing patients to ionizing radiation. In pediatric practice, MRI plays an increasingly significant role due to its safety profile and superior soft tissue contrast. However, performing MRI in children poses unique challenges, primarily due to the requirement for complete stillness during the scan to obtain high-quality images. Since most young children may not remain immobile voluntarily, sedation becomes necessary in many cases to facilitate the procedure.

 Sedation in children undergoing MRI, although beneficial for cooperation and image quality, can influence various physiological parameters. One such concern is body temperature regulation. The MRI suite environment is typically cool, and children—especially infants and toddlers—are more susceptible to thermal instability. Their larger body surface area relative to weight, limited subcutaneous fat, immature thermoregulatory mechanisms, and reduced shivering response make them particularly prone to hypothermia during procedures conducted under sedation.

 Furthermore, sedative medications can impair the central thermoregulatory centers, decrease metabolic heat production, and reduce behavioral responses to cold. This, combined with the relatively lower ambient temperature in MRI suites and the immobility induced by sedation, can lead to clinically significant drops in core body temperature. Mild hypothermia, if unnoticed, may prolong recovery time, alter drug metabolism, increase oxygen consumption, and in severe cases, cause cardiovascular or metabolic disturbances.

 Despite these known concerns, routine monitoring of temperature during sedated MRI procedures is often not recorded, primarily due to the logistical challenges posed by the MRI environment and lack of immediate clinical signs. In this context, evaluating the magnitude and trend of temperature change in children undergoing MRI under sedation becomes highly relevant.

 Rationale for the Study

 There is limited literature, particularly in the Indian clinical context, on the extent of temperature alterations in children sedated for MRI. Understanding these changes is essential to recognize at-risk age groups, identify contributing factors such as duration of scan and formulate strategies for prevention and monitoring. A prospective observational approach can provide real-world insights into current practices and outcomes, thus supporting better clinical decision-making and patient safety.

MRI is challenging in paediatric cases as it is difficult lying still in a noisy and enclosed scanner. Many children require anaesthesia/ sedation to achieve acceptable MRI quality. However, sedation and general anaesthesia reduce the ability to regulate body temperature. Several factors potentially influence the body temperature during MRI. The optimal functioning of the MRI magnet requires a room temperature of approximately 19–22°C and low humidity, which could contribute to a decrease in body temperature or even hypothermia in young children. The duration of MRI scan also influences the body temperature. Sedative drugs used for MRI also affect body temperature. Conversely MRI generates radio frequencies (RF) that are absorbed by the body and converted into heat, which may result in an increase in body temperature, especially in children due to their large body surface area (BSA) relative to body volume. temperature management is further complicated because it is difficult to monitor temperature during the MRI

This study is designed to study the effect of MRI on core body temperature in children under sedation during MRI scanning. The primary aim was to determine the proportion of sedated children undergoing an MRI scan who experience hyperthermia (tympanic temperatures of greater than 38°C) or hypothermia (tympanic temperatures less than 36°C).

The strength of the magnetic field is measured in Tesla (T); most clinical scanners have a magnetic field strength of 1.5 T or 3.0 T.(our hospital have 3.0 T) The stronger 3.0 T scanner may potentially increase the body temperature more than the 1.5 T. The change in body temperature depends on body composition and the ability to thermoregulate.  Both hypo- and hyperthermia can lead to complications.

In our study we will measure the tympanic membrane temperature by Ear thermometer ( Beurer ear thermometer ). We will measure pre-procedure baseline temperature and post procedure tympanic membrane temperature of children for MRI. Tympanic membrane temperature is core body temperature , which is convenient to measure.