Related Experiment Video
Updated: Aug 8, 2026
Making MR Imaging Child's Play - Pediatric Neuroimaging Protocol, Guidelines and Procedure
Published on: July 30, 2009
Brain magnetic resonance imaging increases core body temperature in sedated children
Yvon F Bryan1, Thomas W Templeton, Todd G Nick
1Department of Clinical Anesthesia and Clinical Pediatrics, Cincinnati Children's Hospital Medical Center and University of Cincinnati, College of Medicine, Cincinnati, Ohio 45229, USA. yvon.bryan@cchmc.org
Insights
Children undergoing sedation for magnetic resonance imaging (MRI) do not experience hypothermia. Instead, their body temperature increases during the MRI scan due to radiofrequency radiation absorption.
Area of Science:
- Pediatric imaging
- Medical physics
Background:
- Pediatric magnetic resonance imaging (MRI) often requires sedation.
- Children are at risk of hypothermia during MRI due to their high surface area-to-weight ratio and the need for a cool environment.
- Active warming devices are typically not compatible with MRI scanners.
Purpose of the Study:
- To investigate the effect of radiofrequency (RF) radiation absorption on body temperature in sedated children during MRI.
- To determine if children become hypothermic or experience temperature changes during brain MRI.
Main Methods:
- Tympanic temperatures were measured before and after brain MRI in 30 sedated children.
- Children received chloral hydrate sedation and were covered with a gown and blanket.
- Average scan duration was 42 minutes.
Main Results:
- Mean tympanic temperature increased by 0.5°C during the MRI scan (from 36.9°C to 37.4°C).
- The temperature increase was statistically significant (P < 0.001).
- No children became hypothermic.
Conclusions:
- Sedated children undergoing brain MRI do not develop hypothermia.
- Body temperature may increase during MRI due to RF radiation absorption.
- Aggressive measures to prevent heat loss may not be necessary for all pediatric MRI patients.
Abstract:
An increasing number of children now undergo magnetic resonance imaging (MRI) under sedation. MRI requires a cool environment. Because children have a larger surface area to body weight ratio than adults and because active warming devices are not MRI compatible, hypothermia as a result of passive heat loss is a risk. Absorption of radiofrequency radiation generated by the scanning process, however, may partially offset this heat loss. To determine the effect of absorbed radiofrequency radiation on body temperature during MRI, we measured pre-MRI and post-MRI tympanic temperatures in 30 children who underwent brain MRI while sedated with chloral hydrate and covered with a hospital gown and blanket. The mean (+/- sd) age was 14.9 +/- 8.6 mo, and weight was 9.8 +/- 2.8 kg. During an average scan duration of 42 +/- 13 min, mean tympanic temperatures increased 0.5 degrees C from 36.9 degrees C +/- 0.4 degrees C to 37.4 degrees C +/- 0.3 degrees C; (95% CI difference, 0.3 degrees C to 0.7 degrees C; P < 0.001). Our findings suggest that children sedated with chloral hydrate for brain MRI did not become hypothermic but rather had increased body temperature despite minimal barriers to heat loss and no active warming. These results imply that aggressive measures to prevent passive heat loss during MRI studies may not be needed in all patients.
Related Concept Videos
01:24Magnetic Resonance Imaging
01:21Imaging Studies for Cardiovascular System IV: CMRI