title: Performance validation of a modified magnetic resonance imaging-compatible temperature probe in children.
abstract: BACKGROUND
  During magnetic resonance imaging (MRI), children are at risk for body temperature variations. The cold MRI environment that preserves the MRI magnet can cause serious hypothermia. On the other hand, hyperthermia may also develop because of radiofrequency-induced heating of the tissues, particularly in prolonged examinations. Because of a lack of MRI-compatible core temperature probes, temperature assessment is unreliable, and specific absorption rate-related patient heat gain must be calculated to determine the allowable scan duration. We compared an MRI-compatible temperature probe and a modification thereof to a standard esophageal core body temperature probe in children.
  
  
  METHODS
  Children undergoing general anesthesia were recruited, each patient serving as his/her own control. Core body temperature was measured using 3 different devices: (1) a fiberoptic MRI-compatible skin surface temperature probe (MRI-skin) located on the child's skin surface; (2) a fiberoptic MRI-compatible temperature probe modified with a single-use sleeve at the tip (MRI-core), located in the nasopharynx; and (3) a standard temperature monitor (STRD) located in the esophagus or nasopharynx. The Bland-Altman method was used for statistical analysis.
  
  
  RESULTS
  We enrolled 60 children aged 7.8 ± 6 years (mean ± SD) weighing 32.4 (±26.4) kg. The estimated difference between the STRD and MRI-core measurements of core temperature was 0.06°C (confidence interval [CI]: -0.02, 0.15), and between the STRD and the MRI-skin 1.19°C (CI: 0.97, 1.41). According to the Bland-Altman analysis, the 95% limits of agreement ranged from -0.9 to 3.4 and from -1.3 to 1.2 between the STRD and the MRI-skin probe and the MRI-core probe, respectively.
  
  
  CONCLUSIONS
  Our results show good agreement between standard esophageal measurements of core temperature and core temperature measured using a modified MRI-core probe during general anesthesia in a general surgical pediatric population. The ability to accurately assess core temperature in the MRI suite may safely allow longer scan times and therefore reduce repeat anesthetic exposure, improve patient safety, and enhance the quality of care in children.
authors.affiliation: Department of Anesthesiology, Tufts Medical Center, Boston, MA 02111, USA. vnasr@tuftsmedicalcenter.org
authors.forename: Viviane G
authors.initials: VG
authors.lastname: Nasr
authors.forename: Roman
authors.initials: R
authors.lastname: Schumann
authors.forename: Iwona
authors.initials: I
authors.lastname: Bonney
authors.forename: Lina
authors.initials: L
authors.lastname: Diaz
authors.forename: Iqbal
authors.initials: I
authors.lastname: Ahmed
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D000768:Anesthesia, General; D001831:Body Temperature; D001900:Boston; D002648:Child; D002675:Child, Preschool; D004780:Environment, Controlled; D004867:Equipment Design; D004947:Esophagus; D005260:Female; D005334:Fever / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005336:Fiber Optic Technology / Q000295:instrumentation*; D006801:Humans; D007035:Hypothermia / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000009:adverse effects*; D008297:Male; D009305:Nasopharynx; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012881:Skin Temperature; D013821:Thermometers