MRI Thermal Imaging of Infants Undergoing Cooling for Hypoxic Ischemic Encephalopathy(HIE)

• Brain temperature [ Time Frame: Day three of cooling ] [ Designated as safety issue: No ]
  MRI data will be used to estimate regional brain temperature
  
  

• Brain temperature upon rewarming [ Time Frame: 2 hours after initial MRI ] [ Designated as safety issue: No ]
  Estimate of brain temperature when rewarmed
  
  

We propose to develop a non-invasive measurement of brain tissue temperature and to apply this measurement of infants under-going cooling for HIE

1. We propose to do this by refining the use of the MRI evaluation of the NAA-H20 frequency shift. This molecular relationship is quite accurate (based on preliminary studies of an NAA-H20 phantom subject to controlled temperature variations) for measuring relative temperature changes.
2. The next step will be to perform further phantom imaging with continuous temperature measurements and to expand the phantom model. This work needs funding support to be completed.
3. At the same time we will be applying the MRI thermal imaging protocol to infants whom have experienced HIE and who are being treated with hypothermia to ameliorate the HIE. We have IRB approval to approach families and to obtain the required data during clinically indicated MRI scans, this data accumulation will add an additional 3-5 minutes to the MRI. We will then perform a second MRI after the infant is rewarmed. We will compare the pairs of readings at two different core temperatures from at least five regions of the brain.
4. We will evaluate results of regional temperature measurements to determine if cooling of the human infant brain is uniform.
5. We will compare the two modalities of cooling to determine if selective head cooling and total body cooling provide similar distribution of cooling.
6. The final goal will be to compare MRI identified injury patterns to the temperature distribution in order to determine if distribution of cooling is related to outcome.