Despite some controversial results, many patients and animal studies have suggested significant benefit of using hypothermia treatment in stroke patient population. However, certain questions for how to applying this therapy properly such as when to start, what is the optimal temperature, how long is the duration, and what is the best hypothermia technology that may avoid the complications including focal soft tissue injuries are still remain questioned.

In this study, we will utilize the linear relationship of temperature vs. chemical shift in MR Spectroscopy to measure the brain temperatures in normal men.

Brain temperature has an interactive relationship with brain cell metabolism. Hypothermia is a known neuronal protectant therapy. It has been proven to be effective in reducing the brain injury in patients post cardiac arrest. However, the role of hypothermia in brain or spinal cord injury such as in either hemorrhagic or ischemic condition remains unclear. Many questions on hypothermia are unanswered. For example, what is the optimal low temperature in order to have the maximum therapeutic effect? How long should hypothermia be applied for? Is there a regional temperature difference between different parts of brain in physiological or pathological conditions? In order to answer these questions, the first step is to have a reliable way of measuring brain temperature accurately. However, invasive technique such as inserting temperature probe to different parts of brain is not practical. Using body core temperature to estimate the intracranial temperature is inaccurate.

To establish a noninvasive means to obtain and monitor brain temperature in a dynamic environment is the essential step in order to studying hypothermia and answering the questions mentioned earlier. MRI brain thermometry is a fast, direct and non-invasive method to estimate the brain temperature with great accuracy. This technique is based on several temperature dependent physical properties in our brain such as chemical shift between metabolites and water. Currently, there is no standard MRI brain thermometry in physiological and pathological conditions such as stroke. We plan to explore and establish MRI brain thermometry. The first step is to establish temperature correlation on measured water temperature.

Then temperature of different regions of brain will be used to compare to the standardized water temperature in normal people.

Inclusion Criteria:

• Normal and healthy

Exclusion Criteria:

• 1. claustrophobia, 2. history of neurological disease. 3. Tattoo and 4. History of lost conscience due to any head injury.

normal and healthy Men