Radiometric monitoring of cerebral cortex temperature

BACKGROUND: Impaired temperature homeostasis is crucial for the development and progression of brain damage in patients with stroke or traumatic brain injuries. Traditional basal thermometry techniques do not provide accurate brain temperature data. Additionally, the location of sensors limits the use of invasive thermometry. Existing non-invasive technologies, such as nuclear magnetic resonance and near-infrared spectroscopy, are either expensive or inaccurate. Microwave radiothermometry is a promising, noninvasive way to measure the temperature of deep tissues, including the cerebral cortex.

AIM: This study aimed to evaluate the accuracy and depth of brain temperature measurements using microwave radiothermometry, compared to data from implanted temperature sensors, and to monitor changes in cerebral cortex temperature during craniocerebral hypothermia.

METHODS: The study had two parts. The first part measured the brain temperature of patients with hemorrhagic stroke after decompressive craniectomy (n=5) using implanted temperature sensors (at a depth of 4–5 cm) and compared results with data from non-invasive microwave radiothermometry. The second part monitored changes in cortical temperature during craniocerebral hypothermia in patients with chronic disorders of consciousness (n=60).

RESULTS: A comparison of the data revealed that the difference between invasive thermometry and microwave radiothermometry did not exceed 0.3°C at a depth of 4–5 cm, corresponding to the cerebral cortex. Despite no change in basal temperature, a statistically significant decrease in frontal cortex temperature by 2.4–3.1°C was reported in craniocerebral hypothermia.

CONCLUSION: Microwave radiothermometry is a noninvasive method for assessing cerebral cortex temperature, allowing for the detection of latent hyperthermia and the monitoring of hypothermia depth.