Microwave sensing of increased intracranial water content.
A new technique to monitor brain edema is described that uses microwave energy to detect increased intracranial water content. By recording the phase of a transmitted microwave signal, increases in intracranial water content on the order of 1% are detected in vivo. These findings suggest that the progression of brain edema on a long-term basis can be assessed by progression of brain edema on a long-term basis can be assessed by our technique. Furthermore, phase changes related to small intracranial pressure variations are observed, indicating that the detection of pathologic pressure variations such as Traube-Hering-Mayer waves and plateau waves is possible by a noninvasive microwave technique.
D000818:Animals; D001929:Brain Edema / Q000175:diagnosis*; D007427:Intracranial Pressure; D008872:Microwaves; D051381:Rats; D011919:Rats, Inbred Strains