Non-Invasive Monitoring of Acute Intracranial Mass Lesions Using Ultrasonic Fingerprinting

Abstract

ABSTRACTPotentially dangerous neurological changes in shock-trauma patients are currently monitored by computer-aided X-ray tomography which is prohibitively expensive and even dangerous for long-term, e.g., comatose, patients. By ultrasound, only low-frequency “diffuse” ultrasonic inspection is feasible through the skull so that the details are irreversible lost in the essentially random scattering process. In order to overcome this inherent limitation, we adapted a continuous computer-controlled ultrasonic monitoring system based on the ultrasonic fingerprinting method originally developed for materials characterization purposes in the nuclear, civil engineering, and aerospace industries. An ultrasonic detector directed at the general area of interest can be used to record and repeatedly update the personal signature of the patient, which is then used as an “ultrasonic fingerprint.” Any abrupt change in this signature indicates the immediate need for further investigation by CT or other sophisticated diagnostic tools. Experimental studies were conducted on both a human skull/gelatin phantom and 5 intact human cadavers. Ultrasonic fingerprinting could detect the secondary effects of volumetric changes occurring at multiple locations and the average detectable volumes of mass lesions were found to be lower than indications for surgical intervention.