Intracranial measurements for neurosurgical aid

The authors point out that although computed tomography (CT) techniques have changed diagnostic procedures in neurosurgery extensively, complementary technologies covering CTs weak points are needed to treat to overcome intracranial diseases. They report on two areas they have been working in that are related to intracranial measurements: measurement of cranial bruit and computer-assisted surgical navigation. In the measurement of cranial bruit the authors tested their new detectors on eleven patients, including five aneurysm cases and four AVM (arteriovenous malformation) cases, and detected the bruit in six patients. The detectors showed better performance, especially at the low-frequency range, than displacement-type detectors. Since the bruit measurement is completely noninvasive, it can be easily introduced into health care examinations. The navigation system developed consists of an articulated pointer, a display apparatus and a personal computer which calculates the position of the pointer on the brain and overlays this position on the tomographic images. >