title: Noninvasive detection of intracranial vascular lesions by recording blood flow sounds.
abstract: OBJECTIVE
  Transorbital blood flow sound recordings have the potential to be used for noninvasive detection of cerebral aneurysms and arteriovenous malformations. We describe our system and experience in detecting intracranial cerebrovascular disease.
  
  
  METHODS
  We investigated the noninvasive detection of intracranial vascular lesions by recording and analyzing the intracranial blood flow sounds. A new small transducer was placed on the unilateral eyelid to record the intracranial blood flow sounds, which were amplified and converted to digital data at a sampling frequency of 2000 Hz to provide a spectral analysis.
  
  
  RESULTS
  No spectral peaks were recorded in 30 healthy adults. Sharp peaks were recorded in 12 of 15 patients with unclipped aneurysms, and broad peaks were recorded in two patients with vasospasm after aneurysmal clipping and in all patients with severe intracranial internal carotid artery stenosis.
  
  
  CONCLUSIONS
  This noninvasive technique has the potential to be very useful in the detection of intracranial cerebrovascular disease, including aneurysm and arterial stenosis, and could be used in mass screening examinations.
authors.affiliation: Department of Neurosurgery, Ube Industries Central Hospital, Yamaguchi, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kurokawa
authors.forename: S
authors.initials: S
authors.lastname: Abiko
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D001157:Arterial Occlusive Diseases / Q000175:diagnosis / Q000503:physiopathology; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000503:physiopathology; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012171:Retinal Vessels