title: Relative attenuation measurements of ultrasound in the liver using the zerocrossing method.
abstract: The zerocrossing method for measurement of the frequency dependence of ultrasound attenuation was used to study the livers of 10 healthy subjects and 9 patients. Increased attenuation in vivo was observed in 5 patients who were seen to have a 'bright liver' during B-scanning. Normal attenuation was seen in 3 patients who had pathologic liver biopsies, but normal B-scan images. Increased attenuation was seen in one patient who had a nodular appearance of the liver during B-scanning; biopsy showed steatosis. These results indicate that the zerocrossing method makes it possible to quantify some of the changes seen in the B-scan image. A detailed description, including block diagrams, is given of a zerocrossing detector which can be connected to a commercially available scanner (Brüel & Kjaer Ultrasound Scanner Type 1846).
authors.affiliation: Ultrasound Department, Herlev Sygehus, University of Copenhagen, Denmark.
authors.forename: K E
authors.initials: KE
authors.lastname: Fredfeldt
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008099:Liver / Q000033:anatomy & histology* / Q000473:pathology; D008107:Liver Diseases / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography / Q000379:methods*