Nobushige HAYASHI1, Nagara TAMAKI1, Yoshiharu YONEKURA1, Kazutaka YAMAMOTO1, Kotoko NAKAJIMA1, Kanji TORIZUKA1, Toshio OGAWA2, Kageyoshi KATAKURA2, Shinichiro UMEMURA2, Mashio KODAMA3
1京都大学医学部附属病院放射線核医学科, 2日立中央研究所第9部, 3日立メディコ柏工場
1Department of Radiology and Nuclear Medicine, Kyoto University Hospital, 29th Department, Central Research Laboratory, Hitachi Ltd., 3Hitachi Medical Co.,Kashiwa
IN VIVO measurement, Sound speed, Fatty liver, Liver cirrhosis, Tissue characterization
A new system to measure sound speed IN VIVO was developed and applied to normal, cirrhotic and fatty livers. Sound speed was measured in 26 normal, 27 cirrhotic and 15 fatty livers. Mean speed was determined at 1538 m/s in normal, 1610 m/s in cirrhotic and 1423 m/s in fatty livers. The difference in speed between the three groups was significant (P values less than 0.001). It was considered that sound travels faster in cirrhotic livers because of their relative hardness over normal livers, and further, that the reduction in sound speed in fatty livers reflected the fact that sound travels more slowly through fat tissue. The method used to measure sound speed through tissue scanned IN VIVO clearly distinguished normal, cirrhotic and fatty livers. This technique would be an important tool for use in the objective and quantitative evaluation of diffuse liver diseases.