西浦 哲哉¹, 渡辺 秀明¹, 河野 義彦¹, 伊東 正博^{1, 3}, 小森 敦正³, 藤本 俊史^{2, 3}, 大黒 学³, 八橋 弘³, 松岡 陽治郎², 石橋 大海³

Tetsuya NISHIURA¹, Hideaki WATANABE¹, Yoshiko KOUNO¹, Masahiro ITO^{1, 3}, Atsumasa KOMORI³, Toshifumi FUJIMOTO^{2, 3}, Manabu DAIKOKU³, Hiroshi YATSUHASHI³, Yohjiro MATSUOKA², Hiromi ISHIBASHI³

¹国立病院機構長崎医療センター研究検査科, ²国立病院機構長崎医療センター放射線科, ³国立病院機構長崎医療センター臨床研究センター

¹Clinical Laboratory, National Hospital, Organization (NHO) Nagasaki Medical Center, ²Department of Radiology, National Hospital, Organization (NHO) Nagasaki Medical Center, ³Clinical Research Center, National Hospital, Organization (NHO) Nagasaki Medical Center

キーワード : cirrhosis of the liver, liver surface, high-frequency probe, non-invasive evaluation, laparoscope

目的：肝硬変患者の肝表面の凹凸不整像を高性能・高周波プローブを用いて超音波検査で観察し, 肝表面の凹凸の深さ(以下, 肝表面凹凸深度) を計測し, 腹腔鏡での観察による肝表面結節像分類と比較することにより, 客観的な肝表面不整度評価および硬変肝表面結節像の分類が超音波検査で可能か否かを検討した. 対象：2003 年10 月‐2004 年10 月の1 年間に腹腔鏡検査と腹部超音波検査をともに行った慢性肝疾患患者56 名(男性25 名, 女性31 名, 平均年齢55 歳) を対象とした. 方法：使用した診断装置はATL 社製HDI-5000-sonoCT で, プローブは高周波リニアプローブL12-5 (5‐12 MHz) を用いた. 超音波検査による肝表面像の分類は, 肝表面凹凸深度(0.1 mm単位) を計測しその値を用いた. 腹腔鏡下肝表面像は0：平滑, 1：軽度不整, 2：中等度不整, 3：高度不整, 4：平坦結節, 5：丘状結節, 6：半球状(葡萄の房状) 結節の7 段階分類を用いた. 結果：腹腔鏡下肝表面像分類と超音波検査で求めた肝表面凹凸深度の相関係数は右葉でρ＝0.943 (P＜0001), 左葉でρ＝0.941 (P＜0001) と良好であった(スペアマン順位相関). 結論：高性能超音波装置で高周波プローブを使用し, 硬変肝表面結節部の凹凸深度を計測することは, 客観的な肝表面不整度評価および硬変肝表面結節像の簡便な分類に有用である.

Purpose: We studied the surface irregularity of cirrhotic livers by ultrasonography (US) using a high-performance, highfrequency US probe. To determine the efficacy of US evaluation of cirrhotic liver, we examined the liver surface by US and compared the results with laparoscopic liver surface classification. Subjects and Methods: The participants in the study were patients with chronic liver disease who had undergone both abdominal US and laparoscopic inspection during the period from October 2003 to October 2004. For US, HDI-5000-sonoCT (ATL Co. Ltd.) with a high-frequency linear probe, L12-5 (5‐12 MHz), was used. The liver surface was examined by US by measuring the depth from the line connecting the tops of two adjacent nodules on the liver surface. Laparoscopic classification of the liver surface was done according to a 7-stage classification system: (0) smooth, (1) slightly irregular, (2) moderately irregular, (3) highly irregular, (4) slightly tuberous, (5) moderately tuberous, and (6) hemispheric tuberous (bunch of grapes). Results: The correlation coefficient between US evaluation of the liver surface nodularity and laparoscopic classification was ρ＝0.941 (P＜0001) for the left lobe and ρ＝0.943 (P＜0001)for the right lobe (Spearman rank order correlation coefficient). Conclusions: US classification of the surface of the cirrhotic liver is possible using a high- performance, high-frequency probe. Furthermore, it is a useful way to non-invasively evaluate the stage of cirrhosis.