篠原 正夫

Masao SHINOHARA

東邦大学医学部消化器内科

Division of Gastroenterology and Hepatology, Department of Subjects Medicine, Toho University, School of Medicine

キーワード : contrast enhancement, diffuse liver disease, ultrasonography, Doppler

本研究の目的は, 造影超音波で肝実質内血管構築の変化を映像化し, さらにその病理組織学的背景を明らかにすることにある. 造影超音波の対象は慢性肝疾患62例 (慢性肝炎31例, 肝硬変31例)と健常ボランティア8例. 病理組織学的検討には22例の手術検体や剖検肝 (慢性肝炎9例, 肝硬変13例)を用いた. 心肺疾患および肝細胞癌症例は除外した. 装置は東芝SSA 380 Aを使用し, カラードプラにより肝S 5領域における肝表面10×30 mmの範囲を観察. 造影剤Levovist ^® 300 mg/dlを使用し, その前後におけるカラーシグナル数を計測した. 病理組織学的検討には病理組織を光学顕微鏡で観察し, 肝表近傍の10×30 mmの範囲における径30〜1000 μmの細動脈数を計測した. 結果は慢性肝疾患においても健常ボランティアにおいても造影前後で比較し, 有意に造影後にカラードプラシグナル数が増加した. 肝病変が進行するにつれシグナル数は多くなる傾向にあり, 特に肝硬変症例においてはChild-Pugh grade Cに進行するにしたがってシグナルが増加した. 病理組織学的検討では, 径30〜124 μmの動脈数は慢性肝炎のほうが肝硬変より有意に多く, 逆に径125 μm以上の動脈血管数は肝硬変群に多い傾向にあった. 以上より, 肝表近傍カラードプラシグナル数は125 μm以上の末梢動脈枝の分布に一致する可能性が示唆され, 慢性肝疾患の病変進展に伴いシグナル密度が増加するのではないかと考えられた.

Purpose: The study aimed to quantify hepatic vascular changes that accompany the development of chronic liver disease using contrast-enhanced color Doppler ultrasonography and histopathological examination. Methods: A series of 62 patients with biopsy- proven chronic liver disease (31 chronic hepatitis, 31 liver cirrhosis) and 8 healthy controls were studied. Altogether, 22 livers (9 chronic hepatitis, 13 liver cirrhosis) obtained at surgery or autopsy were subjected to histopathological examination. Patients with cardiopulmonary disease or intrahepatic tumors were excluded. Intrahepatic color Doppler signals were scanned and counted at the liver surface in a 10×30 mm rectangle from liver segment V using color Doppler sonography (SSA 380 A) before and after contrast enhancement with SHU 508 A (Levovist ^® ). Small arteries 30-1000 μm in diameter were counted on the histopathlogical specimen by microscopy. Results: The number of color Doppler signals increased significantly after contrast enhancement in both patients and controls. The number of color Doppler signals was elevated before and after contrast enhancement when chronic liver disease was present, especially in cases of Child-Pugh grade C liver cirrhosis. Histologically, more arteries 30-124 μm in diameter were present in patients with chronic hepatitis than in those with liver cirrhosis, whereas more arteries ≧125 μm in diameter were present in patients with liver cirrhosis than in those with chronic hepatitis. Conclusion: Intrahepatic color Doppler signals are probably derived from peripheral arteries larger than 125 μm in diameter, and the signal density in these arteries increases with progression of the chronic liver disease.