安原 一彰¹, 木村 邦夫², 中村 広志¹, 岩垂 信¹, 宮島 泰夫³, 大藤 正雄⁴

Kazuaki YASUHARA¹, Kunio KIMURA², Hiroshi NAKAMURA¹, Makoto IWADARE¹, Yasuo MIYAJIMA³, Masao OHTO⁴

¹千葉社会保険病院内科, ²千葉社会保険病院健康管理センター, ³(秩)東芝那須工場超音波技術部要素技術担当, ⁴千葉大学医学部第一内科

¹Department of Internal Medicine, Chiba Social Insurance Hospital, ²Department of Health Care Center, Chiba Social Insurance Hospital, ³Technology Engineering Group, Ultrasound Systems Engineering Department, Nasu Works, Toshiba Corp, ⁴The First Department of Medicine, Chiba University

キーワード : Color Doppler, Liver tumor, Velocity histogram, Turbulence, Tissue characterization

Tumor blood flow and hepatic arterial flow were studied with a color Doppler instrument to clarify differences in the blood flow. The flow spectrum was analyzed with velocity histography to investigate all the elements of velocity. Blood flow was classified into 3 types; a high-peak type that showed a peak of high speed elements, a flat type that showed various speed elements almost equally, and a low-peak type that showed a peak of low speed. Thirty-one of 35 tumor blood flows were the flat or low-peak type. Most hepatic arterial flows were the high-peak type (16 of 22 flows). Low-peak type and flat type flows with small elements of opposing directions were obtained only in the tumor blood flow. Using a phantom experimental unit of blood flow model, we used a velocity histogram to study turbulent flow just after the stenotic part. Turbulent flow appeared as a low-peak type with elements of opposing directions, resembling that of tumor blood flow. Emphasis of color flow mapping was observed just after the stenosis with the turbulent mode. These findings suggest that turbulent flow may be a characteristic of tumor blood flow and that liver tumor may be detectable by investigating turbulent flow with color flow mapping. By analyzing the characteristics of tumor blood flow with Doppler. we will be able to clarify the tissure characterization of liver tumors.