兵藤 公一¹, 平井 都始子¹, 大石 元¹, 山田 麗子¹, 廣橋 里奈¹, 本田 伸行¹, 打田 日出夫¹, 本多 基春², 田中 考²

Koichi HYODO¹, Toshiko HlRAI¹, Hajime OHISHI¹, Reiko YAMADA¹, Rina HIROHASHI¹, Nobuyuki HONDA¹, Hideo UCHIDA¹, Motoharu HONDA², Kow TANAKA²

¹奈良県立医科大学放射線科・腫癌放射線科, ²GE横河メディカルシステム（株）超音波事業部プローブ開発部

¹Department of Radiology/Oncoradiology, Nara Medical University, ²Probe Offering Department, Ultrasound Business Division, GE Yokogawa Medical Systems, Ltd.

キーワード : Acoustic couplant, Superficial organs, Paraquest, Low attenuation, Acoustic impedance

Various types of acoustic couplant gels have been used for superficial ultrasound examination, but it is difficult to attain optimum images in some cases. To cope with this problem, some new acoustic couplant gels have recently been developed. Such gels are primarily designed to have low attenuation and to optimize acoustic impedance against human derma. Similarly to such types of acoustic couplant gel, Paraquest also features low attenuation (0.5 dB/cm at 5 MHz) and the ability to match acoustic impedance to derma (1.58×10⁶kg&・m^-2・s^-1). Paraquest's physical characteristics and clinical usefulness were compared to those of conventional couplants. Paraquest has advantages in terms of allowing for high-resolution and high-contrast B-mode images, and fine color flow mapping images, especially when high frequency probes are used. Low attenuation induced multiple-reflection artifacts. However, such artifacts could be reduced through the proper selection of gel thickness. Paraquest, low-attenuation acoustic couplant gel, was considered highly useful in the ultrasonographic diagnosis of superficial organs.