光本 保英¹, 南 竜城¹, 森 敬弘¹, 内田 卓弥², 藤田 幸二², 小宮山 恭弘², 本庶 元³, 大見 甫⁴, 山川 忠弘⁵

Yasuhide MITSUMOTO¹, Ryuuki MINAMI¹, Takahiro MORI¹, Takuya UCHIDA², Koji FUJITA², Yasuhiro KOMIYAMA², Hajime HONJYO³, Hajime OHMI⁴, Tadahiro YAMAKAWA⁵

¹JR大阪鉄道病院消化器内科, ²JR大阪鉄道病院生理検査部門, ³大津赤十字病院消化器科, ⁴南海電鉄健康管理センター, ⁵GEヘルスケア・ジャパン株式会社超音波本部

¹Department of Gastroenterology, JR Osaka Railway General Hospital, ²Physiological Laboratory Division of Medical Image Center, JR Osaka Railway General Hospital, ³Department of Gastroenterology, Japanese Red Cross Otsu Hospital, ⁴Nankai Railway Healthcare Center, ⁵GE Healthcare Japan Corporation, Ultrasound Division

キーワード : fusion imaging, GPS marker, volume navigation, HCC, local treatment

目的：肝癌局所療法に超音波での病変描出は不可欠である．Bモードで同定出来ない病変に対し，超音波とCTやMRIとのFusion Imaging技術や，造影超音波を併用して治療する機会も増加しているが，これらの手法を用いても実施困難な場合がある．そこで，画像上にマーキングしたポイントを常にトラッキングし表示出来る機能であるGPS markers機能が，Bモードで同定出来ない肝癌の同定に有用か，さらに局所療法のガイドとしての応用についても評価した．方法：ファントムを用いて目的病変近傍に1点あるいは2点のGPS markerをセットし，ファントム接触面とプローブとの角度を変えた場合や回転させた場合にガイドマークがどのように変化し，どうすれば目的病変を同定し易くなるかを検討した．その結果を実際の造影超音波に応用した．結果：目的病変を同定し一致させるには，プローブの位置・角度・回転全てを一致させることが必要で，GPS markerを目的病変近傍に2点セットし，2点ともプラスマークに表示させるとプローブと体表面との角度，回転角度が再現可能であった．結語：肝癌局所治療のポイントは治療目標となる腫瘍を明瞭にかつ再現性よく描出することである．プローブと体表面との角度，回転角度を再現するには術者の技術に頼るしかなかったが，GPS markers機能を用いて2点のGPS markerを目的病変近傍にセットし，どちらもプラスマークになるようにプローブをコントロールすることで再現でき，標的病変断面の維持が可能であった．

Purpose: Visualization of a lesion by ultrasonography (US) is indispensable in the local treatment of hepatocellular carcinoma (HCC). Although treatment using contrast US and fusion imaging technologies that combine US images with those obtained using CT and MRI is increasingly being applied to lesions undetected by B-mode US, adequate treatment is sometimes difficult to accomplish. We attempted to determine if GPS markers, which enable us to continuously track points marked on the image and display them, was useful in identifying HCC lesions that B-mode US had failed to detect and was therefore useful in guidance in local treatment. Methods: One or two GPS markers were set in an area adjacent to the target lesion in a phantom, and when the angle between the contact surface of the phantom and the probe was changed and the probe was rotated, we investigated the appearance of the guide and looked for a way to detect a target lesion more clearly. We applied our results in using contrast US. Results: To detect the target lesion and synchronize it, we had to adjust for the combined effects of the placement of the probe, the angle of the probe, and the rotation of the probe. When two GPS markers were set in an area adjacent to the target lesion and both were displayed as plus signs, it was possible to reproduce the angle and rotation angles between the probe and surface of the body. Conclusion: Clear and reproducible visualization of a target tumor is essential in the local treatment of HCC. Although has often been left up the skill of the examiner to reproduce the angle and rotation angle between the probe and body surface, image reproduction was achieved and continuous visualization of a cross-section of the target lesion was made possible by setting two GPS markers adjacent to the target lesion while controlling the probe so that both markers were displayed as plus signs.