田中 幸子^{1, 2}

Sachiko TANAKA^{1, 2}

¹大阪がん循環器病予防センター, ²大阪府立成人病センター

¹Osaka Center for Cancer and Cardiovascular Disease Prevention, ²Osaka Medical Center for Cancer and Cardiovascular Diseases

キーワード : manual for abdominal ultrasound in cancer screening and health checkups, pancreatic cancer, pancreatic duct dilatation, pancreatic cyst, hypo-echoic area

膵臓は，肋骨や胃の背側に存在するため，超音波検査ですっかり描出するのが困難な臓器である．無症状の人を対象とした検診で見落としてはならない最も重要な膵臓の病気は膵がんであるが，膵内にとどまるごく微小な病変をとらえないと根治可能な早期がんが発見できないので，診断がとても難しい．膵臓の超音波スクリーニング検査で大切なポイントとして，以下の3点があげられる．①体位変換，高周波プローブの活用，場合により胃充満法などを用い，可能な限り広い範囲を観察すること，②膵がんの直接所見である低（等）エコー像や間接所見（副所見）である主膵管・分枝膵管の拡張像を的確に検出し，早期の膵がんを見落とさないこと，③膵がん高危険群である主膵管拡張と膵嚢胞を拾い上げることである．この3点について，検診判定マニュアルに沿って解説した．

The pancreas is a slender organ located behind the ribs or stomach filled with gas. As such, it is difficult to observe the entire pancreas with ultrasonography. The most important disease that must be detected during screening of asymptomatic people is pancreatic cancer. In order to detect curable pancreatic cancer without invasion to surrounding tissue, small and faint signs of pancreatic cancer must be detected. The following three conditions are key to successful screening. The first is to observe the broadest area of the pancreas using various postures such as head up, right side up or left side up with a high-frequency ultrasound probe, as well as the liquid-filled stomach method. The second is not to miss the direct or indirect signs of pancreatic cancer. The direct sign is a hypo- (or iso-) echoic area, and the indirect sign is main or branch pancreatic duct dilatation. The third is to detect pancreatic duct dilatation and/or pancreatic cysts as high-risk signs for pancreatic cancer. In the present manuscript, we describe the manner of ultrasound screening of the pancreas based on the Manual for Abdominal Ultrasound in Cancer Screening and Health Checkups.