川端 聡¹, 田上 展子¹, 尾羽根 範員¹, 津村 京子¹, 仙崎 菜々恵¹, 森 亘平¹, 植野 珠奈¹, 山片 重人², 西村 重彦², 山田 晃³

Satoshi KAWABATA¹, Nobuko TAGAMI¹, Norikazu OBANE¹, Kyoko TSUMURA¹, Nanae SENZAKI¹, Kohei MORI¹, Juna UENO¹, Shigehito YAMAGATA², Shigehiko NISHIMURA², Akira YAMADA³

¹住友病院診療技術部超音波技術科, ²住友病院外科, ³住友病院消化器内科

¹Department of Ultrasonography, Sumitomo Hospital, ²Surgery, Sumitomo Hospital, ³Digestive Tract Internal Medicine, Sumitomo Hospital

キーワード : acute cholecystitis, ultrasonography, ultrasonography findings, elapsed time, diagnostic imaging

目的：急性胆嚢炎における各種超音波検査（US）所見が発現する時間帯を明らかにすることで診断精度の向上が望めるかを検討した．対象と方法：2010年1月から2015年2月までの急性胆嚢炎128例のうち，発症日時が特定でき，US施行までの期間に積極的治療が行われていなかった69症例（男性41例，女性28例，平均年齢54.0歳）について，時間経過に伴う各種US所見（胆嚢腫大，胆泥，壁肥厚，壁内低エコー帯，胆嚢周囲液体貯留，膿瘍形成）の出現頻度を調べた．結果と考察：時間経過とともに腫大，胆泥および壁肥厚，低エコー帯，周囲液体貯留，膿瘍形成の順に出現頻度が増加した．発症後10時間以内に検査された70.0％（7/10）には腫大しかみられず，また腫大しかみられなかった10例全例が発症後15時間以内にUSが施行されており，腫大のみでも15時間以内であれば急性胆嚢炎を否定できないと考えられた．また発症24時間以降にUSが施行された91.7％（33/36）には少なくとも腫大＋胆泥＋壁肥厚がみられ，発症後24時間以降で腫大，胆泥，壁肥厚の何れもみられない場合は急性胆嚢炎の可能性が低いと考えられた．結論：急性胆嚢炎における各種US所見の出現順序と，それらが発現する時間帯を把握することで診断精度の向上が望めると考えられた．

Purpose: To investigate the possibility of improving the diagnostic accuracy by identifying the time course of various Ultrasonography (US) findings of acute cholecystitis. Subjects and Methods: The subjects were 69 patients (41 male and 28 female patients, mean age: 54.0 years old) who developed acute cholecystitis between January 2010 and February 2015, in whom the onset date and time could be identified and active treatment was not performed prior to US examination. We investigated the time-course incidences of various US findings (gallbladder enlargement, biliary sludge, wall thickening, intramural hypoechoic layer, fluid retention around the gallbladder, and abscess formation). Results and Discussion: The incidences of swelling, biliary sludge, gallbladder wall thickening, hypoechoic layer, fluid retention around the gallbladder, and abscess formation increased over time in this order. Swelling alone was noted in 70.0% (7/10) of patients who were examined within 10 hours after onset, and all such patients were examined by US within 15 hours after onset, suggesting that acute cholecystitis cannot be ruled out within 15 hours, even though only swelling is observed. In 91.7% (33/36) of patients who were examined by US 24 or more hours after development, at least swelling + biliary sludge + wall thickening were observed, suggesting that when swelling, biliary sludge, and wall thickening are not observed 24 or more hours after development, acute cholecystitis is unlikely. Conclusion: Diagnostic accuracy may be improved by investigating the order of the development of various US findings of acute cholecystitis and the time course of their development.