杉山 高¹, 中村 元哉¹, 佐藤 慎祐¹, 氏次 初枝¹, 梅原 慶太², 土井 俊²

Koh SUGIYAMA¹, Motoki NAKAMURA¹, Shinsuke SATOH¹, Hatsue UJITSUGU¹, Keita UMEHARA², Shun DOI²

¹浜松南病院 エコー室, ²浜松南病院 整形外科

¹Department of Ultrasound Medicine, Hamamatsu South Hospital, ²Department of Orthopedic Surgery, Hamamatsu South Hospital

キーワード : ultrasonography, rib, fracture, chest ultrasound

目的：正常肋骨および肋骨骨折の超音波像を検討し，その走査法，走査上のチェックポイントおよび病変部位の新しい表示法を提案する．対象と方法：対象は，2006年8月‐2011年2月までの54ヵ月間に肋骨骨折が疑われエコー検査を実施したもの83名で，この内，肋骨骨折と診断したもの44名（男性24名，女性20名），平均年齢64歳（24‐84歳）を対象とした．方法：1） 肋骨エコーの検査体位と拡大画像による走査法，2） 正常肋骨のエコー像，3） 骨折類似像，4） 骨折所見に基づくチェックポイント，5） 病変部位の新しい表示法を提案した．結果：被検者の検査体位は斜位または側臥位で行った．非骨折部位の肋骨と軟骨ではエコー像に違いがあり走査によっては骨折類似像がみられた．肋骨骨折のエコー所見は，圧痛部位に一致し骨折段差（step sign）と骨表面の血腫が主なものであった．骨折部位の表示は，時計軸を用いたことで，遡及性のある客観的な病変部位の表示が可能であった．結論：肋骨骨折のエコー検査は，拡大画像でリニア探触子を圧痛部位に走査し，step signと骨表面のecho free spaceであり，肋骨骨折の診断にエコー検査が簡便で有用と思われる．今後，肋骨骨折が疑われる場合，積極的にエコー検査の施行が望まれる．

Objective: The aims of this study were to examine the ultrasound images of normal ribs and rib fractures, present an examination checkpoint, and propose a new representation and scanning method for rib lesion sites. Subjects and methods: Forty-four patients (24 men, 20 women) with an average age of 64 years (range, 24- 84 years) were selected from a group of 83 patients who underwent diagnostic ultrasound for suspected rib fractures over a period of 54 months from August 2006 to February 2011. The following points were investigated: (1) Body position of subject and scanning methods, (2) Ultrasound images of healthy ribs, (3) Images resembling fractures, (4) Checkpoints based on rib fracture ultrasound findings, and (5) Proposal of a new representation of lesion sites. Results: The subjects underwent ultrasound diagnosis in the oblique or lateral recumbent position. Depending on the scanning method used, healthy ribs and costal cartilages had different appearances on ultrasound images and were confused with fractures. Ultrasound findings indicating rib fractures were mostly cortical step-offs (step sign) and hematomas on the surface of the bone, consistent with the location of tenderness. Fracture sites were displayed using the clock method, which allowed retroactive and objective display. Conclusions: Ultrasound examination of ribs was performed by scanning locations of tenderness using a linear transducer to produce enlarged images. Both step signs and echo-free spaces on the bone surface were scanned. Ultrasound examination of rib fractures was easy to perform and effective as a diagnostic tool. It is preferred in suspected rib fracture cases.