胸大肌的超声解剖及其撕裂的声像图特点

目的：探讨胸大肌的正常声像图表现及超声诊断胸大肌撕裂的临床价值。方法：应用高频超声获取20例健康志愿者的双侧共40条胸大肌的系列长轴及短轴切面声像图，观察胸大肌的走行及其声像图表现。回顾性分析北京大学第三医院18例胸大肌撕裂患者的声像图资料，进行分型诊断，并对照其磁共振成像（magnetic resonance imaging, MRI）、外科手术和超声随访结果。结果：高频超声可以清晰显示正常胸大肌的位置、走行和结构。18例胸大肌撕裂患者平均年龄（37.2±15.6）岁，均有不同原因和程度的外伤史，如举重、篮球和撞击等，其中3例有MRI结果，9例行外科手术治疗，6例为超声随访。18例胸大肌撕裂病例中，超声均给出了损伤的解剖学定位和损伤范围，其中11例发生于左侧，7例发生于右侧。按照损伤部位可以分为3类：7例为肱骨端肌腱损伤（其中1例发生于胸骨头，2例发生于锁骨头，4例为锁骨头和胸骨头联合损伤），5例累及肌肉肌腱连接处，6例累及肌腹；部分撕裂者为12例，表现为回声减低，内部结构不清晰；完全断裂者为6例（其中3例发生于肱骨端肌腱，1例为肌肉肌腱连接处，2例位于胸大肌肌腹内），表现为纤维断裂，回缩，伴有或不伴有血肿形成，通过动态实时观察可以判断胸大肌撕裂范围及断端情况。结论：高频超声可以清晰显示胸大肌走行及其相关结构，超声检查能够诊断胸大肌及其肌腱的损伤程度和范围，可以用来指导胸大肌撕裂的临床治疗。

Sonographic fingdings of pectoralis major and its tears

Objective:To investigate the normal sonographic anatomic characteristics of the pectoralis major and the clinical value of ultrasound in diagnosing the extent and location of the pectoralis major tears.Methods:High frequency transducer was used in scanning the pectoralis major.The ultrasono-graphic images of 40 normal pectoralis major were obtained from 20 healthy volunteers with both sides. Longitudinal and transversal views were performed and stored.The distal tendon was identified in the transverse plane coursing superficially to the long head of the biceps brachii tendon inferior to the level of the subscapularis tendon.Eighteen cases of pectoralis major tears were analyzed retrospectively,with MRI,surgical and ultrasound follow-up results correlation respectively.Results:High-frequency ultra-sound could clearly show the anatomic orientation of the normal pectoralis major.The fibers converge was like a fan into three laminae that twisted upon each other at 90°before coalescing into a single tendon of insertion.In the study,1 8 patients of pectoralis major muscle tears [average age:(37.2 ±1 5.6)years] sustained injuries during weightlifting,basketball and impact.Three of the eighteen patients had MRI re-sults;nine had surgical correlation;six were followed by ultrasound.Eleven were injured on the left side,and 7 on the right side.Seven were involved in the distal tendon (1 in sternal head,2 in clavicular head,4 in both sternal and clavicular head),five were involved the musculotendinous junction,6 were involved muscle belly.Twelve cases were partial-thickness petoralis major tears(4 in the distal tendon, four in the muscle tendon junction,4 in the muscle belly),with the partial fiber intact,echogenicity de-creased and the internal structure disordered;6 cases (3 in the distal tendon,1 in the muscle tendon junction,2 in pectoralis major muscle belly)were completely disrupted,with fiber fracture and retrac-tion,accompanied with or without hematoma formation.Conclusion:High-frequency ultrasound can clearly show the anatomic structure of the pectoralis major.Ultrasonography can diagnose the pectoralis major tears with the extent and location of injuries,and can be used to help the clinical treatment.