枕下三角的超声解剖学研究

目的探讨枕下三角境界及内容物的检查方法与超声解剖学特点,为临床检查枕下三角提供超声影像学资料。方法对100例健康成年人枕下区进行超声检查,描述枕下三角境界的超声判定及解剖关系;阐述枕大神经的走行特点,测量头下斜肌表面枕大神经的横截面积;记录椎动脉V3段管腔内径(D)、收缩期峰值流速(PSV)、舒张期末流速(EDV)、阻力指数(PI)。结果 (1)寰椎后结节左侧约1 cm处纵切声像图显示寰椎后弓呈"短弧形"强回声,其后上方为头后大直肌、后下方为头下斜肌,三者分别构成枕下三角的底、内上界和外下界。(2)寰椎侧块处纵切声像图显示侧块为"平台样"强回声结构,其后方为椎动脉V3段、下方紧接寰椎后弓;后弓后方为头下斜肌、后上方为头上斜肌,头上斜肌构成三角的外上界,后弓与椎动脉V3段之间为枕下神经所在区域。(3)枕大神经长轴声像图显示神经从头下斜肌下缘发出后向内上走行于头下斜肌及头后大直肌与头半棘肌之间;不同性别头下斜肌表面枕大神经横截面积两侧比较,差异均无统计学意义(P>0.05)。(4)寰椎侧块处横切声像图显示椎动脉V3段呈"倒U形"绕侧块进入枕骨大孔,排除发育不良者,测V3段D为(3.52±0.39)mm、PSV及EDV分别为(43.33±9.05)、(21.87±5.86)cm/s、RI为(0.49±0.11)。结论超声是检查枕下三角及其内容物的理想方法。

The Sonoanatomy Study of Suboccipital Triangle

Objective To investigate the scanning method and sonoanatomy of suboccipital triangle for clinical assessment. Methods One hundred healthy adults confirmed by clinical examination were enrolled.Ultrasound scan was performed on their suboccipital region to describe the orientation and anatomical relationship of boundary.The route of greater occipital nerve(GON) would be described and it′s cross sectional area would be measured on the imaging.Some indexes of the third segment of vertebral artery(V3) would be measured such as internal diameter(D),peak systolic velocity(PSV),end-diastolic velocity(EDV)and resistance index(RI). Results(1)Sagittal scanning beside the posterior tubercle of atlas(PT) revealed that the superomedial and inferolateral boundary were formed by the rectus capitis posterior major(RCM) and obliquus capitis inferior(IOM)respectively;the floor was formed by the PA.(2)Sagittal scanning through the C1 lateral mass(LM) revealed that the superolateral and inferolateral boundary were formed by the obliquus capitis superior(SOM) and obliquus capitis inferior(IOM)respectively;the V3 was behind the PA.(3)The GON came under the IOM and goes superiorly.In terms of cross sectional area of GON,there was no significant difference between left group and right group(P>0.05).(4)Transverse scanning through the LM shown the V3 presented as the "inverted-U" sign.Except for dysplasia,the measured values of the V3 were 3.52±0.39(D),(43.33±9.05) cm/s(PSV),(21.87±5.86) cm/s(EDV) and 0.49±0.11(RI).Conclusions Ultrasonography is an effective tool to examine the suboccipital triangle.