呈振荡型血流频谱的椎动脉颅外段闭塞的经颅多普勒超声鉴别诊断

目的探讨经颅多普勒超声（TCD）在鉴别一侧椎动脉颅外段闭塞和锁骨下动脉盗血综合征Ⅱ期（SSSⅡ期）所致的椎动脉颅内段振荡型血流频谱中的作用。方法采用TCD筛查出一侧椎动脉颅内段呈振荡型血流频谱改变者42例，其中SSSII期组25例、椎动脉颅外段闭塞组17例，患者的病变均经DSA证实。另选25名健康体检者为对照组。比较三组TCD血流动力学参数的差异。计量资料采用中位数（25％～75％分位）表示。结果①SSSⅡ期组、椎动脉颅外段闭塞组患侧椎动脉均为收缩期反向、舒张期正向血流频谱。SSSⅡ期组逆转的收缩期时相较长；椎动脉闭塞组逆转的收缩期时相较短暂，频谱呈小尖波改变。SSSⅡ期组患侧椎动脉收缩期流速为[44（30～60）]cm／s，舒张期流速为[20（18～32）]cm／s；椎动脉颅外段闭塞组为[（27（11—34）]cm／s、[18（14～24）]cm／s，两组比较差异均有统计学意义。（2）SSSⅡ期组健侧椎动脉收缩期流速为[101（60～134）]cm／s，搏动指数（PI）为1．5（1．3～1．8）；椎动脉颅外段闭塞组分别为[53（45～79）]cm／s、1．0（0．9～1．1）；健康对照组为[55（44～66）]cm／s、0．9（0．8～1．0）。SSSⅡ期组与椎动脉颅外段闭塞组、健康对照组比较差异均有统计学意义；椎动脉颅外段闭塞组与健康对照组比较差异无统计学意义。③束臂试验或运动试验后，SSSⅡ期组收缩期逆转信号均增强，椎动脉颅外段闭塞组逆转信号改变不明显。（4）TCD与DSA诊断SSSⅡ期的敏感性为100％（25／25），诊断椎动脉颅外段闭塞的特异性为88．2％（15／17）。结论椎动脉颅内段振荡型血流频谱不仅见于SSSⅡ期，还可以见于椎动脉颅外段闭塞的患者。TCD的椎动脉血流频谱、血流动力学参数对比有助于其鉴别诊断。

Differential diagnosis of extracranial vertebral artery occlusion of bidirectional flow spectrum with transcranial Doppler ultrasonography

Objective To investigate the effect of differentiating the unilateral extracranial vertebral artery occlusion and subclavian steal syndrome stage Ⅱ （SSS Ⅱ ） lesions caused oscillatory flow spectrum at the intracranial segment of vertebral artery with transcranial Doppler sonography （TCD）. Methods The oscillatory flow spectrum changes at the intracranial segment of unilateral vertebral artery in 42 patients were screened using TCD, of those, there were 25 patients in SSS Ⅱ group, and 17 in extracranial vertebral artery occlusion group. All the lesions were confirmed by DSA. Besides, 25 healthy subjects were selected as control group. The differences of TCD hemodynamie parameters of the 3 groups were compared. The data were indicated with the median （25% -75% ）. Results （1）The ipsilateral vertebral arteries in the SSS Ⅱ and extracranial vertebral artery occlusion groups were systolic reverse and diastolic forward flow spectra. The reversed systolic phase was longer in the SSS Ⅱ group, and the reversed systolic phase was shorter in the extracranial vertebral artery occlusion group. The spectrum changes showed small sharp waves. The systolic and diastolic velocities of the ipsilateral vertebral arteries in the SSS Ⅱ group were 44 （30 -60） cm/s and 20 （ 18 -32） cm/s, respectively; those in the extraeranial vertebral artery occlusion group were 27 （ 11 -34） cm/s and 18 （14 -24） cm/s, respectively, and there were significant differences between the two groups. （2）The systolic velocity of the contralateral vertebral artery in the SSS Ⅱ group was 101 （60 -134 ） cm/s, the ptdsatility index was 1.5 （ 1.3 - 1.8 ） ; the extracranial vertebral artery occlusion group was 53 （45 - 79） cm/s and 1.0 （0.9 - 1.1 ）, respectively, and the control group was 55 （44 - 66） cm/s and 0.9 （0.8 - 1.0）, respectively. There were significant differences between the SSS Ⅱ group and the extracranial vertebral artery occlusion and the control groups. There were no significant differences between the extracranial vertebral artery occlusion and control groups. （3）After tourniquet test or exercise test, the reversal signals enhanced during the systolic period in the SSS Ⅱ group. The changes of the reversal signals were not obvious in the extracranial vertebral artery occlusion group. （4）The sensitivity of TCD and DSA in the diagnosis of SSS Ⅱ was 100% （25/25）, and the specificity in the diagnosis of the extracranial vertebral artery occlusion was 88.2% （15/17）. Conclusion The oscillatory flow spectrum in the intracranial segment of vertebral artery is not only found in patients with SSS Ⅱ, but also found in patients with extracranial vertebral artery occlusion. The vertebral artery flow spectrum and the hemodynamic parameters of TCD contribute to its differential diagnosis.