目的 采用场强为3.0T的时间飞跃法磁共振血管成像术（3.0T TOF MRA），观察突发性聋患者后循环动脉的内径及行程，为突发性聋的血管病因学提供理论依据。  方法 回顾性分析180例单耳突发性聋的患者和102名对照组患者的颅脑3.0T TOF MRA图像数据。在对两组患者的临床资料，包括年龄及性别分布、外周血低密度脂蛋白（LDL）、总胆固醇（TC）及甘油三酯(TG)水平、纤维蛋白原水平及基底动脉血流速度进行对比后，进一步对比3.0T TOF MRA下两组患者的基底动脉内径及行程，椎动脉内径及优势方向和程度，小脑下前动脉(AICA)的显影状态及内径，大脑后动脉(PCA)P1段和后交通动脉（PCoA）内径及行程等指标，并进行统计学分析。  结果 临床资料显示，突发性聋组外周血中LDL水平升高比例（34.44%）及显著升高比例（11.22%）明显高于对照组的升高比例（15.69%）及显著升高比例（4.9%）（P<0.01）。突发性聋组外周血中出现TC水平升高比例（24.44%）及显著升高比例（11.11%）明显高于对照组的升高比例（19.6%）及显著升高比例（2.94%）（P<0.05）。3.0T TOF MRA影像结果显示，突发性聋组基底动脉平均内径［（3.32±0.75）mm］相对于对照组平均内径较窄［（3.50±0.54）mm］（P<0.05）；突发性聋组仅左侧AICA显影率（10%）低于对照组（24.51%）（P<0.05），突发性聋组双侧AICA均不显影率（38.89%）高于对照组（26.47%）（P<0.05），两组患者AICA显影状态的总体分布差异具有统计学意义（P<0.01），突发性聋组显影的左侧AICA平均内径为(1.04±0.24) mm，与对照组内径（1.16±0.28）mm相比较窄（P<0.05）；突发性聋组左侧PCA P1段内径为(1.27±0.54) mm，与对照组内径（1.42±0.52）mm相比较窄（P<0.05），突发性聋组右侧PCA P1段的内径为(1.25±0.58) mm，与对照组内径（1.41±0.51）mm相比较窄（P<0.05）；突发性聋组仅左侧出现胚胎型大脑后动脉(fPCA)比例（3.33%）低于对照组（9.8%）（P<0.05），突发性聋组出现双侧fPCA比例（13.89%）高于对照组（4.9%）（P<0.05），两组患者fPCA出现位置的总体分布差异具有统计学意义（P<0.01）。  结论 突发性聋患者基底动脉及其分支存在狭窄，同时LDL及TC水平升高，动脉狭窄与血脂升高可能存在一定关联。

Objective To study the patterns and diameters of posterior circulation in patients of sudden sensorinerual hearing loss(SSHL), and to provide anatomical evidence for the vascular etiology of SSHL.   Methods The craniocerebral images of 3.0T time of fly magnetic resonance angiography (3.0T TOF MRA) of 180 patients diagnosed with sudden deafness in one ear and 102 control patients were retrospectively analyzed. Clinical data including age and gender distribution, level of low-density lipoprotein(LDL), total cholesterol(TC), triglycerides(TG), fibrinogen and velocity of blood in basilar artery were compared. Subsequently, diameter and patterns of basilar artery, diameter and dominance of vertebral arteries, visible rate and diameters of anterior inferior cerebellar arteries (AICA), and diameter and patterns of P1 segment of posterior cerebral arteries(PCA) and posterior communication arteries（PCoA）were compared between the two groups. Statistical method  were used for analysis.   Results Clinical data showed that the proportion of increase (34.44%)and significantly increase(11.22%) of LDL level in peripheral blood of SSHL group were higher than that of the control group (15.69% and 4.9%), and the proportion of increase (24.44%)and significantly increase(11.11%) of TC level in peripheral blood of SSHL group were higher than that of the control group (19.6% and 2.94%). MRA imaging result  showed that the mean diameter of basilar artery in SSHL group(3.32±0.75 mm) was narrower than that in the control group (3.50±0.54 mm)(P<0.05);The imaging rate of only left AICA in SSHL group(10%) was lower than that in the control group (24.51%)(P<0.05);The invisible rate of bilateral AICA in SSHL group (38.89%) was higher than that in the control group (26.47%)( P<0.05);The overall distribution of AICA imaging status in two group was statistically significant(P<0.01). The mean diameter of imaged left side AICA in SSHL group (1.04±0.24) mm was narrower than that in the control group (1.16±03.28) mm (P<0.05). The mean diameter of left side P1 segment of PCA in SSHL group(1.27±0.54) mm was narrower than that in the control group (1.42±0.52)mm (P<0.05);The mean diameter of left right side P1 segment of PCA in SSHL group(1.25±0.58)mm was narrower than that in the control group (1.41±0.51) mm (P<0.05). The proportion of fetal posterior cerebral artery (fPCA) only on the left side of SSHL group(3.33%) was lower than that of the control group(9.8%)(P<0.05);The proportion of bilateral fPCA of SSHL group(13.89%) was higher than that of the control group(4.9%)(P<0.05);The difference in the overall distribution of the presence of fPCA between the two groups was statistically significant(P<0.01).   Conclusion There is stenosis of the basilar and branch arteries, due to a high level of low-density lipoprotein and cholesterol in patients of SSHL.