Objective      To evaluate the capability of magnetic resonance tomographic angiography (MRTA) to represent three-dimensional relationship between the facial nerves and the adjacent blood vessels

and to discuss the diagnostic value of MRTA in vascular compressive hemifacial spasm(HFS).        Methods      Clinical data and MR data of 210 HFS patients were reviewed retrospectively and then were compared with the operation results.        Results      MRTA presented a total of 215 symptomatic sides in the 210 HFS patients

including 5 patients with bilateral symptoms. There were 109 symptomatic sides with vascular compression on facial nerves

86 with neurovascular contacts

and 9 with dubious contacts

implying that the positive rate reached 94. 9%. Among the 205 healthy sides

12 were identified with vascular compression

23 with neurovascular contacts

and 6 with dubious contacts

indicating that the positive rate was 20%. The anatomical relationship between the facial nerves and the adjacent blood vessels had statistically significant difference between the symptomatic sides and the healthy ones in the HFS patients

and there was a positive correlation between the symptoms and neurovascular contacts or vascular compression on the facial nerves (P0.01). Of 80 surgical patients

78 patients were found with vascular compression or neurovascular contacts

and 2 patients had no responsible vessels. The preoperative MRTA results of 71 patients were in complete accordance with the results found in the surgery. And among 4 patients with negative results of MRTA

3 were found with vein responsible vessels. With the operation results as the gold standard

the sensitivity and the diagnostic accordance rate of MRTA were 96.2% and 95.0%

respectively.        Conclusion       MRTA is a non-invasive and effective method for diagnosing the reasons of HFS before the operation. The spatial relationship between the facial nerves and the adjacent blood vessels can be clearly represented

and reliable imaging evidences can be provided for the diagnosis and treatment of HFS.