The Clinical Value Of The 3.0T Magnetic Resonance Angiography In Patients With Hemifacial Spasm

Objective To investigate the clinical value of the 3.0 T magnetic resonance imaging(MRI) and magnetic resonance angiography(MRA) in the preoperative etiological diagnosis for neurovascular compression patients in patients with hemifacial spasm (HFS),and to discuss the MRI feature and clinical significance of vertebrobasilr dolichoectasia(VBD) through morphological observation and measurements of Facial Nerve and blood vessels on MR Images and make sure the relationship between facial nerve and blood vessels.Materials and Methods 40 cases of HFS were subjected to routine MRI and 3D-TOF-MRA check up preoperatively.40 cases were examined on the axial position of the brain stem with T1WI/3D-TOF-SPGR.Using multi-planar reconstruction(MPR),curved planar reconstruction (CPR),maximum intensity projection (MIP),and volume rending technology (VR),which were shipped with the MRI software.Then the axial position and reformed slices from the axial position were compared with rank,To discuss the the relationship between facial nerve and blood vessels and make sure the responsibility blood vessels and its pathway.Result①The roots of the facial nerve involved sides were compressed by vessel in 38 cases of 42 cases,vessels were closed to or far from the the roots of the facial nerve in 2 cases.The origins of responsibility bloods including the anterior inferior cerebellar artery (AICA),the posterior inferior cerebellar artery(PICA),vertebra artery(VA),base artery(BA).The roots of the facial nerve were compressed by responsibility vessel in 6 cases were confirmated by vertebrobasilar dolichoectasia surgery.②To study the travelling course ofⅦcranial nerves between patient group and control groups,and to obtain the normal data of their optimal displaying angles.Compared with the roots diameter of the facial nerve in control groups,the roots diameter of the facial nerve involved sides in patient groups were dwindled obviously.The difference of both groups observed data including the length of facial nerve traveling in cisternography and angles of the nerves on the transversal and sagittal planes on MPR image were not statistical significance(P>0.05).③The roots diameter of the facial nerve involved sides in patient groups were dwindled obviously compared with the sides which were not involved.The angles of the nerves on the transversal planes on MPR image were dwindled synchronously.The difference of other observed data were not statistical significance(P>0.05).④The composition of the responsibility blood vessel were associated with the factor of age.The anterior inferior cerebellar arteriae(AICA) and posterior inferior cerebellar arteriae(PICA) were due to the responsibility blood vessel in young patient group.The other way round,in old patient group,the responsibility blood vessel were vertebral arteriae(VA) and basilar arteriae(BA).⑤The spasm degree of HFS were associated with the degree of neurovascular compression by responsibility blood vessel(P<0.05).⑥The relationship between responsibility blood vessel and facial nerve were divided into four types.⑦Compared the microvascular decompression surgery with preoperative MRI examination and analysed the results.Conclusion There was statistical correlation between the vascular compression of the root exit zone (REZ) of facial nerves and the symptoms of HFS. 3D TOF SPGR could improve the sensitivity, specificity and accuracy of detection that vascular contacted or compressed on nerve roots,and provide an important reference value for clinical diagnosis and MVD surgery.