The Anatomy Relationships Between The Cisternal Segment Of Trigeminal Nerve And Its Adjacent Vessel

Objective: This study is based on the advantage of magnetic resonance imaging of posterior cranial fossa,using three dimensional time of flight(3D-TOF)sequence and three-dimensional fast imaging employing steady state acquisition(3D-FIESTA)sequence to research the morphology of the cisternal segment of trigeminal nerve and the anatomy relationships between the cisternal segment of trigeminal nerve and its adjacent vessel,which would supply reliable imaging evidence for the primary trigeminal neuralgia.Methods:1 The general T2-FLAIR sequences were used in 108 volunteers without trigeminal neuralgia symptoms to eliminate intracranial disease.After that,each volunteer was adoptde by 3D-TOF and 3D-FIESTA sequences.2 All 3D-FIESTA MR images were performed separately at the position of oblique sagittal and coronal reconstruction.Measure the length of the cisternal segment of trigeminal nerve,the angle between the cisternal segment of trigeminal nerve and pons,the shape of the cisternal segment of trigeminal nerve and its cross section,the shortest distance between the cisternal segment of trigeminal nerve and its adjacent vessel(superior cerebellar artery,anterior inferior cerebellar artery,base artery,vein),the corresponding orientation to the cisternal segment of trigeminal nerve,and the percentage of the cisternal segment of trigeminal nerve position.Results:1 The length of the right cisternal segment of trigeminal nerve was1.022±0.225 cm,the length of the left cisternal segment of trigeminal nerve was 1.004±0.206 cm,the difference of the right and the left was not statistically significant with paired t-test(P=0.311);the right angle between the cisternal segment of trigeminal nerve and pons was 42.964±14.067°,the leftangle between the cisternal segment of trigeminal nerve and pons was35.452±12.027°,the difference of the right and the left was statistically significant with paired t-test(P=0.00);2 Using Spearman correlation analysis,the length of the right cisternal segment of the cisternal segment of trigeminal nerve had no correlation with age(r=-0.128,P=0.188);the length of the left cisternal segment of the cisternal segment of trigeminal nerve had no correlation with age(r=-0.063,P=0.519);the right angle between the cisternal segment of trigeminal nerve and pons had low positive correlation with age(r=0.195,P=0.043);the left angle between the cisternal segment of trigeminal nerve and pons had had no correlation with age(r=0.152,P=0.116);3 In 88 cases,the inner margin of the right cisternal segment of trigeminal nerve was smooth,the angle between the cisternal segment of trigeminal nerve and pons was 44.625±14.275°,in 20 cases,the inner margin of the right cisternal segment of trigeminal nerve was tortuous,the angle between the cisternal segment of trigeminal nerve and pons was38.446±16.256°,the difference was not statistically significant with two independent samples t-test(P=0.112);In 84 cases,the inner margin of the left cisternal segment of trigeminal nerve was smooth,the angle between the cisternal segment of trigeminal nerve and pons was 39.363±10.039°,in 24 cases,the inner margin of the left cisternal segment of trigeminal nerve was tortuous,the angle between the cisternal segment of trigeminal nerve and pons was 21.767±7.611°,the difference was statistically significant with two independent samples t-test(P=0.000);4 The shortest distance between superior cerebellar artery and the cisternal segment of trigeminal nerve had no significant difference between right or left with chi-square test(?2=3.843,P=0.279),the shortest distance between anterior inferior cerebellar artery and the cisternal segment of trigeminal nerve had no significant difference between right or left with chi-square test(?2=0.758,P=0.985),the shortest distance between vein and the cisternal segment of trigeminal nerve had significant difference between rightor left with chi-square test(?2=12.560,P=0.006);5 The distance between three types of right cisternal segment of the cisternal segment of trigeminal nerve and ipsilateral superior cerebellar artery had significant difference with chi-square test(?2=14.751,P=0.022);the distance between three types of left cisternal segment of the cisternal segment of trigeminal nerve and ipsilateral superior cerebellar artery had significant difference with chi-square test(?2=14.016,P=0.029);6 The most location of superior cerebellar artery closest to ipsilateral cisternal segment of the cisternal segment of trigeminal nerve was at15%-70% from the beginning of the cisternal segment of trigeminal nerve;the most location of vein closest to ipsilateral cisternal segment of the cisternal segment of trigeminal nerve was at 0-20% from the beginning of the cisternal segment of trigeminal nerve.Conclusions:1 The 3D-TOF and 3D-FIESTA sequence of MRI have obvious advantages in providing a clear view of the relationships between the cisternal segment of trigeminal nerve and its adjacent vessel,and can be considered as the first choice of imageology examination to study the anatomy relationships between the cisternal segment of trigeminal nerve and its adjacent vessel.2.The cisternal segment of trigeminal differ greatly in morphology,but basic bilateral symmetry in the same individual.3 The left angle between the cisternal segment of trigeminal nerve and pons was less than the right,and the right angle between the cisternal segment of trigeminal nerve had low positive correlation with age,which may because of the atrophy and rotate of the pons.4 The superior cerebellar artery and the wein had the closest relationship with the cisternal segment of trigeminal,there was no deformation of nerve root in normal population of this study.5 The type ? cisternal segment of trigeminal nerve had closer relationship with the superior cerebellar artery.6 The most location of superior cerebellar artery closest to ipsilateralcisternal segment of trigeminal nerve was at 15%-70% from the beginning of the cisternal segment of trigeminal nerve;the most location of vein closest to ipsilateral cisternal segment of trigeminal nerve was at 0-20% from the beginning of the cisternal segment of trigeminal nerve.