【作者】 轩昂；

【导师】 史大鹏；

【作者基本信息】 郑州大学 ， 影像医学与核医学， 2009， 硕士

【摘要】 背景和目的视交叉周围肿瘤可压迫视交叉、视神经和视束造成视力减退、视野缺损等症状,本文对累及视交叉的视交叉周围肿瘤进行影像-临床-实验室检查,研究视交叉周围肿瘤与视力、视野及视诱发电位的关系,为临床诊断及研究提供依据。资料与方法搜集2007.9至2008.12期间手术病理证实的100例视交叉周围肿瘤行高场（西门子3.0T或1.0T）视交叉MRI、视力、视野及视觉诱发电位（VEP）检查。视交叉MRI常规做冠状位、矢状位、轴位T₁WI、冠状位、轴位T₂WI;层厚/层间距:3.0mm/0mm,FOV为210mm×210mm,矩阵为256×256;2次采集。所有MRI图像均由两名从事MRI诊断的专业人员双盲读片。1.视交叉受压位置及移位方向分类:根据视交叉受压位置及移位方向分为三类:A类:肿瘤从视交叉下方压迫视交叉,使之上移,其中单纯压迫视交叉者为A1类,除向上压迫视交叉外同时压迫视交叉前和/或后者为A2类;B类:肿瘤从视交叉上方压迫视交叉,使之下移,其中单纯压迫视交叉者为B1类,除向下压迫视交叉同时压迫视交叉前和/或后者为B2类;C类:视交叉被肿瘤包埋或显示不清。2.视野改变:将视野缺损类型分为7型,分别为正常视野、一侧暗点、单一象限缺损,颞侧偏盲、颞侧偏盲越过中线扩展至鼻上和/或鼻下象限、向心性缩小、全盲。将视野损害程度分为小于1/2象限、1个象限、2个象限、3个象限、4个象限5个级别。3.视诱发电位改变:将VEP表现分为5级:Ⅰ级—潜伏期正常,波形清楚平滑;Ⅱ级—潜伏期正常,波幅降低,或波幅正常但潜伏期延长;Ⅲ级—潜伏期延长,波幅降低;Ⅳ级—波形异常,潜伏期延长,波形难以辨认和分析;Ⅴ级—反应消失,平直。4.统计学分析:实验数据采用SPSS13.0软件包处理,采用秩和检验,以a=0.05为检验水平。结果一.视交叉周围肿瘤生物学特性与视功能的关系:1.视交叉受累及视交叉周围肿瘤大小与视功能改变的关系:所有视交叉受累患者中,直径小于30mm的视交叉周围肿瘤较直径大于30mm视交叉周围肿瘤,其视力下降程度、视野损害范围大小、视诱发电位改变级数轻。视交叉周围肿瘤大小与视力下降程度、视野损害范围、视诱发电位改变级数的差别有统计学意义（P＜0.05）。2.视交叉受累及视交叉周围肿瘤内部结构与视功能改变的关系:所有视交叉受累患者中,视交叉周围肿瘤内部结构与视力下降程度,视野损害范围大小、视诱发电位改变的级数依次为囊性最轻,囊实性次之,实性最重;三组比较有统计学差别（P＜0.05）。3.视交叉受累及视交叉周围肿瘤病理类型与视功能改变的关系:本组病例包括垂体瘤、颅咽管瘤、脑膜瘤、脊索瘤、胶质瘤、生殖细胞瘤、结核瘤、Rathke囊肿、血管母细胞瘤,视交叉周围肿瘤性质与视功能下降程度,视野损害范围大小、视诱发电位改变的级数不具相关性（P＞0.05）。二、视交叉形态位置异常与视功能的关系:1.视交叉受压位置及移位方向与视力下降的关系本组病例中,3例（6眼）为A1类改变,其中光感～0.1者2眼,0.2～1.0者3眼;54例（108眼）为A2类改变,其中光感～0.1者19眼,0.2～1.0者75眼,视力大于1.0者14眼。3例（6眼）为B1类改变,视力大于1.0者3眼,0.5～1.0者3眼;15例（30眼）为B2类改变,其中光感～0.1者4眼,0.2～1.0者23眼,视力大于1.0者3眼。25例（50眼）为C类改变,其中无光感者3眼,光感～0.1者18眼,0.2～1.0者27眼,视力大于1.0者2眼。视力下降程度C类＞A类＞B类;A2类＞A1类;B2类＞B1类;相互间比较有统计学差异（P＜0.05）。2.视交叉受压位置及移位方向与视野损害的关系本组病例中,A1类表现为正常视野3眼,视野异常累及颞上象限3眼,颞下象限1眼,鼻下象限1眼,鼻上象限0眼;A2类表现为视野异常累及颞上象限105眼,颞下象限95眼,鼻下象限55眼,鼻上象限4眼。B1类表现为正常视野4眼,视野异常累及颞上象限1眼,颞下象限1眼,鼻下象限1眼,鼻上象限1眼;B2类表现为累及颞上象限13眼,颞下象限25眼,鼻下象限3眼,鼻上象限1眼。C类改变无1眼表现为正常视野,视野异常累及颞上象限45眼,颞下象限34眼,鼻下象限24眼,鼻上象限9眼。视野损害程度C类＞A类＞B类;A2类＞A1类;B2类＞B1类;相互间比较有统计学差异（P＜0.05）。3.视交叉受压与视诱发电位异常的关系A1类视诱发电位＜Ⅲ级者5眼,视诱发电位≥Ⅲ级者1眼;A2类视诱发电位＜Ⅲ级者53眼,视诱发电位≥Ⅲ级者55眼。B1类视诱发电位＜Ⅲ级者6眼;B2类视诱发电位＜Ⅲ级者24眼,视诱发电位≥Ⅲ级者6眼。C类改变视诱发电位＜Ⅲ级者17眼,视诱发电位=Ⅲ级者33眼。视觉诱发电位异常C类＞A类＞B类;A2类＞A1类;B2类＞B1类;相互间比较有统计学差异（P＜0.05）。结论1.视交叉周围肿瘤的大小、内部结构与视功能的损害有相关性（P＜0.05）。2.视交叉周围肿瘤的性质与视功能的损害无相关性（P＞0.05）。3.视交叉受压下移时,视功能损害最轻,视交叉受压上移时较重,视交叉被包埋或显示不清时,视功能损害最重（P＜0.05）。4.视交叉受压下移时视野缺损发生的顺序由高向低为颞下象限→颞上象限→鼻下象限→鼻上象限;视交叉被包埋或显示不清及视交叉受压上移时,顺序为颞上象限→颞下象限→鼻下象限→鼻上象限。5.颞侧偏盲越过中线扩展至鼻上、鼻下象限为视交叉周围肿瘤最常见的视野缺损类型。更多还原

【Abstract】 Background and PurposeTumors around optic chiasm can oppress optic nerve,optic chiasm,and optic tract,thus leading to decreased vision and visual field defects.In this research these tumors were checked in image-clinic-laboratory examination to study the relationship between their MRI presentations and vision,visual field and evoked potential in order to offer evidences for clinical diagnosis and further researches.Materials and methods100 patients had tumors around optic chiasma which were proved by operations and pathology in the people,hospotal of Henan province from September 2007 to December 2008.They were examined by hypsifield MRI(Siemens 1.0T or 3.0T MR scanning unit),visual field,vision and visual evoked potential(VEP).Optic chiasma was routinely scanned in coronal,sagittal,axial T1WI and coronal,axial T2WI. Scanning parameters:slice thickness/slice distance:3mm/0mm,FOV 210mm×210mm,matrix 256×256;collection twice.All MRI images were read by two professional staffs double-blindly.ⅰClassification according to localization and displacement that optic chiasma was oppressed:the team could be divided into three types.Type A:the tumor oppressed the optic chiasma from the bottom,made it up;Type A1:only oppressed the optic chiasma,Type A2:oppressed the optic chiasma from front or back at the same time. Type B:the tumor oppressed the optic chiasma from anodic,made it down;Type B1:only oppressed the optic chiasma,Type B2:oppressed the optic chiasma from front or back at the same time.Type C:the optic chiasma was embedded by tumor and unclear.ⅱvisual field change:the visual field defects had 7 types:normal visual field,half blind-spot,one quadrant defect,bitemporal hemianopia,bitemporal hemianopia beyond central line and expand to upper and/or subtus quadrant of nose,concentric contraction,ablepsia totalis.It had 5 levels according to the degree of visual field defects:less than 1/2 quadrant,1 quadrant,2 quadrant,3 quadrant,4 quadrant.ⅲVisual evoked potential change:VEP had 5 grades:gradeⅠ-latency period was normal,waveform was clear and smoothing,Ⅱ- latency period was normal,wave amplitude was cut down,or wave amplitude was normal but latency period was longer,Ⅲ- latency period was longer,wave amplitude was less than normal,Ⅳ-waveform was abnormal,latency period was longer,waveform was hard to recognize and analyze,Ⅴ-reaction was disappear and waveform was straight.ⅳStatistical analysis:experimental data was handled with SPSS 13.0 software in rank sum test.Test of significance was considered as a=0.05.ResultsⅠRelationship between the bionomics of tumor around optic chiasma and visual functionⅰRelationship between the size of tumor around optic chiasma and the change of visual functionPatients with tumors around optic chiasm whose diameter was less than 30mm had lower degree of impaired vision,smaller visual field demage extent and lower stage of visual evoked potential changes than those patients with tumors around optic chiasm whose diameter was more than 30mm.The size of tumors around optic chiasma and the descendent degree of visual acuity,visual field damage extent and stage number of visual evoked potential change have statistically difference(P＜0.05).ⅱRelationship between the internal structure of tumors around optic chiasma and the change of visual functionIn all patients,the internal structure of tumors around optic chiasma according to the descendent degree of visual acuity,visual field damage extent and stage number of visual evoked potential change were spina bifida cystica(most slightly),spina bifida cystica-kernel,kernel(most severe).There were statistical difference among the three groups.ⅲRelationship between the pathological type of tumor around optic chiasma and the change of visual functionThis group contained hypophysoma,craniopharyngioma,durosarcoma,chord blastoma,neurogliocytoma,germ cell tumor,tuberculoma,Rathke’s cyst,hem ngioblastoma.There were no relationship between the character of tumors around optic chiasma and the descendent degree of visual acuity,visual field damage extent and stage number of visual evoked potential change(P＞0.05).ⅡRelationship between the abnormal shape,malposition and the visual functionⅰRelationship between the oppressed location,dislocated direction of optic chiasma and the descendent degree of visual acuityIn this group,3cases(6 eyes) was Type A1,light perception～0.1 in 2 eyes,0.2～1.0 in 3 eyes,54 cases(108 eyes) was Type A2,light perception～0.1 in 19 eyes, 0.2～1.0 in 75 eyes,visual acuity exceeding 1.0 in 14 eyes.3case(6 eyes) was Type B1,visual acuity exceeding 1.0 in 3eyes,0.5～1.0 in 3 eyes,15cases(30 eyes) was Type B2,light perception～0.1 in 4 eyes,0.2～1.0 in 23 eyes,visual acuity exceeding 1.0 in 3 eyes.25cases(50 eyes) was Type C,no light perception in 3 eyes,light perception～0.1 in 18 eyes,0.2～1.0 in 27 eyes,visual acuity exceeding 1.0 in 2 eyes. The descendent degree of visual acuity:Type C＞Type A＞Type B;Type A2＞Type A1,Type B2＞Type B1.There were statistical difference among the three groups(P＜0.05).ⅱRelationship between the oppressed location,dislocated direction of optic chiasma and the visual field damageIn this group,Type A1 was normal visual field in 3 eyes,abnormal visual field in upper temporal quadrant in 3 eyes,inferior temporal quadrant in 1 eye,inferior nasal quadrant in 1 eye and upper nasal quadrant in 0 eye.Type A2 was abnormal visual field in upper temporal quadrant in 105 eyes,inferior temporal quadrant in 95 eyes, inferior nasal quadrant in 55 eyes and upper nasal quadrant in 4 eyes.Type B1 was normal visual field in 4 eye,abnormal visual field in upper temporal quadrant in 1 eye, inferior temporal quadrant in 1 eye,inferior nasal quadrant in 1 eye and upper nasal quadrant in 1 eye.Type B2 was abnormal visual field in upper temporal quadrant in 13 eyes,inferior temporal quadrant in 25 eyes,inferior nasal quadrant in 3 eyes and upper nasal quadrant in 1 eye.Type C was normal visual field in 0 eye,abnormal visual field in upper temporal quadrant in 45 eyes,inferior temporal quadrant in 34 eyes,inferior nasal quadrant in 24 eyes,upper nasal quadrant in 9 eyes.The visual field damage degree:Type C＞Type A＞Type B,Type A2＞Type A1,Type B2＞Type B1.There were statistical difference among the three groups(P＜0.05).ⅲRelationship between the oppression of optic chiasma and visual evoked potentialType A1 was VEP＜gradeⅢin 5 eyes,VEP≥gradeⅢin 1 eye,Type A2was VEP＜gradeⅢin 53 eyes,VEP≥gradeⅢin 55 eyes.Type B1 was VEP＜gradeⅢin 6 eyes,Type B2 was VEP＜gradeⅢin 24 eyes,VEP≥gradeⅢin 6 eyes.Type C was VEP＜gradeⅢin 17 eyes,VEP≥gradeⅢin 33 eyes.The abnormal degree of visual evoked potential:Type C＞Type A＞Type B,Type A2＞Type A1,Type B2＞Type B1.There were statistical difference among the three groups(P＜0.05 ).ConclusionsⅰThe size and internal structure of tumors around optic chiasma have correlation with visual function damage(P＜0.05).ⅱThe character of tumors around optic chiasma have no correlation with visual function damage(P＞0.05).ⅲWhen optic chiasma was oppressed and moved down,the visual function damage was the lightest.It was more serious when optic chiasma was oppressed and moved up,and most serious when optic chiasma was embedded and unclear(P＜0.05).ⅳWhen tumors oppressed optic chiasma from the anodic and made it down,the subsequence(from high to low) that visual field defect happened was inferior temporal quadrant,upper temporal quadrant,inferior nasal quadrant,upper nasal quadrant,when optic chiasma was embedded by tumors or unclear and the tumors oppressed optic chiasma and made it up,the subsequence was upper temporal quadrant,inferior temporal quadrant,inferior nasal quadrant,upper nasal quadrant.ⅴThe most common type of visual field defect was bitemporal hemianopia beyond central line and expanding to upper nasal quadrant and inferior nasal quadrant.更多还原