Brainstem corticospinal tract diffusion tensor imaging in patients with primary posterior fossa neoplasms stratified by tumor type: A study of association with motor weakness and outcome
Brainstem corticospinal tract diffusion tensor imaging in patients with primary posterior fossa neoplasms stratified by tumor type: A study of association with motor weakness and outcome
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DOI：
10.1227/01.neu.0000306098.38141.81
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发表时间：
2007-12-01
期刊：
影响因子：
4.8
通讯作者：
Johnson, Glyn
中科院分区：
文献类型：
--
作者：
Lui, Yvonne W.;Law, Meng;Johnson, Glyn
目的：扩散张量成像（DTI）可以在活体内描绘脑干白色物质束。本研究的目的是确定是否异常的DTI指标和纤维束成像与神经功能缺损和临床状态的患者原发性后颅窝tumors.METHODS：审查原发性后颅窝肿瘤谁接受磁共振成像与DTI的患者进行。患者按肿瘤类型（边界清楚或浸润性病变）分层。分数各向异性（FA）彩色图被用来定位脑干内的皮质脊髓束。测量FA、平均扩散率和特征值。进行纤维束造影。采用Bonferroni校正进行多重比较，在每个患者组内评估DTI指标与临床状态之间以及DTI指标与神经系统检查结果之间的相关性。患者组（浸润性病变与界限分明的病变）之间的DTI指标也进行了比较。结果：30例患者进行了研究（平均年龄，14.1岁; 16名男性，14名女性）。18名患者有浸润性病变，12名患者有边界清楚的病变。12名患者（4名界限清楚，8名浸润）在体检中表现出运动无力（4名右侧，3名左侧，5名双侧）。病灶边界清楚、无力的患者对侧皮质脊髓束的平均弥散系数较高，FA较低（P < 0.05）。在浸润性肿瘤患者中没有观察到这种相关性。在总共102个患者年的随访中（平均随访期，4.2年），17名患者（6个界限清楚的病灶和11个浸润性病灶）表现出完全缓解或疾病稳定，6名患者（3个界限清楚的病灶和3个浸润性病灶）表现出疾病进展或死亡。浸润性病变患者和边界清楚的病变患者的DTI指标无差异。肿瘤边界清楚且预后差的患者皮质脊髓束的横向特征值测量值明显低于临床状态较好的患者结论：原发性后颅窝肿块边界清楚者，脑干皮质脊髓束平均弥散系数增高、FA降低与对侧运动障碍有关;可以观察到较低的横向特征值，具有不利的临床结果。
OBJECTIVE: Diffusion tensor imaging (DTI) allows in vivo delineation of brainstem white matter tracts. The purpose of this study was to determine whether or not abnormalities of DTI metrics and fiber tractography correlate with neurological deficits and clinical status in patients with primary posterior fossa tumors.METHODS: A review of patients with primary posterior fossa tumors who underwent magnetic resonance imaging with DTI was performed. Patients were stratified by tumor type (well-circumscribed or infiltrating lesions). Fractional anisotropy (FA) color maps were used to localize the corticospinal tracts within the brainstem. FA, mean diffusivity, and eigenvalues were measured. Tractography was performed. Correlations between DTI metrics and clinical status and between DTI metrics and neurological examination findings were assessed within each patient group using Bonferroni correction for multiple comparisons. Comparisons of DTI metrics were also made between patient groups (infiltrating lesions versus well-circumscribed lesions).RESULTS: Thirty patients were studied (mean age, 14.1 yr; 16 male, 14 female). Eighteen patients had infiltrating lesions and 12 had well-circumscribed lesions. Twelve patients (four well-circumscribed and eight infiltrating) demonstrated motor weakness on physical examination (four right, three left, five bilateral). Patients with well-circumscribed lesions and weakness had higher mean diffusivity and lower FA in the contralateral corticospinal tract (P < 0.05). No such association was seen in patients with infiltrating tumors. In 102 total patient-years of follow-up (average follow-up period, 4.2 yr), 17 patients (six well circumscribecl and 11 infiltrating lesions) demonstrated complete response or stable disease and six patients (three well-circumscribed and three infiltrating lesions) demonstrated progressive disease or death. No differences were seen in terms of DTI metrics between patients with infiltrating lesions and those with well-circumscribed lesions. Patients with well-circumscribed tumors and a bad outcome had significantly lower transverse eigenvalue measures in the corticospinal tracts compared with those with a more favorable clinical status (P < 0.05).CONCLUSION: In patients with well-circumscribed primary posterior fossa masses, higher mean diffusivity and lower FA in the brainstem corticospinal tract are associated with contralateral motor deficits; lower transverse eigenvalue may be observed with an unfavorable clinical outcome.