Kollias S S, Barkovich A J, Edwards M S
Department of Radiology, University of California, San Francisco.
Pediatr Neurosurg. 1991;17(6):284-303. doi: 10.1159/000120613.
A retrospective analysis of the magnetic resonance (MR) images in 53 pediatric patients with pathologically proven suprasellar tumors was performed, in an attempt to identify the characteristic MR features of these tumors and assess the capability of MR to predict a histologic differentiation. The tumors analyzed included 29 astrocytomas, 11 craniopharyngiomas, 4 germinomas, 3 pituitary adenomas with suprasellar extension, 2 teratomas, 1 spindle cell tumor, 1 primitive neuroectodermal tumor, 1 arachnoid cyst and 1 chordoma of the clivus with suprasellar extension. Thirty patients received intravenous Gd-DTPA as part of their MR exam. Certain MR features, while not pathognomonic, are quite helpful in the differentiation of craniopharyngiomas from chiasmatic/hypothalamic astrocytomas. Presence of a high signal intensity component on T1-weighted images, cyst formation with macrocystic predominance, irregular, heterogeneous solid portion, and smooth ring cyst wall enhancement represent the key characteristics of craniopharyngiomas. Solid predominance with microcysts, long T1 and T2 relaxation times, intense enhancement after contrast administration and extension along the posterior optic pathways are the typical MR findings of chiasmatic/hypothalamic astrocytomas. Presence of diabetes insipidus in correlation with the MR findings of a well-marginated, round or lobular tumor with prolonged T1 and T2 relaxation times, which enhances strongly after Gd-DTPA administration may be the clue in the diagnosis of suprasellar germinomas. Teratomas can be separated from other pediatric suprasellar neoplasms on the basis of internal heterogeneity with presence of fat, calcium and various soft tissue densities. Tumors invading the suprasellar cistern by extension are easily differentiated by identification of the primary site of origin. The above features, while not pathognomonic, are quite helpful in making a specific diagnosis.
对53例经病理证实的鞍上肿瘤患儿的磁共振（MR）图像进行回顾性分析，以确定这些肿瘤的特征性MR表现，并评估MR预测组织学分化的能力。分析的肿瘤包括29例星形细胞瘤、11例颅咽管瘤、4例生殖细胞瘤、3例向鞍上扩展的垂体腺瘤、2例畸胎瘤、1例梭形细胞瘤、1例原始神经外胚层肿瘤、1例蛛网膜囊肿和1例向鞍上扩展的斜坡脊索瘤。30例患者在MR检查时接受了静脉注射钆喷酸葡胺（Gd-DTPA）。某些MR表现虽然不是特异性的，但对区分颅咽管瘤和视交叉/下丘脑星形细胞瘤非常有帮助。T1加权图像上高信号强度成分的存在、以大囊为主的囊肿形成、不规则的异质性实性部分以及光滑的环状囊肿壁强化是颅咽管瘤的关键特征。以微囊肿为主、T1和T2弛豫时间长、注射造影剂后强化明显以及沿视束后段延伸是视交叉/下丘脑星形细胞瘤的典型MR表现。与边界清晰、圆形或分叶状肿瘤的MR表现相关的尿崩症，其T1和T2弛豫时间延长，注射Gd-DTPA后强化明显，可能是鞍上生殖细胞瘤诊断的线索。畸胎瘤可根据内部存在脂肪、钙和各种软组织密度的异质性与其他儿童鞍上肿瘤区分开来。通过确定原发起源部位，容易区分通过扩展侵犯鞍上池的肿瘤。上述表现虽然不是特异性的，但对做出明确诊断非常有帮助。
