脊髓内室管膜下瘤与星形细胞瘤的MRI对照研究

目的：：对比分析脊髓内室管膜下瘤与星形细胞瘤的MRI特征，提高影像学诊断水平。方法：回顾性分析经手术病理证实的16例脊髓内室管膜下瘤和20例星形细胞瘤的MRI表现，比较二者病变部位、累及范围、生长方式、信号特点、有无强化、边界是否清楚、有无囊变及瘤周情况等。结果：脊髓内室管膜下瘤位于颈段5例、颈胸段8例、胸段2例及胸腰段1例，星形细胞瘤位于颈段7例、颈胸段5例、胸段6例及胸腰段2例，差异无统计学意义(P>0.05)。室管膜下瘤纵轴长度(88.30±23.47)mm、瘤椎体数目(4.67±1.26)个，星形细胞瘤纵轴长度(55.16±19.56)mm、椎体数目(3.41±1.10)个，差异有统计学意义( P<0.05)。室管膜下瘤多呈偏心性生长、水肿不明显或仅轻微水肿、边界清楚、较少囊变，与星形细胞瘤比较差异有统计学意义( P<0.05)。室管膜下瘤平扫T1WI呈等或稍低信号14例、混杂信号2例；T2WI呈均匀高信号14例、混杂高信号2例；增强扫描示病变无强化11例、部分轻度强化或点片状轻度强化5例。星形细胞瘤平扫T1WI呈等或稍低信号11例、混杂信号9例；T2WI呈高信号12例、稍高信号6例和混杂信号2例；增强扫描无强化4例、轻度强化7例、明显强化9例。结论：脊髓内室管膜下瘤与星形细胞瘤在生长方式、边界、形态、瘤周水肿及强化程度等存在差异，有助于二者诊断及鉴别诊断。

Comparison of MRI between Subependymoma and Astrocytoma in Spinal Cord

Objective:To compare and analyze the features of MRI of subependymoma and astrocytoma in spinal cord, and to elevate the iconographic diagnosis level. Methods: The MRI manifestations of sub-ependymoma ( 16 cases) and astrocytoma ( 20 cases) in spinal cord confirmed by operative pathological results were retrospectively analyzed, and the disease regions, involved ranges, growth patterns, signal features, presence or absence of enhancement, being well-or ill-defined, presence or absence of cystic degeneration, and the conditions around the tumors were compared. Results:The numbers of cases with subependymoma in the cervical, cervico-thoracic, thoracic, and thoracolumbar segments of spinal cord were 5, 8, 2, and 1 ca-ses, respectively;while those of cases with astrocytoma were 7, 5, 6, and 2, respectively;and the differences were statistically insignificant ( P>0.05) . The longitudinal axis length and involved vertebral body number of subependymoma were (88.30±23.4)mm and (4.67±1.26), respectively; while those of astrocytoma were (55.16±19.56)mm and (3.41±1.10);and the differences were statistically significant (P<0.05). Most sub-ependymoma was eccentric, with not-obvious or only slight edema, well-defined, and with few cystic degen-eration, which was significantly different from astrocytoma ( P<0.05) . In patients with subependymoma, when MR plain scan, 14 displayed isointensity or slightly low signal intensity and 2 displayed mixed signal intensi-ties in T1WI;14 displayed homogeneous high signal intensity and 2 displayed mixed high signal intensity in T2WI. After intravenous administration of contrast medium, the mass was not enhanced in 11 patients, and partially mildly enhanced or mildly enhanced in punctiform or lamellar pattern in 5 patients. In patients with astrocytoma, when MR plain scan, 11 displayed isointensity or slightly low signal intensity and 9 displayed mixed signal intensities in T1WI; 12 displayed high signal intensity, 6 displayed slightly high signal intensity,and 2 displayed mixed signal intensities in T2WI. After intravenous administration of contrast medium, themass was not enhanced in 4 patients, mildly enhanced in 7 patients, and markedly enhanced in 9 patients.Conclusion: Subependymoma and astrocytoma in spinal cord are different in terms of growth pattern, boundary,appearance, edema around the tumor, and enhancement degree and so on, which is helpful for the diagnosisand differential diagnosis.