脊柱不典型单发转移性恶性黑色素瘤的MRI表现:与脊柱血管瘤鉴别

MRI diagnosis of atypical solitary metastatic malignant melanoma in spine:Differentiation from spinal hemangioma

目的探讨MRI对脊柱不典型单发转移性恶性黑色素瘤与血管瘤的鉴别诊断价值。方法回顾性分析13例脊柱不典型单发转移性黑色素瘤患者及40例脊柱单发血管瘤患者。对所有患者均行1.5T MR扫描,采用T1W、T2W、脂肪抑制T2W序列和增强扫描。观察病灶的信号特征,平扫分为低、等、高信号,增强扫描分为低、等、稍高及明显强化。测量病灶的最长径,然后取平均值。结果脊柱单发转移性黑色素瘤T1WI低、等及高信号比例分别为76.92%(10/13)、15.38%(2/13)及7.69%(1/13),T2WI低、等及高信号比例分别为61.54%(8/13),30.77%(4/13)及7.69%(1/13);92.31%(12/13)的脊柱单发转移性恶性黑色素瘤增强扫描表现为明显强化。与脊柱血管瘤比较,转移性黑色素瘤长径大于血管瘤(P<0.001)。脊柱血管瘤和不典型转移性黑色素瘤之间T1WI与T2WI信号特征、增强扫描强化特征差异均有统计学意义(P均<0.05)。结论MRI对鉴别脊柱单发不典型转移性黑色素瘤与血管瘤有一定的临床应用价值。

Objective To evaluate the value of MRI performance for the differential diagnosis of atypical solitary metastatic malignant melanoma from spinal hemangioma. Methods Thirteen patients of atypical solitary metastatic malignant melanoma and 40 patients of spinal solitary hemangioma were retrospectively analyzed. Conventional MR imaging （T1WI, T2WI, and fat suppressed T2WI） and enhanced imaging were performed at 1.5T MRI. The signal intensities （SIs） of spinal lesions were qualitatively evaluated on conventional imaging and were described as hypointense, isointense, or hyperintense. The spinal lesions were qualitatively categorized into minimal enhancement, iso-enhancement, slightly hyper-enhancement, or strong enhancement on contrast-enhanced imaging. The lesions＇ maximum diameter was also measured and the mean value was obtained. Results The qualitative assessment of SIs on T1WI showed that 76.92% （10/13）, 15.38% （2/13） and 7.69% （1/13） of atypical solitary metastatic malignant melanoma were hypointensity, isointensity and hyperintensity respectively. The qualitative evaluation of SIs on T2WI were found that 61.54% （8/13） of atypical solitary metastatic malignant melanoma with hypointense, 30.77% （4/13） with isointensity and 7.69% （1/13） with hyperintensity, respectively. About 92.31% （12/13） of atypical solitary metastatic malignant melanoma displayed strong enhancement on contrast-enhanced imaging. There were significant differences in SIs on T1WI, T2WI and contrast-enhanced imaging between atypical solitary metastatic malignant melanoma and hemangioma （all P〈0.05）. The maximum diameter of atypical solitary metastatic malignant melanoma was significantly higher than that of spinal hemangioma （P〈0.001）. Conclusion MR imaging would be practicable for differentiation between atypical solitary metastatic malignant melanoma and hemangioma in spine.