采用MR波谱鉴别附件区良、恶性实性肿瘤的价值

MR spectroscopy for differentiating benign from malignant solid adnexal tumors

目的探讨氢质子MR波谱（1H-MRS）鉴别附件区良、恶性实性肿瘤的价值。方法回顾性分析106例（114个肿瘤）经手术病理证实，附件区实性病变为主的肿瘤患者资料，其中良性肿瘤44个，恶性肿瘤70个。术前均行常规MRI和1H-MRS检查。记录代谢物氮-乙酰天冬氨酸（NAA）、胆碱（Cho）、肌酸（Cr）、脂质峰（Lip）、乳酸（Lac）的峰值积分，以峰值较稳定的Cr峰为参照，计算NAA、Cho、Lac及Lip峰与Cr峰的峰值积分比值（分别为NAA/Cr、Cho/Cr、Lac/Cr及Lip/Cr）。采用独立样本t检验比较良、恶性肿瘤代谢物峰值积分比值的差异，采用ROC曲线下面积评价峰值积分Cho/Cr鉴别良、恶性肿瘤的效能，并确定鉴别二者的阈值。结果114个病灶均测出Cho峰，112个可见NAA峰（良性43个、恶性69个），70例可见Lip峰（良性21个、恶性49个），16例可见Lac峰（良性7例，恶性9例）。良、恶性附件肿瘤的峰值积分Cho/Cr和Lip/Cr分别为（4.8±2.5）和（9.6±3.3）、（6.4±4.0）和（10.5±4.6）分，差异均有统计学意义（t值分别为－8.826、－2.915，P〈0.05）。良、恶性肿瘤的峰值积分NAA/Cr分别为（1.4±0.7）和（1.6±1.0）分，差异无统计学意义（t值为－1.523，P〉0.05）。峰值积分Cho/Cr鉴别附件肿瘤良、恶性的ROC曲线下面积为0.902，以7.2分为阈值进行鉴别诊断，诊断恶性肿瘤的敏感度、特异度、准确度分别为80.0%（56/70）、88.6%（39/44）和83.3%（95/114）。结论在体1H-MRS对附件区良、恶性实性肿瘤的鉴别诊断有价值，其中Cho峰值意义最大。

Objective To investigate the ability of proton magnetic resonance spectroscopy （1H-MRS） for differentiating benign from malignant solid adnexal tumors. Methods One-hundred and six patients （114 tumors） with surgically and histologically proven solid adnexal tumors （44 benign, 70 malignant） underwent conventional MR imaging and 1H-MRS. Single-voxel spectroscopy was performed using the point resolved spectroscopy localization technique with a voxel size of 2.0 cm ＆#215; 2.0 cm ＆#215; 2.0 cm. Resonance peak integrals of choline （Cho）, N-acetyl aspartate （NAA）, creatine （Cr）, lactate （Lac）, and lipid （Lip） were analyzed and the Cho/Cr, NAA/Cr, Lac/Cr and Lip/Cr ratios were recorded and compared between benign and malignant tumors using independent two-sample t test. Receiver operating characteristic （ROC） curve analysis was used to evaluate the diagnostic performance of Cho/Cr ratio for differentiating benign from malignant tumors. Results A Cho peak was detected in all 114 tumors, NAA peak in 112 tumors （43 benign and 69 malignant）, Lip peak in 70 tumors （21 benign and 49 malignant）, and Lac peak in 16 tumors （7 benign and 9 malignant）. The Cho/Cr and Lip/Cr ratios were 4.8±2.5, 6.4±4.0 in benign versus 9.6 ± 3.3, 10.5 ± 4.6 in malignant solid adnexal tumors, respectively, with a statistically significant difference （t values were-8.826 and-2.915,P〈0.05）. The NAA/Cr ratio were 1.4 ± 0.7 in benign versus 1.6 ± 1.0 in 〈br〉 malignant solid adnexal tumors, with no statistically significant difference （t=-1.523,P〉0.05）. When the Cho/Cr threshold was 7.2 for differentiating between benign and malignant tumors, the sensitivity, specificity, accuracy were 80.0%（56/70）,88.6%（39/44） and 83.3%（95/114） respectively. Conclusions The 1H-MRS patterns of benign and malignant solid adnexal tumors differ. The Cho/Cr ratio can help clinicians differentiate benign from malignant tumors.