Mansour Sahar Mahmoud, Gomma Mohammed Mohammed Mohammed, Shafik Peter Nashaat
1Department of Radiology (Women's imaging unit), Kasr ElAiny Hospital - Faculty of Medicine - Cairo University, Cairo, Egypt.
2Department of Radiology, National Cancer Institute- Faculty of Medicine - Cairo University, Cairo, Egypt.
Br J Radiol. 2019 Sep;92(1101):20190134. doi: 10.1259/bjr.20190134. Epub 2019 Jul 18.
To assess the impact of MR spectroscopy (MRS) on the detection of malignancy in ovarian masses.
This prospective work included 230 females that had 245 adnexal/ovarian masses. Tumours were spotted by preliminary pelvic ultrasound. Masses assessed by MRI, multi- or single-voxel spectroscopy. Patients' spectra were assessed for peaks of lactate (Lac, 1.31 ppm), lipid (Lip, 1.33 ppm), N-acetyl aspartate (2.0 ppm), acetone (A, 2.05 ppm), choline (Cho, 3.23 ppm) and creatinine (Cr, 3.4 ppm) and the mean values of the (Cho/Cr) ratios were performed by a semi-quantitative approach. The operative pathology served as the standard of reference.
Cho peak twofold higher than the average noise level was detected in 72% of the malignant and only 5.4% of the benign masses with an accuracy of 83%. Adding lactate to the choline enhanced the accuracy to 93%. The mean Cho/Cr ratios of the malignant ovarian masses (2.8) were significantly higher than that of the benign ones (1.2) . We used a receiver operating characteristic curve to determine the best cut-off value (1.7) for the mean Cho/Cr ratio to discriminate malignancy with sensitivity: 81.2%, specificity: 93.3 %, positive-predictive value: 92.9 %, negative-predictive value: 82.4% and accuracy: 87.1%.
The simultaneous presence of choline and lactate peaks in MRS examination of the ovarian masses minimizes the overlap between benign and malignant categories. N-acetyl aspartate and acetone are the metabolites for diagnosing complex cystic masses as benign teratoma, endomterioma and tubo- ovarian abscess.
MRS is a non-contrast based and fast MR sequence that gives an idea about tissue components could be used to improve the sensitivity and the accuracy of detecting malignancy in ovarian masses.
评估磁共振波谱（MRS）对卵巢肿块恶性病变检测的影响。
这项前瞻性研究纳入了230名患有245个附件/卵巢肿块的女性。通过初步盆腔超声发现肿瘤。对肿块进行MRI、多体素或单体素波谱分析。评估患者波谱中乳酸（Lac，1.31 ppm）、脂质（Lip，1.33 ppm）、N-乙酰天门冬氨酸（2.0 ppm）、丙酮（A，2.05 ppm）、胆碱（Cho，3.23 ppm）和肌酐（Cr，3.4 ppm）的峰值，并采用半定量方法计算（Cho/Cr）比值的平均值。手术病理作为参考标准。
在72%的恶性肿块和仅5.4%的良性肿块中检测到Cho峰值高于平均噪声水平两倍，准确率为83%。将乳酸与胆碱结合可将准确率提高到93%。恶性卵巢肿块的平均Cho/Cr比值（2.8）显著高于良性肿块（1.2）。我们使用受试者工作特征曲线确定平均Cho/Cr比值的最佳截断值（1.7）以鉴别恶性病变，敏感性为81.2%，特异性为93.3%，阳性预测值为92.9%，阴性预测值为82.4%，准确率为87.1%。
在卵巢肿块的MRS检查中，胆碱和乳酸峰值同时出现可使良性和恶性类别之间的重叠最小化。N-乙酰天门冬氨酸和丙酮是诊断复杂囊性肿块为良性畸胎瘤、子宫内膜瘤和输卵管卵巢脓肿的代谢物。
MRS是一种基于非对比剂的快速MR序列，可提供有关组织成分的信息，可用于提高卵巢肿块恶性病变检测的敏感性和准确性。
