Analysis of MRI Values and Hemoglobin and Total Protein Concentrations of Cystic Ovarian Tumors

BACKGROUND: Endometrioma generally shows higher intracystic signal intensity (SI) than mucinous cystadenoma (MCA) on T1 -weighted imaging (T1 WI). Nonendometrioma-associated malignant ovarian epithelial tumors (nonendometrioma group) often show higher intracystic SI than benign tumors on T1 WI, while the converse is true for endometrioma and endometrioma-associated malignant tumors (endometrioma group). However, it is sometimes difficult to differentiate between hemorrhagic and mucinous content based on SI on T1 WI. Hemoglobin (Hb) and protein are both speculated to shorten T1 . PURPOSE: To examine MRI values and Hb and total protein (TP) concentrations in ovarian tumors. STUDY TYPE: Prospective. SPECIMEN: In all, 182 samples from 167 cystic ovarian tumors. FIELD STRENGTH: 1.5T, spin-echo T1 WI, fast spin-echo T2 WI. ASSESSMENT: The in vivo intracystic/psoas major muscle SI ratios were determined as references for intracystic SI. T1 and T2 values, cystic content inversion times (TIs), and Hb and TP concentrations were determined to evaluate differences between 1) endometrioma and MCA; 2) benign, borderline, and malignant tumors in the nonendometrioma group; and 3) those in the endometrioma group. STATISTICAL TESTS: Wilcoxon's rank-sum test, Kruskal-Wallis test. RESULTS: In endometriomas (n = 43) and MCAs (n = 27), mean T1 and T2 (TP, Hb concentrations) were 428 and 162 msec (52.7, 12.00 g/dl) and 1639 and 600 msec (7.1, 0.06 g/dl), respectively (all, P < 0.0001). In the nonendometrioma group (epithelial benign, n = 56; borderline, n = 20; malignant, n = 25), these values were 1657 and 696 msec (6.4, 0.35 g/dl), 1235 and 400 msec (13.5, 0.83 g/dl), and 1184 and 311 msec (19.7, 0.84 g/dl), respectively (all, P < 0.0001). In the endometrioma group (endometrioma, n = 43; borderline, n = 3; malignant, n = 8), these values were 428 and 162 msec (52.7, 12.00 g/dl), 427 and 108 msec (16.6, 3.07 g/dl), and 1010 and 268 msec (24.2, 1.56 g/dl), respectively (all, P < 0.05). DATA CONCLUSION: TP and Hb concentrations were higher in the contents of endometriomas than MCAs, leading to lower T1 and T2 values. In the nonendometrioma group, TP and Hb concentrations were higher in the cystic contents of borderline and malignant tumors than benign tumors, leading to lower T1 and T2 values. Conversely, the cystic contents of borderline and malignant tumors in the endometrioma group showed lower TP and Hb concentrations compared to endometriomas, leading to higher T1 and T2 values. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:1133-1140.