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

Abstract

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.