Validation of magnetic resonance relaxometry R2 value and cyst fluid iron level for diagnosis of ovarian endometrioma

Figures & data

Table 1. Demographics and baseline characteristics of the study cohort.

Baseline characteristics of four groups	OMA n = 178		EAOC n = 41		Non-OMA n = 57		Non-EAOC n = 31		P-value
Age at diagnosis, y*	38.1	8.775	51.2	10.897	43.4	16.729	46.3	14.523	<0.001 ^1)
Parity, n**	0	0–3	1	0–3	0	0–3	1	0–3	0.294 ^2)
Tumor size, mm**	60	10–193	140	42–225	72	29–301	104	30–255	<0.001 ^3)
CA125 U/ml**	61.0	7.0–1504.0	188.0	8.0–6272.0	15.0	4.0–108.0	25.0	7.0–871.0	0.720 ^3)

Figure 1. Cyst fluid R2 values and total iron levels among the four groups. This figure shows the distribution of R2 values (A) and total iron levels (B) for each studied group. a vs. b, P < 0.001 by the Kruskal-Wallis test followed by Bonferroni's correction.

Table 2. CF total iron levels and R2 value for each group.

	OMA n = 178		EAOC n = 41		Non-OMA n = 57		Non-EAOC n = 31		P-value
R2, s^−1	22.800 ^a	6.730–51.770	7.600 ^b	4.800–31.220	9.025 ^b	5.960–25.320	10.335 ^b	4.600–27.400	<0.001*
Total iron, mg/L	247.016 ^c	27.706–1046.280	20.119 ^d	0.888–237.619	0.865 ^d	0.000–27.293	11.051 ^d	0.437–201.730	<0.001*

Figure 2. Correlation between cyst fluid total iron concentrations and R2 values. Patients in the area surrounded by the dotted line showed higher R2 values than expected from total iron levels.

Table 3. Correlation of all types of iron-related compounds with oxidative marker (8-OHdG) and all antioxidant markers (bilirubin, HO-1, and TAC) in the cyst.

	8-OHdG		Bilirubin		HO-1		TAC
	r	p	r	p	r	p	r	p
Total iron	0.226	0.083	0.389	0.004	0.636	<0.001	0.655	<0.001
heme iron	0.072	0.592	0.577	<0.001	0.484	<0.001	0.348	0.004
free iron	0.554	<0.001	0.333	0.024	0.398	0.001	0.554	<0.001
OxyHb	−0.119	0.441	−0.010	0.941	−0.151	0.290	0.022	0.880
MetHb	−0.116	0.454	−0.010	0.945	−0.137	0.338	−0.008	0.955

Table 4. Correlation of R2 values with iron-related compounds and antioxidants in the cysts.

	Total iron		heme iron		free iron		OxyHb		MetHb		8-OHdG		Bilirubin		HO-1		TAC
	r	p	r	p	r	p	R	p	r	p	r	p	r	p	r	p	r	p
R2, s^−1	0.758	<0.001	0.520	<0.001	0.655	<0.001	0.173	0.195	0.221	0.096	0.162	0.369	−0.237	0.414	0.575	<0.001	0.422	0.008

Figure 3. Concentration of bio-elements (cations) in the contents of ovarian cysts. a vs. b, P < 0.05; b vs. c, P < 0.001; and a vs. c; P < 0.001 by the Kruskal-Wallis test followed by Bonferroni's correction.

Table 5. Correlation of R2 values with bio-elements (cations) in the cysts.

	Ca		Cu		Fe		Mg		Zn
	r	p	r	p	r	p	r	p	r	p
R2, s^−1	0.591	0.016	0.415	0.110	0.748	0.001	0.217	0.418	0.472	0.065

Data availability statement

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.