Table 1. Key MRI Findings of Ovarian Endometriotic Cyst, DIE, or Other Related Diseases.

		MR/CT Sign	MRI/CT Findings	References
Ovary	Ovarian endometrioma	T1-high signal multiplicity	Multiple high signal cysts on T1WI	[31]
		T2-Shading	Marked T2 shortening or gradations on T2WI	[31,33]
		T2 dark spot sign	Discrete well-defined markedly hypointense foci within the cyst on T2WI	[32]
	Decidualization		Linear, broad-based nodular, or polypoid structures with high SI similar to placental tissue on T2WI	[43,44]
	Polypoid endometriosis		Polypoid mass, slightly high SI similar to endometrium on T2WI	[46,47,48]
			Punctate high signal foci on T1WI
			Peripheral rim by fibrous tissue on T2WI
			Strong enhancement on contrast enhanced-T1WI
			Small cysts on T2WI
	EAOC		Emergence of enhanced mural nodules within the ovarian endometrioma	[7,57,58]
			Increased tumor size (> 9 cm)
			(suggestive) Dissapearance of shading on T2WI	[59]
DIE			Hypointense nodular lesions (T1/T2WI)	[5,60,61,62]
			Soft tissue thickening with irregular, indistinct, or stellate margins (T1/T2WI)
	Posterior cul-de-sac obliteration (pouch of Douglas, rectouterine/ retrovaginal space)		Retroflexed uterus	[69]
			Elevated posterior vaginal fornix on T1/T2WI
			Intestinal tethering or tethered appearance of rectum in the direction of the uterus on T2WI	[69]
			Faint strands between the uterus and intestine on T2WI	[69]
			Fibrotic plaques or nodules covering the serosal surface of the uterus on T2WI	[69,70]
			Retrouterine fibrous mass on T2WI	[69,70]
			Intraperitoneal fluid displacement	[70]
	Torus uterinus, USL		T2-low intensity thickening or mass with regular or irregular margins on MRI	[63]
	Ovary	Kissing ovary	Bilateral ovaries are located in the posterior cul-de-sac or at the cornua of the uterus on MRI	[75]
	Round ligament		Thickened and irregular with a nodular appearance on MRI	[77]
	Rectosigmoid colon	‘Fan shaped’/‘mushroom cap’	Focal thickening of the rectal wall as an umbrella-like head of a mushroom on MRI	[64,81]
	Bladder endometriosis and vesicouterine space		Hypointense nodular formation on T1/T2WI	[60,85]
Extra-pelvic endomtriosis	Abdominal wall endometriosis		On CT, homogeneous density	[93]
		Gorgon’ sign	Linear infiltration irradiating peripherally from a central soft tissue nodule on CT	[93]
			On MRI, hypointense solid mass on T2WI with/without hyperintense hemorrhagic cysts on T1WI	[97]
	Diaphragmatic endometriosis		Hyperintense nodule on T1WI, mostly right side	[100]

DIE = deeply infiltrating endometriosis, EAOC = endometriosis associated ovarian carcinoma, SI = signal intensity, T1WI = T1-weighted image, T2WI = T2-weighted image, US = ultrasonography, USL = uterosacral ligament