Type:
Educational Exhibit
Keywords:
Pathology, Education, MR, Genital / Reproductive system female
Authors:
N. M. Saloum1, A. Alrashid2, M. Abdelhafeez2, S. A. M. Ibrahim2, A. Kambal2, A. E. Mahfouz2; 1Doha, Doha/QA, 2Doha/QA
DOI:
10.26044/ecr2019/C-0444
Findings and procedure details
On ultrasound,
ovarian endometriomas appear homogeneous,
hypoechoic cyst with diffuse low-level echoes,
commonly termed ‘ground glass’.
Endometrioma can be multi-locular and have thin or even thick septations.
The close proximity of both ovaries is known as "kissing ovaries" which is caused by adhesions and is considered a sign of pelvic endometriosis.
The MRI standard protocol which is mostly used is,
T2-weighted fast spin echo sequence,
T1- weighted fast spin echo sequence,
and T1-weighted fast spin echo fat saturation sequence.
The T1-weighted fat saturated technique plays an important role in the small lesions (less than 1 cm) and helps in differentiation between hemorrhagic and lipid component of the lesions,
so it plays role in differentiation of endometriomas from dermoid cysts and the increased detection of small implants.
The injection of (Gadolinium) as contrast medium doesn’t have any advantage over the non-contrast MRI except if malignant lesions are suspected.
MRI findings of endometrioma are,
ovarian cystic mass with high signal intensity on T1-weighted images and low signal intensity on T2-weighted images.
The cause of this is repeated hemorrhage which result in high protein and iron concentration which is called “shading phenomena”.
Benign endometriomas show restricted diffusion.
MR imaging features that are suggestive of malignant transformation of an endometrioma is the development of enhancing mural nodules.
Multiple T1-hyperintense adnexal cysts are specific for endometrioma.
Hematosalpinx should be considered specific for pelvic endometriosis and appears of T1-weighted hyper intensity within a dilated fallopian tube.
MRI findings of endometriosis either pelvic or extra pelvic depend on the contents of these implants which is mainly include degraded blood products and protein,
and the signal intensity varies according to the stage of the hemorrhage.
The acute hemorrhage is of low signal intensity (dark) on the T1-weighted images and T-weighted images,
while the lesions containing chronic degraded blood products like methemoglobin gives high signal intensity (bright) on T1-weighted images and low signal intensity (dark) on T2 weighted images.