T2 relaxometry mapping in demonstrating layered uterine architecture: parameter optimization and utility in...

We evaluate the feasibility of T₂ relaxometry mapping of the uterus and demonstrate its diagnostic utility in endometrial carcinoma and adenomyosis and discuss the optimum imaging parameters as used in our institute.

Institute review board approval was obtained and multispin echo (MSE) imaging of the pelvis was done with variable time to echo in three patients, two with endometrial carcinoma and one with adenomyosis. T₂ parametric maps and curves were plotted and the T₂ times of the diseased endometrium, superficial and deep myometrium were established.

T2 mapping of the uterus is feasible and demonstrated the four-layered uterine architecture with T₂ times of the diseased endometrium, inner myometrium and the outer myometrium being determined. The fourth myometrial layer was demonstrated in all the three cases on the parametric maps. The two cases with endometrial carcinoma had thinning and irregularity of the myometrial fourth layer which helped in predicting superficial myometrium invasion. Thickening of the fourth myometrial layer was demonstrated in the case with adenomyosis, which we believe might be a new imaging finding of adenomyosis.

Thinning and irregularity of the myometrial fourth layer in cases of endometrial malignancy might help in identification of superficial myoinvasion-this might be a new imaging armamentarium in nulliparous females where uterine preservation might be a consideration. The T₂ relaxation times of the myometrium and endometrium described here will help optimize the time to echo for the acquisition of MSE for relaxometry of the female pelvis. Advances in knowledge: Thinning and irregularity of the fourth myometrial layer helps in the identification of superficial myometrial invasion with a greater confidence and helps triage patients for uterine preservation when necessary. T₂ relaxometry might be undertaken in those nulliparous women with endometrial carcinoma in whom demonstration of no myometrial invasion will make them candidates for uterine preservation. Thickening of the fourth myometrial layer in adenomyosis requires further evaluation in a larger cohort of patients as an additional imaging finding. T₂ relaxation times of endometrial carcinoma is different from the normal endometrium in the three cases imaged, thus, further studies evaluating the T₂ values in a larger cohort might help in differentiating diseased from the healthy endometrium. T₂ time of the pelvic tissue described in the study will help select the time to echoes for MSE imaging of the female pelvis in further studies.