Which imaging modality best demonstrates the anatomy of the uterus?
MRI has superior soft tissue contrast compared to US or CT and best demonstrates uterine anatomy.
The uterus consists of three zones with differential T2-weighted signal intensity on MRI: endometrium, inner myometrium (also called the junctional zone), and outer myometrium. The glandular endometrium has high T2-weighted signal intensity, the inner myometrium has low T2-weighted signal intensity due to presence of dense smooth muscle, and the outer myometrium has intermediate-slightly high T2-weighted signal intensity that contains more blood and less dense layers of smooth muscle. Sometimes, a very high T2-weighted signal intensity endometrial canal containing fluid is also seen.
The cervix similarly demonstrates three distinct zones: a high T2-weighted signal intensity layer of endocervical glands (along with lower signal intensity longitudinal mucosal ridges [plicae palmitae]) that is contiguous with the endometrium, a low T2-weighted signal intensity inner cervical stroma that is contiguous with the junctional zone, and an intermediate-slightly high T2-weighted signal intensity outer cervical stroma that is contiguous with the outer myometrium. A very high T2-weighted signal intensity endocervical canal containing fluid may sometimes also be seen.
