junctional zone, genitourinary tract, genitourinary system, uterus, woman, Art in Anatomy, Ashley Davidoff MD, adenomyosis, MRI

MRI of the Uterus Showing a Normal Junctional Zone

A T 2 weighted MRI in the sagittal plane (left) reveals a normal e uterus with characteristic premenstrual appearance (left image).  The image on the right  is an overlay showing the endometrial cavity in yellow, then a light mauve color of the junctional zone or inner myometrium, and finally the outer myometrium (maroon).

The junctional zone is low intensity on T2  due to decreased water content, and is formed by smooth muscle cells that are tightly packed.  The extracellular matrix and water content are sparse.

Description

A T 2 weighted MRI in the sagittal plane (left) reveals a normal e uterus with characteristic premenstrual appearance (left image).  The image on the right  is an overlay showing the endometrial cavity in yellow, then a light mauve color of the junctional zone or inner myometrium, and finally the outer myometrium (maroon).

The junctional zone is low intensity on T2  due to decreased water content, and is formed by smooth muscle cells that are tightly packed.  The extracellular matrix and water content are sparse.  It usually measures less than 8mm.

Adenomyosis is a disease of the myometrium caused by misplaced or ectopic endometrium in the myometrium resulting in thickening of the junctional zone.  Leiomyomas can affect the junctional zone or the myometrium beyond the junctional zone.