What is sonohysterography (SHG)?

SHG is a technique used to improve US visualization of the endometrium and uterine cavity by instilling sterile saline into the uterine cavity while scanning the uterus transvaginally. The endometrial lining and contents of the uterine cavity are outlined by fluid. The image shows a benign endometrial polyp (arrow) outlined by dark fluid in the uterine cavity in a woman with menorrhagia.