Diagnostic Ultrasound - Abdomen and Pelvis

Ovaries
Anatomy: Pelvis
CYCLIC CHANGES OF OVARY
Developing follicles
Cumulus oophorus
Corpus albicans
Corpus luteum
Dominant follicle
Mature follicles
(Top) During the follicular phase of the menstrual cycle, several follicles begin to develop, but by days 8-12, a dominant follicle has
formed, and the remainder begin to regress. On day 14, the follicle ruptures and the egg is released. After ovulation, a corpus luteum
forms, and if fertilization does not occur, the corpus luteum degenerates into a corpus albicans. (Middle) Longitudinal TV ultrasound of
the ovary at the early follicular phase is shown. Note the developing follicles of variable size at the periphery of the ovary. (Bottom) TV
ultrasound shows a dominant follicle developed in the late follicular phase days before ovulation. This should not be confused for a
pathologic cyst.
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