An ovarian ultrasound is a common imaging technique used to examine the health and appearance of a woman’s ovaries. This non-invasive procedure helps healthcare providers assess their size, shape, and internal structure. Understanding what a normal ovary looks like on an ultrasound can offer clarity when reviewing scan results.
The Basics of Ovarian Ultrasound
Ultrasound technology uses high-frequency sound waves to create images of internal body structures. A transducer emits these sound waves, which bounce off organs like the ovaries. The echoes are captured and converted into real-time images on a monitor.
For ovarian assessment, two main approaches are used: transabdominal ultrasound, where the transducer moves over the lower abdomen, and transvaginal ultrasound, where a slender transducer is gently inserted into the vagina. The transvaginal method often provides a more detailed view due to its closer proximity.
Visualizing a Healthy Ovary
A normal ovary typically appears as an almond or oval-shaped structure, measuring about 2 to 5 centimeters (cm) in length. Its internal structure, the ovarian stroma, usually shows a homogeneous echotexture, meaning it appears uniform in density.
Within this stroma, small, fluid-filled sacs called follicles are commonly visible. These appear as small, rounded, anechoic (dark) areas. In women of reproductive age, multiple follicles, typically 2 to 9 millimeters (mm) in diameter, can be observed along the periphery. Their presence and number indicate normal ovarian function.
Normal Changes Across the Lifespan and Cycle
The appearance of a normal ovary changes throughout a person’s life and across the phases of the menstrual cycle. In pre-pubertal individuals, ovaries are generally smaller and may contain very few visible follicles or none at all. Their average volume is less than 1 cm³ in younger children, gradually increasing with age.
During the reproductive years, ovarian appearance is dynamic. In the early part of the menstrual cycle, several small follicles begin to develop. One of these will typically become a dominant follicle, growing larger than the others, sometimes reaching 18-25 mm before ovulation. After the release of an egg (ovulation), the ruptured follicle transforms into a corpus luteum, which appears as a thick-walled, often round or irregular structure, measuring around 1.9 to 3 cm in diameter. This temporary structure eventually regresses if pregnancy does not occur.
In post-menopausal individuals, ovaries become smaller and may be more challenging to visualize due to their reduced size and the absence of active follicular development. They often appear atrophied, measuring around 2.0 x 1.5 x 1.0 cm, and typically contain no or very few follicles. The mean ovarian volume in postmenopausal women is significantly lower compared to reproductive-aged women, often around 2.2 mL.
Understanding Your Ultrasound Report
An ovarian ultrasound report describes various aspects of your ovaries. For a normal finding, you might see terms such as “normal size” or “within normal limits,” indicating the ovaries fall within typical dimensions for your age and reproductive status. The report may also state “homogeneous echotexture,” confirming the uniform internal appearance of the ovarian tissue.
The presence of “antral follicles” or “follicles present” is a normal finding, especially for individuals in their reproductive years, often with a count of 5 to 10 small sacs per ovary. If a corpus luteum is present, it will be described, as it is a normal post-ovulatory structure. Reports typically note “no adnexal mass identified” or “no free fluid,” which are also indicators of a normal scan. Understanding these terms can help you interpret your results and discuss them with your healthcare provider.