What are black circles on ultrasound?
The transducer uses sound waves to create images of your ovaries and other pelvic organs. A polycystic ovary has many fluid-filled sacs, called follicles. Each dark circle shown above is one follicle in an ovary.
That circle is known as the Yolk Sac (YS). It is a membrane that is connected by a tube to the embryo, and acts as the start of the circulatory system. The Yolk Sac also is what provides nourishment to the growing fetus until the placenta is fully formed.
For example, most of the sound waves pass right through a fluid-filled cyst and send back very few or faint echoes, which makes them look black on the display screen. But the waves will bounce off a solid tumor, creating a pattern of echoes that the computer will show as a lighter-colored image.
On an ultrasound cancerous tissue shows up black and dense tissue is still white, therefore cancers are easier to distinguish.
Different colors are showcased depending on how the sound waves reflect off a substance. Most images are black and white, but you'll notice different shades in an ultrasound scan. The different shades represent the sound waves passing through or reflecting off material densities.
Placental lakes are pools of blood that show up on scans as black areas. They lie on the surface of the placenta or deeper inside. The image shows the placenta. The lakes are above the baby on the front wall of the womb (uterus), and can be seen as three small, black areas on the surface of the placenta.
Melanoma, which means "black tumor," is the most dangerous type of skin cancer. It grows quickly and has the ability to spread to any organ. Melanoma comes from skin cells called melanocytes. These cells produce melanin, the dark pigment that gives skin its color.
Because sound waves echo differently from fluid-filled cysts and solid masses, an ultrasound can reveal tumors that may be cancerous. However, further testing will be necessary before a cancer diagnosis can be confirmed.
Melanoma is a cancer that begins in the melanocytes. Other names for this cancer include malignant melanoma and cutaneous melanoma. Most melanoma cells still make melanin, so melanoma tumors are usually brown or black.
On ultrasound, they are usually smooth, round and black. Sometimes cysts do not have these typical features and they are difficult to distinguish from solid (non-fluid) lesions just by looking. These may need further testing to confirm they are cysts. Doctors sometimes describe these as “complex cysts”.
What color are benign tumors?
On the skin, you can often see and feel benign tumors. They may be: Discolored (often red or brown). Firm or soft when you press on them.
The Imaging Center's protocol is to tell patients their results must come from their doctor. “Plenty of patients ask, but techs should not give information and should not even react to what they're seeing on the image,” Edwards said.

Just remember that FLUID is always BLACK and TISSUE is GRAY. The denser the tissue, the brighter white it will appear in ultrasound, with the brightest WHITE being BONE.
By definition, flow towards the transducer is depicted in red while flow away from the transducer is shown in blue. Different shades of red and blue are used to display velocity. Lighter shades of color are assigned to higher velocities.
Typically, red and blue colors are used to highlight the blood flow in one direction or the other regarding the probe's position. The speed of the blood flow is shown with a color scale. Usually, blood flow away from the probe is shown in blue, while blood flow toward the probe is red.
What are the Imaging findings of ovarian cyst? On ultrasound, the cysts are characterized by anechoic (black) fluid filling the cyst cavity and thin walls. Simple cysts are less than 20-25 mm in diameter. If an ovarian cyst has recently ruptured, one will see fluid in the pelvis.
If one or more M features were present in the absence of a B feature, the mass was classified as malignant. If one or more B features were present in the absence of an M feature, it was classified as benign.
Ultrasound. Lipomas appear as soft variably echogenic masses, commonly encountered on ultrasound. If encapsulated, the capsule may be difficult to identify on ultrasound 5.