How to Read an Ultrasound Report: Learn What Colors & Numbers Mean

An ultrasound is a medical imaging test that uses high-frequency sound waves to produce images of the inside of your body, such as organs, muscles and other soft tissues. The radiologist or ultrasound technician will then interpret the images and your doctor will communicate any findings with you at a later appointment.

Ultrasound report reading involves interpreting all the numbers, abbreviations and sometimes even colors, which can be overwhelming. This article will break down what they all mean, helping you better understand your results and prepare any questions for your upcoming appointment. For expecting patients, it will also break down how to read pregnancy ultrasound reports.

What’s in your ultrasound report?

Your ultrasound report includes images from your scan and an assessment made by the radiologist, ultrasound technician or other specialist. The report may contain technical medical terminology and other complex data. Some possible details in the report include:

• Type of scan performed (e.g., abdominal ultrasound)
• Technique used (Doppler, endoscopic, etc.)
• Reason for the scan 
• Findings and impressions
• Specific measurements (e.g. fetal anatomy or cysts)
• Comparisons to previous scans, if applicable

What do black, white and gray represent on an ultrasound picture?

An image showing what different colors mean on an ultrasound

The ultrasound probe, also called a transducer, sends high-frequency sound waves into your body through a sound-conducting gel. The sound waves bounce off your internal structures, whether liquid, soft tissues or bone, and the ultrasound machine converts the collected sound waves into images in shades of black, white and gray. The intensity of the shade you see represents the density of the structure the sound wave encountered.

What does black on an ultrasound mean?

Black in an ultrasound image represents liquid, like amniotic fluid or a fluid-filled cyst. Most sound waves pass through fluid-filled areas, with only a small amount reflected back, making the area appear like a black spot on ultrasound results.

What does white mean on an ultrasound mean?

White represents very dense structures like bone or kidney stones. Sound waves directed at bone easily reflect back, appearing bright white on the ultrasound image.

What does gray mean on an ultrasound mean?

Gray in an ultrasound represents different types of tissue. The darker the gray, the denser the tissue, since only some of the sound waves are reflected back. Lumps or masses typically appear as dark gray spots on an ultrasound.

Doppler ultrasound color meanings

Red and blue colors on Doppler ultrasound for arterial and venous blood flow

Most ultrasound images are only black, white and gray. However, if you have a Doppler ultrasound, you may also see colors in your image. Colors are only seen in Doppler ultrasounds, which capture images of the direction and speed of blood flow in your vessels. What do the colors mean on an ultrasound? The following sections will overview the various meanings.

Is color on an ultrasound bad?

Color on an ultrasound is not negative; it is a useful way to categorize features like blood circulation. Different colors indicate various vascular areas, helping the ultrasound technician understand what they’re observing.

What does red and blue mean on an ultrasound?

Red and blue on Doppler ultrasounds have specific meanings. Blood flowing toward the transducer (arterial blood flow) appears in red, whereas blood flowing away from the probe (venous blood flow) appears in blue.

This means that arteries, carrying blood away from the heart, are displayed in red, while veins, which bring blood back to the heart, appear blue. Deviations from these color patterns may signal blood flow abnormalities and warrant additional investigation.

What do yellow or orange mean on an ultrasound?

Yellow/orange are not usual Doppler colors. When yellow does appear, it is typically at the interface between red and blue. Yellow can suggest blood flow issues or turbulence, which is important for diagnosing blood vessel conditions and initiating appropriate intervention.

What does green mean on an ultrasound?

Most Doppler ultrasound systems don’t use the color green, unless they are particularly advanced. When green does appear, its meaning can vary depending on the machine’s parameters. It’s important to ask your doctor to help interpret this color, as the results will depend on the specific color map used. In some machines, green may represent one aspect of blood flow, while in others, it could have a completely different meaning. Color maps can differ from machine to machine.

Some possibilities for green include:

• Areas with very low-velocity blood flow, such as in capillaries. 
• Tissue perfusion, which is blood being delivered to tissues and organs. If there is green, this means your body is getting enough blood supply. Less or no green colors can mean impaired perfusion, possibly pointing to organ conditions.
• Replacement color for yellow/orange, meaning it is diagnosing blood turbulence.

How to read ultrasound report numbers

Now that you have a solid understanding of what your report shows, you can see how your ultrasound images support the radiologist’s findings.

Upon first glance of an ultrasound picture, you’ll notice numbers and acronyms at the top of your image. These don’t have anything to do with the contents of your scan. Instead, they’re used by the hospital or imaging clinic to identify each patient and record the ultrasound equipment settings used, along with any other hospital or clinic-specific information they collect. Additional data may include your name, the hospital reference number and other such identifying information.

Ultrasound image of a newborn’s right kidney in the sagittal plane. The information in the blue boxes is collected by the hospital or imaging clinic for administrative purposes only.

Understanding contrast and common visual effects

During your ultrasound, the technologist, sometimes called a sonographer, will adjust the ultrasound machine settings and probe angles to get the best image possible. Depending on your situation, you might even receive a contrast agent. Changing settings and angles provide different views, while the contrast agent improves the quality of your images. The following terms describe visual effects in your ultrasound images:

What is attenuation?

Attenuation is the reduction of signal intensity from the probe, producing a shadowy effect that makes the area look darker. This helps the radiologist clearly distinguish between different types of tissue.

What is enhancement?

Enhancement refers to the efforts made to improve ultrasound images.

• Preprocessing enhancement methods increase the intensity and clarity of the sound waves to produce better images.
• Postprocessing enhancement techniques refine the quality of captured images.

What is anisotropy?

Anisotropy is an image artifact, meaning a spot or feature in the ultrasound image that is introduced by accident and does not exist in the tissue being scanned. Such image artifacts disappear when the angle of the probe is changed.

Tips on how to read an ultrasound

The following tips will explain the basics of how to read an ultrasound picture, and what it means.

Tip 1: Review your radiology report findings first

Before reviewing any images, it’s important to first examine the findings in your accompanying radiology report, when available. They usually provide a short paragraph with an overview of any findings or impressions.

Access to your imaging results does not replace reviewing those findings with your doctor during a scheduled appointment. This is a critical step because your healthcare provider interprets the results along with other scans or your overall medical history.

Get early access to your ultrasound results

• Online Access
• Easy Sharing
• Permanent Storage

Tip 2: Orient yourself

This is possibly the most challenging aspect of reading an ultrasound since it’s not always clear what exactly you’re looking at. Ultrasound images appear in gradients of black and white which can be tough to distinguish, and certain organs or body parts can be easily mistaken for others.

It’s important to remember that with most ultrasounds (excluding transvaginal ultrasounds), you are looking at a mirror image. In other words, the left side of the image shows the left side of the body part, and the right side of the image shows the right side of the body part.

Most ultrasound pictures have a cone-like shape: the narrowest end of the cone is the top of the image, where the ultrasound probe was first placed on the body. Start your review there. Much of the topmost section will be gray, representing layers of tissue. Below, where the image widens out into a fan shape, is the area of the body that the ultrasound was scanning for—and the reason you had the appointment in the first place.

Tip 3: Remember what the shades of black, white and gray mean

As covered earlier, it’s important to remember that different colors represent various aspects of an ultrasound. Black areas in your images indicate fluid, while tissue appears gray. The brighter the gray tone, the denser the tissue. The brightest white represents bone. Keep these distinctions in mind as you review your images to differentiate between tissue, bony structures and fluid-filled areas. For Doppler ultrasounds, refer to the color meanings discussed earlier in this guide.

Tip 4: If you have repeat imaging, compare to previous ultrasounds

How to read pregnancy ultrasound reports: Understanding your baby’s ultrasound pictures

Many parents and family members are excited to examine pregnancy ultrasound images and check the progress of the baby’s development. All the above tips still apply, but there are also a few additional things to look for in your fetal ultrasound image.

Locate the uterus

One of the first tips for how to read an ultrasound for pregnancy is to find the uterus. The uterus will be a clear, dark, pear-shaped section in the ultrasound image. What you can see in a pregnancy ultrasound will depend on how far along you are. For instance, you might see the yolk sac in early pregnancy ultrasounds, but it is gradually absorbed by the embryo and disappears before the second trimester.

Ultrasound image at 7 weeks pregnant shows the embryo and the amniotic, gestational and yolk sacs within the uterus.

Locate the fetus

Since ultrasounds use sound waves instead of radiation to create images, they are widely used to monitor fetal growth and progress, as well as measure gestational age and confirm if there’s sufficient amniotic fluid. The development of the fetus will change dramatically during each trimester of pregnancy.

• First trimester: In early pregnancy ultrasounds, you’ll see the small bean-shaped fetus in amniotic fluid inside the gestational sac. The yolk sac and umbilical cord might also be visible.
• Second trimester: Limbs will become apparent, and the head and body will be increasingly proportionate. External sex organs will develop, though you’re unlikely to be able to distinguish the baby’s sex at this point unless the fetus is in the correct position.
• Third trimester: Female and male genitalia become more defined, as do eyes, hair and nails. In preparation for labor, the baby may move heads down into the fetal position later in the pregnancy.

Ultrasound image of a fetus at 11 weeks pregnant (first trimester).

Understand common fetal measurements and acronyms

In a pregnancy ultrasound image, you’ll see letters and numbers, typically listed down the side or along the bottom of the image. These are the fetal biometric measurements recorded by the ultrasound technician to assess fetal development. Here’s a list of some of the most common measurements:

• AC: Abdominal circumference, to assess development and growth
• BPD: Biparietal diameter, measuring the distance between the two sides of the baby’s head, to assess age in later trimesters
• CRL: Crown-rump length, used to assess gestational age between weeks 6-13
• FL: Femur Length, measured during the second and third trimesters
• GA: Gestational age, which may change as the fetus develops and affect the estimated date of birth
• GS: Gestational sac, to assess growth, may be called the mean gestational sac diameter (MSD)
• HC: Head circumference, a development measurement taken in the second and third trimesters

There may also be other fetal measurements taken to identify abnormalities during certain weeks of pregnancy. For example, the Nuchal Translucency measurement (NT) is taken late in the first trimester and measures the amount of fluid behind the embryo’s neck to assess the risk of chromosomal abnormalities like Down syndrome.

Getting your results

A pregnant person looking at their pregnancy ultrasound report on PocketHealth

Turnaround times for ultrasound results can vary widely depending on the facility and your doctor’s availability. Often, patients wait a week or more and receive their results during a follow-up appointment. With PocketHealth, you don’t have to wait as long—your results are securely accessible as soon as the report is available, allowing you to review them often before your follow-up visit.

Your imaging results are interpreted by a radiologist—an expert in medical imaging—who carefully reviews your scans and provides a detailed report of any findings. This report is then sent to your referring doctor, who, with a deeper understanding of your medical history, can offer further insights and recommendations.

To better understand your ultrasound reports, Report Reader provides clear, straightforward definitions for medical terms. Simply tap or click on any underlined words to reveal their meaning. This is paired with illustrations and highlights of anatomy in your ultrasound pictures to help you better understand your results and prepare for follow-up appointments.

Frequently asked questions

Here are some common questions regarding understanding ultrasounds.

How do you check your ultrasound report for abnormal results?

When looking at an abnormal vs normal ultrasound report, it can be challenging to decipher the terminology. Certain terms may indicate whether results are within expected baselines. For instance, words and phrases that may suggest normal results include:

• “No evidence of”
• “Expected size and placement”
• “Normal”
• “No abnormal findings”

Possible terms that may indicate irregularities found in the ultrasound include:

• “Indeterminate”
• “Abnormal”
• “Findings”
• “Suspect”
• “Hypoechoic” (which can also be a normal finding)

Despite these possible phrases, it’s important to remember that there are often many benign explanations for abnormal findings. Usually, any impressions or suggested next steps from the radiologist will be included in the ultrasound report. In such cases, questions about these should be discussed with your medical provider.

What is a USG report?

USG stands for ultrasound sonography. The term sonography is often used interchangeably with ultrasound, as both refer to the same imaging technique. Additionally, a sonogram refers to the actual image produced by the ultrasound, not the technique itself. Patients curious about a USG report meaning can simply think of it as the same as an ultrasound report.

What does an ultrasound show?

Ultrasounds can be used for multiple conditions and purposes. They excel at assessing soft tissues and fluid-filled structures (such as cysts), provide real-time imaging for guiding doctors during procedures or evaluating fetal movement and can also help show blood flow within vessels, such as during a Doppler ultrasound. Some common reasons to have an ultrasound include:

• Gynecologic conditions, such as polycystic ovarian syndrome
• Breast ultrasounds for screening and diagnosing breast conditions like cancer or nodules
• Assessing bladder and kidney conditions, such as kidney stones
• Prenatal evaluation of the patient and fetus

Does red and blue on ultrasounds mean cancer?

While many patients wonder if red and blue on ultrasound reports are bad, they are usually only found in Doppler ultrasounds and represent the direction of blood flow. They do not indicate cancer.

Take control of your health journey

PocketHealth makes it simple to keep track of your ultrasounds. All of your ultrasound images are in one secure location and can be accessed online anytime. Reports can also be easily shared with other physicians in your care team, if needed. Additionally, it makes it easy to track health changes over time, such as with repeat imaging. When used in conjunction with your medical provider’s professional advice, it is a powerful tool for organizing and understanding your imaging results and your health.

PocketHealth MyCare Navigator gives personalized insights into your health and identifies any recommended follow-up steps. This feature can also generate individualized questions to ask your doctor based on the findings in your report, ensuring you make the most of your consultation.

Published: May 16, 2024