Wondering how to measure a breast mass on an Ultrasound? Here’s 10 strategies for measuring just about any type of breast mass you’ll ever encounter.

Figuring out how to measure a breast mass with well defined borders on an Ultrasound can seem straightforward. But are you truly measuring it the correct way? In a manner that ensures that the size and the shape of the mass are not underestimated? And how should those measurements change when a mass has an irregular shape or margins, or is located within a milk duct? Should those findings be included within the measurements of the mass? Let’s explore how you should (and shouldn’t) measure a mass on a Breast Ultrasound.

Mistake 1: Measuring the Height Dimension of a Mass Twice

The most common mistake in measuring breast masses on an Ultrasound is measuring the height, or A-P (anterior-posterior) dimension twice. A breast mass measurement should include 3 measurements: a length, a height, and a width. Length and width are horizontal measurements on a Breast Ultrasound, parallel to the skin and chest wall layers, and height is a vertical measurement, 90 degrees perpendicular to the length and width measurements. Thus, the measurements should be horizontal, vertical, and then horizontal again. It’s helpful to look at this in term of volume, which is really what a measurement is specifying; how that mass is occupying that particular space within the tissue. Including 2 vertical, or height measurements means that the width of a mass, crucial to specifying a true volume, or representation of the mass within the tissue, has been overlooked.

Mistake 2: Not Measuring the Longest Lie of a Breast Mass

The next crucial step in measuring a mass on a Breast Ultrasound is measuring the longest lie, or length of a mass. This often means that the length, height or width measurements are not exactly horizontal or vertical in nature, but slightly obliqued, to include the largest portion of the mass. When a breast mass is measured only in exact horizontal or vertical planes, it’s longest borders can easily be excluded, which can far underestimate the size and shape of the mass. An example of this is when a lobulation is excluded from the measurement of a mass because it’s in a slightly oblique plane. It is crucial to recognize, however, when the longest lie of a mass starts to become an entirely different plane. Such as when a horizontal measurement is not longer horizontal at all and is much closer to a vertical plane. In such an instance, a slightly smaller lie should be used when measuring a mass in order to keep as closely as possible to the true nature of the horizontal and vertical planes.

Mistake 3: Measurements that are Not Perpendicular to Each Other

Even more critical than including a length, a height and a width, and measuring the longest borders of a mass is ensuring that any measurements taken are perpendicular to each other. Most of the time, the longest lie of a mass is at a slightly oblique angle. The second set of measurements should follow this oblique angle, and be place exactly 90 degrees orthogonal, or perpendicular to the first set of calipers. This ensures that not only the true size and the shape of a mass are recorded, but also that the 3 measurement planes are represented and accurate in respect to one another. This also applies to transducer orientation. Complementary imaging planes, that are perpendicular to each other should be used. For example, Radial and Anti-Radial should be used together, and Sagittal should be used with Transverse. Using Anti-Radial and Sagittal, or other imaging planes that are not orthogonal to one another will mean that one or more dimensions (length, height or width) of the mass is not accurately represented.

Mistake 4: Including More than One Set of Measurements on the Same Image

Check out the image below. This is a striking example of what not to do! Including more than one set of measurements on the same image can make the sizes of the different aspects of the mass hard to discern from one another. It makes it challenging to match each set of calipers to its corresponding measurement. It’s also unprofessional. Our job as a Sonographer is to produce high-quality, diagnostic images. When we take shortcuts, such a sloppily throwing calipers willy-nilly on an image, it throws out all the other efforts that we spent on image optimization out the window. Your image is only as good as the information that it conveys, and if that information is jumbled, then it is a disservice to both the patient and the Radiologist. Another way to look at this is from a legal standpoint. Ultrasound images are discoverable items in a lawsuit. If that image was presented in a courtroom, would it easily and accurately display the necessary information? Look at every Ultrasound image that you take from a legal standpoint, and get in the habit of always presenting your best light in every image that you take. Listed below are two types of breast masses in which this issue commonly presents itself on a Breast Ultrasound: a hematoma and a complex mass.

Hematoma

A hematoma is a pocket of blood in the breast. It begins as an anechoic mass in the acute phase, turning more hyperechoic as it coagulates and ages. Most commonly, hematomas present with an inner cystic component (anechoic or with low level internal echoes) and an outer hyperechoic portion, representing the different phases of coagulation throughout the mass. Some clinics, depending on protocol, measure only the outer hyperechoic border, which entails just the normal 3 measurements: length, height and width. But other clinics also measure the inner cystic component, which ads a second set of measurements to the mix. Note that the term “cystic” does not imply that the inner portion is a breast cyst that’s filled with watery cyst fluid, rather it is describing blood that is in the acute phase which is either completely anechoic inside or anechoic with low level internal echoes, representing blood that is beginning to coagulate (the appearance of each of these is “cystic” on an Ultrasound). Anechoic (cystic) masses on Ultrasound can be watery fluid, blood vessels, pockets of infection, serous fluid or blood. Measuring the inner compartment can help demonstrate that a hematoma is coagulating, or becoming less cystic and more hyperechoic over time. If the cystic component gets smaller over time, replaced by hyperechoic coagulated blood, this helps confirm the diagnosis of a hematoma, vs its more sinister cousin, a breast cancer with hyperechoic components, or a mass with desmoplasia. Measuring the outer borders of the hematoma can demonstrate that the mass is shrinking and going away slowly over time as the tissue absorbs the hematoma. This is also an important diagnostic criteria for a hematoma vs something more suspicious in nature in the breast. A suspicious breast mass will not decrease in size and be absorbed by the body. If the protocol involves measuring both of these entities the inner component and the external margins, then it should be performed on separate images. The first set of images, in two imaging planes (radial and anti-radial) should measure the inner cystic portion of the hematoma, and the second set of images should measure the outer borders of the mass in both transducer orientations with and without color Doppler.

Complex Breast Mass

A complex mass on a breast Ultrasound has both a solid and a cystic component. It’s important to measure any solid portions within a complex mass separately from the outer cystic borders of the mass, especially if the solid components contain internal vascularity. First, measure the entire mass as a whole (the outer cystic borders) in 2 perpendicular imaging planes, including a length, width and height and color Doppler images. Next, measure any solid portions of the mass, including any irregular edges (except spiculations) within the measurement in both transducer planes. Measurements of both the solid portions and the cystic outer borders should not be performed on the same Ultrasound image, but separated, for a more professional image with a clearer delineation between sets of calipers.

Mistake 5: When You Should (And Shouldn’t) Include Mass Margins in a Measurement

Let’s talk margins. But first, a little terminology. Margins are the edges of a breast mass on an Ultrasound. A breast mass has circumscribed edges when the edges of the mass are well defined. Circumscribed margins are pretty straightforward to measure, as long as the measurements include a length, width and height; are perpendicular to each other; and include the longest lie of the mass. Non-circumscribed margins are edges that are ill-defined, hazy, or obscured. The key to measuring a non-circumscribed mass is to carefully delineate where each edge of the mass is while scanning live by scanning in and out of the mass, to truly recognize where each end begins. Once each edge has been delineated while scanning live, then the image can be frozen and the outer borders measured. The next type of breast mass margins are lobulated margins. Lobulations are rounded projections from a mass. When the lobulations are large (> 2 mm), the mass is shaped like a cloud, and it’s known as a macrolobulated mass. When the lobulations are small (< 2 mm) in size, the mass is shaped more like a carnation flower and it’s known as a microlobulated mass. Both macro and microlobulations should be included within the measurements of a mass, in both imaging planes. Next up are angular margins, which are pointed edges protruding from a mass. With angular margins, the mass is shaped like a starfish. Angular margins should be included within the measurements of a mass. The last type of margins are spiculated margins, which are linear extensions from a mass, like octopus legs. Spiculations should be excluded from the measurements of a mass on a Breast Ultrasound.

Mistake 6: Don’t Forget That Thick Echogenic Halo!

A thick, echogenic halo around a mass is a type of border that can be found around malignant masses on a Breast Ultrasound. The border of a mass is the tissue that immediately surrounds a mass. A malignant breast mass first spreads by infiltrating adjacent tissues via angular, microlobulated and spiculated margins. In an effort to stop the growth of the mass, the body launches a host response in the form of tissue fibrosis. The combination of the tissue fibrosis from the body’s host response and the irregular margins of the breast mass attempting to spread form a thick, dense, hazy, echogenic halo around some malignant breast masses on an Ultrasound. With fast growing breast masses, the body has not yet had time to launch a host response, so there may be no thick, echogenic halo visualized. A thick, echogenic halo is also known as desmoplasia, and it’s considered part of the breast mass. It should be included in the measurements of a mass on the Ultrasound image. The desmoplastic mass should be measured in two perpendicular imaging planes, with and without color Doppler, including the 3 mass dimensions: length, height and width.

Need a quick how-to-guide on identifying the features of breast masses on an Ultrasound? This can help you with that: A START-TO-FINISH GUIDE TO PERFORMING A BREAST ULTRASOUND (be sure to check out the section on “characterizing breast masses”).

Mistake 7: Including Adjacent Fat Within the Measurement of the Mass

On a breast Ultrasound, fat lobules can look mass-like and can either be mistaken for a mass, or accidentally be included within the measurements of an adjacent mass. The hallmark feature of fat in the breast is the white, hyperechoic cooper’s ligaments running through the fat. When first encountering an area that looks like a mass in the breast, look to see if there’s any white lines visible within the mass. If white lines are visualized, then the area is composed of fat. When encountering a mass in the breast that does not have hyperechoic lines running through it, carefully check all sides of the mass, looking for white lines running through the tissues either anterior, posterior, medial or lateral to the mass. If white lines are visualized, then this is fat that is adjacent to the mass and is not considered part of the mass and should be excluded from the measurements of the mass. There’s 2 caveats with this system of looking for white lines. The first is that lipomas, an encapsulated tumor of fat, are composed of fat and when isoechoic in color will have white lines running through them even though they are a distinct breast mass. The second caveat is a breast mass known as a hamartoma, which is composed of various amounts of fat, glandular and fibrous tissue, and therefore will contain tissue with white lines (fat) within it. Both lipomas and hamartomas are encapsulated and will have distinct, circumscribed borders. With the exception of these two circumstances, it’s important to watch out for fat lobule pseudo-masses and also for fat that’s adjacent to a breast mass that can look like it’s part of a mass when it’s not.

Mistake 8: Watch Those Posterior Borders

Breast masses can be extremely dense, especially when they are malignant. The first thing that should be done when a breast mass is encountered is to lower the frequency to its lowest level and increase the far field TGC and then to carefully look at the posterior borders of the mass. One of the most common breast mass measuring rookie mistakes is only measuring the anterior portion of the mass and excluding the bottom half of the mass because it is not visible on the Ultrasound image due to improper image optimization. This is also true for large breast masses. Always know where your borders are! You have not properly visualized the posterior edge of a mass unless you can see a distinct bottom margin and visualize the tissue below the mass all the way down to the chest wall. If you cannot see the tissue below the mass, then your frequency is too high and your far field TGC is too dark.

Mistake 9: Using a Field of View That’s Too Narrow

When measuring structures or masses in many parts of the body, such as the ovary, the field of view (FOV) of the Ultrasound image should be narrowed in order to exclude any extraneous information and focus only on the AOI (area of interest). The opposite is true in Breast Ultrasound. The FOV should never be narrowed when imaging a breast mass because it’s crucial to have information about how the mass is located and interacting with it’s environment. The first consideration is location. Knowing the depth of the mass, and visualizing the position of the mass within the tissue can help determine if the mass matches the location on a Mammogram image. The next consideration is interaction. How is the mass interacting with surrounding tissues? Is is within a milk duct? It it invading the nipple, skin or chest wall? Are there adjacent satellite nodules? None of these things can be ascertained in the FOV is narrowed.

Confused about the FOV Ultrasound control? This article can help with that: 20 ESSENTIAL ULTRASOUND CONTROLS EVERY SONOGRAPHER SHOULD KNOW AND HOW TO USE THEM

Mistake 10: Underestimating or Overestimating Mass Size

One of the easiest things to do, especially when first learning breast Ultrasound, is to underestimate the size of a breast mass. This most commonly occurs when measuring ductal masses and when measuring breast masses in the sagittal and transverse transducer planes rather than radial and anti-radial.

Ductal Measurement Woes

When measuring a mass that’s associated with a milk duct, the milk duct should be excluded from the measurement of the mass. A common misconception is that the milk duct is the mass, rather than the material that’s inside of the mass. A mass within a duct can either be completely contained within the duct, most commonly displaying a portion of anechoic duct on one or both ends of the mass, or a ductal mass may spill out of the milk duct, forming an irregularly shaped mass with a ductal component to it. When a mass has overgrown the anterior and posterior borders of the duct, the margins of the mass should be used as a border in which to measure the mass, excluding any ends of anechoic duct protruding from the mass. When a mass is contained within the duct, then just the solid material within the duct should be measured, excluding any sections of anechoic duct off one or more sides of the mass.

Transducer Plane Matters When Measuring Breast Masses

Two transducer planes have been created for and are used exclusively in breast ultrasound imaging: radial (RAD) and anti-radial (ARAD). The radial plane follows the course of the milk ducts, which course in a linear pattern in the breast from the periphery to the nipple. Most suspicious breast pathology is ductal in origin, making the radial plane the most accurate viewpoint for viewing mass size, shape and margins. The radial plane follows a linear path through the breast, like rays of the sun or spokes on a wagon wheel. The anti-radial plane is 90 degrees orthogonal (perpendicular) the the radial plane. When used together, they provide the most accurate representation of a breast mass in 3 dimensions. Sagittal and transverse are standard imaging planes used in both general and vascular ultrasound. The sagittal plane is a vertical plane, represented by up-and-down slices through the body. The transverse plane is perpendicular to the sagittal plane, which takes horizontal (side-to-side) slices through the tissue. When sagittal and transverse planes are used to measure breast pathology, they underestimate breast mass size, shape and margins because they do not align with the milk ducts, where most worrisome breast pathology forms. Sagittal and transverse are used in breast Ultrasound to take negative (normal) images behind the nipple (subareolar) and also used when imaging the axilla.

Learn why transducer orientation is so essential in breast Ultrasound and how to scan in different planes here: TRANSDUCER ORIENTATION AND BREAST ULTRASOUND: STOP DOING THIS

Conclusion

There’s many things to consider when measuring a breast mass, such as the lie of the mass within the tissue, ensuring that measurement calipers are perpendicular to one another and that a length, a height and a width are recorded. Mass margins, borders and any ductal component are also important considerations when measuring masses on a breast Ultrasound. Knowing what to measure is as important as what not to measure. Underestimating mass size and shape and measuring in the incorrect plane are the most commonly encountered mistakes. You are now equipped with the tools to measure anything that a breast Ultrasound can throw at you. Go forth and measure!

What should you do after taking measurements? Follow this step-by-step guide: A START-TO-FINISH GUIDE TO PERFORMING A BREAST ULTRASOUND. (Need a starting point? Look at the “breast Ultrasound protocols” section).