Diagnostic Review of Breast Masses

Upon completion of this tutorial the learner will be able to:   1. Explain the ultrasound, ACR BI-RADS® method of classifying a breast mass. 2. Discuss sonographic characteristics of benign breast masses. Congratulations! You have completed the Diagnostic Review of Breast Masses tutorial. Listed below are the key points presented in this tutorial. Take time to review the material before you try the final quiz.   Download and print a copy of the detailed Course Review.   In this tutorial, you have learned to:   1. Explain the ACR BI-RADS® method of classifying a breast mass, and 2. Discuss sonographic characteristics of a benign breast mass.   Siemens Healthineers would like to express our appreciation to Dr. Richard G. Barr M.D., PhD. for sharing his knowledge and giving a critical review of the tutorial content. The reproduction, transmission or distribution of this training or its contents is not permitted without express written authority. Offenders will be liable for damages.   All names and data of patients, parameters and configuration dependent designations are fictional and examples only.   All rights, including rights created by patent grant or registration of a utility model or design, are reserved.   Please note that the learning material is for training purposes only!   For the proper use of the software or hardware, please always use the Operator Manual or Instructions for Use (hereinafter collectively “Operator Manual”) issued by Siemens Healthineers. This material is to be used as training material only and shall by no means substitute the Operator Manual. Any material used in this training will not be updated on a regular basis and does not necessarily reflect the latest version of the software and hardware available at the time of the training.   The Operator Manual shall be used as your main reference, for relevant safety information like warnings and cautions. Note: Some functions shown in this material are optional and might not be part of your system. The information in this material contains general technical descriptions of specifications and options as well as standard and optional features that do not always have to be present in individual cases.   Certain products, product related claims or functionalities described in the material (hereinafter collectively “Functionality”) may not (yet) be commercially available in your country. Due to regulatory requirements, the future availability of said Functionalities in any specific country is not guaranteed. Please contact your local Siemens Healthineers sales representative for the most current information. SieScape, eSie Touch elasticity imaging, VTi, VTIQ, Virtual Touch technologies, ACUSON S2000, and ACUSON S3000 are trademarks of Siemens Medical Solutions USA, Inc. BI-RADS is a registered trademark of the American College of Radiology (ACR).    Copyright © Siemens Healthcare GmbH, 2019 Breast imaging-reporting and data system or BI-RADS® is a classification method developed by the American College of Radiology (ACR). Originally used to standardize reading of the mammogram, BI-RADS now encompasses ultrasound. This tutorial presents this classification as ultrasound often provides additional imaging of masses described with the ACR BI-RADS® categories. The focus of the content is on the ultrasound findings of breast mass. Most patients seen in the ultrasound department for a breast ultrasound have had a mammogram. Masses seen with mammography show border changes1 without giving information on the internal composition. The importance of mass appearance becomes clear when using the American College of Radiology Breast Imaging Reporting and Data System (ACR BI-RADS®). Often shortened to simply BI-RADS, this method of assessing risk and describing a breast mass provides a common language for clinicians.1, 2 Originally designed for use with mammography, descriptions now include ultrasound imaging.   This section gives an overview of the classification. Look for examples of these categories throughout the tutorial. Learn More about ACR BI-RADS® Categories Learn more aboutACR BI-RADS® categories. Tab TitleTextCategory 0 & 1The BI-RADS category 0 indicates an incomplete mammographic exam. Findings assigned this category have an unknown risk of malignancy needing further imaging such as comparison to earlier exams, a diagnostic mammogram or ultrasound. 1-4      Category 1 is a negative finding for both mammography or ultrasound. There are no architectural distortions, asymmetries, mass, or worrisome calcifications imaged. Malignancy risk is nonexistent and the patient may return to routine clinical follow-up and image screening intervals.1-4   This image shows an example of a category 1 ultrasound finding of normal-appearing fibroglandular tissue.Category 2There is no risk for malignancy with a category 2 mass for either ultrasound or mammography. Examples of a category 2 finding are a simple cyst, lymph node, known stable surgical changes, macrocalcifications, vascular calcifications, and breast augmentation. Also included in this category are stable or biopsy-proven fibroadenomas. The patient has routine clinical follow-up and continued screening. 1-4     A category 2 mass seen with sonography may be round or oval with circumscribed margins (left diagrams). Scattered microcalcifications may be evident either within the mass or breast tissue. The image (right) shows a category 2 mass on the ultrasound image. Image courtesy of Dr. Richard G. Barr M.D., PhD Radiology Consultants, Inc, Youngstown, Ohio USA.Category 3Masses that are probably benign fall into this category. The category 3 mass is expected to still be stable with a short-term follow-up of 6 months. Chances of malignancy in this type of mass is less than 3 percent globally, occurring in 18 percent of ultrasound examinations. These patients have the choice of either follow-up exams or a biopsy of the mass. 1-4     An example of this type of finding on a mammogram is a focal asymmetry, circumscribed solid mass, or a solitary punctate group of calcifications. Ultrasound examples include a fibroadenoma, complex cyst, or a cluster of microcysts. 1-4   This diagram (left) shows BI-RADS category 3 findings with circumscribed margins, parallel orientation to the chest wall, and an oval shape. The mass may also have large, gentle lobulations at the margins which remain intact. The ultrasound image (right) shows a category 3 mass in the right breast on a sagittal, radial plane superior to the nipple. Image courtesy of Dr. Michael Golatta M.D., PhD, University of Heidelberg, Department of Gynecology, Breast Unit, Heidelberg, Germany.Category 4Suspicious lesions which result in a biopsy recommendation fall into the BI-RADS category 4. The probability of a malignant mass ranges from 2 – 95 percent. Due to this wide range and variability of imaging findings, this category has three subdivisions. Sonography shows an irregular shaped mass with spiculated margins with an orientation non-parallel to the chest wall. 1-4     Masses in category 4 begin to lose margin clarity with even one area appearing indistinct (left mass) raising suspicion.  Lobulations become smaller (microlobulations, middle mass) with margins decreasing in clarity (right mass). The mass also begins to become heterogeneous. 1-4     Category 4a is a mass that has a low suspicion for malignancy (less than 10 percent). Examples of masses that could fall into this category include masses with partially circumscribed or angular borders, abscesses, complex cysts, and cysts with solid internal components. 1-4   Category 4b masses have a chance between 50 and 90 percent of malignancy with a classification of moderately suspicious. Examples of this type of mass includes solid masses with indistinct borders or groups of microcalcifications without a definite mass. 1-4     A Category 4c finding indicates a high probability of malignancy. This mass would not fit into category 5 (discussed in separate tab).Category 4 Images  This image shows a BI-RADS category 4a mass located in the left breast. The left dual shows the mass on the transverse, radial plane while the right dual shows the same mass on the sagittal, antiradial plane. This oval-like mass shows indistinct lateral margins (brackets) with angular borders (arrow).   This is a BI-RADS category 4b mass located in the outer right breast on the sagittal plane seen on the left dual. The transverse image is on the right dual. This mass shows indistinct borders with a heterogenous internal composition.   This image shows a BI-RADS category 4c mass in the right breast on the antiradial (left dual) and radial planes (right dual). This mass lacks distinct borders and shows internal microcalcifications results in the classification of a BI-RADS category 4c mass.   Images courtesy of Dr. Michael Golatta M.D., PhD, University of Heidelberg, Department of Gynecology, Breast Unit, Heidelberg, Germany.    Category 5 & 6Category 5 masses look like a malignancy on the images and have less than 5 percent chance of being a benign process. Biopsy is the recommended course of action. Imaging findings for these types of masses include spiculations, fine, linear calcifications, clustered microcalcifications, architectural distortion, irregular shape, and a high density (radiopaque) mass on the mammogram (see the Discussion section for further information on benign versus malignant appearances on ultrasound). 1-4 The category 5 mass includes indistinct margins, irregular shape, and spiculations on the ultrasound image. 1-4     A BI-RADS category 6 is a biopsy-proven malignancy. This category is only used for diagnosed cancers that are incompletely removed or as part of treatment response follow-up exams.   This image of a BI-RADS category 5 mass shows multiple spiculations, posterior shadowing, microcalcifications, an irregular shape, and growth through tissue planes. Image courtesy of Dr. Richard G. Barr M.D., PhD Radiology Consultants, Inc, Youngstown, Ohio USA.     Ultrasound is the first modality to help diagnose palpable breast masses in the younger woman. In the case of a mammographic finding, ultrasound gives more information on internal mass composition. The multiple ultrasound modes available, 2D-mode, color Doppler Imaging (CDI), and elastography, give information on the internal mass characteristics, vascularity, and the mechanical properties of the targeted pathology. This section gives information on multiple modes used to characterize the solid breast mass. There are many optimization tools available for the 2D-mode, ranging from gain settings to harmonics. In this section, we will look at SieScape Panoramic™ imaging and Custom Tissue Imaging or CTI. Learn More about SieScape Learn more about SieScape. Tab TitleTextConstructing the ImageSieScape imaging is a method that gives an extended field of view image using preprocessing of data acquired during imaging.5 Allowing the global display of large structures, this type of data processing results in a high-resolution, grayscale image.   Multiple images create the extended field of view (EFOV) during real-time scanning. As you move the transducer across a structure the system senses the direction (arrow) while acquiring multiple frames (red box).6 When adding new frames to the data set, the system keeps the earlier information.5 Feature and pixel matching allows the system to create a composite of the adjacent frames creating the EFOV image.5-7   The resulting SieScape image is a composite of all the acquired frames.7 This BI-RADS 2 (Benign) mass shows posterior enhancement, complete capsule, wider-than-tall growth, and a homogeneous internal structure.4, 12, 17  The Image This SieScape image of a fibroadenoma shows the entire mass as well as the surrounding tissue giving a global view. This mass would be classified as a BI-RADS 2 (benign) as there is a homogeneous internal echo pattern, enhanced through transmission, and is wider-than-tall.1, 2, 4 Learn More about CTI Learn more about CTI. Tab TitleTextHow it WorksOne of the first things we learn is that the average speed of sound in tissue is 1540 m/s.5 However, this is an average, tissue such as fat has a slower speed.8, 9 Custom Tissue Imaging or CTI allows for adaptation of the speed used to calculate the round-trip time, and thus adjusts for average (CTI 0), slower (CTI 1 and 2), or faster time (CTI 3 and 4). To understand the importance of this feature we need to review how the ultrasound system determines where to place the returning echo on the image.   A pulse sent into the tissue from the transducer travels at an average speed of 1540 m/s (CTI 0). The system uses this time it takes for the echo to return from the tissue to calculate the depth of a structure. The longer the time it takes the echo to return the further away the structure. The speed of sound and round-trip time of the pulse determines the depth of the structure.5, 10 In most tissues, the sound beam is brought into focus, like a corrective eyeglass lens that focuses an image on the retina.   This seems straight forward until we consider tissue differences, specifically in the breast. Fatty tissue has an approximate speed of about 1460 m/s while glandular breast tissue, breast cancers, and fibroadenomas have a faster speed.8, 10, 11 This difference in the real and assumed speed of sound results in a decrease in the signal uniformity (coherence). This phase aberration decreases sensitivity through increases in the signal-to-noise ratio,10 and constructive and destructive interference.9Image ComparisonsUsing Custom Tissue Imaging, or CTI allows the system to calculate the speed of sound based on the selected setting. In the presence of a tissue – speed mismatch, small details become blurred due to the miscalculation of the structure location.9    This image shows the same mass with two CTI settings.  Using CTI 0 (left image), tells the system to use the average speed of sound in tissue (1540 m/s).5, 10 If the actual tissue speed differs, we lose axial and lateral resolution. In the case of these images, the tissue and breast mass are denser resulting in a faster than average speed of sound. Changing the CTI setting to 4 (right image) corrects the speed-of-sound mismatch. Compare the internal architecture of the mass and the surrounding tissue planes.   These images show the opposite effect using fatty breast tissue. CTI 1 (left image) matches the speed-of-sound in fatty tissue while the right image (CTI 4) assumes a faster-than-average speed resulting in an image with less detail. The axial and lateral resolution increases or decreases depending on the type of tissue imaged. When using CTI, you must consider both the structure and depth.   The ABVS is an automated ultrasound transducer that attaches to the ACUSON S2000 system. This transducer acquires full-field 3D volumes of the breast via the system protocol. Allowing for automatic acquisition of each breast in a pre-defined sequence, the system scans the breast beginning with the right and ending with the left. Each view has a pre-defined label showing the side (right or left) and location of the imaged breast.   A key advantage of volume acquisition is the ability to visualize the entire breast and any abnormalities in simultaneous axial, longitudinal, and coronal views. Image slices can be changed after acquisition allowing for a survey of the whole breast with a single volume.   Learn More about ACUSON S2000 ABVS Images Learn more about ACUSON S2000 ABVS images. Tab TitleTextFibroadenoma ACUSON S2000 ABVS 3-on-1 image showing a large fibroadenoma. The nipple marker (☒) has been enlarged to aid in viewing. This fibroadenoma fits into the BI-RADS category as a 3 (Probably benign: short-interval follow-up recommended) as it has a round shape, an intact capsule, smooth margins, and large lobulations.1, 2, 4Magnify Tool ACUSON S2000 ABVS 3-on-1 image showing a large fibroadenoma using the magnify tool to enlarge the area of concern (coronal view, large left). PhyllodesThe phyllodes tumor has a similar appearance to the fibroadenoma; however, has a different cellular makeup. Meaning leaflike, phyllodes tumor stromal growth occurs between cystic spaces.1 Presenting later in life than a fibroadenoma, in the fourth decade, this large, unilateral tumor has the potential for malignancy.1, 2   Clinical findings show a nontender, mobile mass possibly with bulging skin stretching, and edema due to the large size. Visually, the skin overlying the mass shows marked vascularity. On the mammogram, this type of tumor images as a circumscribed, oval, or lobulated mass without calcifications.1, 2     This sagittal image shows a hypoechogenic, well-circumscribed mass with a cystic part. Due to the rapid growth and size, tumors develop internal necrosis and hemorrhage which images as complex or cystic areas.1 This is a characteristic finding with the phyllodes tumor.2 These masses have characteristics that would put them in the BI-RADS ultrasound category 3 (Probably benign: short-interval follow-up recommended),4 a biopsy would be justified.1 Arrow - pectoralis muscle. The nipple marker (☒) has been enlarged to aid in viewing.   This transverse image of the same mass shows the anechoic ribs (asterisk) with strong posterior shadowing.  Compare to the enhancement seen posterior to the phyllodes tumor. The posterior enhancement see with the phyllodes tumor is due to the high stromal cellularity and lack of desmoplastic response.1 The nipple marker (☒) has been enlarged to aid in viewing. Vascular imaging of the breast does not include the use of spectral Doppler resistive index (RI) due to overlapping values between malignant and benign masses.1, 2, 12 The use of color and power Doppler imaging does aid in showing the number, location, and tortuosity of vessels found within the solid mass. Contrary to Doppler imaging in other areas of the body, when imaging the breast mass keep the color box angle at 90-degrees.13 Vessels within the breast mass tend to be tortuous1 making it difficult to obtain the angles used in other areas of the body. As a result, angling the color box to the right or left may decrease imaged flow.    Can you think of how your clinical site could use Doppler imaging in the breast?      Learn More about Using Doppler in the Breast Learn more about using Doppler in the breast. Things to look for when using Doppler imaging in the breast: 1, 2, 12   1. Documenting the presence and location of vascularity. 2. Separating a solid from a complex cystic mass. 3. Differentiating ducts from vessels. 4. Separating a mass from a fat lobule. 5. Determining the presence of a lymph node versus a fat lobule. 6. Showing a fibrovascular stalk with an intraductal tumor. 7. Separating new tumor growth from scar tissue. 8. Proving the presence or absence of hyperemic flue due to inflammation. 9. Verifying clot in breast veins. 10. Creating movement in a complex cyst via power output adjustments. Color Doppler velocity imaging is simply the conversion of the Doppler shift to a color value. Performed as an adjunct to 2D-mode imaging, the CDV image is the superimposition of flow velocity onto the grayscale image. To create the real-time image, the system sends a pulse from a set of crystals to obtain the data for the 2D-mode image. For the color data, the transducer sends a pulse from a separate set of crystals.5, 10 The use of these sequences results in a slower frame rate as the system needs time to send, receive, and process the data.5     Learn More about CDV Learn more about CDV. Tab TitleTextImaging Tips2, 141. Increase sensitivity by:     a. Decreasing the pulse repetition frequency (PRF; Scale).     b. Using a small color box to obtain the fastest frame rate.     c. Keeping the color box as close to 90 degrees as possible as many breast mass vessels         course parallel to the transducer. 2. Check for correct color gain by increasing until noise appears and then decreasing until just       removed. 3. Adjust color baseline. 4. Set the color write priority higher than the 2D-mode priority. 5. Increase color persistence.The Image This dual image shows a lobulated mass with central flow (right, dual). Reducing the velocity scale, set at 3.5 cm/s, increases the sensitivity. The red color hue shows flow away from the transducer while flow towards the transducer has a blue hue. Using the 2D-mode characteristics, this mass has the BI-RADS characteristic of a category 4 (Suspicious: biopsy) due to posterior shadowing, heterogeneous internal appearance, and a taller-than-wide size.1, 4, 17   CDE uses the strength or power of the Doppler signal to create the image rather than the velocity or direction of flow. The color hue assignment with CDE shows the blood flow within the ROI. Also included is the tissue attenuation to determine the intensity of the signal with a brighter hue indicating a higher intensity signal.10Using the amplitude of the RBC movement rather than the velocity allows for creation of a non-directional color image. As a result, CDE has less angle dependency, aliasing, and increased sensitivity.5, 10 CDE allows us to determine the perfusion of a selected area,5 in our case the lobulated breast mass.      Learn More about CDE Learn more about CDE. Tab TitleTextImaging Tips141. Check for correct power gain by increasing until noise appears and then decreasing until just       removed. 2. Use a scale setting that decreases flash artifact. 3. Adjust the filter settings. Lower filters increase sensitivity and flash artifacts while higher filters decrease     sensitivity and flash artifacts.  The Image This is a biopsy-proven fibroadenoma with internal flow. The color bar, found in the upper left of the image, shows that a single color represents the flow within the vessels. This brighter hue shows a higher signal intensity. Though a known fibroadenoma, this mass would fit into the BI-RADS category 4 (Suspicious: biopsy) due to the heterogeneous internal pattern, and areas of indistinct margins (arrow). A complement to other ultrasound imaging modalities, elastography enables visualization and quantification of tissue stiffness. Long known as a sign of disease and malignancy, visualizing tissue stiffness aids the clinician in diagnosis. Virtual Touch™ technologies, eSie Touch™ elasticity imaging, VTi, and Virtual Touch™ IQ provide elasticity imaging for the breast. The use of these tools during breast imaging adds another tool for the clinician.   Elasticity tools work by measuring how much strain tissues show in response to stress.  The relationship between stress and strain gives information about the mechanical stiffness of the imaged tissue.   Shear Wave Speed and Elasticity values may vary among manufacturers! Download and print a copy of the Understanding ARFI and New Elastography Quantification Technologies white paper.   Learn More about eSie Touch elasticity imaging Learn more about eSie Touch elasticity imaging. Tab TitleTextGrayscale Image This image shows a grayscale map used for the strain elastogram (right dual) as shown by the color bar found on the left of the image of a biopsy-proven fibroadenoma. Stiff tissue has a darker color assignment than softer tissue. The QF or quality factor above 50 (yellow box) indicates minimal movement and a higher correlation of tissue position between image frames. This mass fits into the BI-RADS category 4 due to the subtle, varied posterior shadowing and a thickened, indistinct margin (arrow).Color Image This image of a fibroadenoma uses a color assignment for tissue stiffness on this strain elastogram. The stiffer tissue displays with blue hues while the softer in red hues as shown by the enlarged color bar (left). The strain elastogram (right, dual) shows the fibroadenoma as stiffer than the surrounding tissue. The fibroadenoma fits into the BI-RADS category 3 due to the homogeneous internal composition, posterior enhancement, taller-than-wide growth, and intact margins.   Remember, eSie Touch elasticity imaging is a qualitative method of finding relative stiffness. Learn More about Virtual Touch Imaging (VTi) Learn more about Virtual Touch Imaging (VTi). This VTi image uses a color-coded mode to display the relative tissue stiffness differences. The softer tissue displays as blue while the stiffer tissue as red (color bar, left). This fibroadenoma has a stiffer tissue composition than the surrounding tissue. This round fibroadenoma exhibits the characteristics of a BI-RADS category 4 due to a heterogeneous internal composition, posterior shadowing (arrowheads), and indistinct margins (arrow).1, 2. 12 The same fibroadenoma imaged with a black and white or grayscale VTi map. The stiffer tissue displays dark while the soft tissue white (color bar, left). As with the color image, the fibroadenoma shows stiffer than the surrounding tissue. Learn More about Virtual Touch™ IQ (VTIQ) Learn more about Virtual Touch™ IQ (VTIQ).   This 2D-mode image shows a rounded breast mass with gentle lobulations. We use terms such as heterogenous and hypoechoic to describe this mass which would fall into the BI-RADS 3 (Probably benign: short-interval follow-up recommended).4 This VTIQ image of the same mass shows the color overlay with shear wave velocities between 6.5 and 0.5 meters per second (m/s) as seen in the color bar on the upper left of the image. The large, adjustable elasticity box is called the 2D shear wave elastogram (2D SWE) while the smaller, fixed ROIs provide the point shear wave elastography (pSWE) values. Two-point quantification measurements of the shear wave speed compare the mass velocity (white text) to the adjacent fatty tissue (green text) found in the lower right of the image.  There is a close correlation between shear velocity and tissue stiffness, with higher velocities indicating stiffer tissue. VTIQ allows us to quantify the stiffness. This section has clinically proven case studies showing the full spectrum of sonographic modalities in diagnosing breast-related pathology. Three case-study examples of lobulated breast masses give an overview of findings seen in the clinical setting.    Note: Images have been cropped with measurement boxes and color bars positioned for optimal viewing and resolution.   Case study images courtesy of to Dr. Richard G. Barr M.D., PhD Radiology Consultants, Inc, Youngstown, Ohio USA. Learn More about a Soft Fibroadenoma Learn more about a soft fibroadenoma. Tab TitleTextPatient HistoryAge: 39   Patient History: Palpable left breast mass.   Imaging: No mammogram performed. Ultrasound findings of BI-RADS category 3 (Probably benign: short-interval follow-up recommended).4   Biopsy findings: Fibroadenoma2D-mode The 2D-mode image shows a 1.5 cm, hypoechoic, well circumscribed mass. Also visible is through transmission (up arrowheads), and edge (refractive) artifacts (open arrows).CDE Color Doppler Energy (CDE) shows moderate internal flow in the biopsy-proven fibroadenoma.Virtual Touch TechnologiesScroll down to see all the images.     This dual image shows the mass (circle) with the 2D-mode on the left and strain elastogram on the right. eSie Touch elasticity imaging shows mass has a stiffness similar to the surrounding tissue. This black and white elastogram (right) shows tissue with white for soft tissue and black for stiff tissue. The darker areas on the elastogram indicate stiffer areas while the lighter indicate softer tissue. Notice the edge artifact (yellow arrow) does not display within the elastogram ROI.    Important! Stiffness displays relative to the surrounding tissue.   This is an image with pSWE within a 2D SWE box. The shear wave imaging (VTIQ) velocity of the mass is 2.0 m/s (12 kPa) with the adjacent fat a velocity of 1.27 m/s (4.8 kPa). In this image, the color bar (upper right image) shows stiffer tissue (6.5 m/s) coded red with softer tissue (0.5 m/s) coded blue. To convert to kPa simply place the value into the following formula: kPa = 3Vs2.15 Learn More about Intermedia Stiffness Fibroadenoma Learn more about intermediate Stiffness fibroadenoma. Tab TitleTextPatient HistoryAge: 23   Patient History: New palpable left breast mass.   Imaging: No mammogram performed. Ultrasound findings of BI-RADS category 3 (Probably benign: short-interval follow-up recommended).4   Biopsy findings: Fibroadenoma    Note: The patient preferred biopsy to the standard follow-up exams. 2D-mode This 2D-mode image shows a wider-than-tall, oval, 2.5 cm mass in the palpable area. The heterogeneous, oval, hypoechoic mass has defined borders.CDE The CDE image shows both central and peripheral flow confirming a solid mass.12Virtual Touch Technologies This strain elastogram shows soft tissue as white and stiff tissue as black (grayscale bar; upper right). A softer area of the mass appears as white area in the anterior part of the mass (arrow). The tissue surrounding the mass displays softer in shades closer to white. The distance ratio or E/B ratio of 0.94 suggests a benign mass. This VTi image also uses white to show soft tissue and black for stiffer tissue (grayscale bar; upper right).  However, shear waves provide the information on tissue stiffness. The image shows a stiffer mass than the surrounding tissue. The E/B ratio (not shown) of 0.95 again suggests a benign mass and the anterior part of the mass shows a softer area. This VTIQ image uses red for stiffer tissue and blue for softer tissue (color bar; upper right). Point shear wave measurements show a velocity of 3.33 m/s (33 kPa) in the mass supporting a benign lesion. A point quantification sample of fatty tissue shows a velocity of 2.12 m/s (13.5 kPa).   Learn More about a Stiff Fibroadenoma Learn more about a stiff fibroadenoma. Tab TitleTextPatient HistoryAge: 28   Patient History: New palpable right breast mass.   Imaging: No mammogram performed. Ultrasound findings of BI-RADS category 4a (Low suspicion: biopsy).4   Biopsy findings: Fibroadenoma2D-mode This 2D-mode image shows the 2.2 cm hypoechoic lesion. Though well-circumscribed, the border shows multiple angular areas (arrowheads) resulting in the BI-RADS category 4a classification.CDE CDE shows moderate flow within the lesion.Virtual Touch Technologies This shear wave image uses darker shades to stand for stiffer tissue and lighter shades to show softer tissue. The mass measures smaller on the elastogram (right; 13.7 mm) than on the 2D-mode image (left; 2.7 mm). While the mass appears stiffer than the surrounding tissue, the E/B ratio of 0.63 is indicative of a benign mass. The lesion to fat ratio of 2.45 suggests a benign process on the strain ratio image. When placing the ROI’s begin with the reference tissue, in this case fat (+; 0.262%). Place the second ROI in the area of interest (x; 0.107%). VTIQ point shear wave measurements show the lesion has a velocity of 2.47 m/s (19 kPa) while the tissue has a velocity of 1.36 m/s (5.55 kPa). This correlates to the strain findings again suggesting a benign lesion. Earlier in the tutorial you learned about the BI-RADS classification of a breast mass used for both mammography and sonography. The terminology in the classification standardizes descriptive terms used in the imaging report. Other mass features you will need to consider when performing the sonographic breast exam include;1, 2, 12, 15   shape, orientation, margins, internal echo pattern, posterior acoustic features, the presence, absence, and type of microcalcifications, and vascularity of the mass. The following section focuses on a single sonographic finding such as the shape or orientation of a mass. In the diagnostic process, the clinician uses all the imaging features to determine the BI-RADS category and clinical treatment for each patient.   Learn How to Evaluate a Breast Mass Learn how to evaluate a breast mass. Checklist TitleChecklist TypeChecklist ContentWhat is the shape?HTMLFigure 1     Figure 1. The oval mass oriented parallel to the chest wall has a greater chance of being a benign mass.  This shape can be found in masses ranging from BI-RADS categories 1 (negative) to 3 (Probably benign short-interval follow-up recommended).4 Figure 2     Figure 2. Like its oval counterpart, the round mass is probably a benign process. The mass in this image would have a BI-RADS classification of 4a (Low suspicion: biopsy).4 Figure 3   Figure 3. This irregularly shaped mass falls into the BI-RADS category 5 (Highly suggestive of malignancy: biopsy).2, 4   Note: This describes the mass shape rather than the margins.2  How is the mass oriented?HTMLAnteroposterior and horizontal measurements help find the orientation of the mass.1 Figure 1   Figure 1. This is an eSie Touch elasticity image of a biopsy proven fibroadenoma. This mass has a wider-than-tall appearance due to growth between (parallel to) the tissue planes.1, 16 The width measures 33.7 mm and height measures 17.7 mm. This type of mass falls into the BI-RADS 3 category (Probably benign: short-interval follow-up recommended).4 Figure 2   Figure 2. This mass has a taller-than-wide appearance due to growth through (non-parallel to) the tissue planes.12 The height measures 2.73 cm and the width 1.62 cm. Notice the elastogram shows the mass larger than the 2D-mode. This finding added to the mass having a stiffer composition than the surrounding tissue also suggests a higher probability of malignancy.  This BI-RADS mass would fall into category 5 (highly suggestive of malignancy: biopsy).4  Describe the mass margins.HTMLFigure 1   Figure 1. Benign masses tend to show smooth echogenic margins (arrows).17 The presence of a margin which has distinct echogenicity differences between the mass and tissue is a feature indicating a probable benign process.4 Due to the complete margins this mass would be classified a BI-RADS category 3 (Probably benign: short-interval follow-up recommended).4 Figure 2   Figure 2. Malignancies tend to grow into tissue17 resulting in a non-circumscribed margin.1, 2  The irregular margins indicate the presence of a probable malignancy fitting into the BI-RADS 4c (Moderate suspicion: biopsy).4 Figure 3   Figure 3. Imaging the breast mass requires careful inspection of the margins for any areas of change. This mass shows spiculations on one area resulting in an indistinct margin (arrow).2 Any angle changes, even if it is only one, raises concern for malignancy placing this mass into the BI-RADS 4b category (Intermediate suspicion: biopsy).1, 4, 12 Figure 4   Figure 4. This biopsy proven fibroadenoma imaged in a virtual format shows both micro- and macrolobulations. Microlobulations measure 1 to 2 mm (double arrow) compare the appearance to the macrolobulations (arrow).12 The microlobulated margin increases the chance of a malignant mass placing these masses in a BI-RADS 4 category (Suspicious: biopsy).4 Figure 5   Figure 5. The margins of this mass have a spiculated appearance due to growth into tissue. This type of mass correlates to the mammographic findings of a spiculated mass with a BI-RADS score of 5 (Highly suggestive of malignancy: biopsy).4, 17 Sonographically, spiculations image as alternating hyper- and hypoechoic extensions into the breast tissue.17 This is the most accurate of sonographic findings12, 17 and we hear this finding referred to as angular margins.12   Spiculated and lobulated are not the same process. Lobulated describes a gentle curved structure while spiculated masses project into tissue. How does the internal architecture image?HTMLFigure 1   Figure 1. An anechoic mass, whether cystic or solid, lacks internal echoes. The simple cyst, as the one seen on this image, would be classified as a BI-RADS category 2 (Benign) lesion.4 Figure 2   Figure 2. This mass has a complex appearance, often called heterogenous, as there are areas of hypoechoic (arrow) and hyperechoic tissue (open arrow). Compare internal mass characteristics to the normal surrounding breast tissue. This mass would be classified as a BI-RADS category 5 (Highly suggestive of malignancy: biopsy).4 Figure 3   Figure 3. This SieScape panoramic image shows both an anechoic (down arrow) and isoechoic (up arrow) mass. Both terms describe a mass in relation to the surrounding breast tissue.2 Both isoechoic and anechoic lesions have a high likelihood of being benign.17 The anechoic mass would be a BI-RADS 2 (Benign) as it is most likely a cyst. However, the isoechoic lesion has some areas of calcifications and an anechoic area resulting in a classification of a BI-RADS category 4 (Suspicious: biopsy).What does it look like deep to the mass?HTMLShadowing and enhancement occur posterior to a structure due to attenuation differences in the imaged structure.5 Compound imaging either eliminates or reduces these artifacts due to the changes in the beam angle direction.5 Images with compound imaging active can show tissue and tissue borders posterior to the imaged anatomy. Figure 1   Figure 1. Shadowing posterior to a mass displays as an area of reduced echoes devoid of information.5 Due to attenuation, or absorption of the sound, this finding is the result of spiculations or desmoplasia.2, 12 Mass shadowing, as seen in the image above places this mass in the BI-RADS 5 category (Highly suggestive of malignancy: biopsy).4 Figure 2   Figure 2. Enhancement is the increase in brightness posterior to a structure (arrows) usually found with a benign process such as a cystic structure. This finding is due to the strengthening of echoes.5 This characteristic cystic finding places these areas in the BI-RADS category 2 (Benign).4 Figure 3   Figure 3. Enhancement is the increase in brightness posterior to a structure (arrows) usually found with a benign process such as a cystic structure. This finding is due to the strengthening of echoes.5 This characteristic cystic finding places these areas in the BI-RADS category 2 (Benign).4 Figure 4     Figure 4. In some cases, there may be no change to the echoes posterior to a mass. Be careful to compare the same type of tissue (double arrows). The edge artifact, or refractile shadowing, can make tissue appear hypoechoic (arrow). Figure 5     Figure 5. This strain elastogram shows a combined posterior echo pattern (arrows) due to different attenuation properties. The internal mass 2D-mode composition appears complex (left dual) and the elastogram shows a stiff mass with an E/B ratio of 1.26. This type of shadowing places the mass in BI-RADS category 5 (Highly suggestive of malignancy: biopsy).4  What do calcifications look like?HTMLFigure 1     Figure 1. Macrocalcifications greater than 0.5 mm (double arrows) and microcalcifications outside a mass of less than 0.5 mm (arrow) are important predictors of malignancy. In the case of a small macrocalcification without shadowing, ductal carcinoma in situ (DCIS) is of concern. This image, shown earlier in the margins section, received a BI-RADS score of 5 (Highly suggestive of malignancy: biopsy).4, 17 The presence of calcifications places the mass in the same category.   Remember, a calcification smaller than the beam width will not shadow.2, 5, 12   Figure 2   Figure 2. This biopsy proven fibroadenoma shows linear microcalcifications. Possibly due to vascular changes within the fibroadenoma, these microcalcifications warrant a short-interval follow up (BI-RADS category 4b)4 even with the biopsy proven identification.Is there flow?HTMLThe presence or absence, location, and velocity of vascularity should not be used to determine a benign or malignant breast mass due to the overlap in findings.12 Slow flow within the breast makes it difficult to image as small vessels easily compress. Other color technical considerations include:1 Low pulse repetition frequency (aka PRF or scale) Low wall filter Increase gain – not enough to create speckle Increase persistence Straight color box Figure 1     Figure 1. Power Doppler (Color Doppler Energy or CDE) uses the amount of flow within the vessel increasing sensitivity and thus, detection of flow.13 This image shows an example of directional CDE using flow towards the transducer as red and flow away from the transducer as blue.  Figure 2   Figure 2. This image shows vascularity in tissue surrounding the mass. In the presence of inflammation, such as with mastitis or an abscess, vascularity increases.2   Explore the links below for the Glossary, References, and Further Reading opportunities. References / Further Reading References / Further Reading 1. Stavros, A.T. (2011). The breast. In Rumack, C.M., Wilson, S.R., Charboneau, J.W., et al., (Eds.), Diagnostic ultrasound (pp. 773-839). St. Louis: Elsevier Mosby. 2. Carr-Hoefer, C. (2012). The breast. In Kawamura, D.M. and Lunsford, B.M., (Eds.), Diagnostic medical sonography: Abdomen and superficial structures (pp. 471-527). Baltimore: Wolters Kluwer Health | Lippincott Williams & Wilkins. 3. Zonderland, H. and Smithuis, R. (2014). BI-RADS for mammography and ultrasound 2013: updated version. 2014 [cited 2017 06/09]; Available from: http://www.radiologyassistant.nl/en/p53b4082c92130/bi-rads-for-mammography-and-ultrasound-2013.html#in53b95d40ee2ac. 4. Raza, S., Goldkamp, A.L., Chikarmane, S.A., and Birdwell, R.L. (2010). US of breast masses categorized as BI-RADS 3, 4, and 5: Pictorial review of factors influencing clinical management. RadioGraphics. 30(5): 1199-1213. 5. Kremkau, F.W. (2016). Sonography: principles and instruments. 9 ed., St. Louis: Elsevier. 6. Nock, L.F., Friemel, B., Sutcliffe, P.L., Tirumalai, A.P., and Weng, L. (1999). System and method for correcting the geometry of ultrasonic images acquired with a moving transducer. United States of America: Office, U.S.P.a.T. 7. Sumanaweera, T.S., Allison, J.W., and Maslak, S.H. (2003). Medical diagnostic ultrasound imaging methods for extended field of view. United States. 8. Weiwad, W., Heinig, A., Goetz, L., Hartmann, H., Lampe, D., Buchmann, J., . . . Heywang-Koebrunner, S.H. (2000). Direct measurement of sound velocity in various specimens of breast tissue. Investigative Radiology. 35(12): 721-726. 9. Yoon, C., Lee, Y., Chang, J.H., Song, T.-k., and Yoo, Y. (2011). In vitro estimation of mean sound speed based on minimum average phase variance in medical ultrasound imaging. Ultrasonics. 51(7): 795-802. 10. Hedrick, W. (2013). Technology for diagnostic sonography. St. Louis, MO: Elsevier. 11. Chang, C., Huang, S., Yang, H., Chou, Y., and Li, P. (2007). Reconstruction of ultrasonic sound velocity and attenuation coefficient using linear arrays: clinical assessment. Ultrasound in Medicine & Biology. 33(11): 1681-1687. 12. Matthew, D. and Rapp, C. (2016). Possible breast mass. In Sanders, R.C. and Hall-Terracciano, B., (Eds.), Clinical sonography: A practical guide (pp. 713-734). Philadelphia: Wolters Kluwer. 13. Hovath, E., Cuitiño O, M.J., Pinochet, M.A., and Sanhueza S, P. (2011). Doppler color en el estudio de la mama: ¿Cómo lo hacemos nosotros? Revista Chilena de Radiologica. 17(1). 14. Allen, P.L. (2014). Appendix: system controls and their uses. In Pozniak, M.A. and Allen, P.L., (Eds.), Clinical Doppler Ultrasound  (pp. 370-374). Edinburgh: Churchill Livingstone Elsevier. 15. Barr, R.G. (2015). Breast elastography. New York: Thieme. 16. Stavros, A.T., Thickman, D., Rapp, C., Dennis, M.A., Parker, S.H., and Sinsney, G.A. (1995). Solid breast nodules: use of sonography to distinguish between benign and malignant lesions. Radiology. 196: 123-134. 17. Rada, D. (2017). The breast. In Hagan-Ansert, S.L., (Eds.), Textbook of Diagnostic Sonography (pp. 581-617). St. Louis, MO: Elsevier. Glossary Glossary 2D-mode imaging (i.e., brightness mode, grayscale, B-mode) – Ultrasound display of the amplitude of echoes returning from the body.  The higher the amplitude, the brighter the display. Acoustic radiation force impulse imaging (ARFI) – This technology uses a track, push pulse, detect sequence to create a qualitative elastogram of soft tissue. Color Doppler Energy (CDE) – Color overlay displaying amplitude of the Doppler signal. Color Doppler Velocity (CDV) – Color overlay displaying velocity of the Doppler signal. Doppler imaging – Display of motion, such as blood flow, as a spectral tracing or color mapping. Echogenic – Having brighter / lighter appearance than the surrounding tissue on a 2D-mode image. Elasticity – Ability of a structure to return to its original shape after compression. Elastogram – The image showing the conversion of tissue strain. Elastography – An imaging method to map the elastic properties of tissue (i.e., stiff vs. soft) to provide information on changes due to disease. eSie Touch elasticity imaging - The conversion of tissue strain to an elastogram using external compression and pixel correlation between image frames. Longitudinal wave (i.e., compression wave) – A sound wave from the transducer into the tissue and vice versa. Point shear wave elastography (pSWE) – ARFI generation of shear wave within a fixed ROI that gives an average velocity measurement in m/s or kPa. Posterior enhancement – An increase in brightness deep to a cystic structure. Qualitative – Subjective assignment of value. In elastography we assign a hue to tissue stiffness changes as it relates to the surrounding tissue. Quality Factor (QF) – Measure of movement on an elastogram between image frames. Region of interest (ROI) – Selection of an area on the image. Shadowing – Blocking or reflection of sound resulting in a dark area deep to a structure. Shear wave – Wave produced perpendicular to the transmit pulse. Stiffness – Tissue deformation in response to force (i.e., compression). Virtual Touch™ imaging (VTi) – ARFI imaging. Virtual Touch™ IQ (VTIQ) –Color-coding of shear wave velocities within an elasticity box combined with pinpoint quantitative measurements.