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Compression elasticity imaging of 

the breast: An overview 

Joseph R. Grajo, MD, and Richard G. Barr, MD, PhD 

One out of every 8 women will 

develop breast cancer during 

their lifetime. Currently, the 

best method of treating breast cancer involves 

early detection. Physicians have 

used palpation for many years as a way 

to detect lumps or nodules in the female 

breast. In fact, regular breast self-examinations 

(BSE) and clinical breast examinations 

(CBE) have long been used 

to detect breast nodules in their earliest 

stages of development. Although the 

effects of BSE on mortality rates from 

breast cancer are debatable, CBE still 

exists as a standard screening protocol 

for breast cancer in women. As an adjunct 

to direct manual palpation, physicians 

have utilized ultrasonography to 

visualize lesions in breast tissue. Lesion 

features are frequently characterized 

based on shape, echogenicity, shadowing, 

margin irregularity, and microlobulation. 

1-3 Ultrasound has been extremely 

important because of its ability to help 

differentiate cystic breast lesions from 

solid lesions. This provides the clinician 

with useful insight into the possible benignity 

or malignancy of a given lesion. 

Dr. Grajo is a Diagnostic Radiology Resident 

at the University of South Florida, 

Tampa, FL, and Dr. Barr is a Radiologist 

at Southwoods Radiology, Radiology 

Consultants Inc., Youngstown, OH. 

18 n APPLIED RADIOLOGY © 

Over the past two decades, various 

new methods have been developed to 

sonographically evaluate the stiffness 

of a lesion. 4-11 These methods offer 

the potential to quantify the formerly 

qualitative-only measurement of tissue 

stiffness; therefore, allowing for 

increased differentiation of cystic and 

solid breast lesions. With the use of 

standard ultrasound equipment and 

new “elasticity imaging” (EI) software, 

the trained clinician can now noninvasively 

differentiate benign and malignant 

breast lesions with high sensitivity 

and specificity. Although the standard 

of care for the diagnosis of breast cancer 

still involves biopsy, elastography 

has the potential to significantly reduce 

the number of biopsies of benign breast 

lesions. 12,13 This would help to alleviate 

anxiety in many patients and to decrease 

the related high healthcare costs 

in the United States (U.S.). This article 

will review the physics behind the elastographic 

technique, the utility of elasticity 

imaging in clinical practice, the 

implications of EI on patient care, and 

possible advances in elastography in the 

near future. 

Defining the technique 

Elasticity imaging, also referred to as 

elastography, offers great potential to 

characterize cystic and solid breast le- 

sions using a combination of standard 

ultrasound imaging and innovative 

software technology. There are 2 main 

categories of elasticity imaging: compression, 

or “strain,” elastography, and 

shear wave elastography. Strain elastography 

is a qualitative method that 

measures stiffness based on soft-tissue 

distortion caused by minimal manual 

compression. Conversely, shear wave 

elastography is a quantitative method 

that relies on the principles of Young’s 

modulus to measure the speed of lowfrequency 

shear wave transmission 

through soft tissue. In the authors’ lab, 

minimal manual compression is utilized, 

usually provided by the patient’s 

respiratory cycle and cardiac rebound, 

to produce strain images. This article 

describes this method. 

Like conventional B-mode sonographic 

imaging, EI differentiates cystic 

breast lesions from solid breast lesions. 

An artifact that occurs with some manufacturers’ 

equipment has been reported 

to characterize cystic lesions with high 

accuracy. The technology can also 

further characterize solid lesions that 

contain both benign and malignant elements. 

In such cases, the clinician can 

aspirate or biopsy the various elements 

in a lesion with the guidance of the 

elasticity software. This allows for obtaining 

appropriate breast tissue more 

www.appliedradiology.com October 2012

A B 

FIGURE 1. Real-time display. In our center, we display both the (A) B-mode image and the (B) 

strain image, or elastogram, side-by-side in real time. The strain image demonstrates “soft” 

areas as bright and “hard” areas as dark. The lesion is hypoechoic on B-mode but appears 

bright on the strain image, indicating that the lesion is “soft.” This lesion was biopsied and 

found to be a fat lobule. 

accurately and helps to provide the pathologist 

with information regarding 

the likely composition of the specimen. 

Besides characterizing the composition 

of breast lesions, EI offers the potential 

to differentiate benign lesions 

from malignant with high sensitivity and 

specificity. The technique is based on the 

differing physical properties of benign 

and malignant lesions, as described by 

clinicians throughout the literature. It has 

long been reported that benign lesions 

tend to be “softer,” with more mobility 

within the breast parenchyma, while malignant 

lesions tend to be “harder,” with 

a propensity for remaining firmly fixed 

within the tissue. 14,15 The theory behind 

elastography is that cancerous and noncancerous 

lesions will demonstrate differing 

amounts of tissue motion relative 

to the normal surrounding breast parenchyma 

when minimal pressure is applied. 

The ability to differentiate soft and 

hard lesions allows the clinician to utilize 

EI to predict the benignity or malignancy 

of breast lesions. This would potentially 

lead to a significant decrease in the number 

of benign breast biopsies and, therefore, 

reduce the overall cost of care. 

The physics of elastography 

Compression EI is performed with 

a standard high-frequency ultrasound 

probe. The returning radiofrequency 

signals are analyzed in real time with 

the standard B-mode algorithm and the 

October 2012 

COMPRESSION ELASTICITY IMAGING OF THE BREAST 

EI algorithm. The EI algorithm analyzes 

the stiffness of a lesion compared 

to the compressibility of its surrounding 

tissue, much like measuring the degree 

of stiffness of a marble suspended 

within a bowl of gelatin. In this model, 

external compression will cause the 

gelatin, and not the marble, to change 

shape. The computer analyzes this degree 

of deformation to determine if the 

lesion is soft or hard. Both the standard 

B-mode image and the EI image are 

displayed in real time. The EI algorithm 

is sensitive for a 0.1% strain and 

uses temporal persistency strategy to 

enhance the descriptive pattern in the 

elastogram. Using this technique in the 

breast, the elastography contrast for 

cancerous and noncancerous lesions 

is between 1000% and 5000%, as opposed 

to the tissue contrast of 1% to 

100% between cancerous and noncancerous 

lesions using conventional imaging 

techniques, such as ultrasound, 

mammography, and magnetic resonance 

imaging (MRI). 16 Motion is provided 

by patient breathing and cardiac 

rebound. If additional compression is 

required, slow minimal palpation with 

the probe can be applied. In patients 

with small breasts, the patient may have 

to hold her breath to limit motion. The 

sonographer must ensure that the lesion 

remains in the image plane during 

the compression cycle. It is important to 

have the probe and lesion perpendicular 

to the scanning table. We record a short 

clip that demonstrates both the compression 

and release stages. The best 

image is selected by cine review for 

subsequent measurements. 

www.appliedradiology.com APPLIED RADIOLOGY © 

A 

B 

C 

FIGURE 2. Benign fibroadenoma in an 

18-year-old woman with a palpable breast 

mass. The patient had had no previous 

mammograms. (A) B-mode imaging reveals 

a hypoechoic lesion with low-level internal 

echoes and (B) peripheral color flow. Measurements 

of lesion length demonstrated 

a smaller dimension on the elastogram. 

Based on the B-mode findings, this lesion 

was classified as BIRADS 4B; pathology 

revealed it to be a benign fibroadenoma. 

n 19


A B 

FIGURE 3. Fibroadenoma in a 42-year-old woman with dense breasts. (A) B-mode imaging 

revealed a hypoechoic lesion with some low-level internal echoes and no posterior acoustic 

enhancement. (B) The lesion appears smaller on real-time compression elasticity imaging. 

Based on B-mode, this lesion was characterized as BIRADS 4. This lesion was proven at 

biopsy to be a fibroadenoma. 

A B 

FIGURE 4. Fibrocystic change in a 72-year-old woman with an asymmetric density on mammography. 

(A) B-mode imaging demonstrates a mostly hypoechoic lesion with posterior acoustic 

enhancement. An additional lobulated hypoechoic area is seen adjacent to this lesion. (B) 

On elastography, the lesion appears smaller with a central bright spot surrounded by darker 

areas. This lesion was biopsied and was consistent with apocrine metaplasia. 

A B 

FIGURE 5. Simple cyst. (A) B-mode imaging demonstrates a simple cyst. (B) A manufacturer’s 

artifact on the strain image shows a dark lesion with bright spots centrally and posteriorly. 

This “bull’s-eye” artifact appears in both simple and complicated cysts. 


While performing an ultrasound on 

a patient with a known breast lesion(s), 

both the standard B-mode image and 

the elastogram are displayed side-byside 

(Figure 1). We can then directly 

compare the relative stiffness of a lesion 

based on its elastic properties in relation 

to the surrounding tissue. In our study, 

we set the ultrasound machine to display 

“soft lesions” as white and “hard 

lesions” as black. This gives us immediate 

insight into the relative stiffness 

of any lesion within the breast parenchyma. 

It is important to emphasize that 

the elastographic technique provides the 

clinician only with the relative stiffness 

of breast lesions within the surrounding 

tissue. Therefore, lesions will exhibit 

varying shades of gray in fatty breast 

tissue as opposed to dense breast tissue. 

To obtain an appropriate dynamic range 

for interpretation, we try to include 

fatty tissue, normal dense breast tissue, 

and the lesion in the field of view. This 

limits our ability to utilize EI in a mass 

screening protocol. 

By displaying the B-mode sonographic 

image and the elastogram sideby-side, 

we can also directly compare 

the relative dimensions of the lesions 

in both image displays. We then predict 

the benignity or malignancy of the 

breast lesion based on size of the lesion 

in the elasticity image compared 

to its size in the B-mode display. Either 

length or area of the lesion in the greatest 

dimension can be utilized to measure 

the magnitude of the lesion. If the 

lesion appears smaller on the elastogram 

based on direct measurement, it 

is characterized as benign. If the lesion 

measures equally or larger on the elastogram 

compared to the B-mode image, 

the lesion is deemed to be malignant. In 

our initial study, we determined that EI 

is able to correctly differentiate benign 

and malignant breast lesions with very 

high sensitivity and specificity. 17-19 

Clinical utility of breast 

elasticity imaging 

Elasticity imaging offers the potential 

to characterize various breast lesions 

in great detail and to provide the 


A B 

FIGURE 6. Recurrent invasive ductal carcinoma (IDC) in a 52-year-old woman with history 

of left breast lumpectomy for IDC. The patient presented with a new mass at the edge of her 

surgical scar. (A) B-mode imaging demonstrates a mostly hypoechoic lesion with some posterior 

acoustic enhancement. (B) Real-time strain imaging shows a uniformly dark lesion, which 

appears larger on the elastogram. 

A 

FIGURE 7. Invasive ductal carcinoma in a 50-year-old woman. (A) On B-mode imaging, the 

lesion appeared suspicious and was classified as BIRADS 5, requiring biopsy. (B) The lesion 

appeared noticeably larger on elastography, even with the naked eye. 

A 

FIGURE 8. Lobular carcinoma in situ. Sonography was performed on this 74-year-old woman 

with a palpable lump in the left breast. (A) B-mode imaging shows a hypoechoic mass with 

ill-defined borders. (B) Compression elastography demonstrates a mostly dark structure that 

appears larger on the strain image relative to the B-mode image. This suspicious lesion was 

biopsied and found to be a lobular carcinoma in situ (LCIS). 

October 2012 

B 

B 


sonographer with an extremely helpful 

adjunct to the standard ultrasound examination. 

The elastographic technique 

is entirely noninvasive and adds only a 

few minutes to the conventional sonographic 

exam. It augments the value of 

the sonogram and allows for immediate 

interpretation of results. In addition, 

elastography provides the clinician with 

detailed characterization of the cystic or 

solid breast lesion that may not be readily 

appreciated on B-mode imaging. 

For example, lesions that appear to be 

solid on B-mode imaging may actually 

be complicated cysts when imaged with 

elastographic software. In the authors’ 

clinical study, 4% of all lesions that appeared 

solid on B-mode were actually 

complicated cysts when viewed as a 

strain image. 20 These lesions can be easily 

aspirated, negating the need for subsequent 

biopsy. 

The clinician can rapidly predict the 

benignity or malignancy of breast lesions 

with EI software and standard B-mode 

imaging techniques. In the authors’ clinical 

study, the size of the breast lesion on 

the B-mode and the elasticity image was 

directly compared. The lesion was determined 

as likely to be benign or malignant 

based on the ratio of the lesion’s size on 

the strain image compared to its size on Bmode 

image. If the ratio is


on a large-scale, multicenter basis, it is 

hoped, then the initial determination 

of a breast lesion’s nature can lead to a 

decrease in the number of benign breast 

biopsies. 

Appearance of benign lesions 

In our experience with EI, benign 

lesions appear smaller on strain images 

compared to the corresponding 

B-mode image (Figures 2 and 3). This 

is based on the relative elasticity of a 

breast lesion within its surrounding 

parenchyma. If a lesion demonstrates 

stiffness similar to normal dense breast 

tissue, it is more likely to be benign 

(Figure 4). In our lab, we also display 

soft structures as white, which further 

demarcates areas of increased elasticity. 

Of particular interest is the easy identification 

of both simple and complicated 

cysts with compression elastography. 

We have shown that cystic lesions demonstrate 

a “bull’s-eye” artifact, featuring 

a dark structure with both central 

and posterior bright foci (Figure 5). 21 

The identification of lesions as benign 

cystic lesions on elastography can lead 

to direct aspiration of symptomatic lesions 

and avoidance of biopsy for complicated 

cysts, which may otherwise 

appear suspicious on standard B-mode 

imaging. In lesions with both cystic and 

solid components, elasticity can help 

guide biopsy to obtain the most useful 

specimen. 

Appearance of malignant lesions 

Due to their increased stiffness, malignant 

lesions appear the same or larger 

on the elastogram when compared to 

the B-mode image. In our center, these 

malignant lesions appear dark on the 

strain images and may demonstrate 

adjacent areas of tissue invasion that 

would not be appreciated on B-mode. 

In the authors’ experience, we can predict 

malignancy based on the real-time 

elastogram with high confidence. Furthermore, 

a recent retrospective review 

has shown the potential to determine 

the aggressiveness of malignant lesions 

and predict the grade of these 

tumors via EI. Limited data analysis 


has demonstrated that more aggressive 

malignancies, such as invasive ductal 

carcinomas (Figures 6 and 7) and invasive 

lobular carcinomas (Figure 8), 

will exhibit higher elasticity/B-mode 

(E/B) ratios compared to mucinous 

carcinomas or ductal carcinoma in situ 

(DCIS), for example. Moreover, initial 

results demonstrate that higher grades 

of IDC correlate with higher E/B ratios 

in a statistically significant fashion. 22 

This observation could have important 

implications for the radiologist’s ability 

to characterize breast lesions, such as in 

classification according to the BIRADS 

system. With the use of elastography, 

one may be able to downgrade or upgrade 

BIRADS 3 and 4A lesions. Further 

validation and standardization of 

this technique is required. 

Conclusion 

Elasticity imaging has demonstrated 

the ability to differentiate benign and 

malignant breast lesions with high 

sensitivity and specificity. Numerous 

imagers have utilized various forms of 

the elastographic technique, including 

color elastography, strain ratio measurements, 

and, most recently, shear 

wave technology, to characterize an 

array of breast lesions. In our practice, 

the authors have produced very favorable 

results with compression elasticity 

images utilizing simple cardiac and 

respiratory cycles to provide the appropriate 

degree of compression for the 

production of strain images. The appropriate 

degree of compression is, in fact, 

a critical aspect of reproducing these 

favorable results. Applying excessive 

manual compression to breast tissue 

will compact the parenchyma and make 

fat appear harder, skewing the interpretation 

of the strain image. The concept 

of applying only minimal compression, 

termed “pre-compression,” is of vital 

importance in obtaining accurate and 

reproducible strain images. 

EI can be particularly helpful when 

working up complicated breast lesions. 

Some lesions may contain both benign 

and malignant-appearing components, 

making it difficult to decide where to 

biopsy within the lesion. Because of the 

distinction between “soft” and “hard” 

lesions provided by elastography, the 

clinician can direct the biopsy needle to 

the more suspicious components within 

a particular breast lesion. The hard component 

of the lesion can be biopsied, 

while the soft component can be aspirated 

with FNA. This will subsequently 

lead to direct needle placement and increased 

biopsy accuracy. It will also 

enhance pathologic diagnosis, as the radiologist 

can provide the pathology lab 

with more detailed information along 

with the specimen itself. 

Over the last several years, we have 

conducted both single-center and multicenter 

trials to demonstrate the effectiveness 

of compression elasticity 

imaging in differentiating benign and 

malignant breast lesions. With strain 

elastography, it is often difficult to interpret 

the elastogram in cases where a 

benign lesion (eg, fibroadenoma, fibrocystic 

change) lies within a background 

of dense breast tissue. The elastographic 

properties are similar and it is 

difficult to determine the boundaries of 

the lesion. Shear wave imaging will be 

helpful in these cases. We believe that 

strain elastography can have several implications 

for the future of breast imaging. 

These include a decrease in number 

of benign biopsies, a reduction in the 

costs of lesion work-up, incorporation 

into the BIRADS classification system, 

and possibly the prediction of breast 

cancer grade. Additionally, the elastographic 

technique can help direct needle 

biopsy and provide useful diagnostic information 

to the pathologist. As such, 

EI may prove to be an important adjunct 

to standard B-mode sonography in the 

evaluation of a breast lesion. 

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