Breast Elastography - SD

Introduction

I am Dr. Shao. I am a director of breast imaging and ultrasound in Tampa, Florida at Moffitt Cancer Center. And today I'll be talking about breast elastography.

Hello, my name is Dr. Shano and I will be giving a talk about breast elastography.

What is Elastography?

Elastography is an imaging technique that depicts tissue stiffness by means of imaging tissue strain from external compression. A software technique integrated into the ultrasound system without any external equipment is utilized. Same probe is used for the B mode and elastography ultrasound imaging. The electrographic information is obtained in real time, and it only takes a few minutes, anywhere from two to five minutes, based on a principle of which is similar to palpation. That's what elastography, print, technique is all about.

On physical exam, as you know, tumors feel much harder than the surrounding tissue with compression or vibration when it is applied to the soft tissues. Ultrasound then can be used to create a map of soft tissue deformation. The results are displayed on an image called gram. The electrogram generates a display of relative stiffness of the lesion to the rest of the image on a color image. And the main colors that you'll be seeing are blue, red, and green. Blue will represent stiff lesions. Red and green represent soft lesions. It is important to have the surrounding tissue included in the image and the use.

Elasticity Scoring System

We will be using a scoring system, which was developed by Dr. Wano from Japan. This is a diagram of all the scoring from one through five. I will be going over each one separately. This is just to give you an overview and as you go from one through five, the one represents the benign lesions, and the five represents the malignant lesions in progression.

The green represents the greater strain, that's why it is soft, and it looks green on the images. And the blue represents a smaller strain, and it is a represents a heart lesion. The real time ELAs gram is superimposed in color on the B scan using a freehand scanning technique. And both are seen on the monitor with the B mode on the right and the ELA on the left.

This is an example of anela of a simple or complicated cyst, and it has a specific appearance of a three layer pattern where you can appreciate the blue, the green, and the red. So this is fairly specific for cystic structure and we all recognize it as such. The compression when is being applied is very important that it is applied in a very light touch. You refer to it as a feather touch. You need to use a lot of gel. There has to be a steady compression, and the compression of normal tissue is necessary to obtain the uniform image of the green. Then the area of pathology is then investigated using the same compression.

This is an example of a breast tissue, normal breast tissue. This is the scan, and this is a fairly glandular, dense tissue. And on gram you can appreciate mostly the green and the reds, which imply that this is a fairly soft area or normal breast tissue.

Elastic Score One

On a elastic score of one, you will see an even strain over the whole lesion, which is, green as well as the surrounding, breast parenchyma. This would be an example of a fibroadenoma. Another example of a benign lesion, which is seen on an ELA would be a typical, hyper coagulate lesion, which is parallel to the skin. However, when you apply the elasticity, you notice that the lesion is all green, and it is surrounded by fairly soft parenchyma, which is red or green. And this is a fibroadenoma.

This is an example of real time scanning with elastography, where you are applying pressure to this, very light pressure. And you notice that the actual lesion and the surrounding tissues sort of blend in together. They all are either, green or red, which implies, that they are soft, not stiff. And on the gray, scale image, this corresponds, to a, lobulated lesion. And this was a fibroid anoma. And this would be given a elasticity score of one.

Elastic Score Two

The elastic score two demonstrates strain over the most of the lesion with some areas being spared, and they are shown as mixed green and blue. It is normally seen with fibroadenoma or complex cyst. However, I would like to show you this particular lesion with the real time clip, again, demonstrating that, when you do the, actual compression, which are fairly light, in this case, it shows both blue and a green areas, which would be typical of an elastic score. Number two. However, if you evaluate the, actual, B mode image, you notice that this is not a very, lobulated lesion, but it is, it is lobulated actually, but it does have some areas of, angular margins and it does have posterior shadowing. So that would be more, suspicious for a malignancy and probably a score of four B or four C. And this turned out to be a, invasive ductal carcinoma after performing a biopsy.

So the point of this case is that for final assessment for lesions, you need to do both, the gray scale imaging and the ELAs as a, single package, and then decide based on the worst characteristics, which are we dealing with a benign or malignant lesion. And as with using the Byre system for any kind of, lesion, you always go with the most worrisome finding, and in this case would be more of the angular margins and the posterior shadowing, as the, as shown for elastic score.

Elastic Score Three

Number three, the strain is at the periphery of the lesion, where it's mostly green and the central portion is blue. This is often seen with intraductal papilloma. I am showing you actually a case of a fibroadenoma where you have centrally, stiffness of, of, image with blue collar. And then, around there is the green and then surrounded by red. So this was a fibroadenoma, elastic score.

Elastic Score Four

Number four has no strain over the entire lesion. It's completely blue, but it is surrounded by the green, normal parenchyma. And this is always seen with most of the time seen with carcinoma. This is an example of a 39-year-old woman with invasive ductal cancer. And on the B scan, you can appreciate a lesion that is irregular, has, angular margins as samples, your shadowing. And on, the ELAs, you appreciated. The lesion corresponds to a blue area, and it is surrounded by benign parenchyma, which is green and, red.

Another, lesion which would be, difficult to distinguish on b scanning itself because it's, hypoechoic, fairly well circumscribed, but has posterior, enhancement. And this could represent a complex cyst, but we cannot exclude, a solid lesion. So we would definitely biopsy this. But with, the help of ELAs gram, we are seeing that this is all blue, which would be consumed with score four, and it's very suspicious for malignancy. And this was after biopsy, a lobular carcinoma.

Elastic Score Five

The elastic score five demonstrates no strain over the lesion and also includes the surrounding areas. And, the, is depicted as blue. And, it's often, or most of the time seen with, cancers, which are usually the, lower or mid, grade cancers, which tend to have desmoplastic reaction. This is a nice example of the lesion, which is very irregular with posterior shadowing. And when you, look at the ela, the actual blue area is larger than the one depicted on, B mode. This was grade to invasive ductal carcinoma. On core biopsy, malignant lesions tend to be larger on strain images than on corresponding B mode images, potentially because of the surrounding desmoplastic reaction that accompanies most of these malignancies. And that's what we would see on the ELAs gram A lesion which appears larger than, on B mode.

Clinical Studies

There are certain, studies that have been, performed. One of them is by Dr. Eno himself. And, he has found that most malignant lesions are either, have either a score, of four or five, and then he has not found one malignant lesion associated with a score of one. Most benign lesions are either one or two, and the, his results showed that Elastography showed a sensitivity of 86.9, specificity of 92.1 and an accuracy of 89, 0.8%.

There is a multi-institutional or multicenter clinical trial that was performed in Italy. And this findings of this trial were presented at RSNA in 2006. 874 lesions were, evaluated. 614 were benign and 260 were malignant. The, evaluation with real time elastography showed a very high specificity in benign lesions, including birads three lesions. The negative predictive value, was 98% for all the lesions, and 96.3% for all the Birads three lesions. Real time, elastography does help, conventional ultrasound in characterizing, breast lesions.

There is a French multicentric prospective study, utilizing 345 lesions in patients in, in 314 patients. This was presented at the European Congress of radiology. Elastography for the lesions of all sizes achieved sensitivity of 80%, specificity of 93%, and per positive predictive value of 85.3%. The negative predictive value was 90.3%. What's interesting about this study is that the sensitivity was best for lesions that were less than five millimeters, which is very helpful because the, those lesions are not well evaluated with, B mode. So this is a great, tool to help further characterize these lesions.

There is also a study that was, conducted, with the Italian group, led by Dr. Martina. Elli was presented at the, European Congress of Radiology in 2007. It was a multi-center study, and, the study demonstrated a negative predictive value for birad three and four lesions to be 98%. And again, interesting finding lesions that were less than five, five millimeters. The negative predictive value was a hundred percent.

Conclusion

So in conclusion, the realtime elastography helps conventional ultrasound in characterizing breast lesions complimentary sign. It is a complimentary sign to the B mode imaging, and it's highly specific for BIO three lesions, and it decreases false positive biopsies. Elasticity imaging may eliminate the need for biopsies resulting in significant cost saving for the health service. Currently, about 80% of breast lesions biopsied are benign. According to the American Cancer Society, a large multicenter study is needed to validate these findings and to determine accuracy of this imaging technique.

Case Presentation

I would like to present you with a case of a 59-year-old female with an invasive ductal carcinoma in her right breast, and, a suspicious right auxiliary lymph nos that were documented on MRI. This is the, B mode and the, ELAs of this lesion, and it has appear, has a score of five because the lesion, on B mode, I'm sorry, on the ELAs gram, appears larger than the one on the B mode. So it was given a, a score of five, and the biopsy demonstrated a, cancer, but because the lymph nodes were abnormal on MRI and ultrasound was performed, and, we were trying to decide based on ultrasound imaging, whether these were abnormal lymph nodes.

So we could not determine from just gray scale imaging whether this is benign versus malignant, using the short to long axis diameter ratio. In which case, in, in, in this case, which was 0.53, which was greater than 0.5, dact IC has demonstrated that most of these lesions would be, metastatic lymph nodes, 75%, but 18% of those could be benign. So ultimately you need to perform a, biopsy. And the, since we were, studying the, actual mass with the elastography, we then decided to also investigate the lymph node. And it takes, it shows a classic, score four lesion, which is consistent with a, malignancy.

Since ultrasound can, cytology can fault negative results, phy seems to have a potential to improve that accuracy of percutaneous biopsy. In our situation, when we biopsy that node, the, results came back metastatic carcinoma and basically it, staged the patient and she did not have to, go through the sentinel lymph node. And as a result, again, the, we are trying to reduce the cost of medicine by performing these procedures. So this also seems to have a great value, especially in breast imaging, possibly in any, other cancers that are often, the lymph nodes are evaluated would be, melanoma. And, we may be able to perform elastography on these, lymph nodes and, maybe make a decision whether we should biopsy them or not. At that time, I thank you for your time.