Breast Ultrasound Indications Technique Normal Anatomy - SD

Introduction

Dr. Anina Wilkes: Hello, my name is Dr. Anina Wilkes. I'm a radiologist at Thomas Jefferson University Hospital in Philadelphia.

I work in the divisions of ultrasound and breast imaging. Within those divisions, we do a whole lot of breast ultrasound.

We use breast ultrasound mainly to compliment mammography, but increasingly we use breast ultrasound to tell us more about masses, to differentiate benign versus malignant masses, to guide us for biopsies and to correlate with other images such as MRI and PET scanning.

The usefulness of breast ultrasound has certainly increased over the years that I've been a radiologist, and I see more usefulness coming in the future with the advent of elastography and more to learn about vascular ultrasound.

When it comes to the breast, I look forward to giving you a lecture on breast ultrasound, the indications, the technique, and the normal anatomy, which is an overview. In the lecture I'll concentrate a lot on what we do. On a clinical basis, you'll see a lot of mammography images and correlate that with the ultrasound and the MRI. Through that, hopefully you'll learn basics of breast ultrasound and an overview of how we use it.

Thank you.

Indications for Breast Ultrasound

Breast ultrasound, indications, technique, and normal anatomy.

We use breast ultrasound most commonly for evaluation of a palpable mass. When a woman comes into our breast imaging center and has a palpable mass, whether it is or is not seen on a mammogram, we always do an ultrasound.

We do evaluation of a mass on a mammogram. Sometimes on a mammogram, you can see a mass that looks like it's going to be benign based on mammographic characteristics, but there's no way to really tell if it's benign unless you do an ultrasound where you can see with almost a hundred percent certainty, whether it's a cyst and if it's a solid mass, you can now have characteristics which can help you differentiate benign from malignant.

We use it as the initial imaging for young women under 30 with palpable masses. If you're 29 and come into our breast imaging center, you'll have an ultrasound as your first examination. You may end up also having a mammogram, but it will usually start with an ultrasound. If you're 31 and come in, you'll start off with a bilateral mammogram, and then we'll always do the ultrasound for evaluation of the palpable mass.

The most fun we have with ultrasound is when we use it for mammographic correlation. We see something on a mammogram, whether it's a mass, a region of increasing focal density, architectural distortion, or some other change from comparing with previous years. We will use ultrasound to help us because sometimes you can do bunches of additional pictures and spot compression views, and I'll show some pictures of that later. You still aren't able to figure it out where an ultrasound can help you characterize that region as being something suspicious or something not to worry about.

We use it a lot in correlation with MRI and more and more with pet scanning and other nuclear medicine correlation. Now that MRI has been recommended as a screening test for high risk women, we see lots of MRIs and sometimes on those MRIs there will be findings that come up that need to be biopsied or further evaluated. Ultrasound is very helpful. The patient will, it won't be that the mammogram leads to the ultrasound, it will now be that the MRI or the PET scan or other nuclear medicine tests will lead to an ultrasound evaluation.

More and more we use ultrasound as guidance for procedures, cyst aspirations, fine needle aspirations for prebi needle localizations, core biopsies, intraoperative localizations, tumor aspirations, and even ablations using ultrasound guidance.

We use ultrasound to evaluate implants, although MRIs become the gold standard, but you can still get lots of information about the breast tissue that overlies the implants.

On the ultrasound exam, we use ultrasound for focal pain. If a woman comes to our center with generalized pain in both breasts, we tend to try not to use ultrasound because we're not in the business of trying to pick up too many false positives, too many little areas that we won't know what to do with. More specifically, if someone has pain that could likely be caused by something that we're going to see on an ultrasound such as a cyst or a fibroadenoma or an abscess, or one of those reasons which can cause focal pain, that's when we'll do the ultrasound. Generalized pain, we usually try to divert to clinical evaluation, rather than doing an ultrasound, here's just some examples of what we've just been talking about.

Clinical Examples of Indications

Here's a 45-year-old woman for routine screening mammogram, and here you can see a region of asymmetry looking a little bit more mass like than there's remaining density in her breast. Conventionally, if you see an abnormality on a mammogram, you're gonna start to work it up using the mammogram. We did some spot compression views, which shows that this is a region of focal asymmetry. Doesn't show many characteristics about it, though. Is it a cyst? Is it solid? Is it normal breast tissue? Here's that spot compression view. The ultrasound actually shows it a whole lot better. You can see it in relief against the normal breast tissue that surrounds it. You can see a lot more of the margins, which are speculated and angulated. You can see a lot more about the contents. This is not a cystic mass, but it's very hypoechoic, compared to the surrounding fat. This has very suspicious characteristics. In addition, when you put a Doppler cursor on, you can see that this is not a cyst, if you were wondering that to be begin with, but it actually has arterial blood flow. The ultrasound let us know that this was a very discreetly marginated defined solid mass, that has internal arterial flow, and that needs to be biopsied. Then we can write then and there, go ahead and do an ultrasound guided core biopsy, which is what we did in this case, and prove this was a cancer.

Here's an example of what I said earlier, which was that you really can't tell on a mammogram whether something's a cyst or a solid mass based just on its mammographic appearance. Here's a very well-defined round mass that looks like it could be something benign based on mammographic characteristics. We did the spot compression view, which shows that its borders are pretty well circumscribed, but we still don't know what it is until we do the ultrasound, which shows that it is not a cyst actually, and that it does have a very angulated part of its border. This is not totally anechoic, but did have internal echoes. It has enhanced through transmission. This is kind of a indeterminate mass. We don't know what this is. We know it's not a simple cyst. It has some suspicious characteristics and some benign characteristics, but it did get biopsied and was proven to be a mucinous carcinoma. You can't always go by the mammographic appearance.

Here's a more vague band of density demonstrated on the mammogram. We did a spot compression view, makes it look a little less vague, but you still can't really characterize what this is on the ultrasound. We can actually see in that area that this was a mass that was inside of a duct. You could actually delineate the entire duct and the mass within it. Just looking at it like this, you can't tell whether or not this is debris solidified debris within a duct or actually an intraductal mass. That's where Doppler helped us, showing us that there was vascular flow within this area. Actually this was a solid intraductal mass, which was amenable to ultrasound guided core biopsy, which was performed. This did prove to be an intraductal cancer.

Again, another mammogram. The mediolateral oblique views of the right and left breast, a metallic marker placed over a region of palpable concern where honestly, I don't see any big difference on the mammogram between this breast and the unaffected side. To further evaluate that, and here are the craniocaudal views. As I said initially in the indications, we always do an ultrasound for evaluation of a palpable mass. Even the spot compression views in this case, unlike the others, didn't really help us out very much. The ultrasound shows us that this is definitely a very abnormal looking area that looks very different than the surrounding tissue. Hypoechoic irregular, Doppler shows vascular flow within this mass. Using the ultrasound characteristics of benign versus malignant, you would put this in the malignant category because it does not have sharply circumscribed margins, but nothing comes in a vacuum. You have to consider this along with the entire clinical picture. In this case, the patient did report to us that she had redness and tenderness and actually pain over this mass, and that this was in the very same location where she'd had an abscess before. When we put a needle in this mass, most of this actually did aspirate as thick kind of pus, and this proved to be an abscess. Even using ultrasound characteristics, sometimes you have to go further with a biopsy to prove whether something is what type of solid mass or what type of suspicious mass it is.

Now that we're using MRI more frequently for screening for high risk women, we're finding just routine screening MRIs, picking up findings that we have to look into. In this case, this routine, MRI picked up an area of segmental linear enhancement that's right here. Using MRI jargon, segmental linear enhancement is what you see when you have, which can be associated in other words, with DCIS ductal carcinoma in situ. This is suspicious enough based on the MRI, but what do you do? Do you do an MRI guided biopsy? You certainly could, but that's much more of a difficult procedure than doing a biopsy using either a mammography or ultrasound. When you do a mammogram of that same area, you do see those classic findings of DCIS further confirming that yes, this is abnormal enhancement. Yes, this is a pretty large area of DCIS. You could do a needle biopsy here or an excisional biopsy needle using needle guidance. What would be much easier for the patient in our view, is to do an ultrasound guided core biopsy. In the case of extensive calcifications such as these, these days, we are likely to see the calcifications on the ultrasound. We aren't in the business yet of looking for calcifications on ultrasound, but when you see a fair region, chances are with high resolution equipment, you are gonna see those calcifications within this region of ducts on the ultrasound. We use the ultrasound as a guide for a biopsy, which was much easier than either doing it on the mammogram or using MRI.

Here's an area where there's a region of asymmetry on the mammogram spot compression view, and it corresponds to an irregular abnormal, suspicious looking mass on the ultrasound.

Here's a similar looking region on the mammogram that actually looked to us like it could have some speculation. Then we did the ultrasound and didn't find anything that looked abnormal or suspicious at all, but rather found normal breast tissue. These are probably some Cooper's ligaments extending into the superficial fascia. This to us looks like just normal breast tissue, and it was so now you can use ultrasound to not only tell you that yes, this corresponds to an abnormal mass, but to reassure you that this region corresponds to normal breast tissue.

Of course, when you're using multiple modality imaging, you're using a mammogram and an ultrasound or an MRI and a mammogram and an ultrasound, you have to kind of look back to the image that, or the modality that was the most suspicious. In this case, this was not suspicious. We don't see anything here. We just see normal breast tissue. On the mammogram, we see something that that alerted us to wondering whether or not there could be something suspicious hiding here. You have to go back to the mammogram now and say, all right, what do you do? Do you compare this with prior studies to make sure this is stable? Do you bring her back in six months to make sure it stays stable? There's a variety of options, but what ultrasound helped us with at this point was that we did not do a biopsy of this region because it's a large enough region that if we were to, if we certainly should have found something on the ultrasound, in that region.

Here's another example of focal asymmetry on a mammogram, which corresponds to a region of normal breast tissue and ultrasound. In this case, we, again, we said, okay, we're not so upset about this area anymore. We don't think it needs biopsy. This woman tells us that she's had previous outside mammograms at an outside institution. We're gonna give it a few weeks, try to get those films. Sure enough, we did, and we could see that this area was perfectly stable for years and years. It was the ultrasound that helped us kind of not be so suspicious of this region and led us away from biopsy so that ultrasound can lead you towards appropriate biopsy and lead you away from unnecessary biopsies.

Here's a man, and this is both breasts Craniocaudal view. On this breast, you see kind of the classic mammographic findings of gynecomastia on this breast, it looks more mass like and doesn't look classic at all. For this breast, we would actually do an ultrasound, and indeed we did find a suspicious mass right behind his nipple, which he could feel, which did turn out to be a breast cancer.

This is another retroareolar mass in a woman with a painful, red, tender breast. In this case, here's the thickened skin. This was an abscess. It looks very much like the breast cancer, the male breast cancer, but again, you have to put everything together with the clinical picture, and come to your diagnosis. Ultrasound can be very, very helpful.

Ultrasound helps us with implants, as I said a little while ago, not so much so, anymore with telling whether or not an implant is ruptured, although we do have ultrasound criteria for that. We usually defer to MRI for implant rupture, but we have criteria if MRI is not available to you to be able to tell whether or not implants are ruptured. We use, we like to use ultrasound for implants more so to look at the breast tissue that surrounds the implants, because sometimes that can be difficult, mammographically. Here we see a mass overlying a breast implant. Here we see signs of intracapsular implant rupture. Here's the implant surface, here's the breast tissue and the skin, and all of this, these hypoechoic regions underneath the surface of the implant are all signs that the implant has ruptured, but that the rupture has not extruded into the region of the breast tissue.

Here's another sign, and it's correlate on MRI with the linguini sign it's called, of intracapsular implant rupture. Here's a person who felt a mass at the two o'clock position of the right breast. When we did the ultrasound, we could see this classic sign of implant rupture. Here's the implant surface, and here's the break in the implant surface with this region of silicone, which is extruded into the surrounding breast tissue. Ultrasound can see intra and extracapsular implant rupture. But now we use MRI to be more specific for the diagnosis, and we use ultrasound more to look for masses in the breast tissue overlying the implants.

Here's a galactogram or a ductogram, which shows a filling defect in the duct. Ultrasound was helpful here because it actually showed the mass, which corresponded to that filling defect, which we then did an ultrasound guided biopsy of and proved that it was a papilloma.

Here's another example of a palpable mass on a mammogram where there are extensive calcifications, which when they look like this, there's a good chance you are gonna see them on ultrasound and that you can use ultrasound as a guide for biopsy. Here are those calcifications on the ultrasound.

Benign vs Malignant Characteristics

Now, most importantly, and most interestingly, we use ultrasound to help us tell whether a solid mass is benign or malignant based on certain criteria which have been well established. I am not gonna go into a lot of detail with this now, but there are categories, and I'll refer you to the birads ultrasound characteristics to differentiate benign from malignant, we'll go through them.

Generally, benign masses tend to be ovoid and shape parallel to the skin surface, have smooth margins. Gentle lobulation are homogeneous and are isoechoic or hypoechoic to the surrounding fatty tissue. Malignant masses tend to be non-parallel. Their margins tend to be spiculated angulated indistinct heterogeneous hypoechoic fat, and have a, not an abrupt interface with a surrounding tissue, but rather are surrounded by an echogenic rim.

Here's an example of a simple cyst. When you see the three classic signs of a simple cyst, you can diagnose a cyst with about 100% certainty, and they are that you have a nice circumscribed margin. The mass is completely anechoic, and there's a nice band of enhanced through transmission behind it, diagnosing cyst with almost 100% certainty.

This is a parallel mass, which has smooth margins, circumscribed margins. In order to call a mass circumscribed, the margins have to be circumscribed over approximately 75% of its borders. Ovoid circumscribed. It has a nice chunky calcification. It has nice sonographic characteristics of a fibroadenoma, which is what this is.

Now, here's another parallel mass, but this isn't what you would call nice and sharply circumscribed. As a matter of fact, these borders are not smooth. They're microlobulated, microlobulated, meaning more than two or three gentle lobulations. They're more than two or three lobulations here. This part of the mass would fall nicely into the characteristic of a benign mass based on its margins and shape. But when you get to this part of it, it does not. This is a mass which we would recommend a biopsy for. It did prove to be a fibroadenoma, particularly proliferative cellular type, but we would not let this go without biopsying it because of this part of the margin.

And then this is just more of that, this falls clearly without the characteristics of parallel. This is actually a mass that is slightly taller than it is wide or non-parallel or vertically oriented rather than horizontally oriented. It's very microlobulated, much more than two or three lobules. Part of the margins are indistinct. You can even see some mild spiculation along part of its margins. This is a suspicious mass, very typical in appearance for what a breast cancer looks like. Very easy to do an ultrasound guided biopsy.

This is also an example of the echogenic halo that can surround some of these masses, which indicates that there, you know, as this mass has grown, that it has set up kind of an inflammatory fibrous reaction around it, which has created this interface.

And then this is an example of a mass that's very poorly kind of seen. It's not sharp, it's not circumscribed, it's kind of fuzzy and hazy. It just has indistinct margins. Classic signs for malignancy.

Here's another classic malignancy, taller than wide ductal extension, microlobulation, angulated margins, not sharply circumscribed. This would be birads category five, definitely ultrasound biopsy.

Another example, showing a little bit more of the characteristics of ductal extension. This is a mass that I like to show you because it brings the point about the internal echo texture. When we talk about masses being hypoechoic or hyperechoic, we're talking about them being hypo or hyperechoic relative to the surrounding fatty tissue. This is the surrounding fatty tissue. This is the mass. This is profoundly hypoechoic relative to the fatty tissue, but it's not a cyst. Actually there are some internal echoes. It doesn't meet the marginal characteristics of a cyst. It's not sharply circumscribed. It's lobulated, it's indistinct. This is a mass that's almost as anechoic as a cyst, but does not have enhanced through transmission and actually is what many cancers will look like. Very hypoechoic in comparison with the surrounding fatty tissue.

Whole Breast Screening Ultrasound

So those are the basic indications. We now talk a lot about whole breast bilateral screening, ultrasound, which may be of benefit for high risk women, women with dense breasts, or women with difficult to examine breasts. Most often in our center, these are the requests that we have for whole breast, bilateral ultrasound for these three subtypes. Otherwise, we do targeted ultrasound. We do ultrasound mainly of those palpable masses of those areas that we see on a mammogram or have been referred to us from abnormal findings on other studies such as MRI.

We at this point try not to do whole breast ultrasound, because of some of the problems that have been associated with it. Just this month, a large multicenter trial preliminary report came out, in the Journal of American Medical Association, by Wendy Berg, which kind of gave results of a large study that she did, of about 27,000 women, where she scanned. We were part of that study, which showed that breast whole breast ultrasound can show more small node negative cancers or cancers that are early and haven't spread to regional node. But that can also bring out more biopsies because of more false positives. With every cancer that you find, you may find many more other small areas that you either have to follow in six month follow up, or actually do a biopsy, which turns out to be benign.

So adding a single screening ultrasound to mammography will yield an additional 4.2 cancers per 1000 high risk women, but will also substantially increase the number of false positives, was the general results of that study, which kind of means that you have to take the results of this study and fit it into your own practice. If you have a practice of women who really are very anxious, they will come for their six month follow ups. They have the insurance to pay for it. They are very reliable patients and want you to biopsy as much as you can just to save them from that one. That may be a cancer, then yes, you will definitely want to incorporate whole breast ultrasound. If on the other hand, you have a population of patients that may not be able to come back at six month intervals who don't have the insurance who are not likely to do that, you may wanna consider sticking with the targeted ultrasound, for your practice.

Embryology and Development of the Breast

So now we'll move on to a little bit about the embryology and development of the breast. The breast is developed in embryonic life along, for both men and women along what are called milk lines, which develop at about the fifth embryonic week. These lines have the potential to develop breast tissue along any part of them. There are cases and people who have anomalous breast tissue, which have formed anywhere from the groin all the way up into the axilla.

The most common spots for anomalous breast tissue are here in the axilla where you can have accessory breast tissue, very common to have extra nipples. Usually what happens is this milk line regresses and just centers then on what's remaining, which will form the breast. But sometimes you can have accessory remnants of this milk line, and you'll have an accessory nipple right underneath of the breast or on top of the breast. Some people can have accessory nipples even down into their groins, both, most likely accessory nipples are right underneath of the breast. Most commonly accessory breast tissue will form right under the armpit.

And here's a statue in Soho, a section in New York, which shows a woman with multiple, multiple breasts. I don't think this ever happens, but variations of the norm due. Here's from the New Yorker magazine. This poor little turtle feels totally exposed, having his shell taken off. That's how women feel when they come into our office for a breast ultrasound. We get them to pretty much strip down and put on this gown and put gel on them. So we have to, before we get off into our discussion of technique, remember that this is a very sensitive exam for women. To try to make them as comfortable as possible. Try to use warm gel. If you can. Have a nice dry towel handy, try to expose only what needs to be exposed. Try to get them in as comfortable position as possible because it's an unusual examination for women to have, and we want them to be as comfortable as possible.

Technique for Breast Ultrasound

We use real time handheld transducer from 7.5 to 13 megahertz dynamic focus, high resolution imaging. We lie the patient in a supine position or semi erect. We can do the exam in any position. That's the beauty of breast ultrasound or ultrasound in general. But in order to have a centered, stabilized, and unmoving breast, the best position is the supine position with the ipsilateral arm above the head and the shoulder elevated, over either a wedge of towels or sheets or what we use as a actual foam wedge. That helps to center and stabilize the breast.

And here's the breast tissue. If you are doing whole breast ultrasound, you do have to realize the breast tissue does extend down to the seventh rib. All the way up to the clavicle extends as far over underneath the armpit to the mid axillary line, and extends as far medially to the sternum. If you are gonna examine the whole breast, you have to make sure you kind of get all the way up to the clavicle, all the way down underneath of what looks like the end of the breast tissue, all the way over to the axilla and all the way over medially to the clavicle.

And then technique and how we scan in which direction, radial, antiradial, sagittal, or transverse, and we'll talk about that in a minute. We label the images according to the mammographic clock. We label the distance. If we're imaging a mass, the distance of that mass from the nipple or areola or margin, we label the area of clinical concern, palpable mass or pain as such.

Here's an example of radial and antiradial scanning. Here's the purpose of this, and this is very breast specific. For those of us that do ultrasound of other parts of the body. We're used to scanning and transverse and sagittal, or sagittal and coronal, but with the breast, we try to follow the normal ductal anatomy of the breast, which radiates from the nipple. So we want the long axis of the transducer to be along the long axis of the ducts.

Now, of course, no breast actually looks like this with the ducts radiating at regular intervals like this, but you're more likely to catch a duct in long axis when the long axis of the transducer is in parallel. So this is radial scanning where you have the transducer oriented in this direction, and you scan radially from the nipple on out to the periphery of the breast. Then antiradial scanning is an attempt to catch the ducts and cross section. Again, you scan from the periphery of the breast inward towards the nipple. So that's radial and antiradial scanning. Of course, you can always scan in sagittal and transverse, as well, or in place of radial and antiradial.

And here's the mammographic clock. You in terms of labeling on the ultrasound image, this would be the 12 o'clock position, three o'clock, six o'clock, nine o'clock. This is how we would like the labels to be, because labeling is very, very important because if this has to be followed in six months or if it goes to biopsy, and especially if there's other masses in that breast as well, you have to really be careful about the local labeling, specifically where this mass is. So this is the left breast. It's at the 12 o'clock position, it's three centimeters from the nipple, and you're scanning in the radial plane. All of those things are very helpful so that someone who's going to be biopsying that or following it up in six months can just basically lay their transducer down on that area and should be able to find it.

Here's another example of that. Here's a convention where we say three centimeters from the nipple. Here's one where we say, left breast, four o'clock radial at the areola or margin. So however you choose to label, just make sure that it's clear what you're saying. Some of our scanners have these little diagrams off in the corner. That's actually not good enough. You can use your diagrams and that will actually put a little mark of where you're scanning, but you also have to add this typed in annotation as well.

And here's a portrait of a woman who we'd like to think is doing a self-breast exam, but I don't know if that's really what the artist intended to show. But when you examine your breasts, or even when we see them on mammograms and ultrasound, we don't actually see the anatomy as it is 15 to 20 lobes. The terminal ductal lobular unit being the functional unit of the breast, which is where most breast cancers form, we don't see those always. Now, some beautiful ultrasound technology will show us those ductal terminal ductal lobular units, which are kind of oriented horizontally, which is why we think that breast cancers grow horizontally in the breast and not, I'm sorry, why breast cancers grow vertically in the breast and not horizontally, because the terminal ductal lobular unit is actually oriented more vertically in the breast than horizontally. That's one theory.

And here you have a nice frank Netter famous medical illustrator, anatomy picture of the breast. I like this one because it kind of shows a little bit like how we see the breast on breast ultrasound. Here's the skin underneath the skin. There's a fatty layer. The subcutaneous fatty layer behind that will be the glands, the ducts, the stroma, everything kind of all together. Then close to the chest wall. There'll be sometimes another fatty layer. Then here's the pectoralis muscle and the ribs. In scanning, it's important that you see all the way through to the chest wall so that you won't miss those small masses which can grow right on the chest wall.

And here's more like what breast anatomy actually looks like. This Ansel Adams photograph of a tree, instead of that diagram that I showed that has the breast ducts radiating kind of nicely in it, regular intervals, what happens is that if you just imagine this is the nipple, the ducts actually branch off in all sorts of irregular patterns. This branch is shorter than that branch. All of the little ductules and terminal ductal lobular units are all kind of mixed up together, which accounts for the ultrasound picture of the breast. This is why we don't see ducts kind of individually and glands individually, because they're all overlapping and all kind of living in the same little space together.

And how we see a breast on ultrasound depends on the amount distribution of fat glandular and ductal tissue, connective tissue, and is dependent on age or hormonal status, whether someone's premenopausal, postmenopausal, pregnant or lactating.

Here's a dense breast mammographically, which corresponds to a dense breast pattern on ultrasound. Here's the skin, here's that fatty layer underneath of the skin, and all of this is the breast tissue. Here's the chest wall muscles, and this is kind of that bright white glandular tissue that you can see with very dense glandular breasts.

This is a predominantly fatty breast on mammogram and a predominantly fatty breast pattern on ultrasound with most of the breasts being made up of these fat lobules. But most of the time, breasts look like something in between, not all dense, not all fatty, but a mixture.

Here's the skin, which shouldn't be any more than two millimeters thick. Here's the subcutaneous fatty tissue. Here's ducts as they kind of interlace in the glandular tissue, which tends to be more echogenic. So the things that are more hypoechoic are fat and ducts, the things that are more echogenic or glands. Again, we're scanning all the way back to that subcutaneous fatty tissue all the way back to the chest wall. Here's the pectoralis muscle.

Sometimes fatty lobules can look very discrete, distinct, and discrete can actually almost look like masses. Here is an example of a lipoma, but fatty lobules on real time scanning can interlace and intergrade, and they don't have abrupt interfaces with the surrounding tissue, and that's how you can tell their fatty lobules.

So I can't overemphasize the importance of real time scanning with breast ultrasound. Looking at static images are really just not enough. You really need to go in there sometimes. Now in most of the world, breast ultrasound is done real time, but in our center, we actually have a breast sonographer who does our breast ultrasound. She'll show us pictures and she'll say, this is a mass, or this is a cyst, or she'll tell us what she thinks, and most of the time what she thinks is right. But sometimes you have to go in and scan for yourself because what may look like a mass on a static image ends up not being a mass when you scan it in the two planes, radial and antiradial or sagittal and transverse.

Here's an example of the two of thickened skin. Two mil greater than two millimeters thick. Here's a male breast, and this is the ultrasound picture of what gynecomastia or the development of male breast tissue will look like, just normal ducts as they radiate from the nipple area. Here are some other ducts. Now with really high resolution equipment, we can actually see inside of the ducts. Here's a little bit of fluid within the lining of these ducts. We can actually see this bright white line, which is the lining of the duct. It almost looks now like we're looking at an endometrial lining. Of course, you don't see this all the time, but sometimes you can. This is just a picture of a perfectly normal duct. And here's fluid in a duct. That's normal to see sometimes with duct ectasia. But what you're looking for when you see particularly prominent ducts or masses or filling defects or areas that look like nodules within the duct wall.

And here's a rib, which you can see when you're scanning all the way through the full thickness.

Lymph nodes are interesting and they occur throughout the breasts, and we see them really commonly as normal structures when we're doing routine breast scanning on a mammogram. This is the typical characteristic appearance of a lymph node with its fatty hilum. On the ultrasound, the fatty hilum is bright because in comparison with the cortex around it, it's, it has more brightness. The fatty hilum is bright on an ultrasound in a lymph node, here's an abnormal lymph node abnormal because it doesn't have a nice centered fatty hilum. Rather, the fatty hilum is displaced over to the side. The lymph node looks a little bit more hypoechoic than it should. It hasn't lost its nice ovoid shape, yet really markedly abnormal lymph nodes will turn round and large. We don't usually use size as a criteria for calling a lymph node abnormal because normal lymph nodes can be quite huge, actually. We use more the shape of a lymph node and whether or not it has a fatty hilum and what that fatty hilum looks like.

Here's a good lymph node and a bad lymph node. Here's the appearance of the good lymph node with the echogenic fatty hilum. Here's the bad lymph node, which actually looks like a suspicious mass, but upon biopsy that showed to be a lymphoma, with kind of a disrupted fatty hilum and abnormal shape.

So for evaluation of masses, size, shape margins, internal echo texture, and acoustic properties, and how this mass appears against its surrounding parenchyma are all things that you look at to try to determine whether a mass has benign characteristics or suspicious or malignant characteristics.

And to do that, we want to adjust our focal zone. Putting the focal zone right at the region of the mass you want your gain to be appropriately set and appropriately set is, since we're judging masses in comparison with the surrounding fatty tissue, you want your fatty tissue to be just right and what's just right. Well, I wish we had a number or something definite to say other than that. The fatty tissue should be kind of a charcoal gray color, or what my coworker likes to call it, a flannel gray. I like that flannel gray because that's what it should look like. It shouldn't be black, it shouldn't be overly bright. It should be a dark gray so that you can judge everything against that. Your time gain compensation curve should be adjusted appropriately so that the fat looks, that charcoal or flannel gray and that your depth is appropriately visioned. And that if you have a mass in the very near field, you can use a gel pad for that. Gel pad can still show things that are very close to the skin. Most modern equipment focal zones will cover that area, but if you feel like your focal zone isn't really getting to the area that's you're seeing, if it's that superficial, use a gel pad, which will bring your focal zone into the zone of the mass.

Other things such as compressing the mass to see if it's compressible, elastography, FTUs position change to see if the mass changes position. All these things can also be used, but more often it's just your basic things that you use with other forms of ultrasound, making sure your focal zone is right, making sure your gain settings are right, and making sure your depth covers the area that you need to see.

Advanced Ultrasound Techniques

We add doppler when we want to find out whether a mass has blood flow or not. Other add-ons to ultrasound equipment have proven to be helpful, such as spatial compound imaging, harmonic imaging, extended field, and 3D doppler we use mainly to confirm whether a mass is solid versus cystic. In other words, if it has, if you throw the doppler on and you see internal blood flow, you know it's not a cyst, lymph nodes, you can sometimes see that nice characteristic fatty hilum, which will show you that this is a lymph node, and not another type of mass. We use doppler for prebiopsy to make sure we're not headed into some particularly vascular area. If you have a choice, you'd rather not do that. Vessel characterization is always being studied to tell whether or not once you see that blood flow. Once you get that waveform, whether or not we can tell something about that waveform, which will help us decide whether this is a waveform associated with benign vessels versus tumoral vessels.

So here's an example of blood flow within a mass. The doppler ultrasound has shown us, here's a good example of something that some of us may call a cyst with debris in it. This almost looks like a level of some sort, except the level's not exactly going the right way. This patient is supine. So if this was a fluid debris level, we should see something like that. So it's kind of off to the side, but still this could just be some concreted debris within a cyst. But then when we put the doppler on, we can see that there's blood flow within this area, arterial blood flow. So that certainly wasn't debris. That's actually a solid component of this.

Now, suspicious looking cystic mass, here's an implant, and here's two masses outside of the edge of this implant. We may think that this looked like silicone because silicone outside of an implant can look exactly like this. But when we put the color doppler on silicone extravasation should not have blood flow in it. These were actually masses outside of the implant and not silicone.

And again, as I said, here's some kind of large dense lymph nodes. Again, we don't necessarily use size, but sometimes density on a mammogram. It shows this characteristic hilar flow doppler does of this lymph node.

Compound imaging is a technique that is particularly good for showing us margins, which are of course one of the things we look at very carefully with masses. Here's a scan done without compound imaging. One done with. Now, it still is not popping out at us, but here I would say I have trouble seeing almost anything. But here, I can see that here's a mass that has spiculation, and made better with the advantage of compound imaging.

What compound imaging does, it steers the transducer array to allow for multiple scanning angles rather than straight down into the breast. It results in a reduction of speckle clutter and artifacts and improves detail of mass margins, and calcification. One little problem is it that features of posterior enhancement, which we rely upon a little bit, are less apparent.

So here's an example of one of those screening MRIs, which show an abnormal enhancing mass, which on traditional conventional ultrasound we really didn't see. We put the compound imaging on and the mass becomes more apparent, and in fact, we see some spiculation associated, and we're able to now measure it and biopsy it using the ultrasound.

Here's one of the disadvantages of compound imaging. Here's conventional imaging where you see this mass. Although, you know, as I said earlier, this actually isn't what I'm gonna call a cyst because it doesn't have totally smooth margins, but it does have enhanced through transmission. In this, in compound imaging, the enhanced through transmission, the clear band of it that you see here is made a little less apparent. So if you do have compound imaging on your ultrasound machines, you're gonna want to use it for marginal analysis, but then kind of take it off and use conventional ultrasound to show whether or not there is enhancement.

Harmonic imaging is another type of imaging that we use for many parts of the body, that has to do with transmitting at one frequency and receiving to the back, to the ultrasound transducer at multiple of that frequency. It produces images that have reduced artifact and reduced reverberation and great to clean up cysts. We use it a lot in the body for liver and kidneys. We can also use it in the breast to make cysts. I'm sorry if this image is a little dark, but actually, if you had questions that there were internal echoes, as long as your background fat is that charcoal or flannel gray, and you put on the harmonic imaging, you can kind of make those artifactual echoes go away. So the point of harmonics is to make artifactual echoes go away. Now, of course, you can make echoes go away by inappropriate gain settings, turning the gain down such, but as long as your gain settings are appropriate from the start, that's when you add the harmonics.

3D improves the visualization of mass margins and improves visual needle localization. We don't use 3D on any kind of routine basis, but I suppose that it can be helpful because we do do ultrasound follow up when patients are on neoadjuvant chemotherapy and they're shrinking the tumor before they actually do the biopsy or take it out. Estimation of tumor volume is obviously better when you see a mass in 3D. We think we do an okay job with that in 2D, but obviously 3D is better.

Panoramic imaging is good for locating multiple masses and correlating those multiple masses with a mammogram because it looks a little bit more like the mammogram. Here's an extended field view of the entire breast. This is the old fashioned water bath, whole breast ultrasound, which really looks more like a mammogram because it maintains the shape. This was done and doesn't done anymore except for sometimes research purposes, but where the breast was actually patient prone and the breast was kind of down in a water bath. But we may see a little bit of a comeback with this as we kind of look more into panoramic imaging.

Conclusion

So that's the end of the presentation. I hope to have provided you with an overview of the many useful ways that we use breast ultrasound, and to refer you to published manuals, which can then take you a step further into distinguishing benign for malignant masses. But most important is your technique. Is your patient positioning, your labeling of the ultrasound images, and your correct usage of this wonderful technology that we have. Breast ultrasound. Thank you.