Ultrasound Cases The Analytical Process - HD

Introduction

Hi, my name is Nida.
Here I am the director of ultrasound at the Mallinckrodt Institute of Radiology in St. Louis.
Today the presentation is going to focus on an analytical process of understanding how to take cases.
This is essentially the way we do it with our residents.
There's a block of seven cases and we will go over the thought process as we arrive at a diagnosis in interpreting the images.
Today we are gonna look at about seven ultrasound cases and go over the process of making a diagnosis using analytical process.
This is essentially the way a radiologist, radiology resident learns how to take ultrasound cases.
Without much ado, let's look at the case one.

Case One

We have a 84-year-old female who presents with progressive nausea, vomiting, vague abdominal discomfort, and failure to thrive at admission.
The labs were mildly elevated liver function tests and elevated alkaline phosphatase.
The past medical history, there is no history of liver disease.
A prior CT scan recently about two years back, did not show any cirrhosis.
Here is the first image from the left lobe of the liver.
At the bottom of the image, you can see some part of the portal vein.
We know you are on the left side and this is the entire left lobe.
The first thing that comes into our mind is that this is a very heterogeneous liver.
It also seems to have some nodularity along the inferior surface.
Apart from that, we don't see any mass lesions or focal lesions in this liver.
The next image is from the right side and you can see the diaphragm there, you can see the right kidney there, there is slight enlargement of the caudate lobe and again, a little heterogeneous appearance.
You almost feel that you could make out few nodules scattered within the liver.
This is the high frequency ultrasound with a linear transducer.
Now you can definitely appreciate the nodularity of the surface and there are some ascites surrounding this liver.
Again, there are few small nodules scattered within the parenchyma.
At this point we are looking at a picture of ultrasound that makes us think that this is a cirrhotic liver with some ascites around it.
And that's essentially what we led the diagnosis with.
But just based on the ultrasound images, we also raised the possibility that we did see these small nodules and they could be regenerating nodules in this cirrhotic liver.
Or the suspicion was that some of them might represent dysplastic nodules.
And based on that and the fact that we don't wanna miss some change or a HCC, we recommended an MRI exam for further evaluation.
This is the MRI exam post contrast, and you can see there are multiple, the entire liver started with multiple nodules and they appear kind of ovoid.
It's a slightly delayed phase, so there is some washout happening peripherally and these are metastatic lesions scattered in the entire liver.
So that gives us a diagnosis of pseudo cirrhosis.
The appearance on ultrasound, which was cirrhotic, was actually a pseudo cirrhosis and this can be seen secondary to diffuse metastatic disease.
Pseudo cirrhosis essentially has the same issues of fibrosis, nodular transformation and distortion of the hepatic architecture.
The metastatic to the liver, especially if metastatic disease is treated with chemotherapy, can result in areas of retracted tumor tissue and scarring between the areas of scarring.
The liver parenchyma is regenerative and that gives that nodular appearance.
This is a common appearance with breast cancer and melanoma.
It's a good thing to keep in mind when the clinical history does not correspond or is not leading directly to a diagnosis of a conventional cirrhotic liver.

Case Two

We have a 63-year-old female with stage four appendiceal adenocarcinoma who is admitted with recurrent small bowel obstructions.
Multiple recent CT scans have mentioned mild intra and extrahepatic dilatation without an obstructing lesion.
On today's ultrasound exam, we see a distinct intra hepatic biliary dilatation.
As you can see, this is a right lobe showing a dilated intra hepatic bile duct with the color Doppler, making sure that we are not being fooled by a blood vessel.
The other two images, again show the dilated duct, but as you come to the junction where the duct, the right hepatic duct becomes the common hepatic duct.
After meeting the left hepatic duct, you see a isoechoic lesion occluding the entire lumen of this bile duct or this bi ductal process.
You can see this has a kind of of a cylindrical approach, isoechoic lesion and on a transverse image it's very difficult to differentiate it from the surrounding liver.
It's almost isoechoic.
In addition, patient also had a left hepatic duct dilatation, which is not seen on these images.
We have a patient who has intra hepatic biliary ductal dilatation on the right and the left side with a isoechoic mass lesion right in the middle in the junctional area.
One of the things that comes to mind is that this could be a Klatskin tumor or just a intra hepatic cholangiocarcinoma.
The findings were diffuse marked intra and hepatic ductal dilatation, a mass which is obstructing the right intra hepatic ductal system centrally and extending into the proximal common hepatic duct.
In view of the known history of an appendiceal carcinoma, we decided that this most likely represent metastatic lesion rather than a primary cholangiocarcinoma.
A CT scan, which was done after the study again shows intra hepatic biliary dilatation on the left hepatic lobe and then in the right side.
And you can see as you go down, the axial imaging when you come to the bifurcation becomes almost difficult to make the right and the left hepatic ducts join.
And right in that region, in the middle you have a isodense lesion which represents the cancer.
As you keep going down axially down, you can again see the bile duct, the extra hepatic distal portion of the bile duct there.
And here's that enhancing lesion corresponding to the lesion we saw within on the ultrasound.
This is a good example of a biliary obstruction secondary to a metastatic invasion.
Keeping in mind the history of the patient presented with.

Case Three

This is a 55-year-old man who presents with left thyroid mass.
As you look at this extended field of view image, you can see that's a trachea in the middle.
We have the right thyroid lobe with the right common carotid artery.
The left thyroid lobe seems to be essentially replaced by a large mass lesion hypoechoic and actually fairly large encroaching onto the isthmus having lobulated margins.
When you focus towards the left side in a transverse image, you identify the common carotid artery and then this is essentially where you should see the jugular vein, the internal jugular vein.
And you do not see any lumen in the internal jugular vein abutting.
It is a little bit oval shaped lymph node.
We have a big mass lesion with lobulated appearance, which has an associated thrombosis of the internal jugular vein with lymphadenopathy.
This type of an aggressive manifestation makes you think of the aggressive variants of thyroid cancer, especially anaplastic carcinoma.
The next slide on a color Doppler shows flow within this thrombus implying that this is tumor thrombus and you can also see that the thyroid cancer appears to have infiltrated the capsule and has distorted the outline of the capsule itself.
The report says that we have a large hypoechoic mass involving the left lobe of the thyroid and the isthmus, the nodule distorts the capsule anteriorly and the left internal jugular vein is thrombosed with internal arterial flow.
We gave the differential of an anaplastic carcinoma.
Now the point to note in this case is that most of the time for thyroid cancers are fine needle aspiration biopsies enough, but when you're dealing with an aggressive variant, you really want to make sure the pathologist has enough information or enough surgical specimen to make a good diagnosis.
And so in cases like this and in cases like lymphoma, we tend to use the core biopsy needle to obtain a core tissue.
And this is what we did in this case.
The pathology came as anaplastic carcinoma of the thyroid.
Anaplastic tumors have a very high mitotic rate and a lymphovascular invasion happens rapidly.
The overall five year survival rate is pretty dismal, ranging from seven to 14% depending on what study you look at.
This was a case of anaplastic carcinoma of the thyroid.

Case Four

We have a 44-year-old male who presents with three months history of bilateral testicular swelling and bilateral inguinal pain.
The patient also is HIV.
We have the images of the right scrotum.
There is a large hydrocele.
The right testes shows small focal hypoechoic areas.
The right epididymis is enlarged and thickened with a heterogeneous appearance.
This is a closeup view of the right epididymal tail region showing a very bulky tail with some amount of vascularity within this epididymis.
This is the image of the left scrotum and this is a much more impressive testicular lesion.
Multiple hypoechoic areas, some of them confluent with each other and of course a bulky epididymal mass.
This is the body tail region of the left epididymal mass and you can see how thickened and heterogeneous it is combining the two.
We have now infiltrative lesions in both the testes and both the epididymides in relatively young patient.
But then the patient also has HIV.
Keeping that in mind, there is a short differential diagnosis.
However, before we talk of the differential diagnosis, we also end up to look for lymphadenopathy.
And these are multiple images through the right inguinal area, the right iliac per iliac area, the retroperitoneal area, and the retroperitoneal left iliac area.
And we can see multiple large lymph nodes all around the major retroperitoneal vessels.
In terms of findings, both testes have multiple small hypoechoic nodules.
The epididymides are diffusely enlarged heterogeneous and hypoechoic.
Bilateral hydroceles are present and bilateral lymphadenopathy is present.
The differential diagnosis would be for this type of a diffuse disease lymphoma, infectious etiology, which might include tuberculosis, sarcoidosis, and very less likely metastatic disease.
In this gentleman because of his age, that is one of the last in our differential list, a right inguinal node excision biopsy was done and that came positive for tuberculosis with acid fast bacilli.
Additionally, an induced sputum AFB culture was also done, which was positive.
This was a case of disseminated tuberculosis in a patient with HIV.

Case Five

We have a 83-year-old female with an incidental gallbladder mass on a CT.
And this is one of those instances when a patient undergoes a CT but then is sent back to ultrasound to make a more affirmative diagnosis.
On the CT, you can see there is a little distortion of the shape of the gallbladder in the region of the fundus.
And here's the other oblique coronal access, which shows that there is definitely some irregularity going on over there with a small hyperdensity.
Also on ultrasound with a curved transducer, we have this large heterogeneous area in the fundus with multiple hyperechoic foci scattered around the periphery.
This is a high frequency transducer, linear transducer showing the same area, a diffuse thickening of the gallbladder wall with some tiny hypoechoic foci scattered within the wall.
And if you put color Doppler, there is no vascular inside, although you do have some artifacts from the color itself, like comet tail artifacts.
This is a classic appearance of focal adenomyomatosis of the gallbladder.
This can many times masquerade like a mass lesion or a tumor on a CT exam or MRI.
But in ultrasound, because of its classic appearance of hyperechoic foci within a thickened wall with comet tail artifacts, this is an easy diagnosis.
This is a benign etiology and does not require any surgical intervention.
So it's important to make this diagnosis.

Case Six

We have a 47-year-old woman who presents with cough.
Obviously once a patient has a respiratory symptom, the first thing to do is to do an x-ray.
We have a chest x-ray here, a PA view, and a lateral view.
And you can see there is a prominent hilar mass on the PA view, which then corresponds to an anterior mediastinal mass on the lateral view.
To further evaluate a CT scan was done and you can see a large anterior mediastinal mass.
The differential for large anterior mediastinal mass is relatively small.
You essentially think of thymoma, a teratoma or a lymphoma.
Now the point of this case being shown as an ultrasound case is that especially if you have a thoracic lesion, which is abutting the pleura and doesn't matter if it is in the anterior mediastinum or if it's in a lung, if it abuts the pleura, it does provide you an acoustic window to do an ultrasound guided biopsy.
And in this case, this is the internal mammary artery and there is enough intercostal space to do the biopsy under the ultrasound guidance.
And that's the reason that this case is being shown.
We went ahead and looked at this case by ultrasound and you can see this is a very good view of this hypoechoic mass lesion from the anterior intercostal parasternal location.
Under ultrasound guidance, a core biopsy needle was introduced and two specimens were obtained from this lesion.
The differential diagnosis we've already talked about, it's a short differential diagnosis for anterior mediastinal masses.
And this lesion and this case did turn out to be a thymoma on pathology.

Case Seven

This is a 57-year-old woman with postmenopausal bleeding.
This is a transvaginal image obtained in a longitudinal fashion of the endometrium.
Couple of important things.
57-year-old woman who is postmenopausal and now present with bleeding.
She is symptomatic in a symptomatic patient.
If the endometrial stripe is about 10 millimeters, then couple of things come to our mind.
One of course is malignancy because if a woman is symptomatic and the endometrial stripe measures more than five millimeters, then essentially the next best way to proceed with would be with a biopsy of the endometrium to rule out an underlying malignancy.
But as an ultrasonologist who is doing this exam, you think to yourself, what else can I do to arrive at a better diagnosis?
And one of the easiest thing to do in an outpatient setting is to inject some saline within the endometrial cavity, what is known as the sonohysterogram.
And that's essentially what we did.
We put in a catheter and injected some saline.
And the moment you inject the saline, you realize it was not the endometrial stripe that was thick, but that there's something in the lumen which becomes much more apparent once it is surrounded by all the saline.
Here are the transverse images of this hyperechoic lesion hanging in there with a small pedicle within the endometrial cavity.
And although the images are not distinctly showing, we were able to demonstrate some vascularity on some of the images.
We did say that this most likely is the endometrial polyp.
It still needs a hysteroscopy and evaluation on pathology.
And a hysteroscopy was done and this was taken out.
It did turn out to be a benign endometrial polyp.
That's a good point to note that instead of rushing to judgment with thickened endometrium should always keep in mind that sometimes an endometrial polyp might be masquerading as a thickened endometrium.

Conclusion

With that, we come to an end to our seven cases and hopefully they will help you improve your practice of ultrasound.
Thank you.