Thank you, Andrew. All right, so as Andrew said, I am Bryce Milligan. I did not intentionally so perfectly match my background to the SCCM theme, but I guess it was meant to be. I have no financial relationships or conflicts of interest to disclose. And let me just go back, I think I had a, so the title of my session is called Trying to Fool Me, Tricky Images in POCUS. Often, ultrasound images or artifacts can be misinterpreted in clinical care, so we're gonna review cases of challenging image adequacy that make interpretation difficult. So case number one, this is a 92-year-old male with a history of dementia, COPD, diastolic heart failure, who transferred from a subacute rehab center with dyspnea, cough, and fatigue. He was hypoxemic, requiring six liters nasal cannula. Referential diagnoses included COPD, healthcare-acquired pneumonia, CHSF exacerbation. So thoracic ultrasound, as a reminder, this is Dr. Lichtenstein's blue protocol for lung ultrasound in the setting of dyspnea. So thoracic ultrasound was completed. This patient had positive lung sliding and had an AB profile on anterior thoracic ultrasound. This is suggestive of a diagnosis of pneumonia. We also did a focused cardiac ultrasound, given his history of heart failure with concern for pulmonary congestion. This included POCUS of the inferior vena cava. So in the setting of heart failure, increase in right atrial pressure would eventually cause distension of the inferior vena cava. So normal right atrial pressure is suggested when the IVC diameter is less than 2.1 centimeters and when there's a collapsibility of greater than 50%. This subcostal view shows both the IVC and the aorta and demonstrates how similar in appearance they are, as well as how close in proximity they are to each other. So how can we definitively tell the difference between the IVC and the aorta? Well, I feel like it's very easy when you compare them right here next to each other, but you won't always have the luxury of comparison when you're reviewing scans or if you just place the probe on a patient. So it would be easy to assume that the image on the right is a plethoric IVC. However, this is the patient's aorta and the IVC is on the left. So here are the differences. First, the IVC is a thin-walled vessel while the aorta has thicker walls. The IVC appears on ultrasound image like it's going through the liver and it has the hepatic vein draining into the IVC while the aorta is positioned below the liver. The IVC empties into the right atrium while the aorta is continuous with a descending thoracic aorta. And the IVC can have respiratory variation while the aorta will not. And also just physically, when you're ultrasounding, the IVC is found more to the right of midline and then if you move over towards midline, the aorta is positioned in front of the vertebral column. So this patient, as you can see when appropriately evaluating the IVC, has a small and collapsible IVC even without the measurements for diameter and collapsibility there. Both vessels can actually appear pulsatile. So if there's any question, you can always do pulsed wave Doppler. And here you can note the differences in velocity and wave pattern between the IVC on the left and the aorta on the right. So for this patient, small and collapsible IVC, AB profile and correlated with his clinical picture suggests a diagnosis of pneumonia over a diagnosis of heart failure exacerbation. And then just to practice, I'm gonna ask for some audience participation on this. So here's a vessel. Who feels like this is the IVC? Just do a raise of hands. Okay. Who feels like it's the aorta? Okay. So this one, I'm not intentionally trying to be tricky. This one is the IVC. This is an example where it's tough. It might have been harder to, or easier to use pulsed wave Doppler because you can actually see some pulsatility on this. But you can see it leading into the right atrium right there and then here's the hepatic vein. Case number two. This was an 80-year-old male with a history of COPD, heart failure with reduced ejection fraction, and a triple A status post-EVAR. He had a CT during this admission that showed a right internal iliac artery aneurysm and he was being followed by vascular surgery. There was a rapid response called on the floor for hypotension, altered mental status, and abdominal pain. He was transferred to the ICU, given IV fluids, and subsequently started on pressors. So, oops, a, let me see if I can get, okay, well that video's not playing, but so a right upper ultrasound, or upper quadrant ultrasound was completed. This patient was having a worsening abdominal exam and he was sitting up a bit to just guard himself. And these were his findings on right upper quadrant ultrasound. Now it's a little difficult to see with this not being mobile, but he, yeah, is there a play? If you highlight over the actual, there you go. Thank you. No, no, no. So I guess looking at this image, knowing how this ultrasound was done, I'm gonna ask for a participation again. So who would feel confident saying that there's no fluid in the hepato-renal recess? Okay, who would not feel confident? Okay, excellent. So a repeat ultrasound was done. Okay, there we go, there's a new one. A repeat ultrasound was done, oh, well, so problems with this one was that the patient was sitting at 45 degrees, and then the caudal tip of the liver was not well visualized, so you can't really evaluate the superior paracolic gutter. A repeat ultrasound was done of this patient in Trendelenburg and revealed this image. And you can see anechoic fluid in the hepato-renal recess. So putting a patient in even just 5% inversion with Trendelenburg increases the specificity of your FAST exam because gravity pulls fluid to the most dependent areas. And then the superior paracolic gutter is included in this image, and that is the most sensitive area for free abdominal fluid. So of note, though, you cannot reliably differentiate on ultrasound that fluid, whether that anechoic fluid is blood or ascites, so clinical context is always important. This patient ended up also having a CT scan. It was done without contrast because he had an oliguric acute kidney injury. And the CT read ascites measured as simple fluid, and it showed an increase in the size of the right internal iliac artery aneurysm from four by 1.7 centimeters to 4.5 by four centimeters. And the vascular exam was limited given the lack of contrast. After this CT was done, this patient decompensated. He was hemodynamically unstable, and labs showed lactic acidosis and anemia, so he was emergently taken to the operating room. So he had an X-LAP with vascular and general surgeries, which showed a ruptured right internal iliac artery aneurysm and hemoperitoneum. He had an abdominal washout and pelvic packing with coil embolization of the internal iliac artery origin and EVAR extension to the external iliac artery origin, or artery, sorry. And I just think it's important to note on this case that even the CT scan read the fluid as simple fluid, so really not just ultrasound, but every finding needs to be taken within the clinical context of the patient. Case number three, this was a 78-year-old male with a history of heart failure with reduced ejection fraction of 20%, AFib, hypertension, hyperlipidemia, and he transferred from an outside hospital with a sodium of 117. His initial chief complaints were weakness, fatigue, nausea, vomiting. He was hemodynamically stable when he transferred, but then soon after arrival to us, he decompensated and was in undifferentiated shock. So a cardiac POCUS was completed on arrival. Here is what we saw, which obviously shows severely reduced LV contractility. The other thing I want to point out in this one is this area, this anechoic area posterior to the heart, so that is representing an effusion, and we'll do some audience participation again. So who thinks that this is a pericardial effusion? Okay, who thinks it's a pleural effusion? All right. So, let's see, let me, here are some not-so-subtle differences, or comparisons to show the difference between pericardial and pleural effusions. Our patient is on the right with increased distance there so that we can more accurately evaluate that effusion. So the differences are from a pericardial effusion is in between the visceral and parietal layers of the pericardium, and a pleural effusion is external to the pericardium. So in order to accurately identify that, it's important to make note of the descending thoracic aorta, because a pericardial effusion will be anterior to the descending thoracic aorta, and a pleural effusion will be lateral and posterior to the descending thoracic aorta. And in our patient, you can even see adalectatic lung, over here, within that pleural effusion. Another thing I want to just make note of, although it's not up here, is that another confounding factor to pericardial effusions can be the presence of an anterior fat pad, which would show itself up here as an anechoic or hypoechoic area. The way you can tell the difference between that and a pleural effusion, I mean, and a pericardial effusion, is looking at the more inferior and posterior areas of the heart. Case number four. This was a 68-year-old female who was admitted with COVID pneumonia. She was requiring heated high-flow oxygen. And for this one, I think it's helpful to get yourself into the mindset. So you're on service with another provider who's going to complete a cardiac and thoracic ultrasound exam. And they come to you after completing the exam with this image. And they're concerned for RV dilation and potentially a pulmonary embolism. So RV dilation is, well, a normal RV is less than two-thirds the size of the LV. And dilation is a ratio of RV to LV greater than 0.9. So, ultrasound is not the best strategy to diagnose pulmonary embolism. But there are some findings that you would expect to see in the setting of pulmonary embolism. And on lung ultrasound, if there's not any other pathology going on, you would expect to see positive lung exciting and an A profile. On venous ultrasound, you might see a DVT. And that, when paired with an A profile in the setting of dyspnea, is 99% specific to pulmonary embolism. And then on cardiac ultrasound, you would expect to see some RV dilation, flattened interventricular septum on a parasternal short axis view, and McConnell's sign, which is decreased free wall RV contractility with spared apical contractility. And then a distended IVC. So let's look at this image again. Now, who feels that this is RV dilation? Okay. And who feels it's not RV dilation? Okay, so it's not. I, this is a very difficult one. I probably would have initially thought that this is RV dilation as well. I find it much harder to evaluate images when I'm not the one who obtained them. But this image was actually a, the probe was flipped. So the probe marker was pointing towards the patient's right shoulder. And you were actually looking at the LV, which was giving a false impression of RV dilation. So when you're looking at images or reviewing images that somebody else has done, how can you tell if the probe is flipped or if there's true RV dilation? Okay. So the LV has thicker walls, which this is, it's a little bit hard to see on this one, especially on the image on the right, the accurately turned one. But if you can see that the LV has thicker walls. The apex is primarily made up of the left ventricle. In the view on the right, you have the luxury of seeing the left ventricular outflow tract. So that is a pretty good indicator that you can use, and you can find that if you're the one doing the exam, you can find that by just like flattening the angle of your probe a bit. And then with the septum vertical, the tricuspid valve is actually a bit closer to the apex than the mitral valve is. Obviously that's easier to assess when the septum is really nicely vertical. And then sometimes you can see the moderator band, which will clearly indicate that it is the right ventricle. Okay, so here's another one. This is, we'll do a pull of hands. Who feels that this is RV dilation? Okay, who feels that it's not RV dilation? All right, everyone's right, this is RV dilation. You can see that the apex is primarily made of the left ventricle. You can actually see the moderator band in this one. And then the tricuspid valve is closer to the apex than the mitral valve is. So case number five, this was a 66-year-old male with a history of COPD who had an elective triple A repair. He had persistent post-op respiratory insufficiency. We were unable to wean him down from six liters nasal cannula for days. So he, on thoracic ultrasound, he had consolidated lung with hepatization. You can see, and I guess just of note, so in early pneumonia, you would, some of the alveoli are filled with inflammatory products and fluid. So that usually presents as B lines, and then in later pneumonia and consolidation, the alveoli are more filled with inflammatory products. So you get this hepatization. So we were concerned for right lower lobe pneumonia. Now, this patient did have right lower lobe pneumonia and was treated for it. But I just wanted to point out that hepatic mirror image artifact can present, can appear like hepatization at times. So here's just a comparison of the two. So on the right is where there's a bit of hepatic mirror image artifact. And as the ultrasound beams hit the diaphragm, which is a highly reflective surface, the tissue underneath the diaphragm repeats on the opposite side. So it can simulate sort of that hepatic tissue. So you can see. And then one other thing that will help you differentiate between hepatic image, I mean, hepatization and hepatic mirror image is the presence of the spine sign. So on an aerated lung, you will not see the thoracic spine, but when there's fluid as in with pleural effusion or consolidation, that creates an acoustic window for the spine to be seen. This hepatic mirror image artifact is usually just in like a limited acoustic window. So if you move the probe to a different area or interrogate with a different angle, it usually fails to reproduce that artifact. Case number six is a 74-year-old male with a history of hypertension and hyperlipidemia. He presented to the emergency room with chest pain and shortness of breath. He had some ST elevation on EKG and a troponin of 0.1. And he was taken to the cath lab with concerns for acute coronary syndrome. He had a PCI done and here was his ultrasound. So this is an apical four or five chamber and visual estimation of his ejection fraction. Would you all say there's normal contractility? You can raise your hand. Or reduced contractility? Okay, yeah, so there's reduced contractility. I would call it moderately reduced contractility. So and I think what is more notable in this image than the contractility is the wall motion abnormalities in the shape of the left ventricle right there, representing the classic appearance of Takotsubo syndrome. So the word Takotsubo is derived from the Japanese words for octopus and pot. And the shape of the clay pots that Japanese fishermen have used resembles the classic apical ballooning shape that the left ventricle takes on in Takotsubo syndrome. As we know, it's the acute and transient wall motion abnormalities causing LV dysfunction. So fractional shortening was done on this gentleman, which is one of our echo measurements that we can do to estimate ejection fraction. And fractional shortening is the change in diameter of the left ventricle from end diastole to end systole. And it's done in parasternal long axis with the M mode marker placed below the tips of the, the tip of the anterior mitral valve leaflet. So in men, which this patient was, the LV, this is a marker for LV dysfunction when it's less than 25%. So fortunately, the ultrasound machine can do this for you, but you can take the fractional shortening and use the Tychols formula to estimate what the ejection fraction is. It takes the diameter and converts it into a volume. And so for this patient, his fractional shortening was 38.8%, which is normal. And that converted into an ejection fraction of 68%, which is normal. So the interesting thing is that we have already looked at this patient's heart, and by visual estimation, we thought it was moderately reduced contractility. So I think one of the biggest take homes is just needing to take note of the limitations. Fractional shortening takes that diameter that you measured and assumes that that is representative of the entire left ventricle when it's not. And clearly in Takotsubo, it's the apical dysfunction that causes the decreased contractility. This patient had an echocardiogram done, which did show the, it confirmed the Takotsubo and agreed with our visual representation of, or our visual estimate of the ejection fraction being 30%. So I think in conclusion, clinical context is the most important. You can't take one ultrasound image and try to make a diagnosis just based on one image. You have to look at multiple images or multiple image modalities, and especially the patient, you know, clinical context. Being aware of the most common image adequacies or misinterpretations can help prevent you from making those mistakes. And then hands-on practice and looking at normals so you can recognize abnormals will be the most helpful. Thank you.

ultrasound images

artifacts

thoracic ultrasound

abdominal ultrasound

cardiac ultrasound

Takotsubo syndrome