Thank you, everyone, for joining us for Essentials of Genital Urinary Imaging, MSES 42. Dr. Strohlo is our track chair, and I am your moderator for today. This session includes three lectures. I'll be taking you through gynecologic emergencies, followed by first trimester emergencies, and second and third trimester emergencies. So time is short. Gynecologic emergencies. I have no financial disclosures. Overview, we have a lot to discuss. Adenexal lesions, including tumors, torsion, and hydrosalpinx in the uterus, IUD position, endometritis, and endometrial cancer, and in the peritoneum, hemoperitoneum, and small bowel obstruction. There is significant overlap, as we know, between adenexal, uterine, and peritoneal cases. And the CTs that you are about to see were obtained as workup for the woman's pain, not to characterize gynecologic lesions. Let's start with adenexal cases. My colleague, Dr. Arboyle, came up with this mnemonic. What do you think about when you see a complex lesion? You think about corpusclidial cyst, hemorrhagic cyst, ectopic pregnancy, endometrioma, tubo-ovarian abscess, adenoma and adenocarcinoma, or ovarian cancer, hydrosalpinx, and dermoid. This is our symbol that we're moving between cases. This woman, you see this lesion. It's cystic and has all of these diffuse, low-level echoes. If she had had this for years, what would you think? You would think about endometrioma. She had sudden onset of pain after working a shift as a nurse. And you can see that there's discontinuity of the wall with adjacent fluid that is complex. And you see that the fluid actually goes into Morrison's pouch. So this is actually a ruptured endometrioma causing the pain. What do we know about endometriomas? We know that annual ultrasound surveillance is recommended because of a low likelihood of malignant transformation. That usually occurs in masses over 9 centimeters, usually in women over the age of 45, usually with a latency period of about five years. If you see rapid cyst growth or significant solvent component with flow, those are worrisome features. This woman, this large cystic mass, unfortunately, we see all these excrescences, papillarities, nodularities, whatever you want to call them. We do not want to see them. And unfortunately, this is a case of ovarian cancer. This is my mnemonic for features we can look for. When I see these features, the more of them I see, the more worried I am about malignancy. That includes size over five centimeters, septations, wall thickening, ascites, and nodularity. So SWAN is the mnemonic. Here we have this serpentine structure. What is this? This is a tube filled with fluid. I'll tell you that she's having fever and cervical motion tenderness. This is on her right side. On her left side, we have this complex cystic lesion with lots of peripheral vascularity. It becomes a little more clear on CT where you see she has these serpentine fluid-filled structures on both sides. In addition, this separate cystic lesion with adjacent inflammation. And now we know we are dealing with pyosalpinges and tubovarian abscess. You can see all the inflammation it's causing to the sigmoid colon. This woman is pregnant. Are we talking about her pregnancy? No. In the adonexa, we have this echogenic lesion and then all these echogenic lines and dots within this lesion. And these are showing us three of the classic features of a dermoid, an ovarian dermoid. What are those features? Four features we can look for on ultrasound that include the Rokotansky plug, that echogenic plug, the echogenic lines, echogenic dots. So we think of hemoglobin, so we think of hair floating in the fluid for those. And then a fat fluid level. The literature shows if you see two or more of those features, you know you're dealing with a dermoid. Going back to our case, here's that Rokotansky plug with that hazy shadowing in back of it. And then we have our echogenic lines and dots, the hair floating in the fluid. This is a different patient showing us the fat fluid level, which is the least common finding in the setting of a dermoid. What do we know about dermoids? Just like endometriomas, annual surveillance is recommended. Again, because a low likelihood of malignant transformation. Usually up to 2% of dermoids, usually the squamous cell cancer, usually takes one to two decades, women over 50, tumors over 10 centimeters in size. This is a former resident who came in with severe pain. The appendix was fine, but in the right end of the X-ray, you see this bilobed cystic lesion. She went on to have an ultrasound. Again, you see this bilobed cystic lesion. There's no nodularity or internal vascularity. The only place flow could be found was right here in between with this arterial waveform. Because of this arterial waveform, folks did not think it could be all that serious and they sent her home. The fellow and I saw it the next morning and this doesn't seem quite right. Called her and she was having continued severe pain despite being given Phenergan and morphine. So we had her come back. 12 hours later, again, you see this bilobed lesion. The only place we could find flow is right here. So despite this waveform, she was taken to the operating room and she had ovarian torsion caused by two contiguous endometriomas. So I encourage our residents and everyone to look at cases twice. I don't know if you've ever seen this diagram. Do you see the nose and the chin of the old woman or do you see the young woman with her nose and eyelash looking away? You want one look at the lesion to come up with your differential and then you wanna step back and get a different perspective and think no matter what it is, even if it's a simple cyst, is there any chance that it's causing a negative impact such as torsion? This one is from the published literature. This is the classic version of torsion where the ovary is big with the follicles pushed to the periphery. Even in this classic published case, you see preserved arterial and venous waveforms. How is that possible? Because the ovaries have a dual blood supply off of the aorta and the uterine artery. So you can see preserved arterial and venous waveforms. So don't trust the waveforms. You need to go on the pain pattern of the patient. And if you see a very resistant waveform like this with components of reversal, that is very worrisome for torsion. This woman's pregnant. We have two gestational sacs. This one has two embryos. Is that why I'm showing this case? No, I'm showing it because she's having all this pain over the left ovary. She has a thecaludian cyst. The ovary is enlarged with these big cystic spaces. This is where her pain is. Why does she have thecaludian cyst? Because she's an IVF patient and is on ovarian hyperstimulation meds. Her pain was so severe, she was admitted to the hospital. Day one, she does have an arterial waveform in that ovary. Day two, the right ovary, also enlarged, has a normal waveform and is asymptomatic. But the left ovary is even larger and basically no demonstrable flow. On day two, you see that she's already developed fluid in Morrison's pouch. And this is ovarian torsion in a pregnant woman. So we have to remember that torsion can occur in pregnant women. This woman came in with severe pain. What do you think the resident thought this was here? Yes, indeed, thought it was the bladder because it's extending towards the midline. Is it the bladder? No. So she goes on to an ultrasound. And at first you think that is the bladder, but then we know that the Foley has decompressed the bladder. And now we know that this is a seven centimeter cystic lesion, and that's right where she's having pain. And this is ovarian torsion mimicking the bladder. So we have to be very careful when these things start extending towards the midline. This is a 12 year old. She came in with pelvic pain right over this abnormality. We see the serpentine structure. We didn't think much of it. 12 hours later, she comes back. That serpentine structure has gotten even bigger. This is where she's having her pain. And so off she goes to the operating room and it turns out this is torsion of the fallopian tube. It happens uncommonly, but usually when a young girl is approaching menarche, as in this case. Now I will caution you, just because you see something serpentine doesn't necessarily mean that you're looking at a fallopian tube. This woman, we see this serpentine structure with all of these internal echoes, but she is not having fever, cervical motion tenderness or vaginal discharge. She gets a CT. Here you see a small bowel feces, abnormal feces within a small bowel loop. And on this image, you see one and two different bowel loops, both narrowed at the same point. Her pain was so severe, she was taken to the operating room for fear of ovarian torsion. But in fact, she has closed loop small bowel obstruction and that's what we were seeing on the ultrasound. So just be careful that just because you see something serpentine does not mean that it is a fallopian tube. At first, this looks serpentine, but then you see that this whole thing is part of the lesion, predominantly cystic with this central solid component. This is what her uterus looked like, marked an endometrial thickening with fluid in the canal. How do we put this together? She has endometrioid ovarian cancer, the second most common type of ovarian cancer. And we know these women have a 25% chance of concomitant endometrial cancer, which this woman does. Let me show you this movie. You see another serpentine structure with internal echoes and look at all of these septations. So you see on both sides, she has these dilated tubes with internal echoes with extensive adhesions. Look at the loculated fluid throughout her abdomen and pelvis. So we have piosalpinges. What is it from? As we look at her on CT, you see the wall thickening along her terminal ileum and cecum. And that what cinches the diagnosis are the lung bases where we see the cavitary lesion and the tree and bud pattern. What is it from? This is all from peritoneal TB. We have our ED docs that do their own ultrasound. So this woman came in, they did the ultrasound, they sent her home. She comes back now with even more pain. So what do you think the ED thought this was? Yes, they thought that was a fibroid uterus, but actually her uterus is right here. So what is this other structure? It's in the left adonexa. You see that it is cystic with all these internal echoes, no internal vascularity, unfortunately no vascularity anywhere. And this is ovarian torsion caused by hemorrhagic cyst. I was surprised that Paul McCartney is not only a great singer, but also a great painter. What is this woman coming in with pain? What does she have, an IUD? Where is it? We can see that it's not up at the fundus where it belongs. It's down in the endocerbics. So we always want to look for these malpositioned IUDs. We want to look on our coronal image. So what should it look like? Here on your right, you see that that T-bar, what I call the T-bar, is flush along the fundal margin of the endometrial canal. This patient, unfortunately malpositioned, inferiorly displaced with the arms going into the myometrium. This woman needs to be informed that she's at risk for unwanted pregnancy. Again, this is what we should be seeing. So make sure you get your coronal reformatted images. Here's one where I was moving too quickly. I saw this, thought the IUD was down in the endocerbics. So I called the ED and told them that the IUD was inferiorly displaced. The sonographer comes in and says, no, no, no, the IUD is up here. Let me show you on the coronals. Perfectly positioned, right where it belongs within the uterus. So what was I looking at down here? Just be careful. The IUD string can be very prominent, so don't be confused. This woman, you see all these echogenic foci with the hazy shadowing. She's got nausea, vomiting, and fever. She's got discharge from the uterus, and this is endometritis with PID, with air along the endometrial canal. This woman, we have this air fluid level. Where is it? It's actually in the uterus with a mass-like lesion down at the cervix. What do we worry about when we see an air fluid level? We worry about infection. And here, this is pyometra. Pyometra is typically seen in dogs, not so often in humans. When it is in humans, it's typically elderly, immobile, incontinent women, often who have medical problems and have had prior pelvic radiation. Fever is actually an uncommon presentation for them. Very rarely, the uterus can actually perforate, spilling the infected contents into the abdominal cavity, and treatment is drained into the uterus. This is a postmenopausal female. Should her endometrium be this thick? How thick is it? It's 20 millimeters. So that's abnormal. We have a differential. But as we keep looking, we see that there's color flow. We should never see that, and it's coming from different locations. And when we put on a spectral tracing, we see that there's an arterial waveform. And unfortunately, this is a case of endometrial cancer. This woman, 38. Should the thickness of her endometrium match her age? No. And we see that there's vascularity coming from different locations within the endometrial stripe. Her ovary on the right, enlarged with this large cystic and vascular component. How do we put this together? This is another case of endometrioid ovarian cancer with concomitant endometrial cancer. And only 38 years old. So age is no longer a predictive factor anymore. Moving to peritoneal cases in our last minute and a half. You see this uterus? It's floating on what? On all of this echogenic material. This free fluid with echoes in it. What is that? That is all clotted blood. On the CT, you see the extensive hemoperitoneum. This case was caused by a ruptured ovarian cyst. But I urge caution. Make sure that you have the ED check a blood beta. We have seen women, urine pregnancy test negative, that come back with a positive blood beta HCG and actually have a low beta HCG ruptured ectopic. So make sure to have them check a blood beta. If that's negative, then we can know that all of this hemorrhage is from a ruptured ovarian cyst. This woman we're looking in the left adonexa, we see this complex lesion with these echogenic foci. Is this in the ovary? Not exactly. When we look on CT, we see the air fluid level here next to the sigmoid with all of this diverticulosis. What is this? This is a diverticular abscess. So again, just because it's a woman doesn't necessarily mean it's an adonexa lesion. So we have reached the end of gynecologic emergencies. Let's now hear from Dr. Baltarowicz, who's going to take us through first trimester emergencies. Thank you. Hello, I'm Dr. Roxana Baltarowicz from the Department of Radiology at Thomas Jefferson University. This talk is on the essentials for first trimester ultrasound diagnoses. I have no disclosures. I'd like to first talk about the normal first trimester that address the chronology, the anatomy and the sonographic signs, and also to highlight some pitfalls. And then I'll turn to early pregnancy failure, discuss the definitive sonographic signs and the suggestive signs of early pregnancy failure. I do want to remind you that first trimester involves one to 13 weeks of gestational age, which is also menstrual age, starting from the first day of the last menstrual period. So when we have a patient with a positive pregnancy test and an ultrasound, we have to answer some basic questions. The first one is, is the pregnancy in the uterine cavity? Is it an IUP? Once we establish that, then we ask ourselves, how certain are we that it is an intrauterine pregnancy? Is it a definite intrauterine pregnancy? Is it probable? Or maybe we can't tell. In that case, it would be a pregnancy of a year. In that case, it would be a pregnancy of unknown location, a so-called PUL. And in that case, we would have to follow it till we're sure. And then the last question is, is this a viable pregnancy or is it failing? I would like to caution you that during transvaginal scanning, the first step should always be the evaluation of the cervix and lower uterine segment to establish that the gestational sac is indeed in the uterus. And that's done by connecting the antecervical wall with the anterior uterine wall and the posterior cervical wall with the posterior uterine wall. Once we do that, we have a normal shape, we have normal continuity, then we can focus on the gestational sac inside the cavity. The first thing that we would see is a little small fluid area within the endometrial cavity surrounded by an echogenic border. And if we can see it, that would be as early as four and a half to five weeks. The next thing that would show up at five and a half weeks is a yolk sac. That's very important structure. That tells us that that's definitely an intrauterine pregnancy. Adjacent to the yolk sac, the next thing that shows up is a little echogenic dot, and that's the embryo. We call this the diamond ring sign for obvious reasons. And that's at six weeks, which is also the same time that the little heartbeat shows up. And after this, all that the embryo has to do is undergo all of its organogenesis during this embryonic period. So it's important to analyze this fluid area. The fluid area in the uterus, the earliest signs is that it has rounded borders. That kind of makes it likely, very likely, but not definite that that's an intrauterine pregnancy. Now, in the olden days of only trans-abdominal scanning, we had something called an intradecidual sac sign, which was a little fluid area surrounded by an echogenic rim burrowed under the cavity line. But that's not a very reliable sign because, look, in this case, we don't even see the cavity line. Are we sure? Could that be a cyst? What is that? There was also a double decidual sac sign, which meant that you have the echogenic border of the sac and a second echogenic border of the maternal decidua. They used to use that. But then came transvaginal scanning, and we saw that, for example, something like this doesn't even have a double decidual sac sign, but it was an intrauterine pregnancy. So we had to evaluate this and found that these signs were absent in 35% of gestational sacs. So they're unreliable. We don't use them anymore. We're gonna wait till we see a yolk sac or an embryo, and that will be definitive. The yolk sac is a definite sign of pregnancy. The embryo forms near its yolk sac, not on the other side of the amnion or anything. The yolk sac has very important functions. It supplies nutrition for the embryo. It has primitive hematopoiesis going on. There's blood gas exchange between the mother and the embryonic blood. It's the beginning of germ cell production. So very important early functions. Now, some of the anatomy includes recognizing the amnion. The amniotic sac is bordered by a very thin membrane. And the only way you really see it is if the beam is perpendicular. It's only five cell layers thick, so it's very thin. You're not gonna see it as the angle falls away from the membrane. On the other side is the chorionic sac, and within that sac sits the yolk sac. I always think of it as the poor little embryo can't play with the little ball because it's on the other side of the membrane. Sometimes you'll see a little line, echogenic line between the abdominal wall and the yolk sac. That's the vitelline duct, also called yolk stock or phallomesenteric duct. Then you can see the umbilical cord coming into the abdomen. You can see a cystic space at the back of the head. That's the rhombencephalon. That should not be construed to be some kind of anomaly. This is the precursor of posterior fossa structures. We see it also in this embryo. We can see the heartbeat in the middle of the embryo. There's the cephalic end and a little bit of an underdeveloped rump end. Here's a very prominent rhombencephalon as we see in these three embryos. Once again, this is normal anatomy. We could see little limb buds show up. In nine weeks, they start to move around, little upper and lower limb buds. Sometimes you'll see a little bit of an echogenic area anterior to the abdominal wall, as we see in these two embryos. That's the physiologic umbilical herniation. We expect that to recede back into the abdomen at 12 weeks. So we're not gonna call any kind of abdominal wall defects before that time. So beginning with six weeks, when the heart begins to beat, that begins the embryonic period that lasts through the end of the 10th week. A very active organogenesis is going on at that time. But at the end of the 10th week, that is at the beginning of the 11th week, the fetal period begins and all the fetus has to do is grow. So at the fetal period, at 11.1 weeks, all the organs are present. The only thing left is for the midgut hernia to reduce back into the abdomen. And by 14 weeks, we can see the mature form of external genitalia and the four chamber heart. Knowing this anatomy, we can avoid some of the pitfalls. For example, this was sent in as a double-headed embryo. It's not a double-headed embryo. There's the rhombencephalon, there's the amnion around it and there's the yolk sac. So you're not gonna make that kind of mistake. Here, this is not some kind of mass growing out of the fetal head. That's the rhombencephalon. That's the yolk sac on the other side of the amnion. Here again, yolk sac, rhombencephalon. Something like this, well, yeah, we would question this. This doesn't quite conform to our anatomy. We'd have to wait and observe this growth and see what happens with this. This does not look normal. Another pitfall is mistaking a blood clot for an embryo. Now, the embryo should be near its yolk sac. This embryo was near its yolk sac, this was not. And this would be moving around, so that was just a blood clot. Here are two other examples of blood clots. They don't have the shape of the embryo, they don't have yolk sacs next to them. We should question this. These were called embryos, but there were adnexal masses that were ectopics. And this was blood in the endometrial cavity with blood clots. You have to be careful. We should look for any kind of structural abnormalities, because chromosomal abnormalities account for 50% of all pregnancy losses. So we should search for abnormal shapes. This was a conjoined embryos, and they had two distinct little heartbeats. And if you think that's very odd and unusual, more recently, we had another case of conjoined embryos, one amnion, one yolk sac, definitely abnormal. We should report any abnormalities, like in this case, this is a 12-week fetus, has a nuchal translucency. That's very significant for this pregnancy. Absent nasal bone is also another significant finding. Any kind of gross deformities of embryos, we should report. Look at this one, looks like some kind of a bug. Sometimes this may herald further investigation to a chromosomal problem that may be occurring with potential future pregnancies. Sometimes an embryo has some type of fluid around it. Now, if the embryo is 7 millimeters or larger and has no heartbeat, then it's a dead embryo, and that could just be edema from the demise. Other times, it could just be cystic hygromas that added to the demise or not of the embryo. So we should mention this in our reports. Now, we have definite signs of early pregnancy failure, and all these criteria are based on transvaginal scans. So the first definite criteria is seeing no heartbeat in an embryo with a coronary length of 7 millimeters or more. Now, another criterion that stands by itself, seeing no embryo in a gestational sac where the mean sac diameter is 25 millimeters or more. So once either one of these is seen, we have a potentially normal IUP excluded. It's a failed pregnancy. Now, this was decided at a consensus conference and published in the New England Journal of Medicine. I remember it by the numbers 7 and 25. 7 is in heaven. Embryo's in heaven. 25 alive. Alive by 25. So maybe that'll help you. We have other definitive signs. Absence of an embryo with a heartbeat more than 14 days after a scan that showed an empty sac, that is a sac without a yield sac. Another criterion is absence of an embryo with a heartbeat 11 days or more after a scan that showed a gestational sac with a yield sac. There's another definitive sign. That's the sliding sac sign, which means the gestational sac is actually sliding out of the endometrial cavity through the endocervical cavity. This is an abortion in progress or an imminent abortion. The only thing to watch out for is make sure it's coming down the middle of the cavity here that it's not a cervical ectopic pregnancy, which would be eccentrically placed. Now, sometimes you have signs of early pregnancy failure, but it's still too early and you want to recommend when to follow the pregnancy. Some clinicians will send the case back in three, five, seven days but there are scenarios when we have to wait longer. So if a gestational sac is empty, nothing's in it, no yield sac, no embryo, we recommend that they wait 14 days. They wait 14 days, no embryo develops with the heartbeat, that's a failed pregnancy. Here's another scenario, a gestational sac with a yield sac, but there's no embryo. So we recommend they wait 11 days. They wait 11 or more days, no embryo, the heartbeat shows up, it's a failed pregnancy. Another scenario, gestational sac has an embryo, but there's no heartbeat. So we recommend wait seven to 10 days for the heartbeat to show up. If none shows up, that's a failed pregnancy. So how do you remember this? I use the numbers 7, 11, 14, they're kind of inversely proportional. So the longer we wait, the less the gestational sac had, like it was empty. And seven days, so we had an embryo, but there was no heartbeat. So they're inversely kind of related. You can also use the 7 for the crown rump length of 7, no heartbeat, that's another important 7 number. Now, there are many suspicious findings, these are not definite signs, and none of these have been proven to be definitive enough in large studies. So they are one of the most common signs of a failed pregnancy. So they are warning signs of possible failure, but we have to prove the failure with definite signs before any final clinical action is taken. So what are these signs? Well, a crown rump length of less than 7 millimeters and the embryo has no heartbeat. Mean sac diameter of less than 25 millimeters and no embryo. Absence of an embryo with a heartbeat less than 14 days after a scan that showed an empty sac without a yolk sac. Absence of an embryo with a heartbeat less than 11 days after a scan that showed a gestational sac with a yolk sac. Other signs, absence of an embryo more than six weeks after LNP. An empty amnion, as we see here, a large empty amnion. There's the yolk sac, no embryo in the amnion. A large yolk sac, seen here, yolk sacs over seven millimeters are abnormally large. And then a small sac size, which we call the first trimester oligohydramnios, which means the sac is so small the embryo can't roll around in there. And if you want a quantitative number, take the millimeters of mean sac diameter, subtract millimeters of crown rump length. And if the difference is very small, less than five millimeters, that's a small sac, that's first trimester oligo. Other findings could be a very regular borders of an empty sac with loss of choriodecidial echogenicities, a solid yolk sac, a calcified yolk sac. More than one yolk sac, in this case, they're solid. So ultrasound, not just HCG, but ultrasound should be used to follow up suspicious ultrasound findings. In most cases, follow up in 10 to 14 days is appropriate. So in conclusion, we should be familiar with the sonographic findings of a normal and abnormal first trimester pregnancy. We should use conservative criteria for the diagnosis of early pregnancy failure. The important ones are an embryo with a crown rump length of seven millimeters or more should have a heartbeat. Remember, seven is in heaven. And a gestational sac of mean sac diameter of 25 millimeters or more should have an embryo, 25, alive at 25. If you don't have these definitive criteria, you should follow with serial HCG levels and ultrasound. And if for whatever reason, you're not sure of your findings, continue following with HCG and ultrasound. So thank you for your attention. So now I'll turn it over to Dr. Roya Sohaii. Hi, I'm Dr. Roya Sohaii and we're going to be talking about second and third trimester OB emergencies. I have no disclosures. We will start by discussing the important placental diagnoses, which present as OB related emergencies. And then move on to look at non OB related maternal emergencies discussing the need and safety of imaging beyond ultrasound in these cases. Important to remember the placenta is a temporary but very vascular organ at the risk of oversimplification. There's lots of blood flow within the umbilical vein. As oxygenated blood is brought to the fetus, the placenta plays a major role in oxygen exchange. And then the fetus also delivers deoxygenated blood to the umbilical arteries. Key point being that both the fetus and maternal blood are at risk if there is a significant hemorrhage. Abruption by definition is the premature detachment of the placenta. It is quite common, 1% of all pregnancies, but it's not always an emergency. Patients present with bleeding, pain, preterm labor. Ultrasound may show the clot, but often doesn't. Marginal abruptions off on the edge of the placenta are the most common. They tend to present as bleeding. Retroplacental abruptions happen behind the placenta, right in here. And they present most often as preterm labor because blood is irritating to the uterus. Preplacental hemorrhages are the most rare, and they are often near the umbilical cord, and they can present with cord compression. Intraplacental extension can happen from any of these areas if the bleed is large enough. Here's an example of a patient presenting with preterm labor at 27 weeks. There is a thick heterogeneous placenta without significant blood flow. And that is because this is a intraplacental and retroplacental blood clot. Here it is after delivery, big blood clot within the placenta. Here is a recent case we had with a very large marginal abruption. And this measured about 12 centimeters, it was quite large. So the sonographer went the extra step to look for fetal anemia. Middle cerebral artery Doppler performed, showing elevated peak systolic velocity, showing fetal anemia. So fetal findings that may lead to intervention include bradycardia, anemia, and non-reassuring, keep an eye on. So the key points with abruption, we wanna look for it in all cases that present in the second and third trimester with bleeding. For large bleeds, it's really important to immediately assess the fetus, look at the heart rate, and if there is bradycardia, deliver the fetus. We also wanna look for anemia and consider biophysical profile. And of course, the pitfall is that the blood can look like the placenta. So a thick placenta is suspicious for intraplacental hemorrhage in the right clinical scenario. We want to assess the lower uterine segment, preferably with transvaginal ultrasound in all pregnancies who present with bleeding. You wanna rule out short cervix and also rule out a low-lying placenta and its complications as the reason for bleeding. With regards to low-lying and placenta previa, definitions are that if the inferior edge of the placenta is within two centimeters of the internal os as seen in this case, then that is a low-lying placenta. If the placenta covers the os even a little bit as seen in this case, then this is placenta previa. The majority of cases, 96% of low-lying placenta will resolve with advancing pregnancy. Placenta previa may also resolve if it is asymmetric and minimally covering. So the recommendation is for follow-up at 32 weeks initially. A very special situation that we don't wanna miss is basal previa. In this situation, there's unprotected submembranous umbilical vessels near the internal os carrying fetal blood. There's two different types. One is when there is a vellumensis cord insertion, which is quite low, and that is why there's vessels near the internal os. The other is when there is multiple placental lobes, like a sex and chariot lobe or beyond. And the vessels communicating between the different placentas are in front of the internal os. Important diagnosis to make, because if the diagnosis is missed, there's only a 40% to 50% survival for the fetus. This is fetal blood that should the cervix open, the baby will bleed. If the diagnosis is made, survival is near 100% because patients are hospitalized early on in their pregnancy, around 20 to 32 weeks, and delivery happens early as well. Here are some examples. Here's placenta anterior and posterior to the internal cervical os with fetal vessels in front. Pulse Doppler proves that this is fetal heart rate. And here's specimens showing how you can have different lobes of the placenta and the vessels travel between them. One of these in front of the internal os will lead to hemorrhage. This is a situation of basal previa from a vellumensis cord insertion. Fetal vessels, including this one, very near the internal os. And it's important to remember that vellumensis cord insertion will often lead to vessels traveling a long distance to get to the placenta. Any one of these in front of the os is basal previa. I think a good rule of thumb is if the cord insertion, umbilical cord insertion, is in the lower uterus, the lower half of the uterus, it's worth doing a transvaginal ultrasound to rule out basal previa. Moving on to another very important diagnosis, placenta accreta spectrum. There are three histopathologic stages, which we can't really distinguish well on imaging. However, accreta is when the placenta attaches to the myometrium without muscular invasion. Increta is when invasion happens into the musculature, but not beyond. And percreta is when it occurs beyond the serosa of the uterus. So let's look at some examples. The risk for placenta accreta increases with the number of prior C-sections. As we see, one prior C-section 11% up to 67% if greater than four prior C-sections. Please note that the risk for accreta is present even with just placenta previa up to 3%. So the persistently low-lying placenta is not a normal placenta, and we have to look for diagnoses such as accreta and basal previa. Sonographic features of placenta accreta is as follows. One of the most important features is the loss of the retroperitoneal hypocoic zone. So behind the placenta, normally there's a hypocoic zone, which is the musculature and the vessels of the uterus. When that is lost, this implies some invasion of the placenta in these areas. These are two different areas of invasion in the same patient, and here is another area that we can see right here. So this is one of the findings that raises suspicion for accreta. Another finding that is discussed in the literature is a lower uterine segment bulge at the areas where the placenta has invaded abnormally, as we can see in this surgical picture as well. The most sensitive indicator for accreta is the presence of these vascular lacuna. These are large, irregular, tornado-shaped vessels within the placenta. And this is different than placental lakes, which rarely show any flow on color. So we see these angular vessels associated with the loss of the hypocoic retroplacental zone, as you see in this case, and also bridging vessels that go directly from the placenta to the uterus. MR is actually not any better than ultrasound in detecting accreta when it is because of invasion at the caesarean scar. And we see similar findings. We see loss of the uterine margin, we see these lacunae within the placenta, and the bridging vessels. Even with the best planned delivery, the outcomes for placenta accreta can be devastating. And there is significant morbidity and sometimes mortality up to 7% reported with this diagnosis. Average blood loss is 3 to 5 liters, and average blood transfusion is 10 units, and much higher. Our record at my institution is over 200 units. So these patients are at risk for DIC, renal failure, ARDS, ureter injury, vesicovaginal fistulas, and death. Next, we're going to leave the placenta to talk about diagnosis with not OB emergencies, how to image, and we'll use some case examples. Usually, there are three main questions that we are dealing with. Can you wait until this pregnancy is over before the imaging? And usually, the answer to that is no. Is there an alternative imaging modality? For example, if the diagnosis is usually made with CT in the non-pregnant patient, can you use MRI? And is there a way to minimize dose if CT needs to be done? It's important to remember that maternal health really does determine fetal health. So we never want to avoid imaging when imaging is necessary. Regarding radiation safety, important to know by looking at this graph that procedures that do not directly irradiate the pelvis are considered safe. If safe is less than five milligrams, which is considered safe in pregnancy. So it is the direct radiation of the fetus on abdomen and pelvis CT, which does potentially impose risk. What about MR versus CT? Well, they have been shown to be diagnostically equivalent for abdominal pain. And the MR we're talking about in pregnancy is one where there's no oral or IV contrast needed. Fair to say gadolinium should be avoided in pregnancy. And this can be done rapidly. So 15 minute timetables have been reported. But of course, MR is less available, especially in some areas. And comes at an increased cost. So here's some diagnoses, examples of maternal mortality. With regards to trauma, it's important to remember that this is the leading non-OB related cause of maternal mortality. Most often from motor vehicle collision or domestic violence. And even though it is somewhat challenging to decide what to do, honestly, what is most important is to do the CT as needed to look for maternal injuries. We're not really, we have ultrasound for things like placental abruption. However, maternal health is incredibly important and we don't want to avoid doing CT for significant trauma in pregnant patients. What about pulmonary embolism? Well, that's the leading cause of pregnancy related death in the United States. It is a difficult diagnosis. Fair to say most guidelines suggest that we start with paying attention to the lower extremity. If there are lower extremity symptoms, then ultrasound should be done. And if that ultrasound is positive, then the pregnant patient goes right for treatment, no other imaging. However, if there are no like symptoms or it's negative, then the next step is a chest X-ray. And then consideration about VQ scan versus CTA. The doses are similar to the fetus. The dose to the mother is more with CTA. The ATS, American Thoracic Society and Society of Thoracic Radiology guidelines are to perform VQ scan over CTA because of the maternal dose to the breast. However, ACR appropriateness criteria says VQ and CTA are equivalent. And in practice, especially in my institution, to be honest, CTA is much more able to be performed and will show more diagnoses beyond pulmonary embolism. And therefore, a lot of places will go directly to CTA. Here's an example, bilateral clots in a 25 week pregnant. Another very important diagnosis to keep in mind is HELP syndrome. This is an acronym that stands for hemolysis elevated liver enzymes and low platelet count. This results in hemolysis, liver dysfunction and thrombocytopenia in the patient. This occurs in women in the third trimester during labor or immediately postpartum and these patients can be extremely sick. They present with lab abnormalities or right upper quadrant pain, sharp shoulder pain, mortality rates up to 17% for moms and 38% for fetuses have been reported. So an extremely important diagnosis. Here are three different examples of this diagnosis from my institution. Here's a case, patient was extremely symptomatic. Ultrasound was honestly not diagnostic at all, maybe mild heterogeneity in the liver. CT performed on the same day shows intraparenchymal hemorrhage. Here's another case that ultrasound suggested hemoperitoneum and subcapsular hematoma. She went to CT immediately and you can see the findings much more clear on the CT. Here is another case presenting with severe pain and the liver looked heterogeneous. CT showed multifocal hepatic rupture. So key point, ultrasound is really not good enough for this particular diagnosis and one should have a very low tolerance. So in conclusion, the take home points, don't miss the important placenta diagnoses. These are the most common causes of emergency in the second and third trimester, most commonly abruption. And then previa and its associations including vasoprevia and placenta accreta, both of which significantly impact mortality for fetuses and mothers. Maternal emergencies also can happen outside of the uterus. Imaging is increasingly used to evaluate abdominal and chest pain in pregnant women. CT may be appropriate in some scenarios such as trauma and PE. And overall carries a very low risk to the fetus. MR can be performed safely and rapidly and is as sensitive as CT for most abdominal pathology. So the generalized large field of view protocols without contrast show a range of pathology that can be clearly diagnosed. Thank you for your attention and now we will move on to the question and answer portion for our session. Thank you.

genital urinary imaging

gynecologic emergencies

first trimester ultrasound

second trimester emergencies

adnexal lesions

placental abruption

maternal diagnostic imaging

HELLP syndrome