OK. Here you go. That's Maria. Uh, she definitely, you know, uh, have been a, a very, very valuable member, uh, for the multi-discipline fetal team here in Cincinnati. She was a staff radiologist in Spain, uh, before she joined us in, um, Cincinnati. And currently, she's for sure the go to person for us, uh, when it comes to, uh, complex, complex fetal congenital anomalies, as well as anal rectal malformation. And um she has also um well published and you would enjoy reading uh some of the publication as well. So I would love for Maria to share with us uh her experience in fetal imaging when it comes to obstructive neuropathy. Maria. So, thank you, Vong. Um, I'm going to, um, start sharing. I think that's OK. Mm. So, good morning. Thank you, Fong, for your kind introduction. Um, yeah, um, I've been here for a while. I love, uh, uh, fetal. I'm a pediatric radiologist, but, uh, doing fetal imaging. I, um, learn more about the, uh, processes that then we see postnatally and the advantage of, uh, being able to uh track what we do on, um, in, in utero to what we see after birth is, uh, helping us to understand better many of the, um, processes that we evaluate. So, um, Today, I'm trying to review uh bladder outlet obstruction from the uh fetal imaging standpoint, uh, combining the use of ultrasound and fetal MRI. Um, they are complementary techniques and I'm going to try to show with examples how, uh, they can help each other. Um, when we talk about, um, bladder out of obstruction, and, and just remember that not all big bladders are going to be the result of uh mechanical obstruction, but when we see these enlarged bladders and the development of oligohydramus, we think about, um, uh, anatomic obstructions, and, uh, this could be frequently urethral valves, but not necessarily. So, urethral atricia or stenosis in isolation, but also in Potentially uh associated with anorectal malformations might be. The, uh, situation that we, uh, are dealing with. And as Doctor Ruano was, uh, describing, uh, we are in, in other, um, uh, cases, uh, in the presence of an extrinsic mass such as a sacrococcygeal teratoma obstructing the bladder or an intrinsic lesion such as an ectopic or an inverted urethrocele that is, uh, obstructing the urethra to different degrees. So, when we do uh imaging assessment, and, and I said that, uh, there are, uh, I mean, we deal with uh two imaging modalities, ultrasound and MRI. Uh, we try to complement each other, uh, the good things that they can, uh, we can obtain from one and the good things that we can obtain from the other one, trying to provide the best approach to the imaging and the most, uh, specific, um, information. So, ultrasound is going to be extremely useful for an accurate assessment of that amniotic fluid volume, we all know. Um, it would be very useful, uh, to track the, uh, umbilical arteries or if it's a single, uh, umbilical artery to track that, uh, artery from the abdominal cord insertion because with that, uh, we will be able to fully understand what structure is dilated. in the abdomen and pelvis. Like on this baby, really early in gestation with anhydramnous um and an enlarged cystic structure that uh you will be tempted to call bladder, but when we analyze on that axial view, uh, you can see that, uh, the, um I'm going to get my pointer. The, this is the abdominal co-insertion. The first structure that we encounter outlined by that single umbilical artery is going to be the bladder and this larger structure that was posterior caudal, and then superior to that, uh, normal size or relatively small sized bladder, uh, was a hydrocps on a baby with cloaca. Uh, the, um, in both techniques, we are going to analyze really carefully the content of the bladder and the bowel, and this is because, uh, in my brain, I'm always thinking about anorectal malformations, but in the context of bladder olid obstruction, you should also think about that. Um, and, uh, some of these anorectal malformations will have, uh, fistulous communications between the bladder and the rectum. And some of those are going to um allow enough material exchange to change the content of those two spaces. And when we have meconium and urine mix, you could see the development of uh enteroliths, as we see on um these uh babies. Uh, let me just minimize my uh screen for uh sharing. Pictures. Uh, here we see in, uh, this was a monoamniotic pregnancy. Uh, so, uh, twin gestation, uh, monochorionic monoamniotic pregnancy, uh, with a discordant malformation. This is the baby with Uh, uh, cloaca that had a hugely dilated bladder containing an enteroli that is even giving a little bit of shadowing. So this, uh, fluid that is around is, um, produced by the normal cowin. Uh, on this other baby, this was a male fetus with an imperforated anus and a really, really dilated. Uh, distal column containing fluid and these uh ecogenic concretions that are those enteroliids that form in that context of, um, fistulous connections in, in a rectal malformations. If we talk about um uh uh uh uh in perforated anus and rectum malformations, one thing that uh you should attempt is to look at the perineum and try to define if you're able to see a normal anal sphincter. Uh, that should show as we see here with, uh, outer ring is hypoechoic because it's the muscle sphincter, and in the center is going to be that ecogenic anal mucosa. If you see that, uh, that will be, uh, most consistent with a patent anus. Uh, although, um, remember, not all anorectal malformations are going to have an imperforated anus. It's really rare, but, uh, So you will still have to uh look all everything that you have on your um imaging. With MRI, um, so I'm moving to MRI and things that we can do with MRI. Um, cystic renal dysplasia or dysplastic changes that we see in the context of obstructive neuropathy might not be evident. On, uh, ultrasound. So, um, I mean, normally we deal with, uh, technical problems, you know, amniotic fluid around, so the acoustic window is not great. Mom can be big. You can try to use a high-frequency transducer, but, um, Many times it's not as detailed as what we can see. Uh, this is the same baby on the same day, uh, where we can see, uh, that the kidneys, in fact, have this, uh, tiny cortical cyst. It's on both sides but more prominent on this left side. And, uh, this is what we see with, uh, cystic, um, dysplastic changes in the context of obstruction, but more sensitive, uh, with MRI. Um, lung volume calculations trying to predict the severity of, uh, lung hypoplasia is going to be done, uh, with MRI. MRI is also going to be um able to help, uh, in the, or reassess the spine because, uh, some of these babies with more complex genitourinary anomalies and anorectal malformations. could have spinal problems and uh as we can see on this baby that end up, um, uh, with, uh, or the final diagnosis was a cloaca, um, you can see that there is sacral hypoplasia. Some other babies could have a tether core or uh dysref defect. Uh, we should also check the external genitalia because also in these complex malformations, we could have, uh, ambiguous or incompletely formed external genitalia. And with MRI we will look again to the bowel content and um uh we have the advantage of some uh physiologic uh contrast materials. So, the meconium is typically bright on the T1-weighted imaging, looks beautiful, like a contrast enema. Uh, on the T-two-weighted imaging, which is what we normally use for the rest of, I mean, the main, uh, sequence that we use for anatomic assessment on our MRIs is going to be dark. So it's a little bit harder to define the most distal end of the rectum. With, uh, steady-state reprecision sequence, um, we will have this intermediate signal. Meconium is seen starting at around 20 weeks in the rectum and then is feeling retrograde uh the entire colon. So by 27 weeks, we expect to see the entire colon filled with meconium as we see on this image. So, looking at that, uh, T1-weighted imaging, uh, is very important. to pay attention to the rectum and uh to see how long is the space between the bladder base and the rectal cul-de-sac. Based on the study from these authors, we should see at least 10 millimeters length um of the rectum. If we don't see that, uh, we could be in the setting of maybe delayed transfer of meconium to the rectum as we see with, uh, um, open neural tube defects, swallowing problems, um, but it could be related to bowel obstruction and it could be also in the context of an rectum malformations. Maria, uh, that's the question. Yes, so, um, let's see, this is, uh, Doctor Callahan, um, was, uh, commenting that fetus doesn't pass meconium in utero. Then why should there be a dilated rectum on antenatal ultrasound in patients with inner rectal malformation? I'm sorry, I'll repeat that one more time. Yes, please, uh, Doctor Callivan. Commented that since fetus doesn't pass meconium in utero. That's not. Why should there be a dilated rectum on antenatal ultrasound in anal rectal malformation? No, I, uh, that's not, uh, the first, uh, statement is not correct. Meconium starts forming in the small bowel by 14 weeks and is migrating distally to the anus, to the rectum. Um, uh, so, and there is, uh, like another, um, element of, um, biliary secretions, uh, uh, pancreatic secretions, uh, the gastric emptiness starts, uh, around, uh, 25 weeks if I'm not wrong. Uh, in the colon, there is, uh, absorption starting already in utero and the, uh, cell declamation. So everything is forming that meconium that is in utero, is present. What I'm saying is that in, what we see What we can see is that the meconium is filling the rectum. Expected to be filled in the rectum and detectable by MRI at 20 weeks. So, uh, when, and precisely when there is an inner rectum malformation within perforated anus, especially a high inner rectum malformation, what we will see is a dilated, uh, distal column because there is an obstruction and yes, you are right. We see that and we see that on ultrasound and MRI, but, uh, we need, uh, I mean, uh we need to understand the, the, uh, the physiology of the meconium. That's what I was trying to explain. I think, I hope I, I answered your question. May I ask a question? Sure, for, yeah. Maria, why is that important to see, I know, uh, um, um, you know, intestinal anomalies in those babies Lutu? I don't know if, uh, because it's important for the audience to know that, uh, oh, I'm going to show you for that. I'm going to show you. Sorry, yes, so, this is just a warm up. But, uh, essentially, uh, we'll, um, make sure that, uh, you know, that there are some mimickers for um uh presence of abnormal content in the colon like this baby that had a bleeding disorder, had an intraventricular hemorrhage, and, uh, blood products in the colon that made this signal, um, higher. Uh, this baby had fluid, definitely in the rectum, but there was no fistula. This was a baby with, uh, congenital diarrhea. You can see with all the fluid-filled bowel. And polyhydramus, by the way. Uh, when there is, uh, impaired swallowing, uh, the rectum might look short and, uh, that's because, uh, there is delayed transfer of meconium without, uh, uh, without having any anatomic problem. So, this is an example of a baby with a large lymphatic malformation that, uh, with impaired swallowing had this physiology of transfer of meconium. To the uh rectum delayed and showing kind of uh for shorten rectum without any problem in the anus. So, moving on to the clinical cases, and sorry for this, uh, introduction, but I thought it was important for you to uh try to understand this. Um, the first scenario that I brought, I thought it was the most, uh, classic, the kind of the straightforward situation, uh, severe oligohydramus already, really early in gestation. This was On the left, uh, a sixteen-week, uh, gestational age, uh, ultrasound, and we can see a huge bladder, um, dilated posterior urethra. We don't even know the gender, but, uh, with this keyhole bladder, um, we, um, hypothesize that, uh, this most likely is going to be posterior urethral valves. And, um, in many cases, we are right of Of course, atricia stenosis for other reasons would be in the differential, but uh when um we see after birth these babies, we will see on uh VCUG during the voiding phase, uh, dilatation of this posterior urethra. And, uh, even with the catheter in place, which in many cases is a critical catheter and we are not allowed to remove, we can see the transition to a normal size, uh, urethra with this linear filling defect, which is the valve. OK. So, in other cases, um, it's, uh, the ultrasound, during the ultrasound, we see dilated bladder, really thick wall, and, um, but we don't see a keyhole configuration, so the urethra is not dilated. So I'm bringing this case that I saw, um, many years back. Uh, the baby had I think uh this baby was looking at the brain is uh around 27, 28 weeks, and, uh, already with the effects of oligohydraneus uh for a while with small lungs and uh we can see the enlarged bladder, it's thick wall. Uh, the MRI, it took us a while to get anatomic views, uh, usually it's at least uh 35, but most of the time it's 45 and close to an hour sometimes. Um, with this larger field of view, you can, uh, keep, uh, assessing anatomic areas and, uh, keep others in your field of view. And, uh, this bladder was most of the time with, uh, the bladder neck not, uh, really well open or maybe faint, but clearly, while the baby was, uh, with a voiding phase, uh, we were able to show this, uh, dilated posterior urethra. Which, uh, after birth, um, we confirmed that was the result of, uh, urethral valves. We can see on this voiding phase, a large or very prominent, um, vesicoureteral reflex and the abnormal, elongated and regulated appearance of that, uh, thick, what we saw in utero thick wall bladder. OK. So now I'm going to uh answer um um Doctor Rao because, uh, in the context of multiple congenital anomalies, um, I think MRI is uh very useful and it is also very useful to think about uh potential um uh malformations that could be associated in the context of bladder or leg obstruction. So, uh, this baby was imaged at 22 weeks at our institution and the um history that uh was provided was um uh uh already a complex congenital heart defect detected, um, an enlarged bladder with abnormal kidneys, a two vessel core, and a radial ray deficiency. So right there, we are thinking really high in the context of maybe uh bacterial association, right? So, starting with the um um external genitalia and um anterior urethra, we can see uh that this uh looks like a male fetus that has an enlarged dilated, um, anterior urethra. Um, by ultrasound, we can see here already, the bladder is enlarged and, um, uh, the kidneys, uh, we can see that there is a left kidney UPJ obstruction or very, very dilated renal pelvis. On the right, uh, we see more non-communicating cyst, uh, some with, uh, this, uh, peripheral distribution as we see with, uh, cystic, um, um, dysplastic changes. In the context of um bladder outlet obstruction. And, um, on this coronal view on ultrasound, you can see, uh, I mean, again, uh the severity of uh decreased amniotic fluid and the, um, bladder that was enlarged, although, uh, the urethra was not, uh, dilated. Um, there was no abnormal content. And here is, uh, on the MRI how we can see. Uh, funny looking out patching on that right side. And what called our attention was, uh, the meconium-filled bowel in the right, uh, abdomen. By 22 weeks, uh, which was the gestational age at the time of imaging. Uh, we should see meconium in the left, uh, or descending sigmoid and the rectum. Uh, on this baby, these areas were not showing any meconium signal, but instead, meconium was, uh, relatively prominent, but just in that right side of the abdomen. So with this, I was It's like, is this a case of um obstruction for, for other reason, or I mean, this baby could have an uh an a rectum malformation. We are only at 22 weeks. Um, if the pregnancy is going to be um uh uh uh maintained, uh, uh, I was recommending, uh, to obtain a follow-up MRI because we could have uh functional changes. Maybe this is just delayed or is this real. So, when we did a follow-up MRI in the third trimester at 31 weeks, Uh, we confirmed that this baby had, uh, this, um, persistent meconium feel and now more dilated, um, bowel that was tapering towards the, uh, bladder. The bladder remained enlarged. Uh, looking at the sagittal view, again, absent rectal meconium or meconium where we expect to see a normal rectum, um, The sacrum hypoplastic, um, there was no, uh, dystrophic defect or any other, um, spinal, uh, findings. The bladder elongated towards the abdominal cord insertion, so we have a patent ureus. And uh on top of that, all the renal findings that we saw, the left kidney, renal pelvis is on, playing on this image. The cystic uh changes on the right kidney. I didn't bring the images here because what I'm trying to bring uh to your attention here is something that You might not um pay attention unless I bring it here. These lungs, these lungs look completely normal even though the baby had oligohydraus, severe oligohydraneus throughout um the entire pregnancy, and there was no fetal intervention to replace that fluid. So, um, when we see, um, uh Uh, airway obstruction, high airway obstruction, we see enlargement of the, um, the lungs, right? So, immediately after this, I was like, OK, I need to look at the trachea and see what's going on because I'm concerned now that, uh, maybe there is an obstruction in the upper airway that could explain why I see normal appearing lungs. And I say normal appearing lungs in volume and in signal. They are normal in signal, uh, and I can bring you, I can go back to that, um, baby with, um, posterior urethral valves. Uh, these are the lungs that we frequently see in this, uh, context of, uh, severe oligohydraas. OK. So, here we go on this sagittal view. This is the nasopharynx airway, uh, retroglossal airway, a little bit of fluid there. And, um, throughout the entire pregnancy, and we try, we try on sagittal plane, there was no fluid through the trachea, uh, fluid posteriorly where the esophagus, um, is. Mm Paying more attention and doing some of the sequences, I saw some fluid to the right of midline connecting with that lower esophagus where we can see branching bronchi. So this baby has um definitely TE fistula because we, the main bronchi are branching from the esophagus. But um this baby And that's what I was, um, raising the main concern at this point of the examination is that this baby um has all the findings that we'll have, uh, we will see in the context of tracheal agenesis, uh, which is, um, If it's complete as, um, I was afraid of, um, this would be a lethal um malformation. And uh with this added um uh substantial, um, uh, finding, um, the patient was, uh, counseled, um, in that way. And, um, based on that also, additional, um, obstetric, um, uh, uh. And considerations were um added like no fetal monitoring during the, uh, the delivery to avoid uh C-section. So, I'm bringing now, um, Uh, the MR necropsy and the specimen, uh, to show you, um, the, um, finding of, um, Tracheal agenesis with the main bronchi arising from uh the uh mid portion of the esophagus. Uh, looking at the bowel, here we have And the, uh, distal colon as we were, um, thinking that, uh, this, uh, was an anorectal malformation and, uh, The MR necropsy with this uh very enlarged, uh, thick wall, um, bladder. And uh this is uh all the specimen um uh display here. Uh, the baby had, uh, urethral atricia, so, yeah, I forgot to mention that when we were doing, uh, that, um, external genitalia assessment, we saw that megalourethra, um, but in between that, um, segment of urethra that was dilated, we didn't see, um, uh, further fluid distention. Uh, connecting with the enlarged bladder. So we didn't know if that was, uh, in the context of megalourethra or, uh, also associated with urethral atricia, um, uh, which, uh, was the case, um, on this baby. So, um, the urethus that was patent, uh, the abnormal kidneys and that, um, fistula connection to the dilated, um, distal colon. In this baby, uh, that in fact had, um, absent perineal openings. Um, so, The main idea that I was trying to bring to the discussion is that, uh, from an imaging point of view, at least, um, as, as fetal imagers is that uh there are different ideologies that lead to bladder outlet obstruction, but uh we should entertain or, um, uh, make sure that we assess the distal bowel, uh, to include an evaluation of potential in ectal malformations. And this is a very challenging. evaluation after birth. These babies, uh, require a long list of, uh, tests, uh, physical assessment, and in utero, we are dealing with just, um, a few, uh, tools, um, that are trying to combine that, um, evaluation, um, maybe bringing at, uh, at the table the possibility of follow-up evaluation. In the third trimester, uh, to make sure that we are not, um, uh, confused with, uh, some dynamic or, or functional changes or anatomic variations in the, um, distribution of the meconium or the transfer of meconium and, uh, also to assess, uh, those, uh, lungs, uh, that, um, may be in the context of, um, Um, uh, fluid replacement therapies are going to be, uh, reassessed, uh, more accurately in, in, in order to predict, um, uh, uh, future lung hypoplasia. So with that, uh, we thank you for your attention. Um, I want to thank all my colleagues at the Fidel Imaging Division at Cincinnati Children's, at my, uh, to all my colleagues at the Fidel Center of Cincinnati. Uh, to all the MFMs that are referring us, uh, patients, and also the clinicians that, um, uh, from that postnatal, um, assessment and treatment, I received, uh, feedback and I am trying, uh, help us to understand a little bit better, uh, what we see in utero. So, um, thank you very much. Uh, here's my email for questions if later, um, you have. Um. Thank you so much. Thank you for the wonderful images that you share and the interesting cases, you know, making us think about um how to really make the correct diagnosis. So, um, correct, you know, um the right therapy option can be offered to the family. And um, so thank you again and um I know Stephanie has a comment to make and then we jump over to Jose. Yeah, very quickly. Thank you, Doctor Calvo. Those are beautiful pictures. Um, from the neonatal perspective, it's always fun to look back, you know, having taken care of some of these patients. I think it's really helpful when we're able to predict anorectal malformation prenatally. Um, from the neonatal perspective, it's obviously very important to understand if that Diagnosis is present because understanding whether these patients require peritoneal dialysis, the need for bowel diversion really complicates their neonatal care. And so it's very helpful for us in counseling the families prenatally as well as being prepared at the time of delivery and thereafter, um, to understand whether that diagnosis is present. Yes, thank you. And uh, it, it is also very useful, um, and throughout the years, I can see how, um, Um, I mean, also the, the degree of, um, I mean, how our reports can um make to the postnatal, um, report, right? Uh, so the neonatologist, you guys are the first ones, uh, bringing, uh, I mean, taking care of the baby and, uh, reviewing those reports and sometimes the findings are very subtle. Uh, maybe the baby still has a patent anus, but the, uh, there is a rectal atricia. And uh there is a bladder outlet obstruction and so the, the, the, um, expedites uh the care in an incredible way. So, yes. And I think Doctor Reddy is gonna tell us more about the care of those kinds of patients in a little bit. Perfect. That's I say something? Yeah, go for it. Yeah, so, uh, um, uh, I think, uh, um, it has you know anomalies, uh, are very difficult to see, uh, sometimes prenatally. Uh, even when we consider isolated luto, we have seen, uh, sometimes nowadays that we treat some cases that, uh, seems to be only bladder problems, even the heart is normal, genetics normal, and then we have seen micro, uh, mega bladder, microcolon, uh, Uh, intestinal hyperstasis, uh, syndrome, which is, which is a very complex disease. Uh, so even when we see isolated, I have difficulties, but I, my question to you, Maria, which is wonderful talk, is that, uh, what do you think about late MRI, you know, MRI during the 2nd, 3rd trimester, because I have seen some babies. I have recently two babies that I treated in utero, one with cystoscopy. And then, uh, for our surprise, the baby had a this mega bladder microcolon uh syndrome. And the second one I did a shunt at 14 weeks and had the same, but the baby started to uh developing. And uh uh throughout the pregnancy, some bowel distention after 26, 27 weeks. So then we did an MRI so that we had some, some abnormalities in the bladder, in the bowel too and postnatally, they confirmed that one of the part, part of the intestine was a thoracic too. So I would like to, to hear your opinion. About that. Yeah, you are right on target. Uh, I mean, the initial evaluation is typically around this twenty-week, uh, sometimes even earlier, and, uh, I was trying to, uh, when I was, uh, trying to explain about the physiology of, uh, what meconium is doing and, uh, when we are expected to see, uh, and, uh, until meconium is not in the bowel, uh, where we expect the rectum, we cannot tell what's going on in that area. So, um, and on top of that, uh, there are anatomic variations or maybe, uh, facial cleft, macrocognetia, brain anomaly that is impairing the swallowing, and so maybe this is a functional situation that we don't see meconium where it's supposed to be or it's delayed or is uh prominent in this area, but maybe it's uh something dynamic that is going to change its functional, um, uh transitory. Uh, so that if, uh, the, uh the, the pregnancy is uh progressing, um, it would be great because it's uh providing an additional um assessment, not just a snapshot at 20 weeks where we have kind of limited Uh, tools to assess, uh, such a complex um potential situation. So, yes, uh, that third trimester MRI is, um, very useful. Um, I mean, we, we do consider that when we do assessment of lung hypoplas. Asia and in the third trimester is going to be much more um uh specific and um uh to, to predict that level of hypoplasia. But um at the same time, we can also look at that bowel and see what's, what's going on and confirm as uh we saw on that uh final case that, uh, yeah, the findings were not just transitory, there was an anatomic, um, problem, yeah. Yeah, I believe in that too, that we need to have a longitudinal evaluation of those babies. Even when you do a biochemistry, for example, many people may ask me if I use biochemistry. It can be very different than 2020 weeks than 28 weeks, then, you know, 32 weeks, so I agree with you. So thank you for your explanation.
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