 I'll look at technique here, describe some normal anatomy, and then discuss the common pathologies. And we're going to look at two pathologies, acute pain and then some mass lesions. You've got two options, trans-adominal sonography using the distended bladder as a window, which is what we do most of the time. An endovaginal ultrasound can be done in adolescent girls, really in some part are technologists, some of them just don't want to do it, they'll only do trans-adominal, there are others who will do endovaginal, and at least in the United States it's sort of a mixed bag, most scans are still trans-adominal and they work well. When we do the trans-adominal, we do a high-resolution 5 to 12 megahertz curvilinear, linear array transducer and larger children, we'll use something between 3.5 to 5 for deeper penetration, and like all studies you obtain images in two planes. Well John Caffe said you've got to recognize the normal if you're going to recognize the abnormal. You've got to know normal, and we know that there are structures in children that aren't present in adults that can be confusing, you know they include the thymus, but they also include the ovary and the uterus, and these change in size and appearance from infancy to adolescence due to hormonal influence. So in the new way there's some stimulation from maternal hormones, but quickly after that the ovary becomes very small in volume and stays like that until about nine years and then it starts to increase as puberty develops, and so its mean volume is less than a cubic centimeter, and the same for the uterus, it's very, very small and starts to increase about nine to ten years of age as puberty develops, maybe two cubic centimeters or less. So that's a key point if you're going to recognize abnormality. Well not only the size changes, but the appearance changes, so in the pre-pupital ovary you may see a homogeneous or heterogeneous ovary that has a lot of unstimulated primordial follicles, and we define those as less than a centimeter, in the pubertal ovary it's heterogeneous again, you have both primordial follicles, but now they are stimulated or functional follicles, and those are defined as between one and three centimeters. This is an urinate, ovary with lots of follicles, that's normal maternal stimulation, these are two-year-olds, this one is relatively homogeneous, ovary this one's got a lot of follicles less than a centimeter, those are normal primordial follicles, this is the range, both of these are normal, this is what you'll see until about eight or nine years of age, then a puberty, ten follicles are stimulated in each cycle, or primordial follicles, they're stimulated, one becomes dominant, the functional follicle, and early in the cycle prior to ovulation it's called the graphene follicle, after it ruptures it's called corpus luteum, the follicles live in the periphery of the ovary, so this is normal, functional follicles we said two types the graphene typically is anacholic or abascular in the first half of the cycle, after ovulation you get the corpus luteal follicle, which may have internal echoes and a rim of vascularity, and both of these follicles are less than three centimeters, so this is the spectrum of the adolescent ovary, you may just see a lot of primordial follicles, nothing stimulated yet, less than nine millimeters or less, or a centimeter or less, in an early cycle you'll see a dominant follicle, it's okay up to three centimeters, and you can see flow in the remainder of the ovary, second half of the cycle after ovulation, the follicle becomes more complex because of hemorrhage, it's the corpus luteum follicle, so a bit more heterogeneous, again up to three centimeters will allow as normal, and you can see flow in the surrounding tissue, the uterus is going to change in size, I showed you that, but in appearance, pre-puberty it's a tube, you can't tell the fundus from the cervix, you can see the intrametral canal in neonates, because of maternal stimulation after a couple of weeks it disappears, and you're not going to see it again until puberty, and if you see it before that you've got precocious puberty, the pubertal uterus, the fundus becomes larger than cervix, the inverted pair of parents, and you see the intrametral canal, this is the neonate, this is a huge uterus, right, that's normal, maternal stimulation, here's the stripe, within a few weeks or a couple months this is going to involute, it's no longer stimulated, and this is what you see until puberty, you see a tube, and it's not a big tube, it's got no differentiation between fundus and cervix, and then, and the pubertal girl is, who goes through puberty in adolescence, you've got the adult configuration, uterus with fundus bigger than cervix, and a stimulated stripe, and the stripe thickness varies with the time of the cycle in the menstrual phase in the first five days, it's up to four millimeters, in the proliferative phase between six and 14 days, and it's measured from here to here, it's four to eight millimeters, and in the secretory phase it's very, very thick, acute pelvic pain, the common diagnoses and the ones I'll discuss are stimulated follicular and corpus luteum cysts, which don't involute or rupture, may cause pain to their size or bleeding, and then nexal torsion, I've elected not to cover pelvic inflammatory disease to focus on some of the diseases that are really sort of specific to children, this is very similar in children and adults, so follicular cysts, normally in the first half of the cycle, these are gonna, you know, involute mid-cycle disappear, become a corpus luteum, sometimes they fail to rupture or involute, and they grow, they're usually up to five centimeters, but they can be larger, they look like a cyst, they're homogenous, they're unilocular, they're anicoic, they're associated with the ovary, here's the ovary, here's unstimulated follicle, here's another one, pain, this measured five centimeters, here's part of the ovary, here's flowing the ovary, this is the cyst, associated with the ovary, you see some ovarian tissue, it's a stimulated follicle, and in order to know, really, and I'm not sure it's that important, but in order to know whether it's a graphene follicle or corpus luteum, just ask the patient what part of the cycle they're in, if it's early, it's the follicular graphene follicle cyst, if it's later corpus luteum. Most of these regress within two cycles, if the cyst remains for three cycles, for more than three cycles, it's probably not a cyst, it may be a teratoma or some tubal cyst, we follow cysts that are greater than five centimeters, because they may not be a cyst and they may not envelope, and we bring them back for six to eight weeks, follow up, we'll do it a couple of times, if it doesn't envelope, they may get additional imaging with MR, they may just have laparoscopic surgery, but this is the recommendation of the College of Obstetricians and Gynecologists and the Association of Sonographers. Well, here's another one, cyst and the left adnexil, we brought it back, disappeared. The hemorrhagic ovarian cyst, those are usually the corpus luteum cyst, and again, they fail to regress or envelope, they're bigger than three centimeters, which makes them some type of a pathologic rather than functional cyst. With blood, the cyst becomes hypercoic in the acute phase, as the blood is resorbed, becomes more complex, so you may see stranding, fluid debris levels, some retracting clot, and the cyst are really abascular. So acutely, if they come in the first couple of days, you're going to see echogenic material in the cyst because acute blood is echogenic, and you may see a fluid fluid level. After that, the hemoglobin gets resorbed and the clot evolves, and you get a stranding pattern, so you can get this classic fishnet appearance, so-called fishnet appearance, and then eventually, the clot will retract against a lateral wall, so the blood clot is retracting, and this is another one's fishnet appearance, you see flow and surrounding ovary, but not in the cyst. So those are so-called simple cysts, they're just follicles of some type that fail to envelope a rupture. The real issue is an nexel ovarian torsion, which is torsion of the ovary in the tube, and if does occur in the neonatal period, but more often in adolescent girls. The ovary is usually normal. In contrast to adults where there's usually a mass, in the adolescent girl, the ovary is normal 90% of the time. We see masses 10% of the time, and the reason the ovary twist is the ligaments are a little bit too lax, and so it twists. It does percent with acute pain, nausea, vomiting, and some of these patients report prior episodes of acute pain. This is what it looks like. The ovary and the tube twist. So you see this very hemorrhagic structure, and if you dissect it, you cut it in half, you've got a lot of blood, and you've got distinctive follicles in the periphery. So translate that to an image. You're going to see a large ovary, at least two to four times normal, and a lot of dilated follicles in the periphery. The ovary, because it's torused, may leave the adnexa and be behind the bladder or the uterus, and you may see the twisted vascular pedicle. So a patient with acute pain, this is the torused ovary, nine centimeters. It's enlarged. Lots of follicles, distended follicles in the periphery, they just can't drain, they get engorged, and this is the normal three centimeters with multiple follicles. Three times larger, that's torsion. There's another one behind the bladder. This is the ovary with multiple cysts, some actually central. This is the normal. You've always got to compare the two ovaries. If one ovary is larger than the other and the patient has acute pain, you've got to suspect torsion. You can also see twisting of the pedicle, the associated tube and ligaments. Here's the ovary, and this is the twisted tube and ligament, so-called whirlpool sign. You can see whirlpool is used commonly for multiple diseases, anything that's got a spiral, people refer to it as a whirlpool. What about color? Typically, it's absent 90% of the time, and so it increases your confidence in the diagnosis. Normal ovary left is really enlarged, it's a little bit more ecogenic, and it's no flow. That's torsion. However, this is the pitfall. Occasionally, you're going to see flow. This is a torsed ovary, seven centimeters big, lots of purple follicles. Here's the normal side, multiple normal follicles, and this ovary, this has got flow. That's because the ovary has a dual blood supply from the uterus and the ovary. Got to compare with the opposite side. If one ovary is larger than the other, and the patient has acute pain, you still have to think of torsion even if you see blood flow. That's been a big pitfall, so in this case, the grayscale wins over the Doppler. Another challenge, and we're going to see some mass. How do you know the pain is due to a mass or is it due to torsion? This patient had had pain, a 16-year-old girl, and has an assist, which was, I think, about four or five centimeters. We put color on, and there was flow in the associated perincoma, nothing in the cyst. This is the normal left ovary for comparison through similar flow. I think if you can see flow in the ovary, you do not have torsion. We'll take this one, a 12-year-old girl with right lower quadrant pain. Here's the bladder. Here's a mass. We didn't know if that was a complex cyst or some type of mass of another mass, but she had acute pain, so the question was their torsion. So we interrogated the perincoma. We could get no flow, maybe a blip of flow, nothing. So if you see absent or maybe high-resistant flow, you've got to think of torsion, and then a laparoscopic correlation may be required. And this turned out to be torsion due to assist adenoma. So I think it's very valuable to put flow in the ovarian perincoma. If it looks normal, I think you're pretty secure to say there's no torsion, but if there's high-resistance, no flow, you've got to think of torsion. And of course, torsion can be intermittent, so we also, you know, tell them at this point it looks normal, but it could be intermittent, and we need to correlate clinically and do a laparoscopic correlation if needed. Occasionally, the tube twists, not the ovary, that's rare, but it can happen. And the symptoms mimic ovarian torsion. The ovary is normal again, okay? So that's what you look for. If the ovary is normal, that's how you separate tubal torsion from ovarian torsion. The tube is dilated, and it may mimic a hydrocell pinks due to pelvic inflammatory disease. But usually in pelvic inflammatory disease, the other findings, clinically, there's drainage, there's pain, the cervix is tender. So if none of those findings are there, and you see only a dilated tube, and the patient has really acute pain, think of torsion. Let me real girl with left lower quadrant pain and vomiting for a day. So we saw this dilated structure next to the ovary, okay? She's 11. She's not sexually active. Here's the ovary. It looks normal. And there's flow in the ovary, okay? And this tubular structure turned out to be a torus fallopian tube. It occurs occasionally, not as common as ovarian torsion, but it can cause acute pain.