Transcription
[Music] I'm Dr. Oxana Baltarowich from Thomas Jefferson University Hospital, and I'm going to speak to you about areas where ultrasound should be the first diagnosis in pelvic pain. I will restrict myself to nonpregnant patients. I have no disclosures.
So the learning objectives here: to describe ideologies for pelvic pain where ultrasound is the first modality of choice. We have other choices: we have CT, we have MRI, we have nuclear medicine, but I would like to discuss areas where we should be doing ultrasound first. So I'll include gynecological conditions, some urinary tract pathology, and GI tract abnormalities. I would like to divide it into acute and chronic conditions.
When a woman experiences acute pelvic pain, the first thing we think of, especially if it's more right lower quadrant or parumbilical, is acute appendicitis. Then we go into causes of the female pelvis, which include gynecologic conditions: hemorrhagic ovarian cyst, ruptured cyst, endometriosis, PID, torsion, thrombus, fibroids; and then renal colic or distal ureteral calculus.
From the chronic conditions of pelvic pain—meaning more than 6 months of pain—I'd like to touch only briefly on fibroids, but then include endometriosis, adenomiosis, pelvic congestion, abnormal IUD position. I will not discuss—I just am mentioning it here—that would be a whole separate lecture; and some chronic bowel conditions.
The reason we favor ultrasound is because there's no preparation; it's safe; there's no ionizing radiation, which of course is cumulative through the lifetime of the patient; there's no ionizing iodinated contrast; it's of course less expensive; but what's even more important is that it's dynamic scanning, and it's interactive with the patient. We can elicit areas that are painful and try to zero in on what is the real cause of the pain.
With acute appendicitis in the pelvis, we will be looking for a blind-ending, non-peristaltic tubular structure with gut signature; that is, this multi-layered appearance with mucosa, submucosa, and the muscularis layers; and then outside of it is the serosa. The structure is blind-ending; it has those layers; it's usually—in the literature there are different sizes—but over 6 mm diameter we get suspicious. The only problem we have with transvaginal imaging is that we cannot compress it because every time we press, the appendix runs up away from us, up into the higher false pelvis. Here's another example of a blind-ending tubular structure filled with low-level echoes, and that was acute appendicitis. This ultrasound is particularly good in young, thin females, certainly in children, and in the pregnant patient. Now it can go into complicated types of appendicitis. So you can see phlegmons where there are these layers of edema and infiltration of the fat; there could be a right lower quadrant collection and abscess; as we can see here, the abscess may have bubbles of gas in it, or it may have quite a considerable amount of gas, but it would be sort of round from several projections and does not elongate like a colon would. We would certainly think of calling Interventional Radiology for the possibility of drainage of such a collection.
Now, an abscess in the pelvis does not just result from acute appendicitis; it could be the result of pelvic inflammatory disease; there can be a perforated diverticulitis, especially in the left lower quadrant; it could be a perforated cancer, which can simulate a perforated diverticulitis; and certainly things could be related to a postoperative collection, postoperative abscess, or postoperative infected hematoma.
Now, the hemorrhagic ovarian cyst, usually the origin is the corpus luteum. The corpus luteum forms after ovulation, and the job of the corpus luteum is to support a pregnancy, so it has very little time to hurry up, get organized, and prepare for the pregnancy. So there is basically like a neovascularization forming, almost like a malignant process, but the vessels are formed quickly—as I say, haste makes waste—and they're very thin and easily can tear, and subsequently corpus luteums often have some hemorrhage inside of them.
Now, the most common appearance of the hemorrhagic ovarian cyst is, first of all, this thin, fishnet-like, lacy, reticular appearance, which is composed of thin linear strands. Notice the excellent sound transmission. Then we can have the retracting clot. After a while, the clot will retract towards one of the walls; the walls are still smooth and thin, and there is excellent sound transmission. Doppler is important because there is absolutely no blood flow within a blood clot. If we see blood clot blood flow within portions of this mass, this would have to be considered solid tissue.
Now let me show you how ultrasound is dynamic. So here was a patient with right-sided pelvic pain. We saw this mass that looked very much like this lacy pattern of the hemorrhagic ovarian cyst, but I noticed this bright reflector, which is odd. Certainly, I wouldn't expect calcium or air or anything inside a mass, so I was wondering, could this be a bubble of gas? Could this be an abscess? So I had the patient move, and the bubble of gas changed position; it went to the non-dependent position. So here's the CT that proved that this—there was indeed gas in this mass—and this was an abscess. So here it shows me that even though things sometimes look very characteristic, ultrasound can go ahead and prove things by changing patient position or doing different maneuvers.
There are unusual appearances due to blood clots that assume unusual shapes and mimic solid components in ovarian tumors. Here, for example, this looks very unusual; here this could be solid; of course, there—nothing—none of this colors with color Doppler. Here's a multiseptated appearance; here's an appearance of a solid clump of soft tissue, yet there is no flow in it by Doppler. This was just a big blood clot. Also, notice that because blood is basically a gelatinous mass, it transmits sound beautifully. So these—one of the features that we would look for is to see—is there sound transmission, and can it jiggle? Sometimes we poke it with the transducer and see the jello jiggle, whereas a solid tumor would not do that. None of those are 100%, but they're helpful.
Now, pain can come, of course, from a ruptured ovarian cyst, and sometimes the pain can be severe. These patients typically are non-febrile; they may have hypotension depending on how much blood loss; sometimes it's difficult to figure out exactly what's going on, and it may be a diagnosis of exclusion. Certainly, we'd be looking for a hemoperitoneum, but the key would be a collapsed or deformed cyst with or without this hemorrhage or internal debris. So of course, this can mimic ectopic, an abscess, etc.—that's why it's often a diagnosis of exclusion.
Now, when the cyst ruptures and if it's a significant bleed, we can see hemoperitoneum. So we may see a very large amount of hemoperitoneum in the pelvis; it can be very homogeneous in the distribution of the echo; and with time, as clots form and fibrin moves in and there's resorption of the clot, we get a very heterogeneous appearance. So it's very variable.
Another condition where we should go with ultrasound first is on pelvic inflammatory disease. Now, once the infection travels up through the uterus and into the tubes, usually the pain can be diffused low in the pelvis. The tube can be thickened; usually we don't see tubes, but now we're starting to see tubes. This one is about a centimeter thick. Here is a salpinx with—ness filled with pus, so that would be a pyosalpinx. Here's another pyosalpinx with the fimbriated end blocked and then a pus fluid level. And in this case, this was an unfortunate woman who went so far as to get acute suppurative salpingitis and slough the entire lining of her tube. Then it moves on to wrap around the ovary; the process continues; you get a tubo-ovarian complex; results in a tubo-ovarian abscess; and then it looks like an abscess anywhere else, with echogenic debris, multi-loculated, ill-defined borders, some possibly some gas; and don't forget to look at the surrounding fat, which can be hyperechoic, similar to fat stranding on CT.
Now, ovarian torsion is commonly brought into a differential diagnosis, even though it's an uncommon event. It accounts for less than 3% of gynecologic emergency surgeries, yet we include it in the diagnosis all the time, but yet it's often even missed, so the salvage rate is actually quite poor—less than 10%. We would really like to improve that. So once we see such a large ovary, very heterogeneous with no internal blood flow—that's really ovarian infarction—we should be doing better than this. This is already a very late finding, so we need early detection to prevent irreversible damage and to preserve fertility, especially in the young patient. Most quote "ovarian torsions" are really adnexal torsions; they pull in the tube into the process, and they may have a mass. This process occurs mostly in prepuberal, adolescent, or women of childbearing age, although it can occur in postmenopausal women after surgery. So pregnancy is a risk; 20% of cases are seen in pregnant women; patients undergoing hyperstimulation syndrome with these large ovaries that can twist and turn around themselves—all of these patients are at increased risk. So here we see a torsion with a mass, underlying mass, and here is a torsion of an ovary with no visible mass. So in almost half of the cases, there is no ovarian mass leading into the twist. So how can that happen? Well, the ovary supposedly twists on itself around some lax ligaments or long vessels or some adhesions; sometimes tubal spasm has been mentioned, and then that serves as a pivot point around which the ovary twists, or abrupt changes in abdominal pressure. So it is possible, post-op, not to have a mass in about half of the cases where we only see the enlarged, swollen ovary.
Now, this torsion differs from testicular torsion in a male. It's very quick and easy to diagnose; you put the probe, the color Doppler on the testicle; you see no flow; the patient has pain; they go to the OR; they have 6 hours to save the testicle—not so in women. Women can go on for days with symptoms. A study here by Hurri showed that the onset to presentation varied from 0 to 210 days, with a mean of almost 8 days of pain, going in and out of emergency rooms. Well, how can this happen? Well, there could be intermittent or incomplete torsion. I'm sure you've seen ovaries twisted around the pedicle up to 10 times, and the ovary has a dual blood supply. This is the preservation of the species, and it's absolutely important to try to keep this ovary alive, so the body has provided two sources of blood flow: from the ovarian artery and from ovarian branches of the uterine artery.
So the most important findings that we see are sonographic, and that would be unilateral enlargement of the ovary. I don't know of any one paper that has said that the ovary was of normal size, so if you compare the two ovaries, the swollen ovary should be well over three or four times the size of the contralateral ovary. That's the most important finding. Then we can see follicles pushed out to the periphery; we can sometimes see an abnormal location of the ovary, which then pops up out of the pelvis, and here it's sitting on top of the uterus; and of course, a mass in half the cases. We can also see a very heterogeneous center, which is explained by hemorrhage into the center of the mass; we can see the twisted vascular pedicle sign, which is the vessels where they're twisted around; you get this concentric stripe-looking appearance, and you can see that with color Doppler, like a little snail, and that has about an 87% pre-op accuracy for the diagnosis.
Now, diagnosing torsion when there is a mass is difficult because sometimes you're thinking, well, maybe, maybe the pain is from hemorrhage into the mass or just the stretching of the capsule in the mass itself, so that's a tough one. Things to look for would be wall thickening around a cyst, as we can see in this case; we can look for internal hemorrhage and internal complexity; and I think this case would be easier for us to diagnose—look at that thick, swollen rim and then the hemorrhage, the bleeding inside the mass.
Now, Doppler is too variable to be all that reliable. It's reliable when there's no blood flow, but what we're trying to do is salvage the ovaries, so we want some blood flow. So there have been a number of papers written over the years showing all different kinds of patterns: normal flow, diminished flow, absent flow, increased resistance, loss of diastolic flow—a variety of different patterns—and the reason for that is that this depends on how, how much blood is still flowing in and out of the twisted ovary before arterial blood flow ceases. So we know that first of all, we'll cut off the lymphatic supply, then we'll cut off the venous supply, and it's going to take a while before we cut off the arterial supply. Also, things can be technical; maybe the machine isn't sensitive enough to be picking up flow, and we know that sometimes normal ovaries show no blood flow, so there's that technical aspect.
Another area that we could think of for doing ultrasound first is if we would consider the patient might have ovarian vein thrombophlebitis. This might be somebody prone to making blood clots. We did have such a patient: 27-year-old woman with right lower quadrant pain; she was 9 months post-delivery, and she came with right-sided pain, and the ovary and everything looked fine, but here we noticed something—it's little soft tissue; we wondered was it the vessel? We put on color; it was indeed in the vessel; we elongated; it was the ovarian vein. So this was ovarian vein thrombophlebitis. Now, usually we think of this in a postpartum period, usually 48 to 96 hours postpartum after c-section, after giving it some time for endometritis to come up, the uterus, but in these patients it's going to be a presentation of fever, pain, and even a palpable mass in the right side of the abdomen, usually postpartum.
Now let's turn towards fibroids. Now that could be a whole lecture in itself, but fibroids are painful, usually from a degeneration, like in these cases. We see cystic degeneration of a fibroid, and in this case we see some gas bubbles, degeneration, release of some nitrogen products. Also, a fibroid can become superinfected, and that would be called a pyomyoma. Here was such a patient, febrile, extremely tender, and here is the CT showing that there's gas in the fibroid. So you have to be clear on whether it's difficult—many times to tell—is this real infection, or is it just based on degeneration? Fibroids can also be painful if they undergo torsion, and here is such a patient with a pedunculated myoma that twisted. It's immediately closely applied to the uterus. And another area where it can be painful is the prolapsing fibroid that is being extruded out of the uterus. In this case, it is bulging out through the external os here, and this one still had a good blood supply, but you can see how this could twist and then undergo torsion and then infarction and necrosis and be painful. Another area is, of course, sarcomatous degeneration of fibroids, which usually occurs in postmenopausal women, although it is possible that it may be in childbearing years.
Now, another separate, whole separate category is distal ureteral calculus. These patients often have flank pain that radiates down towards the right lower quadrant or towards either quadrant. So an elegant way to do this would be to look from below with transvaginal to try to find the distal ureteral calculus, as we see in these cases. This would obviate a CT scan. For a young woman, we would look at the kidneys, see whether there's hydronephrosis or not, and then is it really necessary to do a CT scan abdomen pelvis for this one tiny little dot that represents the obstructing calculus and subject this young woman to at least 500 equivalent chest x-ray dose of radiation for that one dot? Seems to me not reasonable. We can also tell whether the ureter is obstructed, like in this case it was obstructed; in this case it was working on the other side, working just fine; and we kept looking—you need at least 5 minutes of evaluation—and no jet came out of the right side. You can also do this vaginally. Here we're looking to see what's with this stone, and it is only partially obstructing, so we can give that information to the clinician.
Now, the area of chronic pelvic pain—these are patients having 6 months of pain. Well, fibroids, yes, they can cause pain by stretching of the uterus, by pressing on the back, or pressing on different organs, pressing, causing backache, pressing on a nerve, causing leg pain, and also causing dyspareunia. So there are a number of reasons why fibroids can be painful, but I'd like to touch upon endometriosis. This disease, I don't think we have cracked completely. This is a beautiful net drawing showing us where these little implants of tissue can go. They can go all over the pelvis; we usually think of them as on an ovary, and then we know adenomyosis is in the myometrium, but it can go on ligaments, on the tube, on the bladder, into the cul-de-sac, into the rectovaginal septum, implant itself on bowel, and then it causes bleeding, which then leads to inflammation, which subsequently leads to fibrosis, and these poor women have years and years of pain.
Now, when endometriosis is painful, one of the things we can look for is an indistinct border around such a collection around, and this is an ovary with two endometriomas. So this hazy, fuzzy border tells us that something else is going on, such as inflammation. Now, I think at this point would be a physician-directed exam. If you're not coming up with a source of pain, I think at this point we would need physicians to really take the time and examine the patient carefully to see where the patient hurts.
Now let me show you an example. This patient had pain in the labial area, in the perineal area, labia, and we know that the round ligament extends from the uterine horn through the deep inguinal ring, through the inguinal canal, and inserts and breaks up as fibers in the labia majora. It's sort of the equivalent of the vas deferens in the male, so it kind of ends here. Endometriosis can track along the round ligament, and here were areas of hyperemia and inflammation, and that's what this patient had. So it only—it takes a specific look and understanding of the disease process to be able to pick up things like this. So I think we all have to try to improve our sensitivity. We all know that it can end up in the abdominal wall in a cesarean section scar, so we would question the patient and directly focus then with high-resolution imaging on the abdominal wall and not into the deep pelvis. This patient had periumbilical, little cystic areas that would bleed every month into her umbilicus. So here we filled it up with gel, and we found several of these endometriomas. I do want to remind you that another thing that we should remember about endometriosis is that it is related to cancer; it has a 3.5-fold increased risk of cancer in women with endometriosis, and the cancers are clear cell carcinoma of the ovary and endometrioid carcinoma of the ovary. So we want—that's one of the reasons we follow them annually—and we would be looking for changes in the endometrioma: more solid nodular components, development of thicker septations, enlargement of the mass. So just keep that in mind when you're checking women.
Adenomyosis is a difficult diagnosis; it's underdiagnosed and causes lots of pain: menorrhagia, dysmenorrhea, dyspareunia, pelvic tenderness, and it requires meticulous scanning. Now, this disease is composed of not just the endometrial glands and stroma in the myometrium, but also a response of smooth muscle hyperplasia or hypertrophy, so that—so we see echogenic islands of heterotopia endometrial glands and stroma in the myometrium, and then around it are these little areas of hyperplasia. So we look for a globular uterus with an asymmetrical thickening of the wall, as we see.
Here we see a very heterogeneous, uh, myometrium. Even a few cystic changes here; lots of little cystic changes. We see pencil-thin shadows. We see a globular-looking uterus with very heterogeneous echogenicity, and sometimes so much so that we can't even see the endometriomyometrial border. Sometimes we can't; we don't even know where to measure an endometrium. Is this all endometrium? Uh, where does it end? Where is the endometrium here? Because this tissue blends with the endometrium, it also—these smooth muscle whirls—in cause these little pencil-thin shadows.
Now, if you encounter this problem where you don't know where the endometrium is, you could do a sonohysterogram, and that helps you see what's going on in the endometrium, and then you can see that that is all here in this case involved with, uh, adenomiosis. So, uh, also look for these echogenic nodules, uh, of this, uh, uh, tissue, uh, and cystic spaces; myometrial, uh, cysts. And is caused most likely subendometriosis myometrial by adenomiosis. And sometimes with sonohysterography, we can actually see the channel, uh, where's the connection to that cystic space, uh, of the, um, uh, the track, the what we call myometrial crack.
There can be an adenomyoma, which is just a focal deposition of this disease—very focal. Here it has ill-defined margins; it can be confused with a fibroid, but it does not have edge shadows. It has a minimal mass effect, that does not calcify, and it has vessels that typically go throughout the area versus fibroid which pushes vessels to the periphery. These are tender areas; fibroids tend not to be tender. They're poorly circumscribed—well circumscribed for fibroids. Pelvic congestion syndrome is another cause of chronic pelvic pain, uh, which is associated with dilated pelvic veins. Women experience a very dull ache, a dragging feeling, a heaviness during prolonged scanning, and when when they lie down, put their legs up, they feel better. A lot of times, uh, it's due to a dilated ovarian vein, uh, which has vessels and congestion around the ovary; may actually have reverse flow down the ovary, uh, and we can always enlarge these with Valsalva maneuver.
So here it looks like some hydrosalpinx, and we fill it in with color; it's definitely a vein. Here's a tangle of, uh, veins around an ovary. We always want to remember that if you—you always want to turn on color Doppler; it'll save you so many times. Here it looks like some, uh, tubular structure; you see here it's vascular. Here it looks like a hydrosalpinx, so you turn it on; it's just a, a large, uh, varix at the end. A few things, uh, in GI category that could be a whole separate lecture, but Crohn's disease and ulcerative colitis certainly can occur in the pelvis. We look for thickening of the bowel wall, uh, fat stranding around the, uh, the infiltrated fat, uh, loss of the multi-layered appearance, uh, and different, uh, uh, complications. We can see it from colitis—usually it's inflammatory. A flare of colitis; Crohn's colitis again; hyperemic, thick-walled, uh, loss of the normal layers. Here, as we see thickened walls, very, um, uh, lost their multi-layered appearance and vascular; that's seen with, um, ulcerative colitis; similar to Crohn's. Here is ulcerative colitis with—you can see destruction of the mucosa and the marked thickening of the walls.
So I'm—I thank you for your attention, and I do, uh, hope that you will consider using ultrasound first in women with pelvic pain for GYN, GI, GU causes, and don't forget about vascular and abdominal wall problems. Try to answer the clinical question, um, to spare the patient, uh, further testing and use ultrasound as a dynamic interactive modality to find the source of the patient's pain. Thank you very much for your attention.