 the essentials of pediatric ultrasound. We're going to look now, going back to acute problems in the scrotum, discuss the ultrasound features of torsion, which is what we're always concerned with, but then look at other features and findings of acute scrotal diseases. So the acute scrotum is defined as acute swelling, scrotal swelling and pain, and it's one of the common presentations to the emergency department or a clinical practice. Ultrasound is still the study of choice. We examine the patient's supine to elevate the scrotum, high-resolution transducer, small-part setting, warm gel, grayscale and Doppler images, and sagittal transfers. Normal, pretty straightforward, ovoid shape, uniform, low to midline level echoes, and you see this linear echogenic mediastinum which contains fibers, tissue, and it supports the tubes and vessels that cross the testers. Occasionally you're going to see a hypochloric band. That's not abnormal, okay? That's not a fracture. Put color on it, because sometimes you can actually see the trans-testicular vessels on grayscale. Also, look for the epididymis. You'll see the head, that's easy, just on top of the testus. It's isochoric to the testus, but you can scan from the head around the testus and see the body and the tail. Testicular vascular anatomy. And this is the key point of doing Doppler and making diagnosis of torsion. The testicular artery comes out of the aorta. The primary blood supply for the testus, and it gives rise to capsular arteries and centripetal arteries. These are the ones that go into the testes. These are the ones you want to see. There are cremasteric and deferential arteries that supply the epididymis and peritasticular tissues, but when we do ultrasound and Doppler of the testus, we want to look at the branches off the aorta. We want to look at the centripetal arteries. So this is a capsular vessel. These are intertesticular vessels, the centripetal arteries, and they can cross from one side to the other. You'll see these vessels in all pubertal testes. Here we are again. In the pre-puberal testes, you may not always see them. Sensitivity of color Doppler. You'll see them maybe up to 83% of the time. If you use power Doppler, you'll see them a little bit more. What do we do in the pre-puberal testes if there is pain? If we can't see color, then all we can do is compare the two sides for ecogenicity and size. That's as good as it gets. Resistive index, the pubertal testes has higher diastolic flow peaks than the pre-puberal testes. The resistive index differs. Pre-puberal, it's higher because there's lower diastolic flow. Puberal, about 0.57 or 6. The key point about Doppler, testicular flow is only reliably shown by placing the Doppler cursor in the center of the testes. You want to see flow in these vessels. You don't want to see it in the periphery or only in the periphery. You have to document it in the center. Common diagnosis, torsion. They're two types, intravaginal, extravaginal, appendicell, torsion, epidetamitis. Less common, vasculitis, aopathic, squirtal, edema trauma. Intravaginal torsion. This is the one you're familiar with. It occurs in pubertal voids 12 to 18 years of age. It's called intravaginal because it occurs within the tunicop. The tunica covers the testes and part of the cord here. And the cause is failure of fusion of the tunica to the testes which doesn't completely close so the testes can twist. Patients present with acute scrotal pain and swelling may have nausea and vomiting. It's an emergency because rapid diagnosis is needed. If you make the diagnosis in first six hours, you get a 100% salvage rate. 6 to 12 hours, 70%, 12 to 24 hours, 20%. 24 hours, it's too light. That's what you get. Hemorrhagic and pharctotestas. Ecogenicity is not reliable alone for the early, early diagnosis. At four hours, it's normal. Four to six, maybe hyper or hyperocolor. 24 hours, you're going to make the diagnosis. It's heterogeneous and then it's too light. Okay? Sensitivity of grayscale for an abnormality, only about 80%. That's why we use color, which we'll get into in a minute. Two hours, the left testicular pain. Right, left. Yeah, you see the midastinum right testis here? It's normal. This was torsion, by the way. Early torsion is shown on the Doppler, which I'll show you. But on grayscale, it's normal. If you wait longer and you have a two-day history of testicular pain, this is what you're seeing. You're going to make the diagnosis. It's torsion, but it's too light. It's not salvageable. Other findings on the grayscale, you can see a large epididymis. Okay? Here it is. Here's the testis, which is enlarged. That's nonspecific because epididymitis can cause that as well. It's just a finding. It doesn't help you in the diagnosis. You can see a redundant spermatic cord. That's useful. Okay? The cord's twisted. And you can see the whirlpool sign. We've seen a lot of whirlpool signs. Here's a whirlpool sign. Mass. This is the cord. This is the cord twisted. Okay? If you see that, that's torsion. That's the grayscale finding. And here it is. That's the cord. It's twisted. Okay? Use Doppler. That's how you're going to make your diagnosis. It's essential. An early torsion on the testis looks normal. You can see absent flow. This is the case I showed you. Okay? Right? Normal is no flow on the left. That's early torsion. Venus flow will disappear before arterial. When there's late torsion, you're going to see a lot of flow in the soft tissues. Nothing in the testis. So early torsion, another one. Right. Left. The left testis is large, right? Compared to the right? Normal flow. No flow. That's torsion. This is late torsion. Very enlarged, heterogeneous. Test is two different patients. Peripheral flow. Because now the cremasteric vessels and the deferential arteries are taken over and you see flow in the soft tissues. There's no testicular flow. That means when you're really concerned about torsion, you've got to document flow in the center. If you see in the periphery, it does not equal testicular perfusion. Look at the cord. Here's another twisted cord. Okay? If you put color on, you may see flow in the cord because the twist is just below the cord here. Or maybe involving part of the cords so the blood can't drain and it gets engorged. And here's our whirlpool again. And on color, you see something that almost looks like the intersception I showed you, the whirlpool sign. Okay. Pitfalls. Well, I showed you that normal flow is reduced in the pre-puberty testis, and all you can do is compare the two sides. Partial torsion, the twist is less than 360 degrees. It can lead to an air and diagnosis. Intermittent torsion, you're not going to make a diagnosis. It's going to be difficult. Detorsion can lead to some confusion. So this is partial torsion, less than 360 degrees. Patient has left side of pain, so this is the right. You see the normal vessels, right? And you see great flow. This is the left. Flows decrease, but look at the Doppler, the pulse Doppler. There's decreased diastolic flow. There's reverse flow, and there's high resistance, okay? There's no diastolic flow. That's partial torsion, maybe early torsion, whatever word you want to use. This was not completely twisted surgery, but it was torsion. Chronic intermittent torsion, I'm not sure how to make this diagnosis, because if it's intermittent, the torsion testis can look normal, and this patient look normal. Came back, had intermittent pain. Came back once more, looked normal, and six months later, that's what it looked like. Here's another finding of intermittent torsion, astridotestis. You get these hypoacholic areas, which radiate towards the mediastion, and they probably represent atrophy and fibrosis, but it's associated with intermittent torsion. Finally, torsion and manual detorsion, which is what they try to do. So you get a reactive hyperemia. So this normal, no-flow torsion, late detorsion, you get incredible, incredible flow. I mean, it looks like epididymorokitis, but the history is going to give you the clue. You knew it was a torsion, so this is just a detorsion. Extravaginal torsion, that's the lesion of the neonate. That occurs in utero. This is the one I showed you intravaginal, where everything twists here. And the neonate, it twists just at the lower part of the cord. Okay? I mean, the findings are going to be the same, but there's a different mechanism supposedly. So the neonate, you diagnose it at birth, there's a swollen red scrotum. It's in utero, and testis can't be salvaged. So swollen red scrotum, neonate at birth. Testis is necrotic, right? Flow only in the soft tissues. That's in utero torsion. Another one, swollen red scrotum. Necrotic testis with incredible flow. Essentially, it's a late torsion, similar to what we see in the adolescent. Okay? Second cause of pain, torsion of an appendage. Memex testicular torsion. This one, though, sort of likes pre-pubertole boys, where torsion is more often in pre-pubertole rather than pre-pubertole boys, but it can affect both ages. And there's a tender scrotal nodule on examination, which has a bluish discoloration called the blue doubt sign. The treatment is conservative. Give them something for pain and leave it alone. There are a number of testicular appendages. These are a little remnants of embryonic ducts. There is the appendix testis on the medial side. Then there's the appendix epididymis and the appendix fast. The one that undergoes torsion most often is this one, this one may, this one I have not seen. And that's... These don't go to surgery, but I have some pathologic cases, occasional in. This is what it looks like. So, on ultrasound, you see a third mass, an extratisticular mass. Here's the testis, here's the epididymis, and now you have this, which is hyper or isocoic to the testis, usually more than 10 millimeters in length. Often the epididymal head gets enlarged, it's reactive, you see a reactive hydrosil, and the squirrel skin may be thickened. That's the diagnosis. Here's another one. The epididymis is enlarged. Here's the appendix, which is enlarged and ecogenic. Testis is normal. You got the normal vessels, you got a lot of flow in the soft tissues, and the appendix, which is tourist is a vascular. And one more. Acute pain. The testis, squirrel skin, thickening, and the appendix is ecogenic and enlarged. Lots of flow in the soft tissue, normal flow in the testis, and nothing in the tourist appendix. What's the pitfall? There's always pitfalls, right? Occasionally you're going to see the normal appendix, not tourist, just normal. It's oval-shaped, and it's really, really small, less than 5 millimeters, whereas the tourist ones are bigger than 10 millimeters, and you've got all the associated findings. And usually you'll see this occasionally if you have a large hydrosil. What happens to these? You leave them alone, they may just involute, but sometimes they infarct and auto-amputate and become those scrotoliths, calcifications that we see. So, acute scrotum, there is a differential. They're clues. I think they're clues to everything. We have to recognize part of it based on patient age, part, clinical features, and part color Doppler. So, thank you for your attention.