On behalf of the RSNA Educational Committee and our track chair, Dr. Diane Strollo, we welcome you to the Essentials of Pediatric Imaging course, number MSCS44. We have four excellent speakers and topics in this course, as you can see here. My name is Edward Lee from Boston Children's Hospital, and I'll be presenting Pediatric Chest Essentials. As we all know, pediatric chest disorders occur in a diverse clinical spectrum, and early and accurate diagnosis is important in order to decrease morbidity and mortality and also improve overall pediatric patient care. And imaging studies play an essential role. Pediatric chest imaging is such a broad topic, so in this presentation with limited time, I'm going to focus on five important topics that all radiologists need to have clear understanding, including CPAM with new classification system, pleural pulmonary blastoma with underlying DICER1 gene mutation and associated tumors, classic cyanogen radiology for pediatric upper airway infections. Top three diagnoses for pediatric large airway neoplasms. And for mediastinum, I will discuss BRAD4 Nusselt carcinoma, which is relatively new mediastinal tumor that is unique to pediatric population. Let's start with CPAM, or previously known as a CCAM, which is a congenital lung malformation. CPAM is a disorganized hematous malformation of the lung communicating with adjacent bronchial tree, usually unilateral, involving one lobe, and they do have normal pulmonary artery supply. Classification of CCAM or CPAM used to be based on Stocker classification, as you can see here. Type 1 is a large cyst, and each individual cyst greater than 2 centimeter. And type 2 is a multiple cyst, less than 2 centimeter in size. And type 3 is very special one, because all of the imaging studies, it appears as a solid lesion, but under the high power microscope, there are multiple tiny cysts, as you can see here, because of that, is a part of congenital lung malformation. Relatively recently, now we have upgraded classification system for CPAM, which is based on the location and or stage of development of the abnormality. Keeping three previous types, type 1, 2, and 3, now we have two new types. Type 0 is a rareless form, malformed small and firm lungs incompatible with life. And type 4 is characterized by large airfield cyst with often associated mediastina shift and localized within the periphery of one lobe. And here, now we have five different types of CPAM. Type 0, firm and small lung, which is incompatible with life, and type 1, large cyst greater than 2 centimeter, and type 2, multiple cysts smaller than 2 centimeter in size, and type 3 is solid appearing mildly enhancing lesion, but under the high power microscope, there are multiple tiny cysts. And type 4, as you can see here, large cysts located in the peripheral portion of the lung often associated with mediastina shift to the contralateral side. That leads us to the next topic, which is pleuroformyblastoma. As you can see here, on imaging studies, it appears very similar to CPAM, however, pleuroformyblastoma is a primary lung neoplasm that only occur in pediatric population. It is rare primary neoplasm of early childhood. It can arise in the lung or visceral pleura. It has three main types, as you can see here. Type 1 is pure cystic type, looks just like CPAM on imaging studies. Type 2 is a combination or mixture of solid and cystic components. And type 3 is pure solid enhancing neoplasm. Although it is difficult to differentiate cystic type 1 and mixed type 2 pleuroformyblastoma from CPAM, which is a congenital lung malformation, there are four helpful clues. Pleuroformyblastoma tends to be multifocal lesions with solid nodular component associated with spontaneous pneumothorax and has family history. The current manager of the choice is surgical resection. And now we have recognized that underlying mutations of DICE1 gene leading to oncogenesis and eventually pleuroformyblastoma. In pediatric patient with DICE1 gene mutations, we should look for other associated tumors frequently developing, including small bowel polyps, as you can see here on this slide, leading to interception, endocrine tumors, cystic renal tumors, and ovarian circularly related cell tumor. Now we're going to move on to our next topic, large airway disease in children. For infection, classic signs and radiology, and for neoplasm, top three diagnosis. Top three diagnosis of pediatric upper large airway infection are viral croup, bacterial croup, and epiglottitis. And as you can see here, patient with viral croup typically presents with barking cough, mild fever, and shortness of breath. In contrast, bacterial croup, patient typically presents with high-grade fever, elevated Y plus Z count, and also shortness of breath. And sore throat, drooling, and high-grade fever are common in pediatric patient with epiglottitis. These three pediatric upper large airway infections are known for classic radiological signs, as you can see here. The subglottic airway narrowing in viral croup appears similar to church stipple, leading to stipple sign. The irregular narrowing of bacterial croup appears similar to candle dripping, leading to candle dripping sign. And enlarged epiglottis in epiglottitis appears similar to thumb, leading to thumb sign. Now we're going to review top three diagnosis for the primary pediatric large airway neoplasms. Enhancing mass in the subglottic airway in infants is usually due to subglottic hemangioma. Large airway intraluminal lesion with long nodules that are often cavitated is due to recurrent respiratory papillomatosis. The most common primary malignant large airway neoplasm in children is carcinoid tumor. For the last topic that we will review today is a breath-forward NUT carcinoma, which is a relatively new mediastinal tumor that is unique to pediatric population, and it occurs typically in the middle mediastinum. Breath-forward NUT carcinoma of the mediastinum is highly aggressive and lethal tumor characterized by balanced chromosomal translocation. It frequently occurs in children and young adult in or near midline structure such as head, neck, or mediastinum. And definitive diagnosis requires karyotype analysis. Before I end my presentation today, I'd like to leave you with a couple of key points. It is important to know new CPAM classification system, now we have five different types. Also, primary lung neoplasms such as pleural pulmonary blastoma, which is due to underlying disol-1 genetic mutation, leading to associated other tumors. And for classic signs in radiology, for viral group, stipple sign, bacterial group, candle dripping sign, and apiculatitis, thumb sign. And for top three pediatric large array primary neoplasms include hemangioma, papilloma, and carcinoid tumor. And unique to pediatric and young adult population, it occurs in the middle mediastinum. It is primary breath-forward NUT carcinoma. Thank you very much for your attention. I'm delighted to introduce our next speaker, Dr. Tracy Kilbon, who will be presenting Pediatric Abdominal Essentials. Thank you. I have no disclosures. Normal bowel gas is evenly distributed throughout the pediatric abdomen with multiple cube-shaped loops. Tubes imply ileosobstruction with loop separation suggesting intra-abdominal fluid and or bowel wall thickening. And in all abdominal x-rays, we should evaluate for gases, masses, stones, and bones. We will start with neonatal essentials, specifically the difference between high and low obstruction. The most proximal obstruction is esophageal atresia caused by inappropriate foregut division. Lack of continuity causes an absence of gas within the abdomen. And the position of the dilated proximal pouch can be identified from the nasogastric tube. If there is gas in the GI tracts distal to the esophagus, this implies a tracheoesophageal fistula. This is more common than the isolated atresia. The radiograph should also be scrutinized for bacterial associations, as in this case, with vertebral and rib anomalies, cardiomegaly, and distal obstruction from an anorectal malformation. Gas-filled loops can be used to predict the level of obstruction with a single bubble indicating gastric or pyloric atresia. This is a rare condition due to developmental arrest and is associated with epidermolysis bullosa. The double bubble of duodenal atresia with no distal gas is due to failure of canalization. A proportion of patients will have some distal gas, and in these cases, one should consider an anomalous bile duct. Remember also that 30% of the patients have trisomy 21 that can be suspected in the setting of 11 paired ribs and cardiomegaly. Duodenal atresia is also associated with other atresias, situs abnormalities, and malrotation. Incomplete duodenal obstruction has several causes and may present with bile stain vomiting. The plain film can be nonspecific or show high-grade obstruction, and therefore an upper GI contrast study is required to define the position of the duodenal jejunal flexure, which should be at the height of the pylorus and to the left of the left pedicle. Let's consider two examples. In this duodenal web, the DJ flexure is appropriately positioned to the left of the left pedicle. Contrast that with this patient in which failed intestinal rotation has caused a low DJ flexure and the short mesenteric root has predisposed to the corkscrew appearance of a volvulus, which is a surgical emergency. The triple bubble of jejunal atresia will present early. This is usually due to a vascular accident, and the presence of calcification implies in utero perforation and meconium peritonitis. The plain film is characteristic and therefore there is no need for an upper GI examination. Some surgeons will require an enema to look for associated colonic atresia that is difficult to see at surgery due to the retroperitoneal position of the colon. Distal obstruction will present later, with failure or difficulty in passing meconium and marked abdominal distension, with the plain film showing multiple distended tubular loops. Once the presence of a normal anus is confirmed, a contrast enema is required to define the etiology. Let's look at the examples. Hirschsprung's is a functional obstruction due to a ganglionic bowel. The enema shows reversal of the rectosigmoid ratio, a sawtooth appearance of abnormal bowel, and a transition point that can be confirmed with biopsy. Functional immaturity, often in infants of diabetic mothers, will show a meconium plaque within a small left colon. Meconium ileus has a high association with cystic fibrosis. Look for the distal ileum that is impacted with meconium, and if the obstruction is severe they may also have a micro colon, which can also be seen in ileal atresia. And finally, let's look at another cause of distension that is usually a very different clinical scenario. Necrotizing enterocolitis is a common GI emergency in preterm and low birth weight neonates. Clues on the plain film, as well as the clinical history, would be tubular bowel loops, Pneumatosis, as evidenced by linear and bubbly gas within the bowel wall, and portal venous gas, both of which can be elegantly shown on ultrasound. A common complication is perforation, which can be difficult to diagnose in the supine neonate. Look for the tubular bowel loops, followed by lucency overlying the liver, and air outlining the falciform ligament. We're now going to move on to essential imaging in the infant and older child. Pneumatic pyloric stenosis classically presents with projectile vomiting and failure to gain weight in a male infant under two months of age. Although an abdominal x-ray may show a distended stomach, the condition should be diagnosed with ultrasound using a linear probe to document the channel length, the thickness of the muscularis, and the failure of the channel to open with a normal feed. The commonest causes of obstruction are appendicitis, interception, and incarcerated hernia. We have already dealt with malrotation. So let's look at some imaging clues. Clues to the presence of appendicitis are a focal ileus, or more diffusely tubular dilated loops in the setting of subacute obstruction. Look at the bones for a scoliosis due to splinting. Look for the stone of an appendicolith, and for an associated inflammatory mass. Imaging using graded compression is highly sensitive and specific for both diagnosis and for identifying complications. In this case, we can see a tubular fluid-filled appendix with an appendicolith. CT should be reserved for complicated or indeterminate cases. Colicky abdominal pain and bloody stools suggest interception. Plain film can show dilated tubular bowel loops, depending on the degree of obstruction, and may show a soft tissue mass. However, ultrasound is the investigation of choice, showing the interception as a donut or Swiss roll in the transverse plane, and as a pseudo kidney in the longitudinal plane. In the absence of a contraindication such as pneumoperitoneum, the patients will proceed to image-guided reduction. A hernia is usually diagnosed clinically, but if not, can be suspected by the presence of small bowel obstruction and multiple tubular loops, and increased soft tissue over the inguinal region. If there is still doubt, this can be confirmed with ultrasound, as in this case, showing a thick-walled bowel loop within the scrotal sac. Finally, we're going to look at neoplastic and inflammatory infectious masses. Let's look at the two commonest causes of intra-abdominal malignancy. Neuroblastoma is seen in a younger age group. It's suprarenal or paravertebral. It encases the vessel, lifting the aorta off the vertebral body, and crosses the midline. And another clue is that 90% are calcified. Compare this with neproblastoma or Wilm's tremor that is seen in a slightly older age group. It's renal, with a claw sign of normal kidney surrounding the tumor, displaces vessels, and is only calcified in 10%. The next three conditions all commonly present as abdominal masses in the developing world. This 12-year-old presented with massive hepatomegaly. Ultrasound revealed multiple liver cysts. The cysts had typical three-layer walls and some central echogenic hidatid sand. Due to the propensity of these cysts to rupture and the number, the patient was put onto antihelminthics. Two months later, one can appreciate separation of the membranes. And at six months, the cyst had assumed a solid configuration and was then removed. These are the accidental intermediate hosts. And as the disease can be disseminated, the rest of the abdomen should be screened, along with the chest and the brain if there are any neurological symptoms. These two patients presented with a palpable abdominal mass and features of obstruction, with plain films showing multiple tubular loops. Note the whirled appearance in both flanks. This is as a result of air outlining multiple Ascaris lumbricoides worms that have caused a worm bolus obstruction. Humans ingest infected material, and the larvae develop in the small bowel into adult worms. In a large infestation, this can cause a bolus obstruction as in these patients, and can also be complicated by volvulus or interception. The worms can be seen on ultrasound as a tubular structure with well-defined echogenic walls, and during real-time evaluation, they can be seen moving within the bowel content. Also important is to screen the liver, as female worms have a propensity to explore and enter the biliary system through the ampullae of vata, causing biliary obstruction and cholangitis. This four-year-old presented with growth failure and abdominal distention with an abdominal X-ray, which showed an apparent abdominal mass, and slightly dilated small bowel loops displaced into the left upper quadrant. Ultrasound did not show a mass, but showed multiple hypoechoic lesions in the liver and spleen, innumerable lymph nodes, some with central necrosis, and small volume ascites. Because of ongoing obstructive symptoms, the patient had a follow-through, which showed an irregular, narrowed terminal ileum and cecum. These findings are characteristic of tuberculosis of the abdomen, seen in patients with disseminated TB, but should be correlated with the skin test and chest X-ray. Although not commonly performed, MRI can show the classic appearance of multiple T2 hypo-intense lymph nodes and granulomas that are characteristic of caseous necrosis, and can aid in diagnosis, particularly in centers where TB is not common. In conclusion, the abdominal X-ray still forms a vital part of essential pediatric imaging. Look for cubes, not tubes, count neonatal bowel loops, and aim for a diagnosis in older children. If it looks weird, consider less common infections. Thank you for your attention, and it now gives me great pleasure to introduce our next speaker, Dr. Ricardo Restrepo. Hello, everyone. I have no disclosures. And on the first half of my talk, I'm going to concentrate on the approach to elbow radiograph in children after trauma. The first thing we should do is to evaluate the soft tissues and look for a joint diffusion. Soft tissue edema is a great clue to where the likely fracture or likely abnormality is. On this radiograph on the left side, there is severe medial soft tissue edema around the elbow. And that's a great clue that the fracture is probably on the medial side, and sure enough, there is an abortion fracture of the medial epicondyle. The posterior and anterior fat pads, great indicators that there is a likely fracture. The posterior fat pad is never normal. As you can see here, it's indicative of a hemarthrosis. The anterior fat pad, on the other hand, can be normally seen, but it should be very small. This particular case is not only prominent, but elevated, producing the cell sign, definitely abnormal, and there is a subtle supracondylar fracture of the humerus. We must remember that the radial neck, the media, and the lateral epicondyle are extra articulars, so fractures may not lead to a joint diffusion. The next step, confirm the joint alignment, and what better than the elbow lines. The anterior humeral line, here on the cartoon, is drawn along the anterior cortex of the distal humerus, and should intersect the capitellum at its anterior to mid-third, as you can see here. On the radiograph on the right, you can see that the anterior humeral line is not intersecting the capitellum, and there is a posterior fat pad indicative of a hemarthrosis, so this is a supracondylar humeral fracture. The next line is the radiocapitellar line, drawn along the mid-aspect of the proximal radius, and it should bisect the capitellum on the AP and lateral views, regardless of the obliquity. On the radiograph here on the right, we can see the radiocapitellar line is not intersecting the capitellum, because there is anterior radial head dislocation, and in addition, there is a fracture of the proximal diaphysis of the ulna. This is a motilla fracture dislocation. Okay, the next step, confirm the order of ossification center development. Most of us are probably familiar with the pneumonic criterion. This pneumonic is very important because it tells us the order in which the ossification centers develop, and it should be very strict, more than memorizing the age at which they ossify. The first one is the capitellum, as you can see there, with the letter C, followed by the radial head, then the internal epicondyle, then the trochlea, followed by the olecranon basin on the lateral view, and finally the external epicondyle. So let's remember that the first to ossify is the capitellum, but the last one to fuse is the medial epicondyle, and that's very important, especially close to skeletal maturity, because it can be confused with an abortion fracture. And the one that occasionally breaks the rule, the knotty radial head. As you can see on this example, the radial head is not ossified, but we already see the medial epicondyle. Then know the pediatric elbow fractures, from most common to least common. The most common by far, the supracondylar, approximately 50 to 70%. You can see a nice example here on the right, with posterior displacement of the distal fragment due to an extension injury. Second, the lateral condylar fracture. You can see the fracture line along the lateral condyle. This is a Salty Harris type 2, but sometimes can be a Salty Harris type 4, as it extends into the unossified trochlea. The radial neck, the olecranon fracture that sometimes can be subtle and picked up on the follow-up radiographs as areas of sclerosis. Then the medial epicondyle. Here you can see that there is significant soft tissue edema marked by the asterisks on the medial side, and there is an inferiorly displaced, a bulged medial epicondyle. Which takes me to the next fractures, which are concomitant fractures. Very frequently there are several fractures in the elbow, so be careful with satisfaction of search. In this particular case, there is also an olecranon fracture. And for the elbow, when in doubt, go for comparison. Great, great tool. And here you can see a normal variant is the radial neck notching. You can see it is a bilateral finding. So when you are in doubt, do a comparison view. The hip in a child with limping, my second half of the talk. I want to start with toxic or transient synovirus of the hip. It is the most common cause of a limp and acute pain in children less than 10 years of age. It is idiopathic, however, very frequently the child has a history of a recent upper respiratory infection. X-rays are non-diagnostic or non-specific, however, they are important to exclude all other pathology such a fracture. Ultrasound is a very good tool and we do it very often because if it's negative, it excludes toxic synovirus and also septic arthritis. Here the ultrasound of the normal right hip shows no infusion. On the left, there is a moderate size anechoic joint infusion with distention of the capsule. However, this does not exclude septic arthritis and you can see it is the differential diagnosis Here we have on the right, the sequela of a child with septic arthritis with complete destruction of the femoral head and the femoral neck, a disastrous complication. So that's the question, toxic synovitis versus septic arthritis. Both of them share the same clinical presentation with an acute onset, fever, limping, pain and elevated inflammatory markers. There is this article in which it was found that a CRP more than 20 and weight-bearing status of the patient are the only independent determinants to differentiate septic arthritis from toxic synovitis. If none of them are present, there is a less than 1% possibility of being a septic arthritis. However, when both are present, the possibility of septic arthritis is around 74%. But remember, when in doubt, do an arthrosynthesis and ultrasound may help guide the puncture. We do not want to delay the diagnosis of a septic arthritis and that's why MRI is not routinely done. However, sometimes we end up doing it. And in an article published in Pediatric Radiology in 2006, they compared toxic synovitis versus septic arthritis on MRI and they found that with septic arthritis, there is usually bone marrow edema, also significant soft tissue inflammatory changes surrounding the hip and decreased head perfusion after contrast administration. On the other hand, toxic synovitis, you can see here, their left side is involved. There is no soft tissue edema. And another finding that they saw is that there is a very small joint effusion on the unaffected or contralateral hip. Moving into Perthes disease. It is the idiopathic vascular necrosis of the femoral head. The etiology is idiopathic, but probably multifactorial, much more common in boys than in girls with a ratio of 5 to 1. And it occurs between 2 and 14 years of age, but peaks around 4 to 8 years of age. X-rays are usually the first and the only imaging modality to diagnose Perthes disease. However, MRI is much more sensitive in the early diagnosis. So let's discuss the appearance of Perthes disease on radiograph. Because the disease is divided in four stages. Stage 1, condensation is the initial stage. You can see that the femoral head is smaller and sclerotic compared to the left one. Stage 2, resortive. You can see there is fragmentation. Also coxa plana, meaning the femoral head is flat and coxa magna. The femoral neck is wide compared to the left one. The third stage, reossification. There are signs of healing. There is less fragmentation and there is some remodeling of the femoral head. And the last one is the residual stage, is when it has healed and there is residual deformity that is according to the severity of the disease. Here we have the classic mushroom appearance of the femoral head. And finally, I'm going to talk about slipped capital femoral epiphysis. It is the most common hip disorder in adolescents. Most are idiopathic, however, obesity is certainly a strong risk factor. It's much more common in African-Americans than Hispanics and is least common in Caucasians. The symptoms, chronic hip or knee pain. In the acute type, the symptoms are usually less than three weeks of duration. On the other hand, when it's chronic, more than three weeks. So this tells us that a slipped capital femoral epiphysis or a SCIFI is not a Salty Harris type 1 fracture. The femoral head slips posteriorly first and then medially. Here on the left, we have a radiograph of both hips. Let's concentrate on the normal one here, right. You can see the very, very sharp margins of the femoral epiphysis. You can see the interlocking facial markings compared to the left one where there is widening and indistinctness of epiphysis and we don't see the interlocking facial markings. Also when we draw the line of Klein on the right, you can see it intersects the lateral aspect of the femoral head. However, on the abnormal left one, it is not. And remember that slipped capital femoral epiphysis can be bilateral. Like in this particular case, both of them are involved. It can be synchronous or metachronous. And that concludes my talk. And now it is my pleasure to introduce Dr. Manohar Manushroff who I know very well from the Hospital for Sick Children in Toronto. He's going to talk about pediatric head and neck topmost diagnosis. Thank you very much. Welcome to this part of the Pediatric Essentials. I'm Manohar Shroff and I'm going to speak to you on pediatric head and neck must know diagnosis. No disclosures from my side. Our objectives today are to review examples of some important categories from emergencies, vascular malformations, to branchial anomalies. Know that 80% of head and neck lesions in childhood are congenital or inflammatory. But we should not forget the occasional malignancy that we see. Let's start with emergencies. These are some classic images. The thumb printing of the epiglottis in epiglottitis in a young child. Note that putting this child supine might compromise the airway. The classic group appearance of hypopharyngeal distention and subclotic edema. This is the normal appearance of the laryngeal airway on the AP view and in group the shoulders are lost due to swelling. This is a very interesting case, classic one. Note the air bubbles or the gas in the retropharys due to a retropharyngeal abscess due to this fishbone. So this is a finding one should not miss. These are uncommon but important infections that we should know. Know the danger space infection, which occurs when a retropharyngeal abscess enters this red danger space, which is between the alar and the deep layers of the prevertebral or the deep cervical fascia. Ludwig's angina is this image in the center, which is submandibular space infection due to autoantigenic causes, which can rapidly compromise the airway, hence an emergency. Lemieux syndrome, which is jugular vein thrombophlebitis, which can cause septic abscesses in the lungs. When we follow infections as retropharyngeal abscesses or phlegmons with CT, important thing is to look at the size of the abscess. It may impact management. Also look for these very unusual and rare vascular complications like in this case, where there was a small blob of extra enhancement because of pseudoaneurysm. This is a more obvious large pseudoaneurysm, infected arterial pseudoaneurysm, very dangerous. This child presented with what appeared to be a minor pencil stab. Always look very carefully for vessel contour in the vicinity of any penetrating trauma. For example, this right CCA, the irregularity around it wasn't visible very nicely under the concave sternocleidomastoid until we did these reformations. Then you can see the pseudoaneurysm very well over here, and this needed urgent surgery. Our next cases are epithelial inclusion cysts. Types depend on cyst lining and include epidermoid, dermoid, and teratoma. Teratomas contain ecto, meso, and ectoderm. They can occur anywhere in the head and neck, but more commonly around the orbits, nose, and lower of the mouth. Let's talk about some normal embryology here. During normal development of the anterior neopore, a dural diverticulum comes out through the future foramen cecum in this area and touches the tip of the nose and then completely regresses. If there's any remnant of epithelial tissue and there's incomplete regression, you get sinuses, dermoids in this region. This is a three-year-old presented with meningitis, and I was actually on call that day doing this case. We saw a nice, small diffusion-restricted lesion which showed surrounding enhancement that was extending towards the foramen cecum. We went and examined the child to see a small punctum at the root of the nose, and I diagnosed this as possibly abscess secondary to dermal sinus. The CT scan done later showed the widened foramen cecum confirming the dermal sinus, and it was actually operated, but this was not an abscess. It turned out to be an epidermoid which had ruptured and caused a clinical meningitis. You can see the poly-white tumor and these ghost cells, classic for an epidermoid. Epithelial incursions also occur in the oral cavity, and when they do occur over here, you have to look for its relationship with the myelohyoid. If it is above the myelohyoid, an intraoral approach is considered for surgery. If it's below the myelohyoid, an external approach is considered for surgery. This is another classic case, a neonate presenting with a large neck mass. Two common differentials are a large teratoma or a large lymphatic malformation in atriazum 21. In this case, this was a teratoma. You can see the complex tissues, cystic and solid tissues on MR, and you can see that on CT in another patient, shows you calcifications and also within the mass, which was a teratoma. Let's come to some vascular lesions. For simplification, you can divide this into common vascular tumors like hemangiomas and vascular malformation like the high flow AVMs or AVFs, which are fairly rare, or the slow flow lymphatic and mixed venal lymphatic malformations, which we see somewhat more commonly. Infantile hemangioma is the most common head and neck tumor of infancy. It proliferates rapidly after birth, followed by a long involution. Often when it comes up to the skin, it has a strong red discoloration. This is a typical infantile hemangioma involving the cervicofacial area, the parotid gland. Intensely enhancing mass, as you can see over here, with flow voids. It has mild increased T2 signal with septation within it. And this was within two years where most of the hemangioma involuted with fatty replacement of the stroke. This is a newborn born with a right occipital congenital hemangioma, a very vascular tumor, as you can see on colored opera ultrasound, supplied by hypotrophic right occipital artery. Infantile versus congenital hemangiomas, the differences are infantile hemangiomas rapidly proliferate and then slowly involute. Most of them will be positive for GLUT1 on immunohistochemistry. Congenital hemangiomas can either involute quickly, the rapidly involuting congenital hemangioma, which are the partially involuting congenital hemangioma, the niche. And they're all GLUT1 negative, but have other associated mutations, like shown over here. Lymphatic malformations are due to obstruction or sequestration of the developing lymphatic system. Most are seen by two years, and when they occur at birth, they're related to plasmodium ones. Like in this case, the large neck mass, that's a lymphatic malformation, which had hemorrhage, and you can see the fluid levels within it. Most lymphatic malformations in older children are seen as cystic lesions on CT or on MR. They typically occur under the sternocleidomastoid muscle, or also can be seen anywhere else in the head and neck. This particular child, three-year-old, presented with acute right-sided proctosis, and you can see the cystic non-enhancing mass, with fluid levels due to hemorrhage in the right orbit. And this was a lymphatic malformation. Also note the tenting of the right globe, which means there's going to be risk for acute loss of vision. So we had to do an urgent canthostomy and then drain the fluid from this lymphatic malformation and put in some sclerosant. We had to do that several times, and the child is still doing well. The thalabrasum duct cyst is the most common congenital neck mass. The duct extends from the base of the tongue, going in very close relationship with the higher bone into the lower neck. It's seen as a well-defined cyst, inseparable from strap muscles. It's often due to hyperintense, but when infected, it will show a thick, enhancing rim. Know that papillary thyroid carcinoma, reported 1% in older people, is extremely rare in children. Let's come to brachial anomalies. The first brachial anomaly is very rare, and you will see cysts in the periparietal region or fistulas, like in this case, and they're often associated with other syndromes. The second brachial anomaly is the most common one, and it's 90% of all brachial anomalies. The cyst is the most common type. Occasionally, you will see fistulae from the palatine fossa to the anterior portion of the sternocleidomastoid muscle. Note that true congenital fistulae do not exist, and they're always secondary to infection or cyst. A common second brachial anomaly cyst will present as a cyst at the angle of the mandible. This is a CT and MR appearance, but when infected, it will show a thick rim enhancement and surrounding inflammation. This is an interesting case, not very common, but a classic sort of finding. If you have recurrent swelling of the left neck or infections of the left neck involving the superior thyroid, then a pharyngoscopy confirms the punctum of the tranquil pulse sinus, and this confirms as third brachial anomaly origin, and this can then be treated as such. These are originating from the thymopharyngeal duct tract, sinuses, or cysts which get repeatedly infected. This is a very important case. This was a very vascular lesion in the left orbit. You can see the color Doppler. So what was it? This was a rhabdomyosarcoma. This is not a hemangioma because hemangiomas don't occur at this age, 7-year-old, and they don't show diffusion restrictions. So don't forget about malignancies in the pediatric age group. Rhabdomyosarcomas are the most common sarcomas in children, and most of them are embryonal. If they are paraplegic in location, look hard for CNS involvement. So I will leave you with this last case of juvenile nasopharyngeal angiofibroma, a classic case of intensely enhancing tumor at the pterygopalata and forsa. Thank you so much for attending, and thank you so much for your participation.

Pediatric Imaging

Dr. Diane Strollo

CPAM

DICER1 gene mutations

Hirschsprung's disease

Elbow radiograph

Transient synovitis

Vascular anomalies