Topic 9 - intro to paeds

Question 1

How might you make your room more welcoming for a paediatric examination?

Answer 1

have a sufficient level of light. A dark room is intimidating and will not reassure a small child
Try to have pictures, books and toys available
the use of a gel warmer
Take time to familiarise yourself with the patient and explain the exam to the parents
dont lie
be silly

Question 2

What are some equipment change you can make for paediatric patients?

Answer 2

• Reduce persistence to compensate for the more mobile child.
• Select high frequency probes to gain the highest possible resolution, especially since children do not require a great amount of penetration.
• A small footprint probe is often useful to image between ribs and to gain access to some areas.
• Use cine loop to overcome moving children.
• Connect a foot pedal to free up your other hand.
• Immobilise the babies with sand bags, or sponges.

Question 3

What should you do instead of breath holds for paeds?

Answer 3

ask the child to push their stomach out. This acts to move the abdominal structures inferiorly.

Question 4

You are just about to perform an abdomen ultrasound on a six-month old. Discuss patient and equipment preparation, and how you would approach the patient and the examination. How might you modify your technique if the patient is distressed?

Answer 4

• Direct explanations and discussion to parents. Four hour fast required, arrange booking time around feeding
• Use warm gel. Ensure the child is warm.
• If child is distressed allow parent to hold. Use toys, noises, objects to distract the child, asking parents to assist.
• Use a high frequency small footprint probe, either linear or small curved array.

• Optimise image and use cine loop throughout

Question 5

What is pyloric stenosis?

Answer 5

• HPS is a condition in which the passage of stomach contents is restricted from passing into the duodenum as a result of gastric outlet obstruction.
• The pylorus, the sphincter muscle connecting antrum to duodenum, allows the passage of chyme out of the stomach, then closes to prevent reflux.
• Obstruction occurs because the pyloric circular muscle hypertrophies, narrowing the pyloric canal.
• The pylorus muscle thickens and the pyloric canal elongates.
• It occurs in infants two to eight weeks of age (can occur up to five months

Question 6

What is the exam prep for pyloric stenosis?

Answer 6

• Patients should be fasted for two to three hours.
• The patient is positioned in an oblique position rotated onto the right side, to allow any fluid to distend the antrum whilst displacing any gas.

Question 7

Where will you find the pylorus?

Answer 7

• The pyloric canal will be visualised between the gallbladder and head of pancreas, anterior to the right kidney.

Question 8

What are some sonographic appearances of pyloric stenosis?

Answer 8

o the ‘doughnut’ sign, which is a transverse section through the pylorus
o and the ‘cervix’ sign in the longitudinal plane.
o the thickened muscle mass is seen as a hypoechoic layer just superficial to the more echogenic mucosal layer of the pyloric canal

Question 9

What measurements are indicative of pyloric stenosis?

Answer 9

o canal length > 16 mm

o muscle wall thickness > 3 mm/transverse

Question 10

What is a dynamic sign of pyloric stenosis?

Answer 10

delayed gastric emptying with little or no passage of fluid through the pylorus or even hyperperistalsis of the stomach

Question 11

What may lead the sonographer to achieve a false positive diagnosis of HPS

Answer 11

1 - using only one of the criteria designated for the diagnosis of HPS.
(In different states of muscular contraction the length and muscle wall thickness alter slightly. This can lead to the possibility of one measurement seeming larger than the given values. To reduce the possibility of this occurring the sonographer must use all information available to them, and ensure that both canal length and wall thickness is increased before HPS is diagnosed.)
2 - obtaining the measurements incorrectly

Question 12

How might HPS measurements be obtained incorrectly?

Answer 12

• Measurements are taken in the wrong plane (for example, an oblique measurement through the muscle wall may give the muscle an incorrect thickness).
• Measurement can be difficult if visualisation of the pylorus is impaired due to position. An overly distended stomach may result in a posterior orientation of the pylorus.
• Measurement can be difficult due to an anisotropic effect. The pyloric muscle can appear hyperechoic if the muscle fibres are 90 degrees to the beam. This makes visualisation of the pylorus difficult.
• Prostaglandin treatment results in mucosal thickening rather than muscle thickening.

Question 13

How can measurement pitfalls be overcome?

Answer 13

by altering the position of your probe to place the pylorus in a more suitable plane for measurement

Question 14

What is intussusception?

Answer 14

• the prolapse of one segment of bowel into another

Question 15

What are the clinical signs of intussusception?

Answer 15

• The child becomes weaker, lethargic and appears pale and listless (shock).
• More than half will pass blood and mucus in the stool.

Question 16

What is the ultrasound tecnique for intussusception?

Answer 16

• Commence scanning in the right lower quadrant and move in a clockwise direction around the abdomen tracing the large bowel gas pattern to the rectum
Then do scans from left to right and top to bottom
• If an intussusception mass is located, examine the mass in longitudinal and transverse planes
• If no intussusception is located, perform a full abdominal ultrasound as many of the symptoms for intussusception are non specific

Question 17

What are some ultrasound appearances of intussusception?

Answer 17

doughnut sign
target sign
sandwich/hamburger sign
•	lack of bowel peristalsis
•	no demonstration of movement or change
•	All of the exterior hypoechoic rings of the target are thicker than 0.6cm

Question 18

Describe the doughnut sign

Answer 18

o A cross sectional scan through the apex of the intussusception shows the “doughnut sign”.
o This appearance is created by a very thick hypoechoic rim, due to severe oedema of the entering and returning intussusceptum walls with resulting obliteration of the interfaces between them.
o The central echogenic focus represents the remaining lumen

Question 19

Describe target sign

Answer 19

o A cross sectional image of the more proximal portion of the intussuscepted bowel where the parietal oedema is less severe, demonstrates a target pattern composed of two concentric rings and an inner circular area.
o The outer ring and the inner circle are hypoechoic and represent respectively the returning and walls of the intussusceptum. They are separated by a hyperechoic ring representing the interfaces between these walls.

Question 20

Describe the sandwhich sign

Answer 20

aka pseudokidney
a longitudinal scan along the affected bowel should demonstrate alternating layers of hypoechoic and echogenic levels. The hypoechoic layers are thought to represent oedematous regions of the bowel wall, with the echogenic central region representing intussusceptum mucosa. Peristalsis should be minimal or absent, with no demonstration of movement or change of the sonographic target.

Question 21

List the names given to the receiving and prolaspsing segments of bowel.

Answer 21

The receiving segment is known as the intussuscipiens. The invaginating segment is known as the intussusceptum.

Question 22

List the differential diagnosis of the standard appearances of intersussception

Answer 22

inflammatory bowel disease;
enterocolitis
intramural haematoma
faeces
normal psoas muscle

Question 23

What is the ‘crescent in a doughnut’ sign?

Answer 23

The “crescent in a doughnut” sign is a specific appearance for diagnosis of intussusception. A cross section through the centre of the intussuscepted bowel demonstrates a central echogenic focus that has a crescent shape. This focus is mesenteric fat that has been pulled into the intussusception, and is best demonstrated at the base of the intussusceptum.

Question 24

What is the measurement used to define appendicitis?

Answer 24

• A normal appendix will compress and be less than 6 mm

* Abnormal will be enlarged and not compress

Question 25

What are some non specific sign of appenidicits?

Answer 25

• 6mm measurement Should be used alongside other findings in children with CF as mucoid material may dilate the lumen
• An appendicolith is highly reflective and casts a posterior acoustic shadow, yet are only seen in 50% of paediatric cases
• Increased colour Doppler flow within the appendiceal wall is a useful sonographic sign for confirmation of appendicitis with a specificity of 96%, but a low sensitivity of only 52% renders it a poor criterion
• Similarly, intraluminal air is not a reliable indicator of acute appendicitis as it is found in both normal and inflamed appendices

Question 26

What are some secondary sign of appendicitis?

Answer 26

• Echogenic mesenteric fat
o A useful method for determining if there is an increase in mesenteric echogenicity is to compare the contralateral side of the patient as a baseline.
• Free intra-peritoneal fluid in the RLQ
• presence of enlarged intraperitoneal lymph nodes
• Potential secondary signs of a perforated appendix are thickening of adjacent bowel wall and echogenic sludge in the urinary bladder

Question 27

What is a choledochal cyst?

Answer 27

• congenital dilatation of a segment of the biliary duct system
• the duct dilates and forms a cystic structure
• idiopathic

Question 28

What are the clinical features of a choledochal cyst?

Answer 28

• Clinical findings can include jaundice, abdominal pain and palpable mass
• clinically mimicking neonatal hepatitis and biliary atresia

Question 29

What are the three types of choledochal cyst?

Answer 29

• Type 1 – dilatation of CBD
• Type 2 – diverticulum of CBD
• Type 3 – choledochocele (dilatation of the bile duct in proximity to the duodenum)

Question 30

What does a choledochal cyst look like?

Answer 30

• a well-defined fluid filled anechoic structure
• separate from the gall bladder
• located within or near the porta
• may be associated intrahepatic biliary duct dilatation
• Nuclear medicine can confirm the diagnosis of choledochal cyst by demonstrating prompt uptake of a tracer by the liver and excretion into the cyst and bowel

Question 31

What is biliary atresia?

Answer 31

• the obliteration or absence of the extrahepatic and/or intrahepatic bile ducts.

Question 32

What is the clinical presentation of biliary atresia and why is it difficult?

Answer 32

• Patients will present with jaundice in the first three to four weeks of life.
• Clinical and laboratory findings are similar to and indistinguishable from neonatal hepatitis.

Question 33

How do you differentiate between neonatal hepatitis and biliary atresia on ultrasound?

Answer 33

• similar in both hepatitis and biliary atresia, with both conditions demonstrating normal to increased liver echogenicity, with biliary duct calibre often normal.
• The diagnostic differentiation using ultrasound is the appearance of the gallbladder and the triangular cord sign.

Question 34

How does the gallbladder appear in biliary atresia and neonatal hepatitis?

Answer 34

• In biliary atresia the gallbladder is small, irregular in appearance or not seen due to the interrupted flow of bile.
• If a large gallbladder is demonstrated the appearances suggest neonatal hepatitis.

Question 35

Describe the triangular cord appearance

Answer 35

• The echogenic fibrotic remnant of the CBD seen adjacent to the portal vein is called the triangular cord sign
• The triangular cord sign is reported to be a reliable diagnostic indicator for biliary atresia and is seen as a triangular region of echogenity immediately superior to the portal vein bifurcation.

Question 36

What are some pitfalls in examining the neonatal biliary tract?

Answer 36

• Fasting
• patient must be completely fasted for a minimum of four hours to ensure that the presence of a small or non visualised gall bladder is not due to normal physiological function.
• If biliary atresia is suspected then further imaging is required to confirm the diagnosis.

Question 37

What is neonatal hepatitis?

Answer 37

• infection of the liver occurring before the age of 3
• The causative agent (bacterium, virus, or parasite) reaches the liver through the placenta, via the vagina from infected maternal secretions
• or through catheters or blood transfusions.

Question 38

What is the ultrasound appearance of neonatal hepatitis?

Answer 38

• With the exception of diffuse hepatomegaly, there are no specific sonographic signs of hepatitis
• unless abscesses (usually bacterial in origin) occur
• gallbladder wall may be thickened, probably from hypoalbuminemia.
• Dystrophic calcifications in the hepatic parenchyma may be seen.

Question 39

What is the most common malignant primary liver tumour in a child?

Answer 39

Hepatoblastoma

Question 40

What is the most common benign primary liver tumour in a child

Answer 40

haemangioma

Question 41

What is the appearance of hamangiomas in children?

Answer 41

• vascular, mesenchymal masses
• may be focal (solitary), multifocal, or diffuse
• Hemangiomas in the liver are often associated with cutaneous hemangiomas as well

Question 42

How do hepatoblastoma appear on ultrasound?

Answer 42

• large, single and solid.
• heterogeneous with poorly defined margins.
• may contain small cysts and irregular calcium deposits.
• The mass will often displace and/or amputate the hepatic vessels.

Question 43

How does HCC appear in children?

Answer 43

second most common liver tumour
• The tumor is often multicentric; masses are solid, rarely calcify, and have variable echogenicity.
• Portal venous invasion is common and easily detected with Doppler sonography

Question 44

Describe the newborn uterus

Answer 44

prominent and thickened with a brightly echogenic endometrial lining caused by in utero hormonal stimulation
• In the first 3 days of life, mean length and mean volume of the uterus are 4.2 cm and 10.0 cm3
• The uterine configuration is spade shaped with a fundus-to-cervix ratio of 1 : 2.

Question 45

Describe the 3 -4 month old uterus

Answer 45

• At 2 to 3 months of age the prepubertal uterus regresses to a smaller size and flat configuration
• with a length of 2.5 to 3 cm and a fundus-to-cervix ratio of 1 : 1
• the endometrial stripe (when seen) appearing as thin as a pencil line.
• This tubular uterine configuration is maintained until puberty.

Question 46

Describe the post pubertal uterus

Answer 46

• The postpubertal uterine length gradually increases to 5 to 7 cm, and the fundus-to-cervix ratio becomes 3 : 1
• The echogenicity and thickness of the endometrial lining then vary according to the phase of the menstrual cycle, as in adult women.

Question 47

Where will you find the neonatal ovaries?

Answer 47

• Because of a typically long pedicle and a small pelvis, the neonatal ovaries may be found anywhere between the lower pole of the kidneys and the true pelvis

Question 48

What are the average sizes of ovaries throughout life?

Answer 48

• neonates and girls younger than 6 years is usually 1 mL or less
• premenarchal girls aged 6 to 11 years ranges from 1.2 to 2.5 mL
• mean ovarian volume of 9.8 mL and between 2.5 and 21.9 mL, in menstruating females

Question 49

What is hydrocolpos

Answer 49

distension of the vagina with serous fluid

Question 50

What is hydrometrocolpos?

Answer 50

distension of both the uterus and vagina with serous fluid

Question 51

What is hematocolpos?

Answer 51

vaginal distension with blood

Question 52

What is hematometrocolpos?

Answer 52

uterine and vaginal distension with blood

Question 53

What can cause vaginal obstruction?

Answer 53

• Vaginal obstruction can result due to an imperforate hymen, a vaginal septum, or vaginal stenosis or atresia.

Question 54

What is Mayer-Rokitansky-Kuster-Hauser syndrome?

Answer 54

results in multiple anomalies, which can include vaginal atresia, a rudimentary or absent uterus and vagina, duplicated uterus, unilateral or bilateral obstruction.
• The fallopian tubes, ovaries and broad ligaments remain unaffected.
• The most common sonographic findings are uterine didelphys with unilateral hydrometrocolpos and ipsilateral renal agenesis

Question 55

Say the M-R-K-H syndrome out loud

Answer 55

Mayer-Rokitansky-Kuster-Hauser

Question 56

What is the second most common cause of primary amenorrhea?

Answer 56

Mayer-Rokitansky-Kuster-Hauser

Question 57

What is precocious puberty?

Answer 57

The early onset of puberty

Question 58

What is the role of ultrasound in precocious puberty?

Answer 58

attempt to demonstrate pubertal changes to the ovaries and uterus.
• assessment is possible by understanding the normal size, shape and appearance of the uterus, for each age group, and being able to demonstrate a variance from the normal.
• Precocious puberty will result in the uterus and ovaries having a more pubertal appearance, with shape and size consistent with pubertal change.

Question 59

What can cause precocious puberty?

Answer 59

can often be the result of a tumour, most commonly in the ovaries, but it also has an association with adrenal tumours, and hepatoblastoma.

Question 60

If precocious puberty is suspected what should the ultrasound scan involve?

Answer 60

assessment of the renal areas and the liver as well as pelvis

Question 61

Describe the formation of uterine anomalies

Answer 61

The fused caudal ends of the two müllerian (paramesonephric) ducts form the uterus, cervix, and upper two-thirds of the vagina.
Fusion typically occurs in the medial portion of the ducts and proceeds in either a cephalad or a caudal direction or both.
The median septum formed by the medial walls of the müllerian ducts then resorbs, leaving a single uterine cavity.
Arrested development of the müllerian ducts, failure of fusion of the müllerian ducts, and/or failure of resorption of the median septum results in variable forms of müllerian duct anomalies (MDAs).

Question 62

What are the most common mullerian duct anomalies to have renal anomalies

Answer 62

uterus didelphys (often with renal agenesis ipsilateral to an obstructed horn)
unicornuate uterus (usually renal agenesis ipsilateral to the side of the absent or rudimentary horn).

Question 63

What are the most common mullerian duct anomalies?

Answer 63

• septate uterus
• bicornuate uterus
• unicornuate uterus
• uterine didelphys

Question 64

When are vaginal septa common and why are they important?

Answer 64

• may be transverse or longitudinal in orientation
• most commonly seen with uterus didelphys
• can occur with other MDAs.
• transverse septum may cause obstruction and result in hematocolpos or hematometrocolpos.

Question 65

What is important when imaging a suspected rudimentary horn of a unicornate uterus?

Answer 65

• important to determine if there is a rudimentary horn and if that rudimentary horn contains endometrium
• This will typically affect management of the patient
• Hydrometra in the rudimentary horn may be mistaken for a uterine or adnexal mass

Question 66

A 14-year-old girl presents with increasing right-sided pain, especially during her periods. Menarche occurred at 12 and she has regular periods. Clinical examination shows a right sided mass. A renal ultrasound has revealed an absent right kidney. Describe your thought process. What are your anticipated ultrasound findings?

Answer 66

An absent kidney always means that there is the possibility of a congenital abnormality of the uterus.
The clinical scenario of normal periods, but increasing pain during the periods and a right-sided mass, raises the suspicion of a unicornuate uterus with a non-communicating rudimentary horn.
You expect to find a hematometra. This will be your most obvious finding but next to the hematometra, there is another uterus with a normal endometrium.
This is not the most common congenital abnormality but it is a clinically significant one because of its associated problems.

Question 67

In cases of suspected hepatic haematoma what are 3 important questions to answer?

Answer 67

1. Is this a hepatic contusion or is it a right subphrenic collection.
2. The second question is whether there is any damage to adjacent structures or and hepatic/portal thromboisis.
3. exclude a traumatic false aneurysm. This could be done with colour flow imaging. Spectral waveforms in the portal and hepatic venous systems would be essential.

Question 68

What are the typical clinical signs of pyloric stenosis?

Answer 68

projectile vomiting, poor weight gain and dehydration.

Question 69

What ultrasound criteria should we use to diagnose a pyloric stenosis?

Answer 69

canal length > 16mm
pylorus muscle wall thickness >3mm in transverse.
This is because in pyloric stenosis, the pylorus muscle thickens and the canal will elongate.
Signs to look out for are the donut sign in transverse through the pylorus and the cervix sign in the longitudinal plane
Other sonographic evidence includes delayed gastric emptying with little or no passage of fluid through the pylorus or hypereperistalsis in the stomach.

Question 70

What are some potential pitfalls when assessing the pylorus?

Answer 70

• Pseudothickening from off-axis planes in both transverse and longitudinal can make the muscle appear more thick than normal.
  Remedy - fan through to determine if you are in the true trans or longitudinal plane
• inadequate distension of the gastric antrum keeps it contracted which makes the muscle layer falsely thickened (similar to the bladder wall).
  Remedy - administer oral fluids to distend or a RPO position promotes fluid to collect at and distend the antrum.
• Mistaking the pylorus for any other GIT structure (i.e. oesophagus).
  Remedy - ensuring the image plane includes landmarks such as the gallbladder and/or pancreatic head within view.