“Abdominal Radiographic Diagnosis in the Newborn” by George Taylor for OPENPediatrics
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“Abdominal Radiographic Diagnosis in the Newborn” by George Taylor for OPENPediatrics


Abdominal Radiographic Diagnosis in the Newborn,
by Dr. George Taylor. Today, we will be discussing an approach to
abdominal radiographic diagnosis in the newborn, using a very simple algorithm that was taught
to me by Dr. Rita Teele, a very important mentor of mine. And it uses the mnemonic bones, stones, gas,
and mass, to organize our visual approach. Let’s begin with bones. Are all of the expected bony structures present,
and are they normal? Here is a newborn with an abnormal abdominal
exam, and a normal pelvis for comparison. And we notice that there is widening of the
pubic symphysis in this baby compared to the normal radiograph on the right, because the
baby on the left has a bladder exstrophy. Here is another baby with abdominal distension
who has a non-specific pattern of distended bowel. But in this situation, the bony findings give
us a clue as to the diagnosis. We see multiple segmentation abnormalities
of the spine. And looking at the pelvis, we see an absence
of the sacrum in a baby who has the VACTERL anomaly and sacral agenesis. Next, we will be looking at stones, or any
abnormal calcification. We look for size, distribution, and location
of the calcifications, and the pattern. Here, we have a newborn with an abnormal prenatal
MRI, in which we see a collection of amorphous calcifications in the right flank, and spinal
curvature. An ultrasound shows us a calcified mass that
is anteriorly displacing a normal kidney and is separate from the adrenal. This baby has an extra-adrenal neuroblastoma. Another baby with a large left-sided abdominal
mass, where the radiograph shows a pattern of amorphous calcifications in the right flank. An ultrasound shows a mass with mixed cystic
and solid components. A CT was performed, showing displacement of
the right kidney inferolaterally by a large cystic and solid mass in the retroperitoneum. At biopsy, it was shown to be a retroperitoneal
teratoma. This baby has abdominal distension with multiple
dilated loops of bowel. And we notice a pattern of eggshell calcifications
in the peritoneum. This baby has calcified peritoneum related
to meconium peritonitis, or prenatal rupture of the bowel. Another baby with bilious vomiting shows us
a pattern of eggshell calcifications in the upper abdomen. But when we focus on the pelvis, we see a
large cluster of abnormal calcifications in the right hemiscrotum, due to meconium peritonitis
that has extended down into the right hemiscrotum by a patent processus vaginalis. Now, this baby, presenting with bilious vomiting,
has a very distended upper abdominal loop. But in the right flank, we notice a collection
of calcifications that looks like collapsed bowel. This is a baby who has ischemic bowel. And when ischemic bowel persists for several
weeks, it can become calcified and have this appearance. Next, let’s look at the gas. And this means both looking at bowel gas and
extraluminal gas. When we evaluate the bowel, we need to see
if there is focal or diffuse distension of the bowel. Is there abnormal distribution or location
or bowel? Are the patterns associated with a high or
a low intestinal obstruction? Is there pneumatosis? Or is there too little gas present? Extraluminal gas means both the presence of
pneumoperitoneum, as well as portal venous gas. Here, we have a six-week-old with bilious
vomiting, where the bowel gas pattern looks pretty normal, except for distension of the
stomach and mild distention of duodenum. An upper GI series is performed, showing malrotation
of the bowel with a corkscrew appearance of the jejunum, consistent with malrotation and
volvulus. This is a baby who is very sick and has a
fixed loop of bowel. And what that means is a dilated focal loop
of bowel that is unchanging over several hours to days. This represents a focal ileus, and often seen
with ischemic bowel in babies with necrotizing enterocolitis. Along those lines, we have a baby with abdominal
distention, a premature baby. And we see a mottled appearance of the bowel. Now, many times normal feces can have this
appearance, but when we see little bubbles of gas in the periphery of the bowel, it increases
the likelihood that this represents pneumatosis intestinalis. And here, a pathologic specimen shows us bubbles
of gas in the submucosa and serosa related to pneumatosis intestinalis. Another baby, who has very distended distal
bowel. And here, the findings are quite subtle. When I’m looking for pneumoperitoneum or pneumatosis,
I use a high contrast setting on our PACS system. And here, the finding is much more obvious. Baby has portal venous gas in the setting
of necrotizing enterocolitis. This newborn presents with temperature instability,
and the x-ray on the left side was performed when the baby was relatively stable. The x-ray on the right side shows us a smaller
heart and pulmonary edema, because the baby is in shock. Now, the reason for the shock is located below
the diaphragm. Here, we see a continuous line of gas in the
baby with necrotizing enterocolitis and perforation of the bowel. This finding is confirmed by a decubitus view
of the abdomen, showing the large amount of pneumoperitoneum. This two-month-old ex-premie with vomiting
shows us that we need to evaluate locations of gas that may not be in the abdomen. Here, we see a collection of gas that appears
to be above the diaphragm. Now, this baby has a hiatal hernia, but the
hiatal hernia contains some unusual contents. Not only is there a herniation of the fundus
of the stomach, there is also herniation of the transverse colon. We have two infants with bilious vomiting. And now, we start looking at the patterns
that are associated with high versus low intestinal obstruction. These two babies have a gasless distal abdomen,
and a markedly distended irregular contour of the stomach, with a dilated duodenal bubble. This is the classic appearance of a duodenal
atresia. We’ve seen this baby before, with a loop of
calcified bowel in the right flank, and a gasless distal abdomen with focal dilatation
of one proximal loop of bowel. By giving positive contrast, we see that there
is marked dilatation of the jejunum related to a child with jejunal atresia and a focal
ischemic loop of bowel in the right flank. Here is a baby that presents with abdominal
distension and failure to pass meconium for 36 hours. And we see a very distended loop of bowel
that appears to be colon, with a mottled appearance of the feces within. And if this is colon, then our differential
diagnosis going from the most distal cause of obstruction includes an imperforate anus
or Hirschsprung’s disease, colonic atresia or stenosis. But if it does not represent the colon, it
could represent very dilated distal small bowel as a result of ileal atresia or stenosis,
or meconium ileus, or multiple atresias. So in this situation, we did a water soluble
enema showing that, in fact, this very distended loop of bowel was not colon. In fact, it was dilated distal small bowel. We see that the caliber of the colon is very
small throughout. Baby has a microcolon. And we have reflux of contrast into the distal
ileum that contains multiple filling defects. This is the result of meconium ileus. So the key teaching point here is that it
is very difficult in the newborn to tell the difference between a distended colon and a
very distended small bowel. Here, we have two ex-premies with abdominal
distention that is quite intermittent. And we see a collection of gas in the left–
in the right hemiscrotum– sorry, left hemiscrotum on this child and contrast containing cecum
and appendix in the right hemiscrotum in a baby with inguinal hernia. These can obstruct and may cause a pattern
of distal small bowel obstruction. Here, we have a baby with a clinical diagnosis
of imperforate anus. We see that there are segmentation abnormalities
in the sacrum. And we notice that there is gas in the proximal
urethra. A prone cross-table lateral view of the abdomen
shows a distended rectum and distal colon and gas in the bladder. This confirms a diagnosis of a recto-urethral
fistula. Now, let’s shift our attention to an evaluation
of masses. And this, to us, means both the presence of
a mass and/or organomegaly. We need to see the location of the mass–
and it’s based on the vector of displacement of other normal structures– the size of the
mass, and the presence of calcification or fat. Here, we have an eight-week-old boy with fever,
failure to thrive, a left upper quadrant mass, and an unusually shaped skull. The radiograph shows us a very dilated, very
enlarged spleen that is confirmed by an ultrasound, and the plain film radiographs showing a very
dense-appearing set of bones with abnormal ends to the bones and no distinction between
the cortex and the medullary cavity, in this baby with osteopetrosis and splenomegaly related
to extramedularry hematopoiesis. Here, we have a newborn with a cough and an
incidental finding of a left paraspinal mass that is subtle on the chest x-ray but much
more obvious on the plain film, in a baby with neuroblastoma. Finally, we have a newborn with marked abdominal
distention and respiratory distress, where the abdomen is gasless except for a small
amount of gas in a centrally-placed stomach. There is hypoplasia of the lungs with elevation
of hemidiaphragms. An ultrasound shows us marked enlargement
of both kidneys with multiple tiny cysts throughout, consistent with a diagnosis of an autosomal
recessive polycystic kidney disease. So in summary, we have a pattern approach
that we can use for the evaluation of the newborn abdomen using the mnemonic bones,
stones, gas, mass. Thank you. Please help us improve the content by providing
us with some feedback.

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