Diagnostic ultrasound ( PDFDrive )

1844 PART V Pediatric Sonography
A
B
FIG. 53.20 Midgut Volvulus: Altered Relationship of Mesenteric Vessels. (A) Normal relationship of superior mesenteric artery (SMA) and
the superior mesenteric vein (SMV). GDA, Gastroduodenal artery. (B) Intestinal malrotation and midgut volvulus; the vein (V) lies to the left of the
artery (A).
A
B
FIG. 53.21 Duodenal Web. (A) Ultrasound shows a markedly dilated duodenum (D) illed with luid. Note the rounded coniguration at the
point of obstruction in the duodenum (white arrow) and the widely patent pylorus (black arrows). S, Stomach. (B) Contrast upper gastrointestinal
image shows similar indings, with the rounded end of the duodenum (white arrow). Black arrow, Pylorus.
Ultrasound for suspected intussusception is best performed
with a 5- to 10-MHz curved array or linear transducer. he
intussusception appears as an oval, hypoechoic mass with bright,
central echoes on longitudinal imaging (i.e., pseudokidney) and
a hypoechoic doughnut, or target coniguration with echogenic
central echoes. 62-64 he hypoechoic rim represents the edematous
walls of the loops of bowel comprising the intussusceptum, and
the central echogenicity represents compressed mesentery,
mucosa, and intestinal contents. Linear array transducers display
the intussusceptum with greater clarity, showing multiple layers
and concentric rings representing the bowel wall, mesentery,
and even lymph nodes that have been drawn into the intussusception
65,66 (Fig. 53.26D). In some cases, anechoic luid is also seen
trapped within the incompletely compressed head of the intussusception.
Rarely, the lead point of an intussusception can be
identiied within the intussusceptum (Fig. 53.27).
Once an intussusception has been documented by sonography,
the patient usually proceeds to nonsurgical reduction, unless
clinical or radiographic evidence of perforation is found. Currently,
air reduction is the most popular method of treatment,
although hydrostatic reduction using water-soluble contrast
remains a viable alternative. Ultrasound-guided hydrostatic
reduction is an alternative method that avoids the ionizing
radiation of standard luoroscopic examinations. 67-70 Sonography
can also be used to identify the ileo-ileal intussusception that
sometimes remains ater the successful hydrostatic reduction of