Diagnostic ultrasound ( PDFDrive )

1848 PART V Pediatric Sonography
A
B
C
D
FIG. 53.27 Ileocolic Intussusception With Lead Point. (A) A small luid-illed structure within this intussusception (arrow) represents the
Meckel diverticulum found at surgery. (B) Intussusception with internal mass representing Burkitt lymphoma. (C) Another patient with intussusception
caused by a juvenile polyp. The mass is dificult to see within the intussusception (arrow). (D) Same patient as in (C). The polyp is easily visible
after the intussusception is reduced (arrows). (C and D courtesy of Clara Neira, MD.)
radiographs include those taken in the cross-table prone position.
Radiographically, the colon can erroneously appear to end in a
high position if the air column fails to progress to the end of
the colon because of impacted meconium. Imperforate anus in
the newborn can be assessed sonographically via a perineal
approach. he low type of imperforate anus passes through the
levator ani muscle complex and is managed with transperineal
anoplasty. Intermediate and high imperforate anus are supralevator
and are managed by initial diverting colostomy. Scanning with
a high-resolution transducer via a midsagittal transperineal
approach gives excellent detail of the wall of the distal rectal
pouch. Fistula location can also be detected in some sonographically
(Fig. 53.31). he study should not be performed in a crying
infant because the increased abdominal pressure moves the rectal
pouch closer to the perineal surface. Haber and colleagues used
a pouch-to-perineum distance of 15 mm with a sensitivity and
speciicity of 100% and 86% in separation of low from high and
intermediate imperforate anus and found that with lack of an
anocutaneous istula and rectal pouch–to–perineal distance of
greater than 15 mm, the diagnoses of intermediate or high
imperforate anus can be made. 83
INTESTINAL INFLAMMATORY
DISEASE
Ultrasound and magnetic resonance imaging (MRI) are being
used more oten to evaluate GI disorders in the pediatric patient,
with decreasing emphasis on CT because of associated exposure
to ionizing radiation. High-resolution linear array transducers
allow direct and detailed evaluation of the intestinal wall, showing
up to ive distinct layers in the wall of normal intestine. Lowerfrequency
transducers can be used to evaluate for mesenteric
edema or abscess collections. Intravenous microbubble ultrasound
contrast has added to the capability of ultrasound in assessment
of inlammatory conditions, especially in the assessment and
follow-up of therapy in Crohn disease. Wall thickening is
nonspeciic 86 and can be seen in a variety of inlammatory