Diagnostic ultrasound ( PDFDrive )

CHAPTER 53 The Pediatric Gastrointestinal Tract 1847
A
B
C
D
FIG. 53.26 Ileocolic Intussusception. (A) Linear transducers clearly show the concentric rings of the edematous intussusceptum (black arrows)
with echogenic fat, mesenteric lymph nodes (white arrow), and a small amount of luid trapped in the center. (B) Intussusception, showing concentric
rings of bowel within bowel. (C) Longitudinal image of intussusception. (D) In another patient, transverse ultrasound shows ileocolic intussusception
with multiple lymph nodes that have been drawn into the intussusception.
substantial bowel ischemia and who may be at greater risk of
perforation during attempted nonsurgical reduction 79,80 (Fig.
53.29). Although such indings may portend more diicult enema
reduction or increased risk of perforation, none are considered
contraindications to nonsurgical reduction procedures.
COLON
Normal Anatomy and Technique
Sonographic evaluation of the colon can be compromised by
the gas and excessive fecal material. However, in most patients
the characteristic haustral markings in the multilayered wall of
the ascending colon can easily be identiied (Fig. 53.30). When
pathologic wall thickening occurs, ultrasound can be used to
assess degree and distribution of wall thickening of the ascending
and descending colon and rectum, whereas the transverse colon
can be more diicult to assess because of bowel gas. Patterns of
inlammation and mural stratiication have been described to
assist in the diagnosis of colitis, with pseudomembranous colitis
easy to diagnose based on its typical pancolonic distribution 81
(Fig. 53.30B). Some authors advocate graded compression for
sonographic evaluation of colonic polyps, although this can be
challenging. 82
Ectopic or Imperforate Anus
Sonography in the neonate can also be used to study imperforate
or ectopic anus. 83-85 In patients with ectopic or imperforate anus,
it is important to determine where the distal end of the hindgut
terminates. Well-known pitfalls in attempting this with plain