Diagnostic ultrasound ( PDFDrive )

CHAPTER 53 The Pediatric Gastrointestinal Tract 1851
conditions, including Crohn disease, 87,88 ulcerative colitis, 88
pseudomembranous colitis, 89,90 neutropenic colitis (typhlitis), 91
infectious colitis, 92-94 allergic colitis, 95 Kawasaki disease, 96 necrotizing
enterocolitis (NEC), 97 hemolytic uremic syndrome, 98 gratversus-host
disease, 99,100 glycogen storage disease type 1B, 101 and
chronic granulomatous disease of childhood.
Causes of Intestinal Wall Thickening
Inlammatory bowel disease (Crohn disease or regional
enteritis, ulcerative colitis)
Yersinia, Campylobacter ileocolitis
Colitis
Perforated appendicitis
Rotavirus
Cytomegalovirus (CMV) infection
Typhlitis
Chronic granulomatous disease
Eosinophilic enteritis
Hematoma (Henoch-Schönlein purpura, trauma)
Hemolytic uremic syndrome
Graft-versus-host disease
Intussusception
Lymphoma
Benign tumor
Tuberculosis (rare)
Celiac disease
Sonography can sometimes diferentiate mucosal from
transmural inlammation. If the inlammatory process involves
primarily the mucosa (e.g., ulcerative colitis, pseudomembranous
colitis, typhlitis), the inner echogenic mucosal layer becomes
thickened and sometimes nodular or irregular, but the outer
muscular layer of the wall remains thin (Fig. 53.32). When the
inlammation involves the entire intestinal wall (e.g., regional
enteritis), thickening of the entire wall is seen (Fig. 53.33). Color
Doppler sonography demonstrates increased blood low to the
thickened intestinal loops with most inlammatory bowel conditions,
with the submucosa containing the main vascular channels
102 (Fig. 53.34). Hypovascularity is more typical in hemolytic
uremic syndrome. 98 Normal bowel wall also shows little signal
with color or power Doppler imaging.
For elective procedures, patients should avoid eating solid
foods for 4 hours before the examination, but noncarbonated
liquids are encouraged to help displace bowel gas and
partially ill the urinary bladder to displace small bowel
from the pelvis. Compression techniques to displace bowel
gas are well established for the evaluation of the cecum and
appendix, ascending colon, descending colon, rectosigmoid
colon, and small bowel loops in the let upper quadrant and
right lower and let lower quadrants. Normal small bowel wall
thickness is less than 2.5 mm and less than 2 mm for large
bowel. 103 Wall thickness of greater than 3 mm is considered
abnormal for the colon. 104 Stratiication of wall layers is well
depicted in normal small and large bowel. Loss of stratiication
B
A
C
D
FIG. 53.32 Inlammatory Disease: Mucosal
Thickening. (A) Infectious gastroenteritis. Mild
mucosal thickening is present in luid-illed bowel
loops. A few enlarged lymph nodes are present
in the mesentery (arrows). (B) Pseudomembranous
colitis. Marked colonic mucosal thickening.
(C) Marked mucosal thickening in a child with
Salmonella colitis. (D) Hemolytic uremic
syndrome. Greatly thickened hypoechoic colonic
mucosa.