Diagnostic ultrasound ( PDFDrive )

CHAPTER 48 The Pediatric Head and Neck 1633
A
B
FIG. 48.11 Parotid Abscess. (A) Two-month-old infant developed swelling along the left ear. Sonogram of the parotid area demonstrates a
round, well-deined, hypoechoic mass without internal blood low within the deep parotid. (B) Contrast computed tomography scan performed 2
days later because of lack of response to intravenous antibiotics demonstrates a large, round, hypoattenuated lesion with partial enhancing peripheral
wall within inlamed left parotid.
A
B
FIG. 48.12 Submandibular Gland Sialolithiasis. (A) Color Doppler of enlarged hypoechoic submandibular gland containing echogenic foci.
(B) Dilated submandibular (Wharton) duct due to multiple obstructing echogenic shadowing foci, consistent with stones (arrows). See also Video
48.1.
supportive with administration of intravenous (IV) antibiotics. 20
In the presence of severe dehydration and especially in neonates
7 to 14 days old with bacterial infection, an intraparotid abscess
may develop. hese collections typically appear hypoechoic or
anechoic with posterior acoustic enhancement and occasionally
a hyperechoic halo 12 (Fig. 48.11). Internal debris may be noted,
and in some patients, hyperechoic foci consistent with gas bubbles.
Ultrasound-guided drainage is useful when abscess is present.
Recurrence is uncommon.
Sialolithiasis is uncommon in children, with 90% in the
submandibular gland and 10% in the parotid. 12,18,20 In 25% of
patients, stones are oten multiple and intraglandular or intraductal
in location. Submandibular glands are prone to calculi because
of the alkaline nature and high viscosity of their secretions. he
Wharton duct is long with an upward course and thus also has
a higher propensity for stone formation. Clinically, recurrent
swelling during eating and superimposed infection may result
from partial or complete obstruction of the duct by a stone.
Sonography is as sensitive as 94% in the detection of salivary
calculi. Features include hyperechoic foci with acoustic shadowing
representing stones (Fig. 48.12, Video 48.1). With duct occlusion,
hypoechoic tubular areas are typically consistent with dilated
ducts. 12,23 About 50% of patients have inlammation of the gland
in conjunction with the calculus, 12 and the gland will demonstrate
a heterogeneous architecture. Although 80% of submandibular
and 60% of parotid stones are radiopaque on x-ray examination,
when more information is needed beyond ultrasound, a CT scan
provides the best detail. 24
Nodal enlargement in the parotid is oten present in association
with cervical adenopathy caused by infection or neoplasm.