Diagnostic ultrasound ( PDFDrive )

CHAPTER
48
The Pediatric Head and Neck
Rupa Radhakrishnan and Beth M. Kline-Fath
SUMMARY OF KEY POINTS
• Ultrasound is an excellent modality to evaluate head and
neck masses in children because of its accessibility and
lack of ionizing radiation.
• Lesion location is an important factor to consider
in evaluation of head and neck masses in
children.
• Common head and neck masses in children are related to
lymph nodes, thyroglossal duct anomalies, branchial
anomalies, inclusion cysts, and vascular anomalies.
• Use of spectral Doppler waveforms can aid in identiication
of arterial components in vascular anomalies to narrow the
differential diagnoses.
CHAPTER OUTLINE
NORMAL CERVICAL ANATOMY
SUPRAHYOID SPACE
Salivary Glands
Normal Anatomy
Inlammatory Lesions
Masses
Suprahyoid Cystic Lesions
Masticator Space
INFRAHYOID SPACE
Thyroid Gland
Normal Anatomy
Congenital Thyroid Lesions
Inlammatory Thyroid Disease
Thyroid Masses
Parathyroid Glands
Other Cystic Lesions
LACKING DEFINITION BY THE HYOID
Congenital Lesions
Branchial Anomalies
Ectopic Thymus
Dermoid and Epidermoid Lesions
Teratomas
Vascular Lesions
Vascular Anomalies
Vascular Tumors
Vascular Malformations
Other Congenital Lesions
Iatrogenic Lesions
Inlammatory Lesions
Lymph Nodes
Fibromatosis Colli
Masses
Pilomatricoma
Congenital Infantile Myoibromatosis
Malignant Neoplasms
NORMAL CERVICAL ANATOMY
he goal in pediatric imaging is to perform a study with the
lowest possible radiation exposure and least sedation to
adequately answer the clinical question. 1-4 Sonography, given a
lack of ionizing radiation and its noninvasive approach, is almost
invariably the initial imaging modality in a child with a neck
lesion. Sonography is cost-efective, widely available, and portable.
Ultrasound can illustrate normal cervical anatomy, evaluate
vascular structures and lesions with spectral Doppler imaging,
and delineate pathology with regard to location, size, and presence
of calciication. Cystic masses are common pediatric neck lesions,
and sonography is also exceptional at distinguishing solid from
cystic lesions and assessing compressibility of lesions. Transducers
with frequencies of 7.5 to 10 MHz are excellent for examination
of the neck.
Limitations of ultrasound technique include the inability to
evaluate bone, small ield of view, and degree of sot tissue contrast.
Because of these limitations, magnetic resonance imaging (MRI)
and computed tomography (CT) are excellent adjunct modalities
that can provide additional sot tissue and bone detail and further
delineate extent of disease. 5
An understanding of normal cervical anatomy is essential to
appropriately evaluate head and neck pathology. he sot tissues
of the neck can be separated into boundaries of the supericial
and deep spaces. 6-8 he supericial fascia is primarily composed
of subcutaneous fat. he platysma muscle, subcutaneous lymph
nodes, and nerves lie within the supericial space. he deep
cervical fascia, encircled by the supericial tissues, contains the
major structures of the neck (Fig. 48.1). he deep cervical fascia
includes supericial, middle, and deep layers (Fig. 48.2).
Simplifying the deep cervical fascial anatomy is best achieved
by dividing the neck into suprahyoid and infrahyoid locations. 6,7
he suprahyoid space includes the areas of the neck between
the skull base and hyoid bone. 6 he infrahyoid space is the area
of the neck between the hyoid bone and clavicles. 7 Some deep
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