Part 2 of a 3 part seminar series on ultrasound imaging and its applications in head and neck

1. ULTRASOUND
IMAGING
APPLICATIONS IN HEAD AND NECK
DrAparna
PG, Dept of Oral Medicine & Radiology,
SDMCollege of Dental Sciences and Hospital

2. Contents:
• PART I: BASICS
• Introduction
• History and evolution of
diagnostic ultrasound
• USG – basic physics
• Parts of an ultrasound unit
• ImageAcquisition Modes
• Tissue characterization
• Ultrasound guided Needle
PART II :
• Buccal mucosa
• US techniques
• Normal US appearance
• OSMF
• Early Malignant changes
• Carcinoma Cheek
• Salivary Glands
• US techniques
• Normal gland appearance
• Inflammatory diseases
• neoplasms
2
PART III:
• Lymph nodes
• Normal US
appearance
• Metastatic node
• Tuberculous node
• TMJ
• Vascular malformations
• Head and neck swellings-
DD at US

3. BUCCAL MUCOSA
3

4. • Fields and Dunn (1973) stated that Collagen is the major source of echogenicity in
tissues
• Different organs display varied echo pattern due to their varying collagen content
• Contracted buccinator: Highly echogenic.
• Relaxed buccinator: Less highly echogenic.
• Subcutaneous tissue: Moderately echogenic.
• Deep adipose tissue: Less echogenic
4

5. Methods for evaluation of buccal
mucosa
Resting and Puffed Cheek
Technique
• Makes the layers taut and
increases visibility
• Accurately defines size of the
lesion
5

6. Methods for evaluation of buccal
mucosa
TongueTouchTechnique
• Better visualisation of details.
• To evaluate superficial mucosal
lesions involving the buccal
mucosa and lesions involving the
anterior half of the tongue and its
lateral borders.
6

7. Methods for evaluation of buccal
mucosa
Fruit JellyTechnique
Fruit jellies’ in oval or conical shapes were placed in upper and lower
gingivo-buccal sulcus (groove between the gingiva and the buccal mucosa)
7

8. Scanning levels
8

9. A1. Lower Border ofThe
Mandible
9

10. A2. Angle of the Mouth to
the Ear Lobule
10

11. A3. Nasal ala to the tragus
11

12. C1.Vertically from
mandible up to the lateral
canthus:
12

13. C2: approximately one-
inch posterior to C1
13

14. C3. Extends from the
angle of mandible to
temporal region
14

15. Buccal space infection
• Abscess vs Cellulitis – Different treatment modes
• To pinpoint the relation of the abscess to the overlying skin,
• To accurately measure the dimensions of the abscess cavity and its precise depth
below the skin surface .
• The vessels of the inflammatory tissue which has a higher blood volume due to
increased permeability of the vessel wall are depicted as a colour flow signal on
Color Doppler images.

16. Different stages of infection :
1) Edematous changes: the echogenicities of the tissues are isoechoic, similar to
the normal or uninfected side but with an increase in the fluid contents.
2) Cellulitis: the echogenicities of the tissues are higher (hyperechoic) than
normal because of massive inflammatory infiltration to the infected region.
3) Preabscess stage: the echogenicities of the tissues are mixed (hypoechoic and
hyperechoic) at the end of cellulitis stage and the beginning of abscess
formation stage.
4) Abscess stage: the echogenicities of the tissues were absent (anechoic)
because of the abscess cavity, which can be solitary or multiple well-defined foci
of pus.

17. Appearance on US images
• ABSCESS
• The gray-scale appearance of an
abscess is a heterogeneic, anechoic,
or hypoechoic mass containing a
variable amount of internal echoes.
• Generally spherical in shape with
poorly defined borders
• Compression of the mass with the
transducer may demonstrate
movement or ‘‘swirling’’ of pus.
• CELLULITIS
• US shows thickening and diffuse
hyperechogenicity of the
subcutaneous fat
• Obliteration of the interface between
the echogenic fat and the dermis.
This is commonly referred to as
‘‘cobblestoning’

18. CELLULITIS
ABSCESS

19. ORAL SUBMUCOUS FIBROSIS
• USG demonstrates the number, length, thickness of the fibrotic bands and pattern
of overall vascularity in the affected area
• The band of hypoechogenicity between the hyperechoic mucosa and the muscle
layer is measured as submucosa
• There is increase in the collagen fibres in OSMF this could be the most possible
reason of increase echogenecity and increased submucosal thickness in USG

21. EARLY MALIGNANT CHANGES

22. Evaluation ofTumour Depth orThickness
• Taylor et al. found that the ultrasound-measured thickness was comparable to
histologically measured thickness; between the two modalities, the difference was
within one mm in 81% cases, and the difference was within two mm in 93% cases
• Tumours as small as one mm were detected and ultrasound could detect tumour
shape and invasion, whereas tumour thickness measured on CT and MRI was more
than that measured on ultrasound and histology
22

23.  SCC of
buccal
mucosa
23

24. SALIVARY GLANDS
24

25. TECHNIQUE
• Highest-frequency transducer possible.
• 5–12-mhz wide-band linear transducers (median frequency, 7–7.5 mhz or
more) are used
• Large tumors and lesions located in deep portions of the glands, 5–10-mhz
transducers may be useful
• When combined with color Doppler imaging, it helps in assessing the
vascularity and nature of the lesion
25

26. Entire salivary glands and all lesions have to be evaluated in at least
two perpendicular planes during a US examination

27. The parotid gland
27

28. • The border between the superficial and deep parotid lobes is created by a plane in which the
facial nerve and its branches are located. Branches of the facial nerve are not visible at US.
• Parts of the trunk of this nerve may be demonstrated only with high-frequency probes
(above 10 MHz)
• RETROMANDIBULARVEIN – US LANDMARK
• The deep parotid lobe can be visualized only partially at US.
• Some areas of glandular parenchyma and possible lesions may be hidden in the acoustic
shadow behind the mandibular ramus
28

29. Left parotid gland and part of the cheek
29

30. 30

31. Normal US appearance
• Normal echogenicity of all major salivary glands is generally homogeneous and
varies from very bright and markedly hyperechoic to only slightly hyperechoic in
comparison to adjacent muscles.
• Depends on the amount of intraglandular fatty tissue.
• Salivary glands with high fat content are hyperechoic in comparison to surrounding
muscles and markedly suppress ultrasound waves, so that the deep lobe is
inaccessible for us assessment

32. 32

33. Stenson duct
• After leaving the parotid gland, the main excretory duct (Stenson duct) lies on the
masseter muscle, about 1 cm below the zygomatic arch, then crosses the buccal muscle
and has its orifice in the parotid papilla at the level of the upper second molar.
• The length of the Stenon duct usually varies between 3 and 5 cm.
• A nondilated duct is usually not visible during US examination
33

34. 34

35. Lymph nodes in Parotid
• In the parenchyma of the parotid gland, lymph nodes may be found .
• They are localized mainly in the area of the upper and lower poles of the gland.
• Normal intraparotid lymph nodes may be oval or have a longitudinal shape
• The presence of a hyperechoic hilum is one of the important criteria for the
normality of parotid lymph nodes .
• Their short axis should not exceed 5–6 mm in the normal state
• With the application of sensitive power Doppler US, central vessels may be seen in
normal parotid lymph nodes.
35

36. Parotid lymph nodes
36

37. The submandibular gland
37

38. • Generally, the shape of the
submandibular gland in longitudinal
and transverse sections is close to a
triangle
38

39. Facial vessels
• The facial artery may cross the
parenchyma of the submandibular gland in
its tortuous course
• The facial vein runs along the
anterosuperior part of the submandibular
gland.
• Medially to the submandibular gland run
the lingual artery and vein.
39

40. Wharton’s duct
• In general, a nondilated duct is not visible at us, but sometimes in slim individuals it
may be visible
40

41. Sublingual Gland
41

42. • On transverse sections, the shape
of the sublingual gland is close to
an oval ; on sections parallel to the
body of the mandible, the shape is
longitudinal and lentiform.
• Along its medial part runs the
excretory duct of the
submandibular gland.
42

43. INFLAMMATORY DISEASES OF
SALIVARY GLANDS
43

44. Acute Inflammation
• Salivary glands are enlarged and hypoechoic.
• They may be inhomogeneous;
• May contain multiple small, oval, hypoechoic areas
• May have increased blood flow at US
• Enlarged lymph nodes with increased central blood flow may be observed in acute
inflammation of salivary glands
44

45. 45

46. Chronic Sialadenitis
• Salivary glands are normal sized or smaller, hypoechoic, and inhomogeneous
• Usually do not have increased blood flow at US
46

47. • At US, chronic and sometimes acute sialadenitis in children , as well as acalculous
submandibular gland sialadenitis in adults show multiple small, round or oval,
hypoechoic areas or lesions distributed throughout glandular parenchyma

48. Granulomatous Sialadenitis
• US features of granulomatous sialadenitis are nonspecific: single or multiple
hypoechoic areas in an enlarged or normally sized gland or diffuse low
echogenicity . Blood flow may be increased
• Mycobacterial disease of major salivary glands may manifest as a salivary gland
mass, clinically indistinguishable from a neoplasm
48

49. Sialosis
• Bilateral, diffuse, and painless enlargement of the salivary gland referred to as
sialosis occurs in diabetes mellitus, chronic alcoholism, hypothyroidism,
malnutrition, and rarely secondary to certain drugs (antibiotic, antipsychotics. And
diuretics).
• US reveals a hyperechoic gland without increased vascularity or focal lesions.

50. Sialolithiasis
• US features of sialolithiasis include strongly hyperechoic lines or points with distal
acoustic shadowing, which represent stones
• In symptomatic cases with duct occlusion, dilated excretory ducts are visible
• Sialolithiasis of the submandibular gland
• US may demonstrate whether the stone is located in the glandular
parenchyma or in the Wharton duct
• In chronic ductal sialolithiasis complicated by chronic or recurrent inflammation, the
gland may lose its function. At this stage of disease, stones located in a nondilated
duct may be difficult to demonstrate
50

51. 51

52. • Hyperechoic bubbles of air mixed with saliva may
mimic stones in theWharton duct and thus be a
diagnostic pitfall
52

53. Sjo¨gren Syndrome
• Advanced stages of Sjo¨gren syndrome may be recognizable at US examination of
the parotid and submandibular glands
• US features - inhomogeneous structure of the gland with scattered multiple small,
oval, hypoechoic or anechoic areas, usually well defined, and increased
parenchymal blood flow
• Hypoechoic or anechoic areas are believed to represent infiltration by lymphatic
cells, destroyed salivary parenchyma, and dilated ducts.
• DD in US:
• Non Hodgkin lymphoma ,granulomatous disease (eg, sarcoidosis), hematogenous
metastases, and benign lymphoepithelial lesions in HIV-positive patients
53

55. NEOPLASMS IN SALIVARY GLAND

56. Benign Neoplasms
• The most common benign neoplasms of major salivary glands are pleomorphic
adenomas (mixed tumor) and warthin tumors
• Definitive differential diagnosis is usually not possible with US even between
benign and malignant tumors.

57. Pleomorphic adenoma
• At US, pleomorphic adenomas are hypoechoic, well-defined, lobulated tumors
with posterior acoustic enhancement
• They may contain calcifications
• The feature of lobulated shape is emphasized in differential diagnosis
• Peripheral vascularity with hypovascular central area in the tumoral lesion is highly
suggestive of pleomorphic adenoma

58. Pleomorphic adenoma

59. WarthinTumor
• Warthin tumors are oval, hypoechoic, well-defined tumors and often contain
multiple anechoic areas
• May also appear in the form of a simple cyst at US

60. • DD at US
• Macroscopic cystic structures, which appear as anechoic areas at US
i. Other BenignTumors
ii. MalignantTumors (Mucoepidermoid Carcinoma, Acinic Cell Carcinoma)
iii. Abscessed Or Necrotic Metastatic Node
• Simple cystic appearance
i. Cystic Carcinomas (Mucoepidermoid Carcinoma, Acinic Cell Carcinoma)
ii. Benign Cysts (Lymphoepithelial Cysts

61. Malignant Neoplasms
• The most common malignant neoplasms occurring in salivary glands are
mucoepidermoid carcinoma and adenoid cystic carcinoma
• less than 30% of focal lesions in the parotid gland are malignant, whereas almost
50% of focal lesions in the submandibular gland are malignant
• US features of malignant salivary neoplasms :
• An Irregular Shape, Irregular Borders, Blurred Margins, Hypoechoic Inhomogeneous
Structure

62. • Malignant tumors may also be homogeneous and well defined
• The internal structure may be not only solid but also cystic or cystic with a
mural solid nodule
• Malignant tumors may have a lobulated shape, similar to that of
pleomorphic adenomas
• The presence of metastatic-appearing lymph nodes accompanying a tumor
in the salivary gland strongly suggests a malignancy

63. ACC of Parotid gland

64. Checkpoint!!!
• An important problem in US is caused by small malignant neoplasms and
metastases, less than 20 mm in diameter, and well-differentiated malignant
neoplasms because they may demonstrate benign features: clear, even margins
and homogeneous structure

65. Metastases
• Salivary glands are very uncommon sites of metastases.
• Primary tumors metastasizing to salivary glands may be located in the head and neck
region, as well as in more distant parts of the body
• Melanoma , spinocellular cancer, breast cancer, and lung cancer may produce
metastases to intraparotid lymph nodes

66. • At US, metastases may be well defined and oval.
• DD at US:
• Sjogren syndrome, Granulomaous diseases

67. Lymphoma
• Primary involvement of salivary glands is rare; they are
usually one of the sites of systemic disease
• A solitary, hypoechoic, homogeneous or inhomogeneous
lesion, which is oval or lobulated or has irregular margins
• Sometimes contains echogenic septa or stripes
• Lymphomatous lymph nodes may demonstrate all the
US features of a simple cyst

68. Effects of Irradiation
• After irradiation, salivary glands become hypoechoic and inhomogeneous at US
• The salivary glands enlarge in the acute phase and later become smaller because
of atrophy

69. To summarise:
• In acute inflammation, salivary glands are enlarged and hypoechoic with increased
blood flow; they may contain multiple small, oval, hypoechoic areas
• In chronic inflammation, salivary glands are normal sized or smaller, hypoechoic,
and inhomogeneous.
• Sialolithiasis appears as markedly hyperechoic lines or points with distal acoustic
shadowing.
• Sialosis appears as enlarged hyperechoic glands without focal lesions or increased
blood flow.
• Advanced Sjo¨gren syndrome include inhomogeneous salivary glands with
scattered small, oval, hypoechoic or anechoic areas, usually well defined, and
increased parenchymal blood flow
69

70. To summarise:
• Pleomorphic adenomas are usually hypoechoic, well-defined, lobulated lesions
with posterior acoustic enhancement that may contain calcifications
• Warthin tumors are usually oval, hypoechoic, well-defined lesions that often
contain anechoic areas and are often hypervascularized.
• Malignant neoplasms of the salivary glands may have irregular shapes, irregular
borders, blurred margins, and a hypoechoic inhomogeneous structure or may
have a benign appearance.
• Salivary gland cysts have well-defined margins, anechoic contents, posterior
acoustic enhancement, and no internal blood flow
70

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