Courtesy : David sutton

1. Imaging of Salivary Glands
25/11/2015
Dr. Y. Madhu Madhava Reddy

2. Salivary Glands
• The salivary glands are exocrine glands (with
ducts), that produce saliva and pour their
secretion in the oral cavity.
• Major (Paired)
• Parotid
• Submandibular
• Sublingual
• Minor : those in tongue, palatine tonsil, palate,
lips and cheeks.

3. Anatomy

4. Parotid Gland
• The parotid gland is located behind the angle
of the mandible, with the anterior part of the
gland lying on the masseter muscle.
• It has a large single duct (Stenson's) that runs
forwards crossing the masseter muscle,
turning inwards at its anterior border to pierce
the buccinator muscle and then opening into
the mouth on a papilla opposite the second
upper molar tooth.

5. Parotid Gland

6. Parotid Gland
• The gland is divided into superficial and deep
parts by the parotid plexus (branches of Facial
nerve), but however they donot innervate the
gland.
• At its anterior margin there is a small separate
accessory part which lies between the duct
and the zygomatic arch.

7. Submandibular Gland
• It is located below the mandible and has
superficial part that lies on the mylohyoid muscle
and deep part that extends deep to the posterior
border of this muscle.
• A single duct ( Wharton’s) emerges from deep
surface of the gland, tunrs around the posterior
border of the mylohyoid muscle and runs deep to
that muscle to open on a papilla at the side of the
frenulum beneath the tongue.

8. Sublingual Gland
• The sublingual gland lies anteriorly in the floor
of the mouth and opens into the mouth
through a number of ducts. Ducts within all of
these glands are evenly distributed and gently
tapered.

9. CT and MRI Anatomy
• Parotid glands have variable amounts of fatty
stroma, thus have lower CT attenuation (-25
to +15HU) than adjacent muscles, LN and
vessels.
• Higher density is seen in Children. In some
adults attenuation of parotid glands
approaches that of muscle, and in these dense
glands, MRI is superior in detection of masses.

11. • There are between 20 and 30 lymph nodes
within the parotid gland, making it a site for
metastatic disease from the scalp, external
auditory canal and face.

13. • The submandibular glands have higher
attenuation than the parotid glands but are
still easily distinguished from the adjacent
musculature.
• The sublingual salivary glands and minor
(accessory) salivary glands which line the
upper aerodigestive tract are not routinely
visualised. The minor salivary glands may give
rise to masses in the parapharyngeal space.

14. • The submandibular and sublingual glands lie within their
respective spaces; they are separated by the mylohyoid
muscle anteriorly but the spaces are continuous with each
other posteriorly where the posterior part of the sublingual
gland and the deep part of the submandibular gland lie in
close proximity.
• The submandibular space is encircled by the superficial
layer of the deep cervical fascia and contains the superficial
part of the submandibular gland together with
submandibular and submental lymph nodes.
• The sublingual space contains not only the sublingual gland
and duct but also the deep portion of the submandibular
gland and duct.

15. • Masses arising in the submandibular space
tend to remain within that space but masses
in the sublingual space may extend to the
submandibular space.
• Parotid tail lesions occasionally present as
masses at the angle of the mandible and may
be mistaken for submandibular masses.

16. Salivary gland Imaging
• Plain X rays ( Stones, Calcifications, Bony
erosions)
• Sialography ( Radiolucent Stones, Sialectasis,
duct displacement)
• USG
• CT
• MRI

17. Plain Films
• Parotid Gland : AP, tangential, lateral, lateral
oblique plain radiographs are useful for showing
calculi, soft tissue swellings.
• Submandibular gland is assessed in lateral
oblique view with patient finger in mouth,
depressing the tongue and pushing the
submandibular gland into the sight beneath
mandible.
• Stone in anterior part of duct are best
demonstrated by placing occlusal film in mouth
and using submentovertical projection.

18. Mandibular occlusal view

19. Sialography
• Can be performed on parotid and
submandibular glands.
• Initial series of plain films are taken to identify
RO calculi.
• Sialogogue ( lemon juice or citric acid ) is given
to dilate duct orifice.
• Duct intubated by means of blunt tipped,
slightly angulated, metal cannula or fine thin
walled polythene catheter with a tapered end.

20. Sialography
• Approximately 0.5 – 1.5 ml of contrast medium (
Lipiodol Ultra fluid or a water soluble medium) is
slowly injected by hand until the duct system is
filled.
• A series of radiographs are taken or substracted
images can be obtained with digital x ray.
• To complete examination few drops of lemon
juice is given to stimulate salivation. Further film
is taken after an interval of 10min, which
normally will show most of contrast medium
cleared from ducts.

21. Sialography
• Indications : Sialoliths, Chronic inflammation
and tumours in parotid, submandibular glands
and duct diseases.
• Contra indicated in acute sialadenitis as it can
exacerbate the condition.

22. Sialograms

23. Sialograms
Normal Submandibular and parotid sialogram study

24. Ultrasound
• Parotid and submandibular glands are
examined using a 7.5MHz or higher frequency
linear array transducer with patients chin
turned away from side being examined.
• Both glands have homogenous echo pattern
with scattered echogenic steaks produced by
branch ducts converging into main duct.
• ECA and retromandibular vein can both be
seen. Few LN’s can be seen within gland.

25. USG

26. CT

27. CT
• The parotid duct will be demonstrated on thin
sections taken parallel to the hard palate. The
gantry angulation should be adjusted to avoid
dental fillings.
• The scan should extend from the skull base to the
level of the hyoid bone, to demonstrate the facial
nerve canal and to ensure that the parotid tail
and the high deep cervical and jugulodigastric
lymph nodes have been included

28. CT
• IV contrast enhancement increases the
conspicuity of salivary masses and affords
some prediction of their nature.
• CT sialography is alternative method of
increasing consipicuity of salivary gland
masses but the technique is invasive and is
not widely practised as MRI is more beneficial.
• Presence of metallic dentures / metallic fillings
can cause artefacts on CT.

29. MRI
• It allows multiplanar imaging and have
intrinsic contrast advantage.
• Reduces artefacts from Dental amalgam.
• Disadvantages are its inability to demonstrate
calcifications, whose presence is important in
diagnosis of pleomorphic adenoma and
sialolithiasis.
• Gadolinium contrast enhancement decrease
the conspicuity of some masses.

30. MRI
• Masses of salivary glands have low T1 signal,
particularly contrasted against the fatty
stroma of parotid. Fat supressed T1 sequences
are superior in determining extent of invasion.
• STIR images are also used.
• MR sialography has been described using
heavy T2WI, which contrast ductal fluid
against stroma. It helps in diagnosis of
Sialectasis upto some extent.

31. • CT and MRI examinations of the salivary
glands are usually requested to evaluate a
mass in the region of a salivary gland.
• Value of CT and MRI is more in detection,
anatomical placement and demarcation of
masses than in their characterisation.

32. Salivary Gland Lesions

33. Sialolithiasis
• 80% develop in submandibular glands as
these glands produce a more alkaline and
viscous saliva and ducts take an uphill course.
• Calculi form as a result of stasis or infection,
once formed predispose to further infection
and stone formation.
• Majority are Radio opaque and seen on
radiographs.
• Multiple calculi are seen in parotid glands.

34. Sialolithiasis
• Patients with duct calculi present with pain
and swelling of gland that is related to meals.
• Sialolithiasis may lead to chronic sclerosing
sialadenitis, it is most common in
submandibular glands.

35. Sialolithiasis
• Sialography can identify both RO and RL
calculi and associated strictures that develop
in ductal system.
• USG can also demonstrate calculi but NCCT is
most sensitive of all these techniques.
• CECT can be performed if abscess is
suspected.

36. Sialolithiasis

37. Acute Parotitis
• Causes: Mumps, sialolithiasis, Staphylococcal
and streptococcal infections may develop in
debilitated, dehydrated patients with poor
oral hygiene.
• Other causes: TB, candidiasis.
• CT : Swollen gland, increased enhancement,
surrounding inflammatory stranding and
lymphadenopathy.

38. Acute Parotitis
• Parotitis may be complicated by abscess
formation, which is seen as an area of non
enhancement on contrast enhanced scans
with an irregular enhancing rim.
• Deep parotid infection may extend to
parapharyngeal space.

39. Acute Parotitis

40. Acute Suppurative Parotitis
• Commonly seen in diabetic patients

41. Chronic Inflammation
• Recurrent infection, granulomatous and auto
immune diseases -> recurrent swelling of the
gland.
• Sialography -> narrowing of ducts with areas
of strictures and dilatation.
• Calculi are seen in 2/3 of cases.

42. Sialectasis
• Dilatation or increased calibre of salivary ducts.
• Most commonly seen in parotid gland and
associated with ascending infections and gland
destruction.
• Etiology: Any condition that causes chronic
inflammation.
• Sjogren syndrome, post infectious, recurrent
sialadenitis, salivary duct strictures, congenital
(rare).

43. Sialectasis
• Different pattern of dilatation:
• Punctate
• Globular
• Cavitary
• Cylindrical
• Fusiform

44. Chronic Inflammation

45. Strictures
• Results from combination of obstruction and
infection.
• Strictures are more sited at orifice of the ducts.
• Small stones pass spontaneously but leaves duct
stricture.
• Ducts proximal to stricture dilate and contrast
medium is retained on postsialogogue film.
• Localized strictures can be dilated using a guide
wire and small balloon catheter.

46. Strictures

47. Balloon dilatation of stricture

48. Myoepithelial sialadenitis
(Mikulicz disease)
• It is characterised by lymphocytic infiltration,
parenchymal atrophy and myoepithelial
islands.
• Involves parotid (85%) and
submandibular(15%)
• Most patients will have Sjogrens syndrome, an
autoimmune disease involving lacrimal as well
as salivary glands causing kertoconjuntivitis
and xerostomia.

49. Sjogrens disease
• Sjogrens may be primary or secondary when
associated with other connective disease (RA).
• Patients with myoepithelial sialadenitis are
44 times more risk of developing lymphoma.
• More common in females between 40 – 60
yrs.

50. Sjogrens disease
• CT and MRI: Bilateral parotid enlargement with
cystic lesions with heterogenously enhancing
parenchyma.
• CT: Honey comb of low density foci in generally
enhancing gland.
• T1WI: multiple low signal lesions uniformly
distributed in gland
• T2WI: multiple high signal cystic lesions reflecting
watery saliva (salt and pepper appearance)
• Punctate changes will progress to globular,
cavitary destructive lesions.

51. Sjogrens disease

52. Malignant Lymphoma
• Accounts for 15% of malignant tumours of
salivary glands.
• 6% of Sjogrens syndrome patients develop
non Hodgkins lymphoma.
• Associated with HIV.
• 80% occur in parotid gland.
• Increased no. Of intraparotid LN’s with
infiltrative characteristics.

53. Malignant Lymphoma

54. Salivary cystic lesions
• 5% of salivary masses
• DD’s:
• Warthins tumor
• Lymphoepithelial cyst
• 1st branchial cleft cysts
• Sialocele
• Ranula
• Abscess
• Necrotic nodes / tumors
• HIV  multiple b/l cysts

55. Salivary cystic lesions

56. Sialosis
• Chr. Non tender enlargement of parotid gland.
• B/L and Symmetric
• Non inflammatory and non neoplastic lesion
• May be ass. With DM and certain medications
• Sialography show splaying of duct system
• CT  b/l enlargement of glands with
preserved density

57. Sialosis

58. Salivary Neoplasms
• Eighty per cent of salivary gland tumours are
found in the parotid glands. The most
common tumour is the pleomorphic
adenoma, the majority of which are benign.
• Carcinomas are rare but the probability of a
salivary gland tumour being malignant is
greatest for masses arising in the smaller
salivary glands.

59. Benign tumors

60. Pleomorphic adenoma
• Typical CT appearance is smoothly marginated
mass which is of higher attenuation that the
surrounding gland and show no significant
contrast enhancement.
• Larger masses are lobulated or show necrosis,
haemorrhage and calcification.
• MRI: Inhomogenous signal, haemorrhage
being manifested as high signal on T1.

61. Pleomorphic adenoma

62. Pleomorphic adenoma

63. Pleomorphic adenoma

64. Warthins tumour
• Second most common benign tumor.
• Typically located in superficial part of parotid.
• It is the heterotopic salivary gland tissue within
parotid lymph nodes.
• B/L in 15% of cases.
• They are well defined and cavitate commonly
leading to cystic appearance on CT.
• M:F = 3:1
• Age of incidence 40 – 70 yrs.

65. Warthins tumour

66. Warthins tumour

67. Warthins tumour
Cystic component with mural nodules
1%  Malignant transformation

68. Parotid lipoma
• 1% of parotid lesions
• CT and MRI show typical findings
• 90% are ordinary lipomas
• 10% infiltrate adjacent structures

69. Parotid lipoma

70. Parotid lipoma
Lipoma of left parotid gland extending to the
deep lobe and anterior parapharyngeal space,
showing high T1 and T2 signal intensity.

71. Malignant Tumors

72. Muco epidermoid Ca.
• 30% of salivary malignancies
• 50% occur in parotid, 45% in minor salivary gl.
• Low grade lesions may appear like benign
tumors.
• High grade lesions show malignant characters.

73. Muco epidermoid Ca.

74. Malignant deep lobe parotid tumor

75. Malignant tumors
• Masses in deep lobe of parotid need to be
differentiated from parapharyngeal pathologies
like carcinoma, sarcoma and neural tumors.
• Metastases and lymphomatous involvement of
parotid gland occur due to presence of
intraparotid LN, a feature not seen in other
salivary glands.
• Mets 2o to skin neoplasms like malignant
melanoma, squamous cell carcinoma of face,
EAM ,scalp and sq. Cell ca of nasopharynx.

76. Malignant tumors
• Following parotidectomy, the surgical void fills
with fat and scar tissue. Recurrent tumour is
best diagnosed with MRI, where distinction
between scar and tumour can be made
because tumour shows greater contrast
enhancement

77. Non epithelial tumors
• Represents less than 5%.
• In children they represent 50%
• Lesions:
• Hemangioma
• Lymphangioma
• Lymphoma
• Lipoma
• Sarcoma....

78. Hemangioma
• 1-5% of salivary gland tumors
• The most common salivary neoplasm in children
(girls)
• 90% are of capillary type
• Cavernous type occur in older children
• Rapid enlargement with bluish skin coloration.
• Typically the lesion regress at adulthood.
• Strong enhancement with phleboliths may be
seen on CT.

79. Hemangioma in 6 months old girl

80. B/L Parotid hemangioma MRI
Marked signal increase in T2WI, signal voids may be seen

81. Lymphangioma
• Lymphangioma simplex, cavernous
lymphangioma, cystic hygroma.
• 5% of all benign tumors in infanct and childhood.
• 90% are present by age of 2 years
• Commonly arising in posterior neck triangle
• Soft tissue painless lesions.
• Multilocular lesion with fluid levels are seen on
T2WI.

82. Cystic hygroma

83. Intra parotid LNs
• Hyperplasia
• Viral / bacterial infections
• Granulomatous disease
• Lymphoma
• Metastatic deposits
• Rapid painful nodal enlargement –
Inflammatory nature.

84. Lymphoma of salivary glands +
Cervical nodes

85. FNAC
• It will correctly predict a benign or malignant
process in approximately 90% of cases and make
a specific diagnosis in 70%.
• Enthusiasm for FNAC of salivary gland masses
varies. It tends to be used in situations where the
clinical picture and imaging suggest a benign
diagnosis and long-term follow-up is planned,
when a metastasis or a mass secondary to a
systemic disease such as lymphoma is suspected,
or when a patient is considered unfit for surgery.

86. Thank you