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牙科放射線學(2)
Salivary Gland Radiography
唾液腺攝影術
陳玉昆副教授: 高雄醫學大學 口腔病理科
07-3121101~2755
[email protected]
學 習 目 標
1. 拍攝唾液腺的方法有那幾樣方式?
2. 拍攝唾液腺的方法的適應症為何?
3. 拍攝唾液腺的方法之優缺點為何?
4. 如何判讀唾液腺的影像?
References
1. Eric Whaites: Essentials of dental radiography & radiology 3rd edition,
Chapter 31, p. 403-414
2. Kaohsiung Medical University Oral Pathology
3. Nahlieli et al. Endoscopic mechanical retrieval of sialoliths. Oral Surg
Oral Med Oral Pathol Oral Radiol Endod 2003;95:396-402
4. What you need to know about cancer. Sci Am 1996;289:28-119
5. http://health.allrefer.compictures-imagessialography.html
Embryology
Histology
Anatomy
本課程會讓你們瞭解以下的重點
:
Physiology
1. 拍攝唾液腺的方法有那幾樣方式?
Pathology
2. 拍攝唾液腺的方法的適應症為何?
3. 拍攝唾液腺的方法之優缺點為何?
4. 如何判讀唾液腺的影像?
Major glands: Parotid
Submandibular
Sublingual
Investigations
Plain radiographic examination
Sialography
Computed tomography (CT)
Radioisotope imaging including PET
(Positron Emission
Flow rate studies
Tomography)
Ultrasound
Magnetic resonance imaging (MRI)
Sialoendoscopy
Plain radiographic examinations
Parotid Panoramic radiography
gland Oblique lateral
radiography
Subman- Panoramic radiography
dibular
Oblique lateral radiography
gland
Lower 90o occlusal
radiography
Wharton’s duct
Sublingual Gland
Parotid
Gland
Submandibular
Gland
Mylohyoid Muscle
Orifice of
Stensen duct
Contrast medium is injected
Refs. 1, 2, 5 into the Stensen duct
Sialography (1)
Parotid
Submandibular
Duct orifice
Duct orifice
Dilation
Dilation
Cannulation
Cannulation
Ref. 1
Preoperative phase
Sialography (2)
To note the position and/or presence of any
radiopaque obstruction
To assess the position of shadows cast by
normal anatomical structures that may overlie
the gland, such as hyoid bone
To assess the exposure factors
Filling phase
Ionic acqueous solutions
- Diatizoate (Urografin)
- Metrizoate (Triosil)
Emptying
phase
Oil-based solutions
- Iodized oil, e.g. Lipidolol (iodozed poppy
seed oil)
- Water-soluble organic iodine
compounds, e.g. Pantopaque
Sialography (3-1)
Contrast
medium
Oil-based
Advantages
Densely radiopaque,
thus show good
contrast
High viscosity, thus
slow excretion from
the gland
Wharton’s
duct orifice
Sublingual Gland
Parotid
Gland
Submandibular
Gland
Ref. 1
Mylohyoid Muscle
Disadvantages
Extravasated
contrast may remain
in the soft tissues for
many months, and
may produce a
foreign body reaction
High viscosity means
considerable
pressure needed to
introduce the
Calculi may
contrast. Calculi
may
be
downthe
the
be forced
forced down
main
main duct
duct
Sialography (3-2)
Contrast
medium
Aqueous
Advantages
Low viscosity, thus
easily introduced
Easily and rapidly
removed from
the gland
Easily absorbed &
excreted if
extravasated
Disadvantages
Less radiopaque,
thus show
reduced contrast
Excretion from the
gland is very rapid
unless used in
a closed system
Sialography (4)
Main indications
To determine the presence and/or position of
calculi or other blockages, whatever their
radiodensity
To assess the extent of ductal and glandular
destruction secondary to an obstruction
To determine the extent or glandular
breakdown and as a crude assessment of
function in cases of dry mouth
Sialography (5)
Contraindications
Allergy to compounds containing iodine
Periods of acute infection/inflammation, when
there is discharge of pus from the duct opening
When clinical examination or routine
radiographs have shown a calculus close to the
duct opening, as injection of the contrast
medium may push the calculus back down the
main duct where it may be inaccessible
Ref2
Sialographic techniques
Sialography (6)
Simple injection technique
Oil-based or aqueous contrast medium is introduced using gentle hand pressure until the patient
experiences tightness or discomfort in the gland,
(about 0.7 ml for the parotid gland, 0.5 ml for the
submandibular gland)
Advantages
Simple
Inexpensive
Disadvantages
The arbitrary pressure which is applied may
cause damage to the gland
Reliance on patient’s responses may lead to
underfilling or overfilling of the gland
Hydrostatic technique
Sialography (7)
Aqueous contrast media is allowed to flow freely
into the gland under the force of gravity until the
patient experiences discomfort
Advantages
The controlled introduction of contrast
medium is less likely to cause damage or give
an artefactual picture
Simple
Inexpensive
Disadvantages
Reliance on patient’s responses
Patients have to lie down during the procedure,
so they need to positioned in advance for the
filling-phase radiographs
Sialography (8)
Continuous infusion pressure-monitored technique
Using aqueous contrast medium a constant flow rate
is adopted & the ductal pressure monitored throughout
the procedure
Advantages
The controlled introduction of contrast media at known
pressures is not likely to cause discomfort
Does not cause overfilling of the gland
Does not rely on the patient’s responses
Disadvantages
Complex equipment is required
Time consuming
Sialographic interpretation
Sialography (9)
A systematic approach
A detailed knowledge of the radiographic
appearances of normal salivary gland
A detailed knowledge of the pathological
conditions affecting the salivary glands
A. Preoperated phase;
B. Emptying
phase; C. Filling phase
Systematic
approach
The
correct
sequence
of sialography
is duct structure within the gland, noting
Assess the
Assess
the degree
of filling
of the duct structure
The branching & gradual tapering of the minor
Assess the main duct, noting
(1)
A,
B,
C
(2)
B,
A,
C
(3)
A,
C,
B
ducts towards the periphery of the gland
The diameter of the duct
The course & direction of the duct
The presence & position of any filling defects
The overall pattern and shape of the ducts
The degree of overall glandular filling
The presence and position of any filling defects
Assess the degree of emptying
Sialography (10)
Normal sialographic appearance
- Parotid gland
The main duct is of even diameter 1-2 mm
wide) & should be filled completely & uniformly
The duct structure within the gland branches
regularly and tapers gradually towards the
periphery of the gland, the so-called tree in
winter appearance
Ref. 1
Sialography (11)
Normal sialographic appearance
- Submandibular gland
The main duct is of even diameter 3-4 mm
wide) and should be filled completely & uniformly
This gland is smaller than the parotid, but the
overall appearances is similar with the branching
duct structure tapering gradually towards the
periphery – so-called bush in winter appearance
Ref. 1
Pathological appearance - calculi
Sialography (12)
Filling defect in the main duct
Ductal dilatation caused by associated sialodochitis
The emptying film usually shows contrast
medium retained behind the stone
Ref. 1
Sialography (13)
Pathological appearance- sialodochitis
Segmented sacculation or dilatation and
stricture of the main duct, the so-called sausage
link appearance
Ref. 1
Pathological appearance
- sialadenitis
Sialography (14)
Dots or blobs of contrast medium within the
gland, an appearance known as sialectasis
caused by the inflammation of
the glandular tissue producing
saccular dilation
The main duct is usually normal
Ref. 1
Pathological appearance
- Sjogren’s syndrome
Widespread dots or blobs of
contrast medium within the
gland, an appearance known as
punctate sialectasis or
snowstorm
Considerable retention of the
contrast medium during the
emptying phase
The main duct is usually normal
Ref. 1
Sialography (15)
Sialography (16)
Normal
acinus
Ref. 1
Sjogren’s
syndrome
Sialadenitis
Pathological appearance - Intrinsic
tumor
An area of underfilling within the gland, due to
ductal compression by the tumor
Ductal displacement – the ducts adjacent to
the tumor are stretched around it, an appearance
known as ball in hand
Retention of contrast medium in the displaced
ducts during the empyting phase
Ref. 1
Sialography (17)
Computed tomography
Indication
Discrete swellings both intrinsic and extrinsic
to the salivary glands
Advantages
Provides accurate localization of masses,
especially in the deep lobe of the parotid
The nature of the lesion can often be
determined
Disadvantages
Provides no indication of salivary gland
function
Small calculi may not be detected
Risks associated with intravenous contrast
media
Ref. 2
Radioisotope imaging
Indications
Dry mouth due to salivary gland diseases such
as Sjogren’s syndrome
To assess salivary gland function
PET for salivary gland tumors
Advantages
Provides an indication of salivary gland
function
Allows bilateral comparison & images all four
major salivary glands at the same time
Compute analysis of results is possible
Can be performed in cases of acute infection
Co-localization of PET with CT or MRI scans
Disadvantages
Provides no indication of salivary gland
anatomy or ductal architecture
Relatively high radiation dose to the whole
body
The final images are not disease-specific
Refs. 1, 2
Flow-rate studies
These are used to investigate salivary gland function
Comparative flow rates of saliva from the major
salivary glands are measured over a time period
Indications
Schimer’s test
Dry mouth
Poor salivary flow
Excess salivation
Advantages
Ionization radiation is not used
L
R
Simple to perform
Provides information on salivary gland function
Ref. 2
Disadvantages
Provides only limited information- no indication of
the nature of underlying diseases
Time consuming
Ultrasound
Indications
Discrete swellings both intrinsic & extrinsic to
the salivary glands
Salivary calculi
Advantages
Ionization radiation is not used
Provides good imaging of superficial masses
Excellent for differentiating between solid &
cystic masses
Different echo signals are obtained from
different tumors
Identification of radiolucent stones
Lithotripsy of salivary stones now possible
Disadvantages
The sound waves used are blocked by bone, so
limiting the areas available for investigation
Provides no information on ductal architecture
Ref. 1
Magnetic resonance imaging
Indications
Discrete swellings both intrinsic & extrinsic to
the salivary glands
Advantages
Ionization radiation is not used
Provides excellent soft tissue detail, readily
enables differentiation between normal and
abnormal
Provides accurate localization of masses
The facial nerve is usually identifiable
Images in all planes are available
Co-localization possible with PET scans
Disadvantages
Provides no information on salivary gland
function
Limited information on surrounding hard
tissues
Ref. 1
Sialoendoscopy
Endoscopic mechanical retrieval of sialoliths
Exploration unit
Surgical unit
Ref. 3
Retrieval of a sialolith
using a basket
Ref. 3
Removal of a sialolith
using a grasp
Grasp
Ref. 3
Open
Grasp
片子橫放
突點朝下
Refs. 1, 2
Summaries
1. 瞭解拍攝唾液腺的方法
2. 瞭解拍攝唾液腺的方法的適應症
3. 瞭解拍攝唾液腺的方法之優缺點
4. 瞭解如何判讀唾液腺的影像