Covers basics of contrast radiography from history to material to techniques for use in head and neck

1. CONT RASTCONT RAST
RADIOGRAPHY

2. Presented by:
Dr. Vibhuti Kaul

3. INTRODUCTION

4. • Any substance that renders an organ or
structure more visible than is possible
without its addition.
• Allows visualization of structures that can
not be seen well or at all under normal
circumstances.

6. DEFINITION
• Contrast is chemical substance which is
introduced in human body via
entral/parentral route to visualize certain
structures not seen in plain radiography.
• It is also used to see vascularity of certain
lesions in CT scan and MRI.

7. • Contrast media is needed because:
- Soft tissue has a low
absorption/interaction ratio
• Absorption is dependent upon:
- Thickness
- Density
- Atomic number

9. TYPES OF CONTRAST MEDIA
• Negative
- Air
- Oxygen
- Carbon Dioxide
- Nitrous Oxide
• Positive
- Barium
- Iodine

10. HISTORICAL BACKGROUND

11. • Strain et al: After 2 months of Roentgen’s
discovery, filled anatomical preparations
with plaster of paris & lead acetate.
• Marcel Guebert: Developed Lipidiol in
1901 for non-imaging purposes. In 1918, its
opacifying properties were discovered.
• Thorotrast: Earlier used contrast agent
based on thorium dioxide, use was
abandoned since it turned out to be
carcinogenic.

12. • Iodine
• Uroselectan
• Benzoic acid molecule

13. STUDIES INVOLVING
CONTRAST AGENTS
• Sialography
• Arthrography
• Angiography
• Lymphography
• Urography
• Barium swallow meal
• Computed tomography

14. REQUIREMENTS
• Radiopaque
• Minimum side effects
• Less viscosity
• Low surface tension

15. CLASSIFICATION

16. CHARR DH (‘88)
Nature of
Material
Iodine
based
Non-Iodine
based

17. CHARR DH (‘88)
Solvent
Conventional
ionic water
soluble
Oil soluble

18. CHARR DH (‘88)
Ionic nature
Monoacidic
monomer
Diatrizoate,
iothalamate
Monoacidic
dimer
Hexabrix
Nonionic
monomer
Iopamidol,
iohexol,
ioversol
Nonionic dimer Iodixanol, iorrol

19. WHAIRES E (‘96)
• Iodine based aqueous solution
- Ionic monomers Eg., Iothalamate,
metrizoate, diatrizoate
- Ionic dimers Eg., Ioxaglate
- Non-ionic monomers Eg., Iopamidol,
iohexol, iopromide
• Iodine based oil solutions Eg., Ethiodol,
pantopaque, lipidol

21. USEFUL FACTS TO
REMEMBER
• Osmolality
• Radiopacity
• Iodine particle ratio
• Non-ionicity

22. CHEMISTRY

23. BARIUM SULPHATE
• White crystalline salt insoluble in water
• Extremely low solubility protects the
patient from absorbing harmful amounts of
metal.
• Readily removed from the body.

24. IODINE
• Atomic weight = 127
• Provides radiopacity; other elements of
RCM act as carrier.
• Fate of drug: On i.v. inj, drug is distributed
rapidly by capillary permeability into
extravascular space (except CNS) & are
rapidly excreted (90% by glomerular
filtration within 12 hrs)

26. HIGH-OSMOLALITY
CONTRAST MEDIA

27. IONIC MONOMERS
• Eg: Diatrizoate, Iothalamate, metrizoate,
ioxithalamate, iodamide, ioglicate
• Composition: salts of sodium/meglumine
with tri-iodinated fully substituted benzoic
acid ring

29. LOW-OSMOLALITY
CONTRAST MEDIA

30. IONIC DIMER
• Eg: Ioxaglate (Hexabrix)

31. NON-IONIC MONOMER
• Eg: Metrizamide, Iohexol, Iopamidol,
Iopromide, Ioversol, Iopentol, Ioxilan etc

33. NON-IONIC DIMERS
• Eg: Iotrolan & Iodixanol

34. GENERAL PROPERTIES OF
CONTRAST MEDIA
• Viscosity
• Osmolality
• Chemotoxicity

35. IDEAL PROPERTIES OF
CONTRAST AGENTS
• Safe
• Non-toxic
• Should not cross
blood-brain barrier
• Similar physiologic
properties when
compared to blood,
saliva
• Inertness
• Opacification
• Low surface tension
• Easy injectability
• Elimination
• Residual contrast
media
• Cost-effective

36. SIALOGRAPHY

37. • Radiographic demonstration of major salivary
glands by introducing a radio opaque contrast
medium into their ductal system.
• The sub-mandibular and parotid glands are
investigated by this method
 Used when a definitive diagnosis is necessary for
a problem with one of the salivary ducts

38. INDICATIONS FOR EXAM
• Stones (Calculi) sialolithiasis
• Obstruction / Strictures
• Pain & Swelling (esp when recurrent)
• Infection
• Masses / Tumors
• Changes secondary to trauma
• When plain radiography is inconclusive

39. CONTRAINDICATIONS FOR
EXAM
• History of contrast media allergies
• Severe inflammation of the salivary ducts

40. ANATOMY OF THE SALIVARY
GLANDS
• 3 pairs---Parotid
SM
SL
• Situated adjacent to OC, aid in initial
digestion

41. ANATOMY OF THE SALIVARY
GLANDS

43. PAROTID GLAND
– Largest salivary gland
– Lies just below the ZYG arch in front & below the
ear
– Parotid duct(Stensons duct) is 5cm long, runs
over the messeter & opens into oral vestibule
opposite 2nd upper molar

45. SUBMANDIBULAR
GLANDS
– Extends posteriorly from below
1st lower molar to angle of mandible
– Forms part of soft tissues on the medial margin of the
mandible & the hyoid bone
– Submandibular duct(whartons duct ) is 5 cm long, runs
forward ,medially and upward & opens into mouth on
side of frenulum

46. SUB LINGUAL GLANDS
 Smallest pair
 Located in floor of mouth on the surface of mylohyoid
muscle.
 Numerous, small sublingual ducts(ducts of Rivinus)
open into floor of mouth
 Ducts may join to form a single(duct of Bartholin)
which empties into the submandibular duct.

47. SIALOGRAPHIC TECHNIQUES
• SIMPLE INJECTION
• HYDROSTATIC
• CONTINUOUS INFUSION – PRESSURE
MONITOR

48. OIL based or aqueous based contrast
medium is introduced until patient
experiences discomfort in the gland.
The Procedure is simple and inexpensive.
Based on patients responses, under or over
filling of gland may occur.
SIMPLE INJECTION

49. HYDROSTATIC
• Aqueous contrast media is allowed to flow
under force of gravity from a reservoir until
patient experiences discomfort.
• Simple , inexpensive.
• Patients have to be in supine position

50. CONTINUOUS INFUSION –
PRESSURE MONITOR
• Using Aqueous contrast medium, a constant
flow is adopted and ductal pressure
monitored.
• No overfilling or underfilling.
• Complex equipment required and time
consuming

51. PROCEDURE
PRE-OPERATIVE PHASE
FILLING PHASE
EMPTYING PHASE

52. PRE-OPERATIVE PHASE
This involves taking pre operative
radiographs
before introducing contrast medium.
For the following reasons :
1. To note the position and presence of any
radiopaque obstruction.
2. To assess the position of shadows cast by
normal anatomical structures that may
overlie the gland, such as hyoid bone.

53. FILLING PHASE
• Relevant duct orifice is
probed, dilated
and cannulated.
• Then a contrast media is introduced into the
duct and radiographs are taken at right
angles to each other.

54. EMPTYING PHASE
• Cannula is removed and patient is advised
to rinse out.
• Lemon juice is given to remove contrast
media after 1and 5 minutes, radiographs
are taken.
• These films can be used as a crude
assessment of function.

55. EQUIPMENT
 Cannulas- Rabinov
type
 (0.012- 0.033inch tip)
 Lacrimal dilators
 Syringe
 Contrast agent-
Sinograffin
 Gauze sponge pads
 Secretogogue
 Focused light
 Magnifying glass

56. PROCEDURE
• Preliminary radiographs
– Detect conditions that do not require
contrast
• Give pt secretory stimulant 2 to 3 minutes
before contrast administration
– Pt asked to suck on lemon wedge
-Opens duct for easy identification

57. • Duct orifice is sprayed with topical anaesthetic
• Duct is cannulated, (dialator may be required),
contrast introduced with fluoroscopic guidance
• Contrast (oil based or water soluble iodinated)
(conc = 240mg/ml)
• Should be injected manually until pt feels discomfort
• Quantity needed may vary btw 1-2 ml

58. • Images taken immediately after contrast is
complete
• After taking req. images ,pt sucks on a lemon
wedge again to evacuate contrast
• Take post-procedure(delayed) radiographs
after 5 minutes to confirm evacuation of
contrast/ demonstrate any residual contrast

59. Dilation with probe of Wharton’s duct
of the submandibular gland.
Cannulation of duct with intravenous
catheter (22 gauge).

60. SIALOGRAPHIC
INTERPRETATIONS

61. NORMAL:TREE INWINTERAPPEARANCE

62. SIALOGRAPHY
Sialograph showing submandibular salivary gland,
resulting in bush in winter appearance

64. Sausage link appearance due to
sialodochitis

65. Dots or blobs of contrast media with in
the gland – sialectiasis in sialadinitis

66. Sjogren’s syndrome

67. • Rotated PA veiw
showing extensive
ductal displacement, in
pleomorphic adenoma
of parotid gland
resulting in BALL IN
HAND appearance

68. STRICTURE/STENOSIS
STRING OF SAUSAGE

69. CLASSIFICATION OF CONTRAST AGENTS USED IN
SIALOGRAPHY (RANKOW RM AND POLAYES IM,
1976)
CONTRAST
AGENTS
Lipid/fat soluble
Iodised oils
Eg Ethiodol,
Lipiodol
Water-insoluble
Organic Iodine
cpds
Eg Pantopaque,
Myodil
Water soluble
Eg Hypaque,
Urograffin,
Omnipaque

70. PROPERTY WATER SOLUBLE FAT SOLUBLE
Viscosity Low High
Surface Tension Low High
Drainage Permit filling of ductal system
under low pressure & facilitate
prompt drainage
Diameter of duct may be distorted & it
is poorly eliminated from finer duct. It
may cause ductal obstruction.
Physiologic
property
More physiologic, i.e. miscibility
with saliva is more
Less physiologic
Patient discomfort Ductal injection accompanied by
little pain or discomfort
Greater degree of discomfort, pressure
may push calculi backward & it may
damage ductal epithelium
Allergic reaction Not significant reaction occur May cause severe foreign body
reaction
Opacification Opacification is low but it can coat
& outline calculi more adequately
Opacification satisfactory. Denser
contrast may obscure debris & small
non-opaque calculi
Absorption &
Excretion
Rapid Slow
Embolism No chances Chances of embolism

71. ARTHROGRAPHY

72. Arthrography
• Used to obtain diagnostic information regarding
the:
– Joint space
– Surrounding soft tissue
– Cartilage
– Lesions of the menisci
• Delineates the joint space and its surrounding
structures
• Largely replaced by MRI

73. Why it is needed?
• The inability of plain radiography to demonstrate
either the articular cartilage or the boundaries of a
synovial space led to the introduction of contrast
media into the joint space followed by X-ray
examination of the joint.
• In the head & neck region, this technique when
employed in the temporomandibular joint it is
known as “temporomandibular joint
arthrography”.

74. • History: Pass in 1939 accomplished the first
use of arthrography in evaluating the TMJ.
• Single contrast arthrography: By
introducing RCM into lower joint space.
The single contrast technique yields more
information about the joint dynamics
• Double contrast arthrography: when RCM +
air is introduced in both upper & lower joint
spaces. Gives more information about the
joint morphology.

75. • Water soluble contrast agents are preferred
in arthrography because they provide
enough contrast to define the intra-articular
structures, and they have the advantage of
being dissipated quickly.

76. Pneumoathrograms
– Air or gaseous medium is used
– 100-150 ml
– Produces painful distention of joint
– Possible air embolism
– Accuracy is considerably less than that when 2 contrast
methods are used

77. Positive or Opaque Arthrography
– Water soluble iodinated
contrast
• Ionic or non-ionic
• 30-100ml can be used
– Contrast is readily absorbed,
tolerated and excreted
– Produces greater diagnostic
accuracy
– Concentration should be no
more than 30%

78. Double contrast Arthrography
– Both gaseous and water soluble contrast
employed
– By using both contrasts less of each can be
used.
• Reducing patient discomfort
• Decreasing chance of air embolism
• Highly accurate diagnostic study

79. Indications and Contraindications for
Arthrography
• Indications:
– Suspected injury of meniscus (tears)
– Suspected capsular damage
– Rupture of articular ligaments
– Cartilaginous defects
– Arthritic deformities (specifically TMJ)
– Congenital luxation ( dislocation) of hip
– Extent of damage from trauma
• Contraindications:
– Hypersensitivity to iodine

80. TMJ Arthrogram
• CT and MRI have largely replaced TMJ
arthrography because they are noninvasive
• Useful in diagnosing
– Abnormalities of the articular disk
• Indications: pain, clicking sound, lock jaw when
chewing sticky candy

81. TMJ Arthrograms
MRI
Tomography

82. ANGIOGRAPHY

83. • Angiography includes arteriography &
phlebography. The first X-ray atlas of
arterial tree was published in England in
1920.
• Diatrizoate, metrizoate, iohexol, iopamidol,
ioxaglate, gadodiamide, SPIO particles can
be used for imaging the vascular system.
• The normal external carotid artery can be
opacified by 3-10 ml of contrast medium.

84. LYMPHOGRAPHY

85. • Requires inj of RCM into efferent
lymphatics.
• Lipiodol & patient blue violet are
commonly used in lymphangiography.
• 1 ml is usually injected subcutaneously
transversely along the base of the toes. Pt &
relatives should be warned of color changes
in skin & urine & of staining of faeces &
sputum. Effects rarely last longer than 2
days.

86. COMPUTED TOMOGRAPHY

87. Why it is needed?
• To obtain a differential change in the
attenuation values of normal & pathological
tissues.

88. • Contrast agents can be administered i.v. or
orally.
• Patients are instructed not to eat or drink for
a few hours prior to injecting the contrast
media because the dye may cause stomach
upset. Patients are made to drink an oral
contrast solution 1-2 hrs before CT scan of
the abdomen or pelvis.

89. ULTRASOUND IMAGING

90. Why it is needed?
• Contrast agents can improve the image
quality in sonography either by decreasing
the reflectivity of the undesired interfaces or
by increasing the back scattered echoes
from the desired regions.
• In the former approach, the contrast agents
are taken orally, & for the latter effect, the
agent is introduced parenterally.

91. • Agents used: simethicone-coated cellulose
• Preparation: ingestion in dosages of 200 to
400 ml results in a homogenous
transmission of sound through the contrast-
filled stomach.
• The 1st commercially available ultrasound
contrast medium was Echovist, which was
introduced in Europe in 1991 by the
German company, Schering.

92. MAGNETIC RESONANCE
IMAGING

93. • MRI contrast agents are classified on the
basis of different changes in the relaxation
times after their injection

94. • They cause reduction in the T1 relaxation
time (increased signal intensity on T1
weighted images)
• Contain gadolinium, manganese, iron as
their active agents.

95. • They cause reduction in the T1 relaxation
time (increased signal intensity on T1
weighted images)
• Appear predominantly dark on MRI & are
small particulate aggregates often termed as
superparamagnetic iron oxide (SPIO).
• Predominantly produce spin relaxation
effects (local field inhomogeneities), which
result in shorter T1 & T2 times.

96. ADVERSE REACTIONS

97. Contrast media side effects
• Reactions due to osmolality
1. Endothelial damage
2. Thrombosis and thrombophlebitis
3. Damage to BBB
4. Vasodilation
5. Vascular pain
6. Hypervolumia and CVS side effects

98. Contrast media side effects
• Reactions due to chemotoxicity
chemotoxicity occurs due to cations
more common with Na than Meg
Damage can occur to
Neurons , myocardium , endothelium ,
RBCs , kidney

99. Contrast media side effects
• Immunological reactions
true allergic reactions are very very rare . Hence
called as anaphylactoid or allegroid reactions .
Basis is
1. Histamine release
2. Inactivation of Enzymes especially ACE and C1
esterase inhibitor
3. Activation of protein cascades like
coagullation,compliment and kallikrein systems

100. Contrast media side effects
• Reactions unrelated to media
1. pyrogenic reactions ( d/t IL-2,TNF
productions)
2. Vasovagal reaction
3. Hypertensive attacks in
pheochromocytoma

101. Contrast media side effects
• Limbic system involvement in reactions (
anxiety and fear )
1. Nausea and vomiting
2. Vasovagal reaction
3. Temperature elevation cardiac
dysrhythmias
4. urticaria

102. Reactions and management
• Minor reactions: 5%
• Nausea/vomiting :
reassure
inj.prochlorperazine (5-10 mg IM)
prevent aspiration
• Mild urticaria
observe
H1 blocker( diphenhydramine 25-50mg IM/IV)

103. Reactions and management
• Intermediate reactions- 1%
extensive urticaria :
H1 blocker + H2 blocker
• Bronchospasm : O2 inhalation
MDI B2 agonist
inj. Theophylline
inj. Epinephrine SC/IV

104. Reactions and management
• Laryngeal edema : O2 inhalation
intubation if required
inj. Epinephrine
• Hypotension : elevate legs
monitor pulse &
manage accordingly

105. Reactions and management
• Severe reactions- 0.05%
Anaphylactoid reactions
c/b hypotension with tachycardia
IV fluids
Inj. Epinephrine (sc/im)
Inj. Hydrocort
O2 inhalation

106. Reactions and management
• Vasovagal reactions
c/b hypotension with bradycardia
O2 inhalation
IV fluids
Inj. Atropine

107. Reactions and management
• Pulmonary edema
Elevate head end
O2
Inj. Lasix
Inj. Morphin
Inj. Hydrocort

108. Reactions and management
• Seizures & convulsions
O2 inhalation
Prevent aspiration
Inj. Diazepam
• Hypertensive crisis
O2
Nitroglycerine
Inj. Lasix
If pheochromocytoma, manage accordingly

109. Reactions and management
• Extravasation of contrast media
Elevation of extremity
Ice packs
Plastic surgery consultation
-if large volume,
-skin ulceration or blistering
-worsening symptoms
Follow up until resolution

110. Prevention is always better
• Identify high risk patients
1. Prior reaction to CM
2. Allergic conditions
3. Asthma
4. Diabetes mellitus
5. Very old and very young
6. Paraproteinemia and increased viscosity
7. Cardiac disease

111. Prevention is always better
• Pre medications required in
I. Previous reaction to CM (11 times high risk)
II. History of allergic conditions
Medications
Tab Wysolone 10 mg qid 2-3 days
Tab Rantac 150 mg bd 2-3 days
Inj Hydrocort 100mg iv
Inj Hydrocort 100mg iv 24 hrs & 12 hrs before procedure and
100 mg iv at procedure

112. Prevention is always better
• Proper hydration required in
I. paraproteinemic conditions
II.hyperviscocity conditions
Don`t allow any type of dehydration
IV fluids: 500- 1000 ml during procedure
3-3.5 Ltrs orally over next 12 hours

113. Prevention is always better
• Drug adjustments
Diabetes mellitus: If on Biguanides,
stop at least 1 week before- avoids lactic
acidosis.
Thyroid disease: continue sulphonyl
ureas for at least 2-3 weeks to avoid
hormonal disturbance

114. Drugs used in Management
• Epinephrine
1:1000 (sc/ im) contains 1mg/ml
1:10000 (iv) contains 1mg/10ml
Precautious use in
Cardiac disease, hypertension & Pt on
B-blockers
• Atropine
0.6-1.2 mg iv monitored by pulse rate
Precautious use in
Glaucoma , BHP
• Corticosteroids: not useful in acute reactions
Hydrocort 100 mg iv
Prednisolone 10 mg oral

115. Drugs used in Management
• Antihistaminics: both H1 & H2 blockers used
Diphenehydramine (H1) 50 mg
Cimetidine (H2) 300 mg
• B2 agonists: used by MDI
Salbutamol, terbutaline
• Lasix: 40 mg iv
monitor electrolytes
• Anticonvulsants
Diazepam 5mg iv
• Antihypertensives
phentolamine ( pheochromocytoma), Nifedipine

116. REFERENCES
• Oral Radiology- White and Pharoah
• Radiography and Radiology for Dental Care
Professionals- Whaites & Drage
• T.B. of Oral & Maxillofacial Radiology-
Freny R. Karjodkar
• T.B. of Oral Radiology- Ghom

117. THANK YOUTHANK YOU