2. It is an agent that changes differential attenuation of
x-ray by increasing or decreasing the density of the
structure.
It is commonly used to enhance the visibility of blood
vessels, gastrointestinal tract etc.
CONTRAST
MEDIA
3. Types of Contrast Media
Positive contrast media.
Negative contrast media.(air /carbon
dioxide)
Paramagnetic contrast media (MRI)
Ultrasonic contrast media(USG)
5. Negative ContrastNegative Contrast
Organs become moreOrgans become more
radiolucent.radiolucent.
X-rays penetrate moreX-rays penetrate more
easily.easily.
Ex: air,CO2Ex: air,CO2
6. Oil based C.M.Oil based C.M.
a)a) It was 1It was 1stst
introduced in myelography by sicard asintroduced in myelography by sicard as
11stst
generation C.M in 1921.generation C.M in 1921.
b)b) it was used for bronchography, HSG,it was used for bronchography, HSG,
pyelography and lymphography.pyelography and lymphography.
c)c) It is rarely used now a days in some specialIt is rarely used now a days in some special
cases like COPD & pulmonary hypertension.cases like COPD & pulmonary hypertension.
7. Disadvantages of Oil BasedDisadvantages of Oil Based
C.MC.M..
Poorly absorbed so forms foreign bodyPoorly absorbed so forms foreign body
granulomata.granulomata.
Pulmonary and peripheral fat micro emboli.Pulmonary and peripheral fat micro emboli.
8. They are water soluble C.MThey are water soluble C.M
It is of two types-It is of two types-
a.a. Renal C.MRenal C.M
b.b. Biliary C.MBiliary C.M
2nd
generation C.M
9. Iodine is main + ve C.M and used as 25% NaI
in 1923.
In 1925,pyridine series developed as-
• uroselectant A(1 iodine atom)
• uroselectant B(2 iodine atom)
This diodinated C.M were used in diagnostic
radiology with satisfactory tolerability.
Renal C.M
10. In 1950, 3 changes were made in pyridine
derivatives.
Changed to Benzene with 3 iodines.
Hydrophillic side chains were added.
Meglumine cation was introduced.
Renal C.M Contd…..
11. WHY IODINE?WHY IODINE?
IODINE(atomic wt 127) provides excellentIODINE(atomic wt 127) provides excellent
radio-opacity due toradio-opacity due to
Higher atomic no: and K-shell electronHigher atomic no: and K-shell electron
binding energy of 34kev which is lowerbinding energy of 34kev which is lower
than but closed to mean energy used inthan but closed to mean energy used in
diagnostic x-rays and thus maximizing thediagnostic x-rays and thus maximizing the
photo-electric effect.photo-electric effect.
12. Iodinated Contrast AgentsIodinated Contrast Agents
Principal classes of iodinated radiologicalPrincipal classes of iodinated radiological
contrast mediumcontrast medium
1). CONVENTIONAL HOCM1). CONVENTIONAL HOCM
Ionic monomerIonic monomer
2). LOCM2). LOCM
Ionic dimerIonic dimer
Non ionic monomerNon ionic monomer
Non ionic dimerNon ionic dimer
15. Iodinated Contrast AgentsIodinated Contrast Agents
IONIC MONOMERSIONIC MONOMERS
Tri-iodinated benzoic acid derivative withTri-iodinated benzoic acid derivative with
Na+ / meglumine cationNa+ / meglumine cation
High osmolality > 1400 mosm/kgHigh osmolality > 1400 mosm/kg
Iodine:particle ratio of 3:2Iodine:particle ratio of 3:2
16. Further classified on basis of % ofFurther classified on basis of % of
compound in the solution.eg. 30%, 70%compound in the solution.eg. 30%, 70%
[ UROGRAFFIN 76%][ UROGRAFFIN 76%]
Sodium is toxic to endothelium & BBB SoSodium is toxic to endothelium & BBB So
avoided in venography and cerebralavoided in venography and cerebral
angiography.angiography.
Ionic MonomerIonic Monomer
17. Ionic MonomerIonic Monomer
Meglumine salts are used for this.Meglumine salts are used for this.
Both pure sodium and pure meglumineBoth pure sodium and pure meglumine
salts are associated with high risk ofsalts are associated with high risk of
ventricular fibrillation so a mixture ofventricular fibrillation so a mixture of
sodium and meglumine is used.sodium and meglumine is used.
19. Ionic dimerIonic dimer
Two tri-iodinated benzene rings with singleTwo tri-iodinated benzene rings with single
carboxyl other replaced by non-ionizing sidecarboxyl other replaced by non-ionizing side
group.group.
Iodine: particle ratio of 6:2Iodine: particle ratio of 6:2
Low osmolality 600 mosm/kgLow osmolality 600 mosm/kg
Examples: loxaglate{Examples: loxaglate{HEXABRIXHEXABRIX}}
LOCM Iodinated ContrastLOCM Iodinated Contrast
AgentsAgents
20. Ionic dimersIonic dimers
Hexabrix is acceptable arteriographicHexabrix is acceptable arteriographic
agent with reduced pain but on i.v showsagent with reduced pain but on i.v shows
toxicity so not to be used in IVU,and CT.toxicity so not to be used in IVU,and CT.
21. Iodinated Contrast AgentsIodinated Contrast Agents
NON-IONIC MONOMERSNON-IONIC MONOMERS
Modified tri-iodinated benzoic acidModified tri-iodinated benzoic acid
derivative with carboxyl group replaced byderivative with carboxyl group replaced by
D-glucose groupD-glucose group
do not dissociate and water-solubility duedo not dissociate and water-solubility due
several hydrophilic hydroxyl groupsseveral hydrophilic hydroxyl groups
Iodine: particle ratio 3: 1Iodine: particle ratio 3: 1
Low osmolality 500-700 mosm/kgLow osmolality 500-700 mosm/kg
26. Iodinated Contrast AgentsIodinated Contrast Agents
Iodine : particle ratio = no. of iodine atoms per molecule ofIodine : particle ratio = no. of iodine atoms per molecule of
CM / no. of osmotically active particles per molecule ofCM / no. of osmotically active particles per molecule of
CMCM
contrastcontrast
mediamedia
iodine particleiodine particle
ratioratio
Ionic monomerIonic monomer 3:23:2
Ionic dimerIonic dimer 6:26:2
Non ionicNon ionic
monomermonomer
3:13:1
Non ionicNon ionic
dimerdimer
6:16:1
31. Iodinated Contrast AgentsIodinated Contrast Agents
Delayed reactionsDelayed reactions
Occur after 1 hour to 1 weekOccur after 1 hour to 1 week
- flu like symptoms- flu like symptoms
- delayed arm pain- delayed arm pain
- rash/ pruritus- rash/ pruritus
- salivary gland swelling- salivary gland swelling
- Steven Johnson syndrome- Steven Johnson syndrome
more common with LOCMmore common with LOCM
32. Contra indicationContra indication
Risk factorsRisk factors
Raised creatinine levelRaised creatinine level
DehydrationDehydration
Congestive heart failureCongestive heart failure
Age over 70 years oldAge over 70 years old