CONTRAST MEDIA
Dr. Ahmed Refaey
FRCR
Types of contrast media
* Iodinated :
* HOCM
* LOCM
* GIT contrast agents
* Barium sulphate
* water soluble contrast media (
Gastrographin)
* MRI contrast agent
* Ultrasound contrast agent
IODINATED CONTRAST
AGENTS
Classification
High osmolar
contrast agents (
HOCA )
Low osmolar contrast
agents ( LOCA )
* Ionic
* Ionic
* Non-ionic
HOCM
• HOCA are in use since the 1950.
*
*
*
*
*
*
*
Urovist.
Urogarfin
Angiovist.
Conray.
Renografin.
Renovist.
Hypaque.
LOCA
Non-ionic
Ionic
Ultravist
Omnipaque
Visipaue
Oxilan
Hexabrix
• LOCA have a lower incidence of adverse
reactions by a factor of 6 for all reactions ,
and by a factor of 9 for the severe
reactions.
Toxic effects
• Vascular toxicity
• Soft tissue toxicity
• Cardiovascular toxicity
• Haematological changes
• Thyroid function
• Nephrotoxicity
Nephrotoxicity
• Incidence of contrast induced nephrotoxicity 5%
• In the majority, renal impairment is temporary
• Predisposing factors :
*
*
*
*
*
*
impairment of renal function
DM
dehydration
old age
large doses of CM
multiple myeloma
Reactions of CM
• Fatal reactions ( death )
-1/140,000 for HOCM
1/300,000 for LOCM
-occur in minutes
-old age
-causes ( cardiac arrest – pulmonary edema
– respiratory arrest – coagulopathy –
laryngeal edema- bronchospasm )
• Non- fatal reactions
1-flushing, metallic taste in the mouth, nausea, sneezing,
cough—common & related to dose and speed of
injection.
2- urticaria
3- angioneurotic edema
4- bronchospasm
5- pulmonary edema
6- arrythmia
7- hypotension
8- delayed reactions: rashes , headaches, itching
*Excluding death, adverse reactions can be
classified in terms of severity as:
• 1- major reactions : those that interfere
with the examination and require
treatment.
• 2- intermediate reactions : those that
interfere with the examination but do not
require treatment.
• 3- minor reactions : those that do not
interfere with the examination and require
only assurance
Risk factors
•
•
•
•
•
•
allergy , asthma
Cardiac disease
Hepatic failure
Poor hydration
Co-administration of: glucophage
Previous reaction to contrast media
- HOCM----- 20%
- LOCM ----- 5 %
• Other factors:
* pheochromocytoma
* sickle cell disease
* hyperprotinemia ( multiple myeloma )
• High risk patients should either:
1 – be premeicated with steroids
2- to be evaluated with other modality (
U/S – MRI )
• Route of administration : intravenous
• Uses :
* CT study
* urography ( IVP- urethrography_
cystography )
* angiography ( arteriography – venography )
* PTC, ERCP, T-tube cholangiography
* hystrosalpingography
* sialography
* fistulography
Urography
IVU
Cystogram
Urethrogram
Angiography
Sialogram
Sialogram
Fistulogram
PTC
PTC
ERCP
T-tube cholangiogram
HSG
HSG
GIT contrast agents
Gastrointestinal contrast agents
• BARIUM SULPHATE
• WATER SOLUBLE CONTRAST
MEDIUM (GASTROGRAFIN )
BARIUM SULPHATE
Barium sulphate
• Thin barium : for upper GI studies, small
bowel follow through, barium enema ---40% BaSO4 solution.
• Thick barium : for double contrast
studies ---- 85% BaSO4 solution
• Advantages :
* excellent coating, allowing the
demonstration of normal and abnormal
mucosal patterns.
* cost
• Complications:
• Exacerbation of GI obstruction above a
preexisting bowel obstruction
• Intraperitoneal extravasation through gut
perforation results in extensive fibrosis
• Contraindication :
• Bowel obstruction
• Bowel perforation
Water soluble contrast medium
(gastrografin )
Water soluble contrast medium
(Gastrografin )
• Oral contrast medium for opacification of
GIT
• Hygroscopic agent
• Undiluted or diluted
• Can be used as a substitute for barium if
GI perforation is suspected.
• In CT , diluted by 1:40
Complications
• Aspiration can cause chemical pneumonitis
• Diarrhea
• Hypovolemic shock if used undiluted
CT contrast agents
• IV contrast medium
• Oral water soluble contrast medium
(gastrografin)
MRI contrast agent
MRI contrast agent
• Gadolinium
• Gd-DTPA
• IV
ULTRASOUND CONTRAST AGENT
• Levovist / echovist
• IV
• All agents consist of radiodense iodinated
Benzene ring.
• Ionic agent typically formulated as Sodium
and or meglumine salts.