2contrast Types of contrast media : The word contrast media means chemical substance sthat due to its high attenuation of X-ray or differential absorption of X-rays from the surrounding tissues permit clear demonstration of an organs or tubular structure .Types of contrast media :1. Intravascular :A. High osmolar-cm or ionic.B. Low osmolar or nonionic.2. Oral.
3HOCM or ionic: Various HOCM are: Sodium iodide and sodium acetrizoate (UROKON) were the first ionic contrast media. Later various benzoic acid derivatives were introduced which were combine with Na+ and Meg+Various HOCM are:Diatrazoate (urografin)Iothalmate (Hypaoue)Metrizoate (Conry)IodamideThese are monomeric ionic contrastRCooII+NaRRI
4HOCM or ionic:Ionic contrast media are hypertonic with osmolality of per lit wich is 4-7 time more than osmolality of plasma.Almost all the adverse effect of these contrast media are due to hyper tonicity.An ideal contrast agent should be :Non toxic.Painless to patient.Low osmolar.It should not be expensiveThe ratio of iodine atoms to ions in HOCM is 3:2
5Low Osmolar Nonionic Contrast In order to reduce the osmolarity and increase the ratio of iodin atom to particle in solution dimericionic contrast agent were produced such as ioxgalate.These compound were having 6 iodine atom for two molecules+NaCoo+NaMEGCooIIIIIIRRR(Ioversol)IIIDimeric CompoundThis Agent is low osmolar but ionicMonomericnonionicIodine 3:1
63.Iopromide (Ultravist) 4.Ioversol 5 Iotrolon(isovist) 6 .Iodoxinal ROHROHIIIIROHRROHIIDIMERICNONIONICIODINE RITIO6:1These Compound are :1.Iopamidol (Niopam)2.Iohexol (omnipaque)3.Iopromide (Ultravist)4.Ioversol 5 Iotrolon(isovist) 6 .IodoxinalThese agent have low osmolality as compared to HOMC and fewer side effect.The only disadvantage is there cost these agent are very expensive.
9Minor Reaction / Effect Moderate adverse effects :Maintain I / v lineAntihistamine mg paeds 2 mg / kg body witeWheeze :Hydrocortisone 100 I / V , O2 therapy.Hypotension with bradycardia O2 , I / V FlaidAtropine 0.6 mg repeat sm total 3 mg.
10Contrast Media Used In M.R.I It enhanced the inherent tissue contrast causes T1 and T2 shortening .Type :A. ParamagneticEX : Gadolinium D.TPA. Causes T1 shortening signal appear bright.B. Super paramagneticEX : Iron oxide manganese for causes T2 shortening signal appear dark .
11Adverse Reactions Minor : 2. Moderate Reactions : Nausea Vomiting SneezingUrticariaPain in armSensation of warmness2. Moderate Reactions :Persistant headacheSevere urticaria and bronchospasmWheezes abdominal crampsHypotension with bradycardia…………Severe vomiting G
12Adverse Reactions 3. Severe and life threatening Laryngeal edema Angioneurotic edemaHypotension with tachycardiaAnaphylaxis (2nd) severeSeizureCardiac arrestPulmonary edemaUnconciousness / no response / pulse less /cardiopulmonary collapse and death
13Mechanism of contrast media reactions: 1:Over dose 2:Anxiety 3:Chemotoxicity 4:Endothelial damage 5:Release of histamine and other enzymes 6:Anaphylaxis.
14Risky group of patients to whom HOCM is not recommended. Extreme age eg infants and old peopleHypertensionDMAsthmaRenal failureLiver failureMultiple myelomaDehydration
15MRI contrast media Generally two type of MRI contrast agents Paramagnetic. Eg Gadolinium and mangnese agentsGadolinium ion is a paramagnetic agent which has 7 unpaired electronsIt is chelated with DTPA because GAD alone is toxic.It cause T1 shortening due to that T1 weighted image appear bright.Different agents in this group are Gadopentate and Gadodamide.These compound are injected by I/v route
16MRI cont,The second group are Superparamagnetic Iron oxide.This agent is specifically used for liver and mainly cause T2 shortening.This has opposing effect and the enhanced area appear black.
17Adverse effect of MRI contrast Metalic taste in mouthNausea vomittingItchinNephrogenic fibrosisUrticaria etc
18Indication of MRI contrast CNS tumorsCrdiac imagingVascular imagingMusculoskeletal imaging
19Ultrasound Contrast agents Small microbullesLeovist.Most commonly usedEchovistAlbunexEchogen
21ORAL contraST AGENT .IWater soluble.Gastromiro.It is iopamidol 61% w/v Gastrographine.It is mixture of sodium andmeglumine diatrozoate 66%w/v
22Indication Suspected perforation LOCM is used if aspiration is a possibilityComplications are hypovolumia,pulmonary edema and allergic reaction
23Barium sulphate Baritop 100 100%w/v for barium follow through E-Z-HD 250%w/v for barium sallow and barium meal examination.E-Zpaque 100% w/v for barium follow throughE-Z paque 60% w/v for small boel enemaPlibar 115% w/v for barium enema.
24Advantages and disadvantages of barium Barium has excellent coating of mucosa as compared to water soluble contrast.It is cheapHigh mortality if leak occure in to the peritoneal cavityMake subsequent CT examination difficult
25ComplicationsPerforation.The escape of barium in to the peritoneal cavity is dangerousAspiration is harmlessIntravasation can result in pulmonary emb
27Pharmacological agents Hyoscine –N-butyle bromide(Buscopan)Adult dose 20mg I/VIt inhibit intestinal motility and gastric secretionAdvantages. Immediate action,short duration of action and it is not expensiveDisadvantages. Blurring of vision,dry mouth,tachycardia and urinary retention.Contraindications.close angle glaucoma,myasthenia gravis,pyloris stenosis etcglucogon can be used in these situations
28Glucogon Adult dose. .3—1mg Childern dose ,5—1microgram/kg Advantages.more potent smooth muscle relaxant than glucogan,,short duration of action and it do not interfer with ttransit time of bowelDisadvantages.hypersensetivity teaction is possible,long onset of action and expensive
29Contraindication of glucogan Adrenal tumors.glucogan can cause sudden hypertension.if hypertension occure,phentolamine can be used for treatmentEndocrine tumors of pancrease
31Emergency drugs used in X-ray department Metacloperamide.For sever vomiting and for fascilitation of barium follow through .Adrenaline.1:1000 sc or i/m injection.used in cardiac arrestAtropine.600micg in 1ml.used for treatment of vasovagal shock(hypotension with bradycardia)Chlorophenirmine.10mg in 1ml.used for sedation and vomiting
32Drugs Sodium bicarbonate 200ml.used to prevent or treat acidosis Aminophyline.250mg in 10ml.for the treatment of bronchospasmDiazepam i/v 10mg.For the sedation and treatment of convulsionHydrocortisone 100mg.In any emergency condition.Dopamine.800mg in 5ml.For treatment of hypotension with tachycardia
33Drugs Frusemide. For pulmonary edema and diuresis Nalaxone.400micg in 1ml.used as antidote for morphine.Protamine sulphate.used as antidote for heparine.Dextrose5% 50ml.for I/V fluid replacementDextrose 50%.as I/V fluid replacementNormal saline 500ml as fluid replacement.
34Treatment of toxic reaction of contrast Angioneurotic edema. I/V lineI/V hydrocortisoneI/V antihistaminesc adrenalineOxygenBronchospasm I/V lineAminophylineHydrocortisoneSevere urticaria.antihistamine or sc adrenaline
35Toxic reactions Hypotension. Elevation of legs No improvement and bradycardia,then give I/v fluid and atropineIf no improvement and tachycardia,then give I/v fluid or dopamine infusion.