Radiographic Contrast RTEC - A 2012
1. SUBJECT & FILM CONTRAST
2. CONTRAST MEDIA
2 types of Radiographic “Contrast”
1. Subject contrast – patient
2. Film contrast– Inherent in equipment – The BLACKS & WHITES ON THE FILM / IMAGE
“Subject” Contrast
Subject Contrast
• Range of differences in the intensity of the x-ray beam
• After it has been attenuated by the subject.
SUBJECT CONTRASTRadiographic object - influenced by
1. Atomic Number of object2. Density of object3. Thickness of object4. 5 materials seen on a radiograph,
– Gas/air, fat, soft tissue (muscle/organs), – bone and metals
Atomic Number
1. Fat = 6.46
2. Water = 7.51
3. Muscle = 7.64
4. Bone = 12.31
TissueSubject Contrast
1. Atomic # of object
2. Density of object
3. Thickness of object
1. Higher atomic # = more attenuation
2. Denser = more attenuation
3. Thicker = more attenuation
PATHOLOGY
1.Pleural Effusion
2.Excessive fluid in lung
3.More dense than air
Pneumothorax
1. Lung collapses
2. No tissue in space
3. Easy to penetrate with x-ray photons
Film Contrast AKA Radiographic Contrast
Radiographic Contrast influenced by:
1. Radiation Quality (KVP)
2. Film attributes
3. Radiographic object (Patient)
What is good contrast ?
1. High contrast (black and white)
2. Low contrast (more shades of gray)
RADIOGRAPHIC IMAGE Radiation Quality = kVp
1. High kVp ↑ 802. Low contrast3. Lots shades of gray4. Long Scale5. Little differences in
adjacent structures
1. Low kVp ↓ 702. High contrast3. Black and White4. Short Scale5. Great differences in
adjacent structures
Contrast changes with the use of a grid
Less scatter radiation – shorter scale = “better contrast”
With Grid No Grid
QUALITY – KVP
• A visible change in contrast will not be seen until kVp is changed 4-12 %
– kVp level change change in kVp
• 30-50 kVp 4-5 % 1-3 kVp• 50-90 kVp 8-9 % 4-8 kVp• 90-130 kVp 10-12 % 9-16 kVp
Scenario• Low subject contrast in the area of interest.
– You want to see the difference between muscle & fat & organs?
• What can be done to attain medical information and define organ structure and function?
• _____________________________________
Scenario• Low subject contrast in the area of interest.
– You want to see the difference between muscle & fat & organs?
• What can be done to attain medical information and define organ structure and function?
• USE CONTRAST MEDIA
Changing Subject Contrast with CONTRAST MEDIA
21
Barium has a higher z#more asorbtion of photons
Contrast Media changes the density of the organs
Purpose of Contrast Media
1. To enhance subject contrast or render high subject contrast
1. In a tissue that normally has low subject contrast.
2. Creates bigger differences in atomic number (z #’s)
Categories of Contrast Media
Negative contrast1. (AIR OR CO2)
2. Radiolucent
3. Low atomic # material
4. Black on film
Positive contrast 1. (all others)
2. Radiopaque
3. High atomic # material
4. White on film
1. RADIOLUCENT - dark on image– AIR, CO2
2. RADIOPAQUE - white on image– BARIUM– IODINE
Negative Contrast
1. AIR / CO2
2. Naturally seen in the
– LUNGS – STOMACH– (gas in intestines)
POSTIVE CONTRAST MEDIA
2 BASIC TYPES OF ‘”Positive” CONTRAST MEDIA
BARIUM Z# 56KVP 90 – 120*
1. NON WATER SOLUABLE
2. GI TRACT ONLY INGESTED OR RECTALLY
IODINE Z# 53KVP BELOW 90*USUALLY 70 – 80 KvP
1. WATER SOLUABLE1. POWDER2. LIQUID3. INTRAVENOUS OR4. GI TRACT
2. OIL BASED1. DUCTS /ORGANS
Positive Contrast Material INGESTED /INSTILLED
– (ORALLY OR RECTALLY)
1. BARUIM
2. IODINES
– GASTROGRAFIN– HYPAQUE POWDER
INJECTED– IV – INTO BLOOD VESSELLS– Organs and ducts
1. IODINES – IONIC OR NON-IONIC
• VESSELLS & ORGANS
2. OIL BASED– DUCTS /ORGANS ONLY
Methods of Administrationof Contrast Material
1. INGESTED / INSTILLED
– (ORALLY OR RECTALLY)
2. INJECTED
– IV – INTO BLOOD VESSELLS
1. RETROGRADE – AGAINST NORMAL FLOW (Vessels
& Organs)
2. INTRATHECAL – Spinal canal
3. PARENTERAL 4. (IV, Intrathecal)
– Injecting into bloodstream
– (anything other than oral)
BARIUM
BARIUM SULFATE
HISTORY OF BARIUM BaSo 4
1. LEAD SUBSTRATE – TOXIC
2. BISMUTH SUBNITRATE – TOXIC
3. THORIUM – RADIOACTIVE
4. BARIUM SULFATE - INERT1. (goes in and comes out the same – not absorbed)
5. NOTE SOME PATIENT MAY SHOW ALLERGY TO SUSPENSION SOL.
Barium Sulfate BaSO+
1. High atomic number
2. Not soluble in water
3. Used to coat the lining of organs
4. Supplied in different thicknesses
5. Used1. Esophogram, UGI, Small Bowel,Lower GI or BE
Barium Sulfate BaSO+
1. Because it is not water soluble – it must be mixed in a SUSPENSION with water
2. FLOCCULATION – when barium clumps (separates from the water)
3. Barium residue in the colon can dry and cause an obstruction
4. Drink plenty of fluids after exam
BARIUM
1. MIXED IN A SUSPENSION
2. MUST BE SHAKEN
3. CHECK THE CAP (LID) FIRST !!!!!!!
4. SUSPENSION – sodium citrate, vegetal gums, flavoring and sweeteners to improve palatability
ADVERSE REACTIONS
1. SUSPENSION MAY CAUSE ALLERGY2. OCG TABLETS (IODINE) ALLERGY3. AFTER EXAM – MAY SOLIDIFY DIFFICULT TO
EVACUATE4. INCREASE FLUIDS, MILD LAXATIVE
5. EXTRAVASATION OF CONTRAST INTO PERITONEUM
BARIUM “THICK & THIN”1. THICK –
1. DOUBLE CONTRAST
2. THIN – 1. SINGLE CONTRAST
BARIUM ORAL OR RECTAL
1. LABELS ARE DIFFERENT
2. CHECK CAREFULLY BEFORE GIVING TO THE PATIENT
Palatability OF BARIUM
1. Chalky taste with barium sulphate/water mixture
1. Contain a flavoring agent, sweetners 1. To disguise the unpleasant taste
2. Thicker or thinner suspensions may be used
3. Many commercial preparations contain carboxymethyl cellulose (Raybar, Barosperse)
1. Which retains fluid and prevents precipitation of the barium suspension in the normal small bowel
GASTOINTESTINAL exams
• BARIUM COATS LINING OF INTESTINE
1. SINGLE CONTRAST - BARIUM ONLY2. DOUBLE CONTRAST – WITH AIR
• CARBON DIOXIDE TABLETS –• FIZZIES / CRYSTALS
3. SODA4. ROOM AIR (LOWER GI)
EXTRAVASATION
1. LEAKAGE THROUGH A DUCT OR VESSEL OR ORGAN INTO THE SURROUNDING TISSUE
2. Barium should not be given in cases of suspected perforation
Extravasation
1. Following a Colonoscopy with biopsy
Extravasation of BA in abd
GASTROINTENSTIALCONTRAST
MEDIAPROCEDURES
1. ESOPHOGRAM / OPMS2. UPPER GI (UGI)3. SMALL BOWEL (SMBFT)4. BARIUM ENEMA (BE)5. GASTRO ENEMA
Drinking Ba for Esophogram
Hiatal Hernia Reflux “heartburn”
Supplies for BE
“DOUBLE CONTRAST” studies with Barium
1. Air used with other contrast agents2. Better to see internal structures
BE – room air mixed with Ba UGI – gas “fizzies” used
DOUBLE CONTRAST EXAMS
1. To achieve double contrast examination of the stomach, air or carbon dioxide gas must be introduced
2. Most radiologists use effervescent tablets (sodium bicarbonate , tartaric acid & calcium carbonate)
3. To react with the gastric contents to produce carbon dioxide
BESINGLE DOUBLE (AC)
UGI double contrast single contrast
DOUBLE CONTRASTWITH IODINE
• Iodine mixed with air of a bladder (canine)
IODINE CONTRAST
Iodine1. Water Soluble2. High atomic # 533. Radiopaque4. Used to radiograph
– Vessels– Arteries– Veins– Function of internal
organs– Gastrointestinal system– Ducts
IODINATED CONTRASTWATER BASED
1. INJECTED
2. VESSELLS/DUCTS1. Ionic2. Non-ionic
3. INGESTED or instilled
4. OPEN WOUNDS
OIL BASED
1. INJECTED
2. NEVER VESSELLS
3. ONLY DUCTS
4. NOT INGESTED
5. OPEN WOUNDS
Gastrointestinal studies:Gastrograffin or Hypaque (Iodine)
1. High atomic #– Close to iodine
2. Water soluble
3. Similar usage as Barium
Gastrograffin
• Water soluble iodine-containing contrast media are of value when there is a suspected perforation or leakage of an anastomosis after operation
• Oral or Rectal use
GASTROGRAFIN
• POWDERED FORM – MIXED WITH H20
• LIQUID IN BOTTLE – MAY BE MIXED
• USED WHEN PATIENTS ARE ILL,• SUSPECTED PERFORATIONS• PRE-OPERATIVELY• (BITTER TASTE) • CAN INCREASE PERISTALSIS (SMB STUDY)
GASTROGRAFIN
1. Bitter taste
2. Better if chilled or mixed with ice
3. Monitor patient closely
Gastrograffin via NG tube
Peptic ulcer
1. Use Gastro2. Contrast may leak 3. Into the peritoneum4. Causing peritonitis
Gastric neoplasm w/ perforation
• EXTRAVASATION OF CONTAST INTO THE PERITONEUM
Gastrografinenema
SINGLE CONTRAST ENEMA
BARIUM (110 KVP) GASTROGRAFIN (90 KVP)
GASTROGRAFINAdverse Reactions
1. Water soluble, safe in the abdominal cavity
– Safe to use if perforation is suspected
2. Very harmful to the lung tissue
– Do not use if aspiration is possible
Never force contrastPatient might aspirate into the lungs!
INJECTABLECONTRAST MEDIA
INVASIVE PROCEDURESIVP / IVU
Intravenous injections are INVASIVE
ALWAYS GET PATIENT’S HISTORY AND CONSENT
BEFORE BEGINNING OR GIVING ANY CONTRAST
MEDIA
Patient Assessment Check List
• Information update !!
INJECTED CONTRAST
1. IODINE BASED
1. IONIC
1. NON IONIC
IODINATED Contrast Agents
IONIC• High Osmolality (Higher
risk of complications)
1. (Hypaque)
2. (Conray)
NON-IONIC• Low Osmolality (Lower
risk of complications)
1. (Isovue)
Iodine Contrast Material
1. Ionic Contrast– Anion -– Cation +– More patient allergic
reactions
2. Ionic contrast media dissociates into two molecular particles in blood plasma =
3. Causing pt reactions
1.Non-Ionic Contrast
• Less patient allergic reactions
Newer Contrast Agents Balance Safety and Visualization
IODINE WATER BASED CONTRAST
1. IONIC
2. LESS $$$ – $25 per bottle
3. MORE REACTIONS
1. NON IONIC
2. MORE $$$– $200 per bottle
3. LESS REACTIONS
CONTRAST REACTIONS
1. > 10 million diagnostic procedures / year
2. Conventional ionic contrast reactions - 10%
3. 1 in 1000 severe
Allergic to Iodine
General Rule:
1. No Iodine Contrast will be given1. Pre – medication is available
2. May or may not react if previous iodine given
REACTIONS & Treatment
USUALLY** WITHIN FIRST 5 MINUTES1. Nausea & Vomiting & Urticaria 2. Hypotension (bradycardia) 3. Hypertension (tachycardia) 4. Bronchospasm 5. Anaphylactoid 6. Seizures 7. Extravasation
ALWAYS –know the locationof drug trays and crash carts
INJECTED IODINE STUDIESGENITOURINARYContrast injected into the VEIN
1. IVP / IVU
2. CYSTOGRAMS(Retrograde may use a foley catheter)
3. GASTROINTESTINAL
4. ERCP – (CBD)
15 MIN POST CONTRAST INJECTION - IVP
CYSTOGRAM
Cholelithiasis
GB STONES
Normal ERCP (checks for stones/blockage in bile duct)
GB STONES
Other InjectedContrast Studies
Cerebral Angiogram
Renal Arteriogram
MYELOGRAM (SPINAL CORD)INTRATHECAL INJECTION
Extravasation
“To BE or not to BE”
1. Massive retroperitoneal air
2. pneumomediastinum3. subcutaneous air4. secondary to bowel
perforation 5. after barium enema
Extravasation of Contrastinto soft tissue of arm
Contrast leaking from bladder
OIL – BASED
IODINECONTRAST
Oil Based Iodine
1. Fatty Acids2. Insoluble in water
1. White on the radiograph = Radiopaque3. Uses
1. Bronchography (lungs)2. Tear ducts3. Salivary glands4. Lymphatic system5. Hysterrosalpingogram6. Galactography (breast ducts)
To check fertility
LYMPHANGIOGRAM
Galactography - Breast Duct
Oral & IV contrast
CT Scan
CT showing Abnormal GB
ORAL & IV CONTRAST (CT/ MRI)
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