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)