Radiographic Contrast

RTEC - A 2010

  1. SUBJECT & FILM CONTRAST
  2. CONTRAST MEDIA

2 types of Radiographic “Contrast”

  1. Subject contrast

patient

  1. 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 CONTRAST
Radiographic object - influenced by

  1. Atomic Number of object
  2. Density of object
  3. Thickness of object
  4. 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

Tissue
Subject Contrast

  1. Atomic # of object
  2. Density of object
  3. Thickness of object
  4. Higher atomic # = more attenuation
  5. Denser = more attenuation
  6. Thicker = more attenuation

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 ↑ 80
  2. Low contrast
  3. Lots shades of gray
  4. Long Scale
  5. Little differences in adjacent structures
  6. Low kVp ↓ 70
  7. High contrast
  8. Black and White
  9. Short Scale
  10. Great differences in adjacent structures

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 kVp4-5 %1-3 kVp

50-90 kVp8-9 %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

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 contrast

  1. (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

  1. 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# 56

KVP 90 – 120*

  1. NON WATER SOLUABLE
  2. GI TRACT ONLY INGESTED OR RECTALLY

IODINE Z# 53

KVP BELOW 90*

USUALLY 70 – 80 KvP

  1. WATER SOLUABLE
  2. POWDER
  3. LIQUID
  4. INTRAVENOUS OR
  5. GI TRACT
  6. OIL BASED
  7. 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

  1. OIL BASED

DUCTS /ORGANS ONLY

Methods of Administration
of Contrast Material

  1. INGESTED / INSTILLED

(ORALLY OR RECTALLY)

  1. INJECTED

IV – INTO BLOOD VESSELLS

  1. RETROGRADE

AGAINST NORMAL FLOW (Vessels & Organs)

  1. INTRATHECAL

Spinal canal

  1. PARENTERAL
  2. (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 - INERT
  5. (goes in and comes out the same – not absorbed)
  6. 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. Used
  6. 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 ALLERGY
  2. OCG TABLETS (IODINE) ALLERGY
  3. AFTER EXAM – MAY SOLIDIFY DIFFICULT TO EVACUATE
  4. INCREASE FLUIDS, MILD LAXATIVE
  5. EXTRAVASATION OF CONTRAST INTO PERITONEUM

BARIUM CONCENTRATION

  1. DIFFERENT FOR EXAMS
  2. W/W RATIO (weight/weight)
  3. Mixture of barium to water – 100 g suspension
  4. “THICK” VS “THIN” BARIUM

BARIUM “THICK & THIN”

  1. THICK –
  2. DOUBLE CONTRAST
  3. THIN –
  4. 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
  2. Contain a flavoring agent, sweetners
  3. To disguise the unpleasant taste
  4. Thicker or thinner suspensions may be used
  1. 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 ONLY
  2. DOUBLE CONTRAST – WITH AIR

CARBON DIOXIDE TABLETS –

FIZZIES / CRYSTALS

  1. SODA
  2. 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

GASTROINTENSTIAL
CONTRAST
MEDIA
PROCEDURES

  1. ESOPHOGRAM / OPMS
  2. 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 agents
  2. Better to see internal structures

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

BE
SINGLE DOUBLE (AC)

UGI
double contrast single contrast

DOUBLE CONTRAST
WITH IODINE

Iodine mixed with air of a bladder (canine)

IODINE CONTRAST

Iodine

  1. Water Soluble
  2. High atomic # 53
  3. Radiopaque
  4. Used to radiograph

Vessels

Arteries

Veins

Function of internal organs

Gastrointestinal system

Ducts

IODINATED CONTRAST

WATER BASED

  1. INJECTED
  2. VESSELLS/DUCTS
  3. Ionic
  4. Non-ionic
  5. INGESTED or instilled
  6. 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

  1. Water soluble
  2. 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 Gastro
  2. Contrast may leak
  3. Into the peritoneum
  4. Causing peritonitis

Gastric neoplasm w/ perforation

EXTRAVASATION OF CONTAST INTO THE PERITONEUM

Gastrografin
enema

SINGLE CONTRAST ENEMA
BARIUM (110 KVP) GASTROGRAFIN (90 KVP)

GASTROGRAFIN
Adverse Reactions

  1. Water soluble, safe in the abdominal cavity

Safe to use if perforation is suspected

  1. Very harmful to the lung tissue

Do not use if aspiration is possible

Never force contrast
Patient might aspirate into the lungs!

INJECTABLE
CONTRAST MEDIA

INVASIVE PROCEDURES

IVP / 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
  2. IONIC
  3. 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

  1. Ionic contrast media dissociates into two molecular particles in blood plasma =
  1. Causing pt reactions

Newer
Contrast Agents Balance
Safety and Visualization

IODINE WATER BASED CONTRAST

  1. IONIC
  2. LESS $$$

$25 per bottle

  1. MORE REACTIONS
  2. NON IONIC
  3. MORE $$$

$200 per bottle

  1. 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 given
  2. Pre – medication is available
  3. May or may not react if previous iodine given

REACTIONS & Treatment

USUALLY** WITHIN FIRST 5 MINUTES

  1. Nausea & Vomiting & Urticaria
  2. Hypotension (bradycardia)
  3. Hypotension (tachycardia)
  4. Bronchospasm
  5. Anaphylactoid
  6. Seizures
  7. Extravasation

ALWAYS –know the location
of drug trays and crash carts

INJECTED IODINE STUDIES

GENITOURINARY

Contrast injected into the VEIN

  1. IVP / IVU
  2. CYSTOGRAMS
  3. (Retrograde may use a foley catheter)
  4. GASTROINTESTINAL
  5. ERCP – (CBD)

15 MIN POST CONTRAST INJECTION - IVP

Cholelithiasis
GB STONES

Normal ERCP
(checks for stones/blockage in bile duct)

GB STONES

Other Injected
Contrast Studies

Cerebral Angiogram

Renal Arteriogram

MYELOGRAM (SPINAL CORD)
INTRATHECAL INJECTION

Extravasation

“To BE or not to BE”

  1. Massive retroperitoneal air
  2. pneumomediastinum
  3. subcutaneous air
  4. secondary to bowel perforation
  5. after barium enema

Extravasation of Contrast
into soft tissue of arm

Contrast leaking from bladder

OIL – BASED

IODINE
CONTRAST

Oil Based Iodine

  1. Fatty Acids
  2. Insoluble in water
  3. White on the radiograph = Radiopaque
  4. Uses
  5. Bronchography (lungs)
  6. Tear ducts
  7. Salivary glands
  8. Lymphatic system
  9. Hysterrosalpingogram
  10. Galactography (breast ducts)

To check fertility

LYMPHANGIOGRAM

Galactography - Breast Duct

Oral & IV contrast

CT Scan

CT showing Abnormal GB

ORAL & IV CONTRAST
(CT/ MRI)