Contrast media 1

Radiographic Contrast Media

RAD TECH 255 SPECIAL PROCEDURES

MERRILLS VOL2RTA BOOK CH 19

Subject Contrast

• Range of differences in the intensity of the x-ray beam, after it has been attenuated by the subject (patient).

Low Subject Contrast

What can be done to attain medical information-

• see the difference between muscle, organs or vessels

Define and outline – organ structure and function

Contrast media

• Defines subtle differences in subject contrast

• Increases atomic number of area injected

• Results in a SHORTER scale of subject contrast

Purpose of Contrast Media

• To enhance subject contrast or render high subject contrast in a

tissue that normally has low subject contrast.

Atomic Number

• Fat = 6.46

• Water = 7.51

• Muscle = 7.64

• Bone = 12.31

Radiographic Contrast : Influenced by…

• Radiation Quality (KVP)

• Film Contrast

• Radiographic object (Patient)

KVP TYPE OF CONTRAST USED DETERMINES KVP RANGE•

BARIUM 90 – 120 kVp

IODINES 70 – 80 kVp(Ionic / Nonionic Water or Oil)

INJECTABLECONTRAST MEDIA

for RT 255 procedures

INVASIVE PROCEDURESThe “o-grams”

ALWAYS TAKE

A “SCOUT”

BEFORE CONTRAST INJECTION

√ PATHOLOGY

√ TECHNIQUE

√ PREP & PRIOR CONTRAST

√ POSITIONING

SPECIAL “o-grams”

• Venogram• Arthrogram• Sialogram• Myelogram• Arteriogram• Angiogram• Galactogram• Hystersalpingogram…….. etc

CONTRAST INJECTION

DOUBLE CONTRAST WITH IODINE - HIP Arthorgram

To check fertility

LYMPHANGIOGRAM

Galactography - Breast Duct

Cerebral Angiogram

SPECIAL PROCEDURESARE INVASIVE

ALWAYS GET PATIENT’S HISTORY AND CONSENT BEFORE

BEGINNING OR GIVING ANY CONTRAST

MEDIA

CONSENTS

• SIGNED AND WITNESSED• AFTER PROCEDURE HAS BEEN EXPLAINED• CHECK DEPARTMENT PROTOCOL• WHO’S RESPONSIBLE ??????

CONSENTS

• ASSAULT verbal threat of harm

• BATTERYUnlawful touching - unauthorized treatment“X-RAY” TAKEN ON WRONG PATIENT

• FALSE IMPRISONMENTRestraints require permission

from patient or authorized person

BLOOD WORK LAB TESTS to check function of kidneys prior to

injection of contrast • WATCH THE UPPER LIMITS• BUN = BLOOD UREA NITROGEN• Merrills pg 214 range is 8 to 25 pg 242 range is 10 - 20

always check with RAD when level above 20• CREATININE levels range:• pg 214 (0.6 - 1.5) pg 242 (0.05 - 1.2)

always check with RAD when level above 1.2 • Indicates function of kidneys • Diseases / dehydration / kidney failure

EGFR (new test)

• Estimated • Glomerular • Filtration • Rate

• More advanced test for • CREATININE levels

Review of Contrast Agents

Types of ContrastRoutes of AdminstrationChemical Components

Contrast Media changes the density of the organs

Therefore changing the Subject contrast will change the Radiographic contrast and film contrastMay need to INCREASE TECHNIQUE FROM SCOUT IMAGE

Contrast Media (review)

• Negative contrast• (AIR OR CO2)

• Radiolucent

• Low atomic # material

• Black on film

• Positive contrast • (all others)

• Radiopaque

• High atomic # material

• White on film

Types of Contrast Media

• Radiolucent-• negative contrast agent• x-rays easily penetrate • areas- appear dark on films

Negative Contrast Media• Air and gas

• complications• emboli-air pockets in

vessels• lack of oxygen

• Radiopaque- • positive contrast agent- • absorbs x-rays• appears light

Positive Contrast Agents• BARIUM • IODINES

Both + & - can be used in same study

2 BASIC TYPESOF CONTRAST material

• BARUIM Z# 56

• NON WATER SOLUABLE

• GI TRACT ONLY INGESTED OR RECTALLY• KVP 90 – 120*

• IODINE Z# 53• WATER SOLUABLE• POWDER• LIQUID• INTRAVENOUS OR• Intrathecal• GI TRACT• Also OIL based• KVP BELOW 90*

Methods of Administrationof Contrast Material

• INGESTED – (ORAL)

• RETROGRADE – AGAINST NORMAL FLOW

• INTRATHECAL – Spinal canal

• PARENTERAL (IV, Intrathecal)– Injecting into bloodstream– (anything other than oral)

Contrast media for SPECIAL PROCEDURES

Diagnostic agents that are injected into

• Circulatory System, Joint Spaces, Ducts

• Body orifices/organs: uterus, breast, salivary & lymph glands

BARIUM – a review

BARUIM SULFATENot used in Special Procedures

Barium Sulfate

• High atomic number• Not soluble in water• Used to coat the lining of organs• Supplied in different thicknesses• Used

– Esophogram, UGI, Small Bowel,Lower GI or BE

Ba ADVERSE REACTIONS

• BARIUM INERT• SUSPENSION MAY CAUSE ALLERGY• OCG TABLETS (IODINE) ALLERGY• AFTER EXAM – MAY SOLIDIFY DIFFICULT TO

EVACUATE• INCREASE FLUIDS, MILD LAXATIVE

• EXTRAVASATION OF CONTRAST INTO PERITONEUM

Extravasation of BA in abd

Ingested CONTRASTGastrografin or Hypaque

• High atomic #– Close to iodine

• Water soluble

• Similar usage as Barium

GASTROGRAFINAdverse Reactions

• Water soluble, safe in the abdominal cavity–Safe to use if perforation is suspected

• Very harmful to the lung tissue–Do not use if aspiration is possible

Gastro – Pathology present

• Bowel • Obstruction

• Note contrast• Seen in

kidneys as well

IODINEIONIC OR NON IONIC

WATER OR OIL BASE

IODINATED CONTRASTiodine z # 53

• WATER BASED

• INJECTED• VESSELLS/DUCTS• INGESTED• Organ function/flow• OPEN WOUNDS

• OIL BASED• INJECTED• NEVER VESSELLS• ONLY DUCTS• NOT INGESTED• OPEN WOUNDS

INJECTION OF IODINEinto Vessels

• ALWAYS A WATER BASED IODINATED COMPOUND

• BOLUS INJECTION• INFUSION DRIP

• IONIC VS• NON IONIC• CONTRAST

• 50 -70 % CONCENTRATE

IODINE WATER BASED CONTRAST

• IONIC• LESS $$$

• MORE REACTIONS

• NON IONIC• MORE $$$

• LESS REACTIONS

CONTRAST MEDIAIODINE

is either: IONIC or NON-IONIC • Osmolarity• # Of Particles (Cations + And Anions -)

– In Solution Per Kilogram Of Water• High Osmolarity

– =more Cations And Anions• Can Upset Homeostasis• Nonionic Have No Charged Particles

Contrast AgentsIONIC• High Osmolality

(Higher risk of complications)

– Diatrizoate sodium (Hypaque)

– Iothalamate meglumine (Conray)

NON-IONIC• Low Osmolality

(Lower risk of complications)

• Gadodiamide (Omniscan) – Iodixanol (Visipaque) – Iopamidol (Isovue) – Iopromide (Ultravist) – Ioversol (Optiray)

• Less money• More reactions

• More money• Less reactions

OIL – BASED

IODINECONTAST

Instilled in ORGAN

Oil Based Iodine• Fatty Acids• Insoluble in water

– White on the radiograph = Radiopaque• Uses

– Broncography (lungs)– Tear ducts– Salivary glands– Lymphatic system– Hysterrosalpingogram– Galactography (breast ducts)

• FAT EMBOLUS IF IT GETS INTO • BLOOD VESSEL

Newer Contrast Agents Balance Safety and Visualization