The document discusses contrast media used in radiology, including positive and negative types. Positive contrast media like iodine and barium are radiopaque, having a higher atomic number that causes more x-ray attenuation. They appear white on images. Negative contrast media like air are radiolucent with lower atomic numbers, appearing black. The document provides examples of contrast media use and characteristics that make for an ideal agent, such as safety, excretion, and homogeneity. Pneumoencephalography is described as an older technique using air contrast for the brain.

1. IN THE NAME Of GOD
Amir al-Muminin, peace be upon him, said:
There is no wealth like wisdom, no destitution like ignorance, no
inheritance like refinement and no support like consultation.
‫املومنين‬‫ر‬‫امي‬(‫ع‬)‫فرمودند‬:
‫هيچ‬‌‫ي‬‫‌نياز‬‫ي‬‫ب‬‌‫ن‬‫چو‬،‫عقل‬‌‫و‬‫هيچ‬‌‫ي‬‫فقر‬‌‫ن‬‫چو‬‫ناداني‬،‫نيست‬‫هيچ‬‫ثي‬‫ر‬‫ا‬‌‫ن‬‫چو‬،‫ادب‬‌‫و‬‫هيچ‬
‫پشتيباني‬‌‫ن‬‫چو‬‫ت‬‫ر‬‫مشو‬‫نيست‬.

2. Contrast Media
September, 2014
Prepared by:
Behzad Ommani
Bachelor of Radiology
Master of Medical Engineering
Instructor Radiology Group

3. Radiographic image
produced by the aftermath obtained when x ray goes through the
body part:
penetration , absorption and hence What you got??
Basic radiographic opacities :
BLACK / GRAY / GRAY / GRAY / WHITE
Air Fat Water/ST Bone Metal/+Contrast

4. Radiographic Contrast
1.Subject contrast
Patient (Range of differences in the intensity of the x-ray beam
After it has been attenuated by the subject)
2. Film contrast
Inherent in equipment
The BLACKS & WHITES ON THE FILM / IMAGE

5. 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

6. Subject Contrast
1. Atomic number of object
2. Density of object
3. Thickness of object
Higher atomic # = more attenuation
Denser = more attenuation
Thicker = more attenuation

7. Case example
PATHOLOGY
1. Pleural Effusion
2. Excessive fluid in lung
3. More dense than air

8. What is good contrast ?
1. High contrast (black
and white)
2. Low contrast (more
shades of gray)

9. Case example

10. Artificial Contrast
1) Use contrast
media
2) Changes subject
contrast
3) Changes
radiographic (film
contrast)

11. Ideal Contrast media characteristic
These materials should be produce High contrast
Should be safe
Easy, fast and completely void or excrete
Homogeneous
Stability Compound

12. Radiographic Contrast Media Type
Radiographic contrast media are divided into positive and negative
contrast agents.
The positive contrast media attenuate X-rays more than do the
body soft tissues and can be divided into water soluble iodine
agents and non water soluble barium agents.
Negative contrast media attenuate X-rays less than do the body soft
tissues. No negative contrast media are commercially available.

13. Type Different
Negative contrast
1. (AIR OR CO2)
2. Radiolucent
3. Low atomic # material
4. Black on film
Positive contrast
1. (all others Such as iodine)
2. Radiopaque
3. High atomic # material
4. White on film

14. Case example

15. Contrast Media Type
Positive
Barium (inert, no hypertonic, no metabolized or absorbed)
Liquid
Paste
Iodine: Tri – iodinated derivatives of benzoic acid
Ionic
Non – ionic
Negative
Air room
Carbon dioxide
Nitrous oxide

16. Contrast Media Negative
 In the past, use to study of Renals, Cyst, Uterus.
 Ventriculography
 Pneumomyelography
 Pneumo arthrogaphy
 Abdomen & Pelvis pneumography
 Today, use as a additive agent = double contrast
 Digestive system (B.S, Barium Meal, …)

17.  Just free Study
Pneumoencephalography (sometimes abbreviated PEG) is a medical procedure
in which most of the cerebrospinal fluid is drained from around the brain and
replaced with air, oxygen, or helium to allow the structure of the brain to show
up more clearly on an X-ray image. It is derived from ventriculography, an
earlier and more primitive method where the air is injected through holes drilled
in the skull.
The procedure was introduced in 1919 by the American neurosurgeon Walter
Dandy.
Headaches and severe vomiting were common side effects
Replacement of the drained spinal fluid is by slow natural production, and
therefore required recovery for as long as 2-3 months before normal fluid
volumes were restored
Modern imaging techniques such as MRI and Computed tomography have
rendered pneumoencephalography obsolete

18.  Just free Study

19. Contrast Media positive
 Positive
1. Carbonaceous Compound
Inorganic (Barium Sulfate, Sodium Iodide , Bismuth suintrate)
Organic ( Urografin, Conray , Hexabrix, Amipaque)
2. Chemical solubility
Solvable
Unsolvable
Water
Oil