Barium ppt - Copy.ppt

1. USE OF BARIUM IN VARIOUS
BARIUM PROCEDURES
DR. AJIT
19-08-04

2.  Barium sulphate continues to be the most
common material for radiographic
visualisation of GIT.
 Barium suspension is made up from pure
barium sulphate ( barium carbonate is
poisonous ) . The particles of barium must
be small ( 0. 1 - 3 micron ), since this
makes them more stable in suspension . A
non-ionic suspension medium is used, for
otherwise the barium particles would
aggregate into clumps. The resulting
solution has a Ph of 5.3 , which makes it
stable in gastric acid.

3. The major advantage of barium sulphate
preparation over water soluble contrast
agent are two folds.
1. lack of significant absorption from bowel
results in radiographic contrast that is not
significantly degraded throughout bowel.

4. 2. Modern formulation designed for soluble
contrast study coat the mucosa in a thin
layer for long period of time, thus allowing
the introduction of a second or negative
contrast agent without significant
degradation. A similar effect cannot be
readily achieve with water soluble agents.

5. DISADVANTAGES:
 Not being absorbable, barium sulphate outside the
bowel lumen is treated as foreign body – resulted
reaction severity depends on where barium is
located.
 If barium suspension is allowed to remain in distal
colon for a long time , a considerable amount of
water can be reabsorbed ,as a result of its
viscosity increased significantly and a barium
impaction can develop
 Subsequent abdominal CT and US are rendered
difficult to interpret. Patients may be asked to wait
for up to 2 weeks to allow satisfactory clearance
of the barium. If also required, it is advised that the
CT and / or US be performed before the barium
study

6.  BaSO4 escaping into the mediastinum or
extra peritoneal soft tissues initially incites
an inflammatory reaction that eventually
causes extensive fibrosis
 Barium escaping into the peritoneal cavity (
barium peritonitis ) results in significant
morbidity and mortality-produces pain and
severe hypovolaemic shock. Despite
treatment which consists of iv fluids,
steroids and antibiotics, there is still a 50 %
mortality rate- of those that survive , 30 %
will develop peritoneal adhesions and
granulomata.

7.  It is therefore imperative that a water soluble
contrast medium is used for any
investigation in which there is a risk of
perforation or in which perforation is
suspected
 Intravasation – this may result in a barium
pulmonary embolus, which carries a
mortality of 80 %

8. Conditions in which no contrast agents should
be given
 1. Suspected toxic megacolon, an enema
even with tap water can make matters
worse
 2. With a known intraperitoneal perforation,
BaSO4 is contraindicated, yet even water
soluble contrast agents are not completely
innocuous – lead to increased intraluminal
distension resulting in additional peritoneal
soiling

9. Water soluble contrast media
 Gastromiro - iopamidol 61 % w / v
- iodine concentration of 300
mg/ml
 Gastrograffin- meglumine diatrizoate 66 % w
/ v and sodium diatrizoate 10 % w / v
- iodine concentration of 370
mg/ml

10.  Indications
1 Suspected perforation
2 Meconium ileus
3 To distinguish bowel from other structures
on CT . A dilute solution of water soluble
contrast media is used so that minimum
artefact shadow is produced
4 LOCM is used if aspiration is a possibility

11.  Complications
1 Pulmonary edema if aspirated ( not LOCM )
2 Hypovolemia in children- due to hyperosmolality of
the contrast media drawing fluid into the bowel (
not with LOCM )
3 Allergic reactions- due to absorbed contrast media
4 May precipitate in hyperchlorgydric gastric acid –
not non-ionics
5 Ileus – may occur in 4 % of patients examined in
the postoperative phase

12. Water soluble contrast agents are preferred in
some conditions when a contrast enema is
being performed for therapeutic reasons –
this include relief of obstruction in
 Meconium plug syndrome
 Meconium ileus
 Cystic fibrosis

13. PARTICLE SIZE
 Precipitated BaSO4 is available in average
particle size 0.3 micron – 12 micron
 Average particle only slightly > 0.3 micron
not used by themselves but employed to
enhance the coating and suspending
properties of larger particles
 Particles toward 12 micron range –
generally used in LOW VISCOSITY HIGH
DENSITY PRODUCTS specially designed
for upper GIT examination

14.  Rate of BaSO4 crystal growth depends on
additives present
temperature
time of reaction
amount of supersaturation
 Some formulations specially designed for double
contrast gastric studies - particle size > 18
micron
 Products for gastric coating – have extreme
heterogeneity in particle size
 Studies for Single Contrast – are more
homogeneous
 A mixture of different sized particles achieves
the highest density , but the resultant viscosity
varies

15. SEDIMENTAION
 Larger particles settle faster and form
denser cake then smaller particles
 Sedimentation also occurs when
suspension is poured into the cup- so to
be filled just before use
 Can decrease the sedimentation rate by
decreasing Barium particle size but this
will lead to increased viscosity

16.  Larger particle HIGHER DENSITY Barium
Suspension for DOUBLE CONTRAST studies should
not be simply diluted and used for SINGLE
CONTRAST studies
When such diluted suspension is ingested there
is rapid sedimentation of barium particles in GIT
So nondependent lumen may contain little barium and
lesion may be missed
 Products for Single Contrast can be diluted
considerably before any settling occurs because of
relatively small size of barium particle

17. FLOCCULATION
 Is a chemical process- reduction in number of
particles by formaton of larger masses is called as
flocculation-leads to coarse precipitation of
Barium particle- it should be differentiated from
sedimentation in which individual particles sizes
are still preserved
 Tendency to flocculate is decreased by adding
surface acting deflocculating agents to the
suspension--- SODIUM CITRATE is typical

18. VISCOSITY
 Viscosity of a fluid represents its resistance
to flow- many solutions and some
suspensions deform permanently and
proportionally to force applied and are
called as newotonian fluid– such fluids have
linear realtionship between stress applied
and resultant shear rate
 In general only low concentration BaSO4
suspension have newtonian properties

19.  Most Barium sulphate exhibits Non
Newtonian flow- that is viscosity varies with
flow rates
 Viscosity -determines flow rate
- influences mucosal coating
 Ideally thick mucosal coat is desired
throughout GIT , unfortunately viscosity can
be increased to certain point before barium
suspension starts to paste and coating
properties are then degraded

20. MEASURING SYSTEMS
 3 Standardized systems used in measuring
the amount of BaSO4 present in a liquid
suspension

21. 1.SPECIFIC GRAVITY
= mass of substance /mass of equal
volume of water

22. 2. WEIGHT TO VOLUME SYSTEM
 Certain weight of BaSO4 added to sufficient water
to obtain predetermined total volume
 Example – 40% W/V Suspension is prepared by
40 gram of BaSO4 And then water is added to
obtain a total volume of 100 ml.
 Example- in barium swallow
300 gm BaSO4 + 70 ml water = 200 % W / V
So for double contrast esophagus studies as we
need 250 % W / V So required amount of water
can be calculated as
70/ 250 x 200 = 56 ml

23. 3. WEIGHT TO WEIGHT SYSTEM
 Certain weight of BaSO4 added to enough
water to obtain predetermined final total
weight
 Example- 40 % W / W suspension is
prepared by adding 40 gram BaSO4 to 60
gram ( 60 ml) of water to obtain a total
weight of 100 gram
 100 % W / W – represents dry powder

24. CLINICAL APPLICATION
PHARYNX
 Anatomical details- HIGHER DENSITY
products-- 250 % W / V Suspension
designed for gastric DOUBLE CONTRAST
examination – fistulas can also be studied
with this
 Pharyngeal function- studied with both
LOW VISCOSITY AND HIGH VISCOSITY
Barium suspension

25. ESOPHAGUS
 Studies include – SINGLE CONTRAST
-- DOUBLE CONTRAST
-- MUCOSAL RELIEF VIEWS
Nature of barium sulphate used depends on
either SINGLE OR DOUBLE CONTRAST
is to be used
For SINGLE CONTRAST studies- MEDIUM
DENSITY ( 100 % W / V ) , LOW
VISCOSITY BARIUM IS BEST

26. This also provide good DOUBLE CONTRAST view
of esophagus but as the procedure is commonly
performed in association with DOUBLE
CONTRAST of stomach – HIGHER DENSITY
BARIUM ( 250 % W / V ) is used
 To study the calibre of esophageal strictures –
BaSO4 tablets with diameter of 12.5 mm are
available- contain 650 mg of barium sulphate

27.  SINGLE CONTRAST-mostly used when
looking for esophageal compression,
displacement or disordered motility. Thus
the majority of esophageal diseases apart
from the motility disorders are best
demonstrated by double contrast technique

28.  For mucosal relief study-barium paste or
HIGH DENSITY suspension is used
 The extra viscosity and prolonged
adherence of paste allows the esophagus to
collapse after a bolus has passed

29. CONTRAINDICATIONS
 The main contraindication to a barium
swallow are situations where there is likely to
be a leakage from the esophagus into the
mediastinum or pleural and peritoneal
cavities. Aspiration into the bronchial tree is
a relative contraindication
 Conflicting evidence as to the seriousness of
barium leakage into the mediastinum
because it may stimulate a fibrotic reaction.
The barium also had a sterilizing effect on
salivary flora . Barium has another
disadvantage in that it may remain loculated
in the mediastinum and obscure follow up
studies for months or even years.

30.  For these reasons it has been traditional
practice to use a water soluble contrast
medium such as GASTROGRAFFIN when
initially investigating a potential esophageal
leak—however the details obtained with these
agents is not as good as with barium and the
possibility of missing esophageal lesions has
been stressed
 The usual policy is to start with a water soluble
contrast medium and, if this shows no major
leakage , to follow it with barium. The later may
then demonstrate the small mucosal tears
which can be missed when using gastrograffin

31.  The main problem using gastrograffin as a
contrast agent occurs if there is any risk of
aspiration into the bronchial tree– aspiration of
gastrograffin causes a very severe form of
chemical pneumonitis and consequent acute
pulmonary edema
 If there is risk of this happening then it is best
to start with a non ionic water soluble contrast
media such as Gastromiro – which causes no
inflammatory changes at all in lung
parenchyma

32. STOMACH AND DUODENUM
 Studies include - single contrast , double
contrast or a combination of the two
techniques called as Biphasic technique
 HIGHER DENSITY , LOW VISCOSITY
BARIUM -- PRODUCES BEST DOUBLE
CONTRAST RESULTS

33.  Barium suspensions suitable for double
contrast radiography may be of medium or
high density and should be of low viscosity
 250 % W / V
 60-120 ml sufficient
 When appropriate double contrast views have
been obtained LOW DENSITY Barium
suspension can be ingested for subsequent
SINGLE CONTRAST study - 35 – 80 % W / V
used

34.  If biphasic examination is being performed ,
most use two types of contrast media –
 First HIGH DENSITY LOW VISCOSITY
suspension is used for double contrast study
--- followed by LOW DENSITY barium
particles used to fill the lumen

35. SMALL BOWEL
 40 – 60 % W / V Suspension is typical
 500- 600 ml barium suspension is generally
sufficient
 Enteroclysis-
- SINGLE CONTRAST-barium suspension having
specific gravity of 1.27 ( 34% W / V ) is preferred
- DOUBLE CONTRAST-barium suspension of
higher specific gravity used ( range of 50 – 95 %
W / V ) is typical

36. LARGE BOWEL
 SINGLE CONTRAST BARIUM ENEMA - needs LOW
DENSITY SUSPENSION OF 12 – 20 % W / V to achieve
some “ see through effect “
 DOUBLE CONTRAST BARIUM ENEMA-Suspension
used is 60 -110 % W / V , so that there will be sufficient
radiographic density in a thin layer ( about 0.2 mm
thick ) for fine mucosal details to be visualized
effectively and the suspension must flow easily so that
it can be manipulated around the bowel , leaving a thin
and even coating that does not flocculate and remain
plastic when dried out

37.  SINGLE CONTRAST BARIUM ENEMA- may be
quicker and less demanding technically but it does
not give detailed view of the mucosa
- is not accurate as DOUBLE
CONTRAST ENEMA in detecting small polyps ( 5
– 10 mm ) and early colitis
Ability to clearly see through overlapping loops
prevents larger lesions being obscured and is
further advantage of DOUBLE CONTRAST
BARIUM ENEMA

38. BARIUM SUSPENSION
 Particle size varies from 0.6 – 1.4 micron to much
larger crystals in a more heterogeneous range of 4 –
50 micron
 BARIUM ENEMA suspension uses smaller and more
uniform particle size
 Particles are coated with various agents to achieve
several basic suspension characteristics
. Rapid flow
. Good mucosal adhesion
. Adequate radiographic density in thin layer
. An even coating which remains plastic and
does not crack
. Absence of artefact or foaming

39.  Terms THIN and THICK suspensions are
often used but are imprecise
 A suspension may be viscous and thick but
with a low Barium content and so is
radiographically THIN
 The flow characteristic of a suspension are not
necessary the same as its radiographic density
 DOUBLE CONTRAST technique is really THIN
LAYER CONTRAST RADIOGRAPHY
 The radiographic density of layer =
Thickness x Barium content in this layer
which reflects the Barium % W / V of the
suspension

40. Use of gases
 Carbon dioxide and less ogten air are used in
conjunction with barium to achieve a double
contrast effect
 For the upper gastrointestinal tract, CO2 is
admininstered in the form of gas producing
granules / powder
 The requirements of these agents are as follows :
1 production of adequate volume of gas 200-400 ml
2 non interference with barium coating
3 no bubble production
4 rapid dissolution , leaving no residue
5 easily swallowed
6 low cost

41.  Carbex granules and fluid satsify most of these
requirements , but have the disadvantage of
being relatively costly
 For the large bowel, room air is administered per
rectum via a pump attached to the enema tube.
Carbon dioxide is said to cause less abdominal
pain but inferior bowel distension when compared
to air

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