lectura Rx simple de abdomen

32 Pages·2009·27.78 MB·English

LECTURA DE RX ABDOMEN
After
 completing
 this
 module
 you
 should
 be
 able
 to
 :

1) Identify
 the
 basic
 anatomical
 structures
 seen
 on
 an
 abdominal
 radiograph
2) Have
 a
 system
 for
 reviewing
 an
 abdominal
 radiograph
3) Describe
 and
 recognise
 four
 simple
 diagnoses
 :

 Pneumoperitoneum

 Large
 bowel
 dilatation

 Small
 bowel
 dilatation

 Renal
 and
 Ureteric
 calculi
BASIC
 CONCEPTS
Introduction
The
 abdominal
 radiograph
 can
 give
 useful

information
 but
 is
 a
 limited
 test
 (see
 reference

below).

All
 abdominal
 radiographs
 are
 AP
 9ilms
 (the

xrays
 pass
 from
 the
 front
 of
 the
 patient
 to
 the

back
 and
 the
 Jilm
 is
 placed
 behind
 the
 patient).
Most
 adults
 are
 too
 big
 to
 '
 9it
 '
 on
 to
 one

radiograph
 and
 so
 will
 often
 have
 two
 9ilms
 to

cover
 the
 whole
 abdomen.
 Make
 sure
 you
 look
 at

both
 Jilms.
 For
 a
 tall
 patient
 occaisionally
 three

Jilms
 are
 necessary
 in
 order
 to
 include
 the

diaphragm
 and
 pubic
 symphysis
 (for
 example
 the

three
 radiographs
 displayed
 are
 for
 a
 single

patient).
DENSITY
 OF
 TISSUES
Four densities are seen on plain radiographs :
            Soft tissues
            Gas
            Bone
            Fat
Soft
 tissues

 appear
 grey.
 For
 example
 the
 solid
 organs
 such
 as
 the
 kidneys
 -­
 annotated
 on
 this

Gas

 appears
 black
 or
 dark
 grey.
 For
 example
 in
 the
 various
 parts
 of
 the
 bowel
 visible
 on
 a
 plain
DENSITY
 OF
 TISSUES
Four densities are seen on plain radiographs :
            Soft tissues
            Gas
            Bone
            Fat
Fat

 appears
 dark
 grey
 but
 ligher
 than
 soft
 tissues.
 Fat
 is
 seen
 throughout
 the
 abdomen
 but
 there

are
 speci9ic
 areas
 to
 look
 for
 fat,
 for
 example,
 the
 properitoneal
 fat
 line
 (annotated
 on
 this
 9ilm).

Fluid

 will
 have
 the
 same
 density
 as
 soft
 tissue.
 For
 example
 the
 bladder
 may
 contain
 9luid
 and
 will

look
 like
 a
 soft
 tissue
 mass
 in
 the
 pelvis.
DENSITY
 OF
 TISSUES

 Bone

 appears
 white
 or
 light
 grey
Calci9ication

 is
 seen
 in
 a
 number
 of
 different
 structures.
 It
 willl
 have
 the
 same
 density
 as
 bone.
 For

example
 :
Costal
 cartilage
 calci9ication
Mesenteric
 lymph
 nodes
Vascular
 calci9ication
 -­
 arterial
 or
 venous
 (phleboliths)
REVIEW THE FILM. SYSTEMATIC APPROACH
Use a systematic approach - look at :
bowel
 gas
 pattern
 :
dilated bowel
an absence of bowel gas
thickened bowel wall
position of bowel gas
abdominal
 organs
 :
are they enlarged?
are they clearly outlined?
is there abnormal gas or calcification overlying the
organs?
bones
 :

increased density
metastases
fractures etc.
free
 gas
 :
an erect chest radiograph is often more useful for looking
for free gas
abnormal
 calci9ication
 :
gallstones
renal calculi
! appendicolith
calcification in the wall of an aneurysm etc.
unusual
 gas
 collections
 :
abscess
gas in gallbladder
gas in kidneys or bladder wall
Deciding if an abdominal film is technically adequate is less
problematic than when reviewing a chest radiograph.
1. Ensure it is the correct patient :
This has become less of a problem with digital
films but it is still vital to ensure the correct film
is being reviewed.
2. Adequate coverage :
The film should include the diaphragms, the
pubic symphysis and the edges of the bowel at
the lateral aspects of the film.
Image 1: is inadequate because the pubic symphysis and
diaphragms are not included.
Image 2 : is inadequate because the edge of the bowel is not visible laterally and the
diaphragms and pubic symphysis are not visible.
Deciding if an abdominal film is technically adequate is less
problematic than when reviewing a chest radiograph.
3. Exposure :
In theory if a film is correctly exposed it should
be possible to see the outline of the psoas muscle
on the film. In practice overlying bowel gas and
soft tissue such as fat may make it difficult to see
the psoas shadow.
4. Rotation :
This is not such a significant problem as
encountered with chest radiographs because the
film is taken with the patient lying supine.
Image 3 : is inadequate because it does not include the diaphragms
and pubic symphysis.
ANATOMY
It is often possible to see an outline of the kidneys due to the fat surrounding them which appears
darker than the soft tissue of the kidneys. The spleen is harder to see on plain film and is usually not
visible.
Normally no bowel is visible in the right upper quadrant due to the large soft tissue mass of the liver.
Occaisionally the liver can extend inferiorly - this is known as a Riedel's lobe.
!
Señala
 en
 las
 radiogra9ías
 previas
 el
 hígado,
 el
 bazo
 y
 los
 riñones.
 Señala
 el
 lóbulo
 de
 Riedel
Look for the psoas muscles. The radiograph shown is from a young man and therefore the psoas
muscles are particularly visible. The absence of a psoas shadow may indicate retroperitoneal pathology.
!
Señala
 el
 músculo
 psoas.
ANATOMY
Although the bladder is full of fluid it is often visible on the the plain radiograph as the fluid will
have the same density as soft tissue. Look for a soft tissue mass in the pelvis.
!
Señala
 en
 las
 radiogra9ías
 previas
 la
 vejiga.
The stomach is seen beneath the left hemidiaphragm and often extends across the midline.
!
Señala
 el
 estómago