Transcript The Abdominal X-Ray

The Abdominal X-Ray
The Abdominal X-Ray:
The abdominal x-ray (AXR) has a much more
limited value in diagnosis than a chest x-ray.
The radiation exposure of an AXR compared
to a CXR is also considerably higher. One AXR
is equivalent to 35 CXRs.
The AXR is of most use in the patient with an
acute abdomen . It may guide further imaging
with other imaging modalities.
As with a CXR , an appreciation of normal
structures is vital.
Abdominal X-Ray Projections:
• Supine 99%
• Erect
• Lateral decubitus.
Knowledge of the anatomy of the abdomen
allows localization of the abnormalities
observed on the AXR.
Anatomy on the Abdominal X-Ray:
Abdominal X-Rays:
Film Specifics and Technical Factors:
The initial assessment of an AXR is the same as
for a CXR:
Film Specifics:
• Name of Patient
• Age & Date of Birth
• Location of Patient
• Date Taken
• Film Number (if applicable)
Film Technical factors:
• Type of projection (Supine is standard)
• Markings of any special techniques used
Assess the Film in Detail:
A simple guide to interpretation is shown
as follows:
1. Dark Shadows
2. White Shadows
3. Grey Shadows
4. Bright white Shadows
BLACK SHADOWES
‘BLACK SHADOWS’ = GASSES
• Intra-luminal gas can be normal.
• Extra-luminal gas is abnormal.
• However, intra-luminal gas can be abnormal if it is
in the wrong place or if too much is seen.
• The maximum normal diameter of the large bowel is
55mm.
• Small bowel should be no more than 35mm in
diameter.
Places to look for abnormal
extra-luminal gas
Under the diaphragm
• In the biliary system
• Within the bowel wall
•
Key to densities in Abdominal
X Ray
•
•
•
•
•
Black: gas
White: calcified structures
Grey: soft tissues
Darker grey: fat
Intense white: metallic objects
Assess the Film in Detail:
Natural presence of gas within the bowel
allows assessment of caliber - although the
amount varies between individuals.
The caecum is not said to be dilated unless
wider than 80mm.
Large and small bowel may be distinguished
by looking at bowel wall markings, as shown in
the box below.
The haustra of the large bowel extend
only a third of the way across the bowel
from each side , whereas the valvulae
conniventes
of
the
small
bowel
transverse the complete distance.
•
It is usual to see small volumes of gas
throughout the GI tract and the absence in
one
region
may
in
itself represent
pathology.
•
For example, if gas is seen to the level
of the splenic flexure and nothing is seen
beyond this , a site of the obstruction at
this site – a ‘cut off’ point is noted.
Abdominal X-Rays:
AXR-3
AXR-4
Small Bowel
Large bowel
Colon with barium contrast •
Small bowel
Large bowel
Small bowel
Barium meal, stomach, duodenum and jejunum
Assess the Film in Detail:
• Intra-luminal Gas:
• Low Small Bowel Obstruction
Assess the Film in Detail:
•
If bowel obstruction is
observed try to look for
the cause . For example
a hernia as the cause of
obstruction.
Hernia
Assess the Film in Detail:
• Extra-luminal Gas:
When bowel becomes obstructed, or
any other gas containing structure
perforates , its contain gas becomes
extra-luminal. Extra-luminal gas is
never normal , but may be seen
following intra-abdominal surgery or
endoscopic retrograde
pancreatography (ERCP).
cholangio Extra-luminal gas
seen on erect CXR.
 Causes of Extra-luminal gas:
Post Abdominal Surgery/ERCP
Perforation of viscous (e.g.. bowel, stomach)
Gallstone ileus
Cholangitis
( infection with gas forming
organisms)
5. Abscess
1.
2.
3.
4.
•
An erect CXR (not AXR) is the best projection
to diagnose a pneumoperitoneum (gas in the
peritoneal cavity).
WHITE Shadows :
WHITE SHADOWS’ = Calcification
Calcified structures are often seen on AXR. The main
question is – does its presence have any important
implications. Calcification can be broadly divided into 3 types:
(1) Calcium that is an abnormal structure - eg. gallstones and
renal calculi
(2) Calcium that is within a normal structure, but represents
pathology - eg. nephrocalcinosis,
(3) Calcium that is within a normal structure, but is harmless eg. lymph node calcification.
Bones are normal ‘white’ structures. On the AXR they
comprise mainly those of the thoraco-lumbar spine and pelvis.
Findings are largely incidental as direct bone pathology would
be investigated with specific views.
Renal Stones
Renal Stones
STAGES OF HYDRONEPHROSIS
HYDRONEPHROSIS AND
HYDROURETER
Kidneys ureters and stones
NORMAL IVU
HYDRONEPHROSIS
HYDRONEPHROSIS
RENAL STONES •
Pancreatic Calcification
GREY SHADOWS:
‘GREY SHADOWS’ = Soft Tissues
Soft tissues represent most of the contents of the
abdomen and feature heavily in the AXR. However,
these tissues are poorly seen when compared to
other imaging techniques such as ultrasound or CT.
The kidneys, spleen, liver and bladder (if filled) can
be seen in addition to psoas muscle shadows and
abdominal fat. Rarely would action be taken on the
basis of this imaging alone.
Splenomegaly
Psoas muscle
Psoas muscle
Psoas Abscess
BRIGHT WHITE SHADOWS:
‘BRIGHT WHITE BITS’ = Foreign Bodies
Foreign Bodies represent an interesting final
observation . Objects that may be seen include
ingested foreign bodies , items in the path of the
x-ray beam such as belt buckles, dress buttons and
jewelry . Other objects may have been deliberately
placed for example an aortic stent, an inferior vena
cava filter or a suprapubic urinary catheter.
Sterilization clips and an intra-uterine device are
common findings in women.
Assess the Film in Detail:
Sterilisation and Surgical Clips
Intra-abdominal foreign bodies
Hernia
Finals Radiology Cases:
Abdominal X-Ray
Case 1:
This 67 year-old women
presented to the surgical
ward with a
distended
abdomen and vomiting.
Present this x-ray
Give a diagnosis and
potential causes
Case 1: Answer
Radiology Report:
Plain abdominal radiograph.
Multiple dilated loops of small bowel
within the central abdomen. Gas is not
seen in the large bowel. No evidence
of hernia or gallstone to suggest
potential cause of the dilated loops.
These findings are in keep with a low
small bowel obstruction.
I would like to know if the patient has
a history of abdominal surgery as the
commonest cause
is surgical
admissions.
The three commonest causes of small bowel obstruction are:
• Surgical adhesions
• Herniae
• Intraluminal mass eg, small bowel lymphoma or gallstone (in gallstone
ileus)
Case 2:
This 71 year-old gentleman
visits his GP complaining of
in his urine. He has had a
number of UTI’s in recent
years.
Present this x-ray
Give a diagnosis and
potential causes
Case 2: Answer
Radiology Report:
Plain abdominal radiograph.
Two rounded radio-opacities
measuring 4cm within the pelvis.
Both opacities are smooth in
outline, laminated in nature, have
the same density as bone and
project over the bladder . No
other renal tract calcification.
Does the patient have a history of
neurogenic bladder?
Given the size of these stones
and history of UTI’s these are
bladder calculi.
Bladder calculi are more common in those with a history of:
•UTI’s
•A neurogenic bladder
•Bladder diverticulum
Case 3:
This patient
was
admitted with poor renal
function.
Present this x-ray
Give a diagnosis and
potential causes
Case 3: Answer
Radiology Report:
Plain abdominal radiograph
Multiple areas of punctuate
calcification project over the renal
outlines bilaterally.
The calcification is within the medulla
of the renal parenchyma. The bones
are normal in appearance.
These findings are consistent with
nephrocalcinosis
Causes of Nephrocalcinosis include:
• Hyperparathyroidism
•Medullary sponge kidney
Systematic approach to viewing
an abdominal film:
1. Start by identifying the name on the film and
the date.
2. What is the projection of the film? Is if PA or
AP? Most are PA.
3. Is the view Supine, Erect or Lateral Decubitus?
Are there erect and supine films? If so decide
which is which.
4. Confirm that an adequate area has been
covered.
5. Check exposure. If the spine is visible most
structures to be seen will be visible.
6. Artefacts may be immediately obvious.
Piercing of the umbilicus is very popular,
especially in young women but genital
piercing is not infrequent. Metallic objects
are obvious. There may be clips or materials
from previous surgery. Occasionally a
retained surgical instrument is seen. Swabs
contain a radio-opaque band.
Solid organs, hollow organs
and bones can be classified as:
•
•
•
•
•
Visible or not visible
Normal in size, enlarged, or too small
Distorted or displaced
Abnormally calcified
Containing abnormal gas, fluid, or discrete
calculi
Bones Look in a specific order
and keep to your regime:
•
•
•
•
•
Lower Rib Cage
Lumbar Spine
Sacrum
Pelvis
Hip Joints
Check bones for:
•
•
•
•
•
•
Cortical Outline
Joint and Disc Space
Trabecular Pattern
General Bone Density
Lysis, Fracture, Sclerosis
Epiphyseal Lines
Solid organs
• Liver – There is soft tissue density in the
right upper quadrant that displaces any
bowel from this area.
• Spleen - Soft tissue mass in the left upper
quadrant about the size of a fist. It may be
clear or obscured but usually is not seen at
all.
• Kidneys – A shadow may be visible. The
left kidney is higher than the right. The
upper poles tilt medially. They should be
about 3 vertebrae in size.
• Psoas Muscles - Form straight lines
extending infero-laterally from the lumbar
spine to the lesser trochanter of the femur.
• Bladder - If the bladder is full, it will
appear as a soft tissue density in the
pelvis.
• Uterus - Sits on top of and may indent the
bladder. It is often not seen on plain films.
• Prostate - Sits deep in the pelvis. Usually
only seen if calcified
Hollow organs
• Stomach - When supine, air in stomach will
rise anteriorly and fluid will pool posteriorly.
• Small Bowel - Gas will be seen in polygonal
shapes due to perstalsis. Normal small bowel
is 2.5 to 3.0 cm in diameter. Valvulae may be
seen crossing the entire lumen. Often little
small bowel is seen on a plain film.
• Appendix - Occasionally an appendicolith is
seen. Less commonly barium from an old
study, or ingested foreign bodies appear in
the appendix.
• Colon - Start in the right iliac fossa with the
caecum that may show fluid levels. Follow
it up to the hepatic flexure, over to the
splenic flexure, and down into the pelvis. It
may be filled with air or faeces. Shape may
altered by redundant bowel. The colon is in
the periphery of the abdomen.
Normal Calcification
* Costal cartilage
* Mesenteric lymph nodes
* Pelvic vein phleboliths
* Prostate gland
Abnormal calcification Calcium
indicates pathology in
*
*
*
*
Pancreas
Renal parenchymal tissue
Blood vessels and vascular aneurysms
Gallbladder fibroids (leiomyoma)
Calcium is the pathology in
* Biliary calculi
* Renal calculi
* Appendicolith
* Bladder calculi
* Teratoma
• Mesenteric lymph nodes may calcify and
be confused with ureteric calculi. They are
usually oval in shape . The line of the
ureter is along the transverse processes of
the lumbar vertebrae . Phleboliths from
calcified pelvic veins may appear like
bladder stones. Calcification may appear in
the ageing prostate , low down in the
pelvic brim. Prostate calcification may also
occur in malignancy but it is not
diagnostic.
• The pancreas lies at the level of the T9 to T 12
vertebrae . Calcification occurs in chronic
pancreatitis and may show the whole outline
of the gland.
• Between the levels of T12 and L2,
nephrocalcinosis may be seen. Calcification of
the renal parenchyma indicates pathology
including hyperparathyroidism, renal tubular
acidosis, and medullary sponge kidney.
• Renal calculi tend to obstruct at certain sites,
especially the pelviureteric junction, brim of
the pelvis, and vesicoureteric junctions.
• Calcification of blood vessels usually affects
the arteries and can be quite striking. The
whole vessel may be outlined by calcium.
Extensive calcification may indicate
widespread atheroma, especially in diabetes.
• Abdominal aortic aneurysms are usually
below the 2nd lumbar vertebra. Calcification
may make them obvious and can give a rough
indication of the internal diameter.
• Abdominal ultrasound is required for
accurate assessment , and to determine the
need for surgery or follow up.
• Gallstones are visible in only 10 to 20% of
cases. Ultrasound is vastly superior but
plain abdominal x-ray is often the initial
investigation in patients with abdominal
pain . The gallbladder may become
calcified after repeated episodes of
cholecystitis . This is called a porcelain
gallbladder and 11% will become
malignant11.
• In the pelvic region bladder calculi may
occasionally be seen. Bladder stones are
usually quite large and often multiple.
Calcification of a bladder tumor may also
occur . Schistosomiasis may
produce
calcification of the bladder wall.
• Uterine fibroids can become calcified
• Sometimes ovarian teratoma may show a
tooth. This is of passing interest although
such an ovarian tumour can undergo
torsion
Systematic approach to viewing
an abdominal film with contrast:
•
When we examine x.ray abdomen with
contrast the following steps should followed:
1. Which organ is examined?
2. Which type of contrast?
3. Is there a pathology or not?
4. The position and view of examiantion?
Types of contrast examinations
1.
2.
3.
4.
5.
Esophagus
Stomach
Small intestine
Large intestine
Kidney, ureters and urinary bladder
Contrast examination of the
esophagus
Barium swallow •
 We see if there is
narrowing or
dilatation .
 if there is filling
defect in the
lumen of
esophagus.
 We see if contrast reached the stomach
Contrast examination of stomach
• We see if contrast reached the stomach and
fill it completely.
• We check contrast and air in the stomach to
detect the position of the patient during
examination.
• We see the wall of the stomach if the is
ulcer or tumor.
• There are two types of contrast positive and
negative we identify them. We see whether
the exam is with double or single contrast.
Ba meal with double contrast
Patient is in supine position
Ba meal with single contrast
Gass in the fandus
Narrowing in the stomach
Patient is standing
Ulcer in the wall of the stomach
Barium meal with single and double
contrast in prone position
Barium meal and follow through
• The patient drinks a contrast medium
containing barium sulfate.
• X-ray images are taken as the contrast
moves through the intestine, commonly at
0 minutes, 20 minutes, 40 minutes and 90
minutes.
Barium meal and follow
through
Barium meal and follow through
Barium meal and follow through
•
Crohn 's disease of distal ileum with stricturing and
sacculation on the antimesenteric aspect (
curved
arrows), and fissure ulcers ( small arrows ). Open arrow
points to ileo-caecal valve.
Barium meal and follow through
• Aphthoid ulceration of terminal ileum (small arrows)Note also "cobblestoning" (larger arrows).
Barium meal and follow through
•
Chronic ileocaecal tuberculosis. The caecum and ascending
colon are retracted craniad and are fibrotic . scarred and
saccilated (curved arrows). The terminal ileum in this patient is
relatively patulous (straight arrows) and probably nodular.
v=ileocaecal valve.
Small Bowel Enema
•
Enteroclysis examination demonstrates a segment of
ileum in the right iliac fossa with wall thickening,
destruction of the normal fold pattern and aneurysmal
ulceration (arrowed) and mass effect
Small Bowel Enema
• Multiple moderate-sized and large diverticula
present.
Barium Enema
Plain x-ray abdomen (erect film) showing multiple air
fluid levels in the loops of jejunum due to small gut
obstruction.
Plain x-ray abdomen showing marked dilatation
of the large gut from caecum to splenic flexure
due to large gut obstruction.
Plain x-ray abdomen showing dilatation of
large gut due to twisted and obstructed
caecum and ascending colon due to volvulus
of caecum
Plain x-ray abdomen showing air fluid level
under the right dome of diaphragm due to
presence of gas in the right subphrenic abscess
Surgical Clips
Extra-luminal gas seen on erect CXR.