It is a ppt of abdominal imaging which includes normal and pathological findings

1. ABDOMINAL
IMAGING

2. BASICS OF ABDOMINAL X-
RAYS AND CT SCAN

3. Abdominal X-RAY
KEY POINTS:
 Check the patient details
 Assess quality
 Systematically review bowel gas, soft tissues, bones
and abnormal calcification

4. Introduction:
 Although anatomy of the abdomen is complicated, many
structures are not clearly defined on a radiograph of the
abdomen, and therefore cannot be fully assessed.
 A systematic approach to abdominal X-ray interpretation is
therefore relatively straightforward. This involves assessment
of the bowel gas pattern, soft tissue structures, and bones.

5.  Indications for Abdominal X-ray
Toxic mega colon.
Bowel obstruction.
Bowel ischemia
Perforation of a viscus with abdominal free air.
KUB for renal tract calculi.
Foreign body

6. Abdominal X-Ray Views
 The two most commonly requested views are:
 Anteroposterior (AP) supine
 Anteroposterior (AP) erect.
 Other views include
 Lateral decubitus—horizontal beam view with the patient
rolled onto one side. A useful alternative to the erect AP
view if patient is unable to sit or stand

7. Technique for supine AP (anterior-posterior) image.

8. Figure 3. Technique for lateral image lying
on the left side.
In each position, the X rays will pass
through the body from front to back
(anterior-posterior). Basal lung fields up to
and including the pubic bone should be
imaged

9. X-ray densities (= whiteness)

10. Normal anatomy
 Examine an AXR as if you are standing in front of the patient; so
left is right and vice versa.
In a normal AXR, the contours of the psoas muscles are visible.
 The liver, kidneys, spleen and bladder can in some cases also be
identified.

11. Can u appreciate
normal organ
contours in this
image.

12. Normal anatomy
on a supine AP image.
Note the (subtle)
organ contours.

13. Normal Small bowel VS Large bowel
Small bowel loops:
AXR shows central, valvulae conniventes
Large bowel loops:
AXR shows peripheral, haustra.

15. Normal anatomy on Abdominal X ray

17. Standing AP image.
Normal configuration
of the colon with
characteristic haustra.

18. ACUTE ABDOMEN ON
PLAIN X- RAY

19. BOWEL OBSTRUCTION:
(3/6/9 rule)
 Key points:
 The upper limit of normal diameter of the bowel is generally accepted as
3cm for the small bowel, 6cm for the colon and 9cm for the caecum (3/6/9
rule).
 Knowledge of the normal appearances of the bowel may help determine
the location of abnormalities
 Any part of the bowel may be visible if it contains gas/air within the lumen.
 It is often difficult to differentiate between normal small and large bowel, but
this often becomes easier when the bowel is abnormally distended.

20. Large bowel obstruction
 Typically present with abdominal pain, distension, and failure of passage of
flatus and stool.
 Large bowel obstructions are far less common than small bowel
obstructions, accounting for only 20% of all bowel obstructions
 The underlying etiology of large bowel obstructions is age-dependent, but in
adulthood, the most common cause is colonic cancer (50-60%), typically in
the sigmoid.
 The second most common cause in adults is acute diverticulitis (involving
the sigmoid colon). Together, obstructing tumors and acute diverticulitis
account for 90% of all causes of large bowel obstruction

22. The large bowel is gas filled
distended down to the level of the
distal descending colon-sigmoid.
Small bowel collapsed.
A typical case of large bowel
obstruction.

23. Large bowel
obstruction
(LBO)
Frontal supine

25. Frontal erect x-ray abdomen showing
multiple air fluid levels with dilatated
bowel loops located at periphery and
paucity of air in small bowel likely
suggest large bowel obstruction.

27. X ray abdomen supine shows
significant dilated large bowel loops
located at periphery of abdomen.

29. Small bowel obstruction (SBO)
 Small bowel obstruction (SBO) accounts for 80% of all mechanical
intestinal obstruction, the remaining 20% results from large bowel
obstruction.
 Classical presentation is cramping abdominal pain and abdominal
distension with nausea and vomiting.
 In developed countries, adhesions are by far the most common cause,
accounting for ~75% of obstructions while in developing countries
incarcerated hernias are much more common accounting for 80% of
obstructions
 Rare causes include tumor.

31. Multiple dilated bowel loops with air
fluid levels located centre of the
abdomen with paucity of air in large
bowel likely suggest small bowel
obstruction.

34. Perforation - Erect Chest X-ray
If perforation is suspected
then an erect chest X-ray
should be performed as well
as an abdominal X-ray.

36. Chest X-ray erect shows free air
under right diaphragm suggest
Pneumoperitoneum.

37. Sigmoid volvulus - 'coffee bean' sign
 Sigmoid volvulus is due to a twist at the base
of the sigmoid mesentery which is in a fixed
position.
 This results in the appearance of a giant
'coffee bean‘ or inverted U, the typical sign of
sigmoid volvulus.

40. Abdominal
Computed
Tomography (CT)….

41. CT OverView:
 X-rays and CT scans work by the same process in that they both
use radiation to create an image.
 An x-ray is a static image in a single projection, which in the past
was developed on film, but nowadays is created with a digital
image. CT scans are a dynamic study with an x-ray tube rotating
360 degrees in a gantry about the patient which can be produce
single "slices" of a particular area of the body imaged or create a 3D
image of that same area.
 The resolution of CT is much greater than plain x-rays but also has
a higher x-ray exposure to the patient.
 Appropriate precautions must be taken prior to the scan to ensure
that the patient has adequate renal function and no history of allergy
before prescribing intravenous iodinated contrast.

42. 3D RECONSTRUCTED IMAGES

43. Indications of CT abdomen:
 Bowel perforation
 Colon cancer
 Intra-abdominal trauma
 Abdominal pain
 Abdominal sepsis
 Bowel obstruction
 Post-operative complications
 Trauma
 Vascular compromise, e.g. aortic aneurysm

44. CT PROTOCOL


49. Hydatid disease of liver
Hydatid cysts result from infection by the Echinococcus, and can result in cyst
formation anywhere in the body.
 Location
 hepatic hydatid infection: most common organ, 76% of cases involve the liver
 pulmonary hydatid infection: second most common organ
 splenic hydatid infection
 CNS hydatid infection
 spinal hydatid infection
 retroperitoneal hydatid infection
 renal hydatid infection
 musculoskeletal hydatid infection

50. CT FINDINGS:
 Fluid density cyst, with frequent peripheral focal areas of calcification, usually
indicates no active infection if completely circumferential. Septa and
daughter cysts may be visualized.
 The water-lily sign indicates a cyst with a floating, undulating membrane,
caused by a detached endocyst.
 May also show hyper dense internal septa within a cyst showing a spoke
wheel pattern.

51. CT scan shows a large fluid attenuation mass( mother cyst) in
the right lobe of liver with multiple irregular shaped internal
daughter cysts occupy almost the entire mother cyst on right
and calcified cyst on left(inactive stage of hydatid cyst)

52. Hydatid disease of liver
Axial section of abdominal CT scan
shows a large well defined cystic
lesion in right lobe of liver with inner
layer detachment giving classic
appearances of water lily.

53. HEPATIC ABSCESS
 Hepatic abscesses, like abscesses elsewhere, are localised collections of
necrotic inflammatory tissue caused by bacterial, parasitic or fungal.
 As with other modalities, the appearance of liver abscesses on CT is variable.
In general, they appear as peripherally enhancing, centrally hypoattenuating
lesions .
 Occasionally they appear solid or contain gas. The gas may be in the form of
bubbles or air-fluid levels .

56. HEPATOCELLULAR CARCINOMA
 Hepatocellular carcinoma (HCC) is the most common
primary malignancy of the liver. It is strongly associated with cirrhosis,
from both alcohol and viral etiologies.
 Several patterns can be seen, depending on the subtype of
HCC. Enhancement pattern is the key to the correct assessment of
HCCs.
 Usually, the mass enhances vividly during late arterial (~35 seconds)
and then washes out rapidly, becoming indistinct or hypoattenuating in
the portal venous phase, compared to the rest of the liver(KEY
FEATURE)