Interpretations of abdominal X-Rays

Question 1

How to confirm patient details on AXR?

Answer 1

• Name
• Hospital Number
• DOB
• Date and time of X-ray
• Establish whether previous imaging is available

Question 2

How to assess the image type?

Answer 2

• Assess projection of image
• Anterior-posterior (supine)
• Anterior-Posterior (erect)
• Exposure•Is the whole abdomen visible? (Diaphragm to pelvis)
• Are you able to see small bowel/large bowel?

Question 3

What is this?

Answer 3

Normal AXR

Question 4

Explain the interpretation of AXR

Answer 4

• Structured approach (BBC)

Bowel (and other organs – SB, LB, Lungs, Liver, GB, Stomach, psoas, Kidney, spleen, Bladder)

Bones (Ribs, vertebrae, sacrum, coccyx, pelvis)

Calcification (eg renal stones, Gallstones, aorta)•

Question 5

What is the difference between the small bowel and large bowel?

Answer 5

• Distribution (SB usually lies centrally, with the large bowel ‘framing’ it)
• SB mucosal folds (Valvulae conniventes) – visible across full width of bowel
• Large bowel wall features haustra (thicker than valvulae conniventes and typically does not appear to traverse the width of the bowel)
• Faeces (mottled appearance in large bowel, due to air trapping in solid faeces)

Question 6

What is circled in the AXR?

Answer 6

Faeces

Question 7

What are the different diameters of the bowel?

Answer 7

• Upper limits
  
  • Small bowel (3cm)
  • Colon (6cm)
  • Caecum (9cm)

Question 8

What are the features of small bowel obstruction?

Answer 8

• Features:
  
  • Dilatation of small bowel (>3cms)
  • Prominent valvulae conniventes

Question 9

What are the causes of small bowel obstruction?

Answer 9

• Causes:
  
  • Adhesions (75%)
  • Abdominal hernias
  • Intrinsic/extrinsic compression (eg tumours)

Question 10

What is this?

Answer 10

Small bowel obstruction

Question 11

What are under-exposed AXR’s look like?

Answer 11

Lighter → harder to read

Question 12

What does an over-exposed AXR look like?

Answer 12

Darker

Question 13

What is this?

Answer 13

Gallstone ileus

Question 14

What are the causes of large bowel obstruction?

Answer 14

Causes:

• Colorectal Cancer
• Diverticular stricture
• Hernia
• Volvulus

Question 15

What is this?

Answer 15

Large bowel obstruction

Question 16

What is this?

Answer 16

Sigmoid volvulus

Question 17

What is the characteristic appearance of sigmoid volvulus?

Answer 17

Sigmoid volvulus:

a characteristic ‘coffee bean’ appearance

Question 18

What is this?

Answer 18

Sigmoid volvulus

Question 19

What is this?

Answer 19

Rigler’s sign

Question 20

What is Rigler’s sign?

Answer 20

In healthy individuals, only the inner wall of the bowel should be visible on an abdominal X-ray. The presence of free air within the abdomen (pneumoperitoneum) can result in both sides of the bowel wall becoming visible (this is known as Rigler’s sign)

Question 21

What is this?

Answer 21

Perforation (free air under the diaphragm)

Question 22

What does a perforation cause?

Answer 22

Free air under the diaphragm

Question 23

What are some inflammatory bowel diseases & their features?

Answer 23

• Crohn’s disease
• Ulcerative colitis
  
  • Thumbprinting
  • Lead-pipe (featureless) colon
  • Toxic megacolon

Question 24

What is thumbprinting?

Answer 24

Thumbprinting: mucosal thickening of the haustra due to inflammation and oedema causing them to appear like thumbprints projecting into the lumen.

Question 25

What is lead-pipe (featureless) colon?

Answer 25

**Lead-pipe (featureless) colon:** loss of normal haustral markings secondary to chronic colitis.

Question 26

What is a toxic megalocolon?

Answer 26

**Toxic megacolon:** colonic dilatation without obstruction associated with colitis.

Question 27

What is this?

Answer 27

Ulcerative colitis showing ‘lead piping’

Question 28

What is this?

Answer 28

Thumb-printing in ulcerative colitis

Question 29

What are some other organs to see on AXR (or look out for)?

Answer 29

* **Lungs:** inspect the lung bases for pathology (e.g. consolidation) as abdominal pain can, in some cases, be caused by basal pneumonia. * **Liver:** a large right upper quadrant structure. * **Gallbladder:** rarely visible on an abdominal X-ray, however, you should quickly inspect for calcified gallstones and cholecystectomy clips. * **Stomach**: visible between the left upper quadrant and midline, containing a variable amount of air. * **Psoas muscles:** the lateral edge is marked by a relatively straight line either side of the lumbar vertebrae and sacrum. * **Kidneys:** both are often visible, the right kidney is lower than the left due to the presence of the liver on the right. * **Spleen:** located in the left upper quadrant, superior to the left kidney. * **Bladder:** has a variable appearance depending on the fullness of the bladder.

Question 30

What bony structures can be seen on an AXR?

Answer 30

* Bony structures commonly visible on abdominal X-ray include: * Ribs * Lumbar vertebrae * Sacrum * Coccyx * Pelvis * Proximal femurs

Question 31

How can bony metastasis be seen on AXR?

Answer 31

* From prostate cancer can be seen as either more white on AXR or sometimes more dark

Question 32

What can be seen as high density (white) areas on AXR?

Answer 32

* Various high density (white) areas of **calcification** or **artefact** may be noted on abdominal X-ray including: * Calcified gallstones in the right upper quadrant * Renal stones/staghorn calculi * Pancreatic calcification * Vascular calcification * Costochondral calcification * Contrast (e.g. following a barium meal) * Surgical clips * Jewellery

Question 33

What is this?

Answer 33

Renal stent

Question 34

What is this?

Answer 34

Renal stone

Question 35

What is this?

Answer 35

Belly-button piercing

Question 36

What is this?

Answer 36

Adhesions - small bowel dilation