Abdominal X-Rays for Phase 4

A Systematic Approach…

…with the clinical context always in mind…

…avoids pitfalls!

General Approach

• Date of Film• Patient Name• Patient Age• Sex• Adequate area

covered

Topics

• Intraluminal gas• Extraluminal gas• Calcification• Soft tissues• Bones• Foreign objects• Periphery of film

• Intraluminal gas

• Extraluminal gas• Calcification• Soft tissues• Bones• Foreign objects• Periphery of film

Normal Intraluminal Gas

• Stomach : Always • Small Bowel : Two or three loops of non-

distended bowel – Normal diameter < 3.5 cm (jejunum)– Normal diameter < 2.5 cm (ileum)

• Large Bowel : Almost always in rectum/sigmoid– Normal diameter < 5 cm (colon)– Normal diameter < 9 cm (caecum)

Stomach gas

Gas in a few loops of small bowel

Gas in rectum

Gas in ascending colon

Large or small bowel?

Small Bowel

• Centrally placed• Narrow angle of

curvature• Multiple loops• Mucosal folds cross

the full width of the bowel (valvulae conniventes)

Large Bowel

• Peripheral• Only a few loops• Mucosal folds

only cross part of the bowel width (haustra)

Small Bowel Obstruction

Mucosal folds go all the

way across

Peripheral loop of caecum

Mucosal folds only partly cross bowel

wall

Large Bowel Obstruction

Some reflux of air into terminal

ileum

Where is the level of obstruction?

Distal descending coloncancer proven at barium enema

32 year old patient, poorly controlled ulcerative colitis, presenting with

bloody diarrhoea and severe abdominal pain

Very dilated transverse colon(>6cm)

Oedematous mucosa descending colon (“thumbprinting”)

Toxic Megacolon

SURGICAL EMERGENCY

Very dilated large bowel

Haustral folds do not cross all the way

across

Normal gas pattern in ascending colon

and caecum

Sigmoid Volvulus

Apex of loop in left upper quadrant

Very dilated large bowel

Normal descending colon

Apex of loop centrally / left upper quadrant

Caecal Volvulus

Management of Volvulus

Sigmoid

• Trial of flatus tube / sigmoidoscopy

Caecal

• Surgical

Faecal Material

• Mottled appearance• Wide range of normal amount• Within large bowel

• Intraluminal gas• Extraluminal

gas• Calcification• Soft tissues• Bones• Foreign objects• Periphery of film

Extraluminal Gas

• Invariably abnormal

• Exceptions– Recent laparotomy / laparoscopy (<5 days)– Gas in biliary tree after biliary intervention

• Only seen if large (>1 litre) amount of gas

Can see both sides of the bowel wall

Gas outlining peritoneal

cavity

Pneumoperitoneum

Erect Chest X-ray is the best initial test for

excluding perforation

Free gas under diaphragm

Pneumoperitoneum

Pneumoperitoneum

Lateral decubitus view

Free intraperitoneal gas

• Intraluminal gas• Extraluminal gas• Calcification• Soft tissues• Bones• Foreign objects• Periphery of film

Normal structures that calcify

Abnormal structures containing calcium

Costal cartilage Pancreas

Mesenteric lymph nodes

Blood vessels/aneurysms

Pelvic vein clots (phleboliths)

Uterine fibroids

Prostate gland Calculi:• Biliary• Bladder• Renal

Gallstones

Renal Calcification

Calculi also within left ureter

Bladder stones

Calcified Aortic

Aneurysm

Pancreatic calcification

• Intraluminal gas• Extraluminal gas• Calcification• Soft tissues• Bones• Foreign objects• Periphery of film

Soft Tissues

• AXR relatively insensitive unless very large enlargement

• May see bowel displacement

Large pelvic mass

Bowel loops displaced

2 hours later

….after bladder catheterisation

• Intraluminal gas• Extraluminal gas• Calcification• Soft tissues• Bones• Foreign objects• Periphery of film

Bone pathology

Generalised problem

OsteopaeniaPaget’s diseaseAnkylosing spondylitis

Localised problem

FracturesOsteoarthritisMetastatic deposits

…abnormalities may be coincidental

Clue : 77 year old with known colon cancer and lower back pain

Sacral metastasis

Ankylosing Spondylitis

Bamboo spine

Fused sacro-iliac joints

• Intraluminal gas• Extraluminal gas• Calcification• Soft tissues• Bones• Foreign objects

lightbulbs toothbrush

Other foreign objects

• Sterilisation Clips – Should both lie in the pelvis

• Surgical Clips– Cholecystectomy

• Hip prostheses• Retained swabs / needles very

rare

• Intraluminal gas• Extraluminal gas• Calcification• Soft tissues• Bones• Foreign objects• Periphery of

Film

Periphery of Film

• Lung bases • Hernial orifices• Subcutaneous tissues

Strangulated right inguinal hernia

Small and large bowel obstruction

Summary

•Clinical context is very important

•Remember to have a systematice approach

CXR Tutor

…series of 9 self-directed learning presentations on Medi-CAL site

Includes tubes and lines, lung cancer, pneumothorax, interstitial lung disease and a quiz

The End