Introduction to abdominal x ray interpretation
- 1. Introduction to abdominal X- ray interpretation Dr G Abraham
- 2. Technical Aspects • Check that it is standard supine AP projection. • Other projections important in surgical abdomen include decubitus radiograph or erect chest radiograph. • Field of exposure – ideally diaphragm to hernial orifices and left to right of abdomen. • Penetration
- 3. Viewing protocol – Abdominal X-ray I. Bones: Ribs, Lumbosacral spine, Pelvis, Upper femur II. Lung bases III. Opacities: Calcifications: Rib cartilage, Vessels, Soft tissues, Mesenteric lymph nodes Concretions: Gall bladder, Kidney, Ureter, Bladder, Pancreas, Appendix, Phleboliths Miscellaneous: Metallic densities, Barium, Enteric coated tablets, Foreign bodies IV. Major organs: Liver edge, Splenic tip, Renal outlines, Urinary bladder V. Psoas margins VI. Gas in bowel: Stomach, Small intestine, Colon VII. Gas outside bowel: Under diaphragm, Liver, Bile ducts, Portal vein, Pockets, Retroperitoneum VIII. Gas in wall of hollow viscus: Bowel , Stomach. Bladder, gallbladder IX. Masses
- 4. Bony review
- 5. Soft tissues/organs • Liver • Lung bases • Psoas muscles • Kidneys • Spleen • Bladder
- 6. • What is the structure coloured blue? • What abnormality does it represent?
- 7. Bowel Gas Pattern • Gas is of low density and forms a natural contrast against surrounding denser soft tissues. It is often difficult to differentiate between normal small and large bowel. • 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’).
- 8. Stomach • If the stomach contains air it may be visible in the left upper quadrant of the abdomen. The lowest part of the stomach may cross the midline. Stomach
- 9. Small bowel – duodenum to terminal ileum • Generally the small bowel lies centrally within the abdomen. • The valvulae coniventes are circumferential folds of mucosa and are seen on an X-ray to pass across the full width of the lumen.
- 10. Large bowel • The retroperitoneal structures of the colon (ascending colon, descending colon, and rectum) are relatively constant in position. Transverse colon and sigmoid colon are variable. If visible, the caecum is often the widest segment. It too has a variable position, but is most often confined to the right iliac fossa. • The longitudinal muscles (taenia coli) and circular muscles of the colon form sacculations called haustra, • Faeces are another clue to large bowel identification which give a mottled appearance. Ascending colon Haustra
- 12. • 61 year old female • Previous laparotomy and incisional hernia repair. Distended abdomen and vomiting.
- 13. Small Bowel Obstruction • epidemiology 1 • 80% of all mechanical bowel obstruction • average age: 64 years • females comprise 60% of patients • presentation • abdominal distension, nausea and vomiting • the level will determine the acuity of presentation • high obstruction presents early, possibly with bilious vomiting • lower obstruction presents late and may have faeculent vomiting • pathology • may be complete or incomplete • causes • adhesional SBO: occurs almost exclusively from prior surgery • herniae (often femoral or inguinal, but incisional occur) • foreign bodies or other masses, e.g. gallstones • rare: small bowel tumours causing intussusception
- 14. • 40 year old female with abdominal pain and vomiting
- 15. Large bowel obstruction • Epidemiology • 20% of all bowel obstructions • Clinical presentation • Presentation is typically with abdominal pain, distension and absolute constipation; eventually sign of perforation • Aetiology • Malignancy • Colorectal carcinoma (most common, 50-60%) • pelvic tumours; direct spread or metastatic disease • Colonic diverticulitis • volvulus • Caecal volvulus (1-3%) • Sigmoid volvulus (3-8%) • ischaemic stricture • faecal impaction/faecoloma (most common cause in debilitated elderly)
- 16. Acute abdominal pain in an ICU patient, male, 65.
- 18. Bowel perforation Clinical Features •severe and generalised abdominal pain (upper) •gradual and localised pain (lower) •anorexia, nausea and vomiting •rigid abdomen and generalised tenderness •guarding and rebound •bowel sounds range from quiet to absent Aetiology •gastric and duodenal ulceration •infection (diverticulitis, appendicitis), ischaemia and cancer •blunt and penetrating trauma •ingestion of corrosive materials •iatrogenic causes (ERCP, colonoscopy, laparotomy, biopsy)
- 19. • Rigler’s sign LUQ • Free intraperitoneal gas is widespread with moderate dilatation of small bowel in particular and there may also be intramural gas.
- 23. Are these urinary tract calculi? • phleboliths
- 24. 73 year old female with abdominal pain and distension
- 25. • 85 year old man from a Nursing home with advanced Parkinson’s disease.
- 26. • 35 year old patient with Crohn’s disease, 3 days of nausea and vomiting • Erect film
- 27. • Supine abdo film of same patient • Residual CT contrast showing ‘thumb- printing’ suggestive of mucosal oedema
- 28. Summary • Abdominal radiographs overall offer a low yield of pathology • A systematic approach is still vital to identifying any abnormalities. • Familiarise yourself with normal appearances of stomach, bowel, major organs, bones and soft tissues. • For the surgical abdomen, identifying normal and abnormal gas patterns is the key
- 29. References • Dr Samuel Withey for cases • https://radiopaedia.org • http://www.radiologymasterclass.co.uk/