Interpret axr and imaging of gist system
- 1. INTERPRETATION OF AXR AND IMAGING MODALITIES FOR GIT By: Dr.Husbani
- 2. Scope of learning: Able to interpret an abdominal radiograph. Able to describe features of bowel obstruction on AXR. Identify free intraperitoneal gas and calcifications on abdominal radiograph. Explain the justification for further imaging investigation of common abdominal pathology.
- 3. X-ray in abdominal pathology: Standard plain film of the abdomen is Supine anteroposterior view. Plain radiograph in acute abdomen Erect CXR-to detect free intraperitoneal gas Lateral decubitus film-rarely done-to detect intraperitoneal air as well
- 4. General:Systematic approach in interpreting any radiograph Check patient’s data Date of examination. Projection: Standard Anterior-Posterior (AP) supine projection, ERECT, decubitus. Image quality (contrast and coverage) whole abdomen should include-from diaphragm to ASIS and cover from left to right. Check for artifact.
- 5. Specific: Points to look for in AXR 1. Analyse intestinal gas pattern, identify any dilated portion of GIT. 2. Look for gas outside the lumen of the bowel. 3. Look for ascites and soft tissue masses in the abdomen and pelvis. 4. If there are any calcification, try to locate exactly where they lie. 5. Assess the size of liver and spleen.
- 6. Intestinal gas pattern Pattern of small and large bowel, easier to appreciate when the bowel is abnormally distended. If the bowel is dilated it is important to try and decide which portion is involved. Normal diameter of the bowel is 3cm for SB, 6cm for LB, 9cm for caecum (3/6/9 rule).
- 7. Normal abdominal radiograph 1. 11th rib. 2.Vertebral body (TH 12). 3. Gas in stomach. 4. Gas in colon (splenic flexure). 5. Gas in transverse colon. 6. Gas in sigmoid. 7. Sacrum. 8. Sacroiliac joint. 9. Femoral head. 10. Gas in cecum 11. Iliac crest. 12. Gas in colon (hepatic flexure). 13. Psoas margin. Should include properitoneal fat
- 8. Small bowel obstruction Centrally located multiple dilated loops of gas filled bowel. Valvulae conniventes are visible Look for evidence of previous surgery may suggests adhesion as the likely cause.
- 9. Distal small bowel obstruction Valvulae conniventes
- 11. Large bowel obstruction Cecum>9cm is abnormal Colon >6cm is abnormal Colon recognized by haustra-incomplete bands across the colonic gas shadows.
- 12. Volvulus Cecal volvulus-proximal small bowel dilatation 'coffee bean‘ sign and dilatation of the proximal large bowel
- 13. Sentinel loop Focal dilatation of bowel due to inflammatory changes underlying the bowel.
- 16. Subdiaphragmatic free gas: •Differential: •subdiaphragmat ic abscess •omental fat interpositioned between the liver and diaphragm •subpulmonary pneumoperitone um •enlarged gastric bubble •Chilaiditi syndrome
- 18. Gas in the wall of bowel
- 19. Ascites Small amounts cannot be detected. Large quantities separate the bowel. Axr with ascites-signs difficult to appreciate.
- 20. Aneurysmal dilatation of the vessel
- 22. Splenomegaly Splenomegaly Bowels are displaced to right side but not dilated
- 23. Artifact and calcification on radiographs Ring pessary Surgical clips Calcified mesenteric lymph node Seminal vesicle calcification Fibroid calcification
- 25. Different types of stent Ryle’s tube , IVC filter double J stent
- 26. pelvic mass There is generalised hazy density of the entire abdomen, A loop of gas filled bowel lies centrally in the abdomen Depends on the size of the mass, Can extend superiorly and displaced the bowel if large enough.
- 27. Other GIT imaging modalities For most intestinal disorder-endoscopy and imaging inx needed. Endoscopy-1st inx-shows mucosal directly and can bx. Imaging-reserved for lesion cannot be seen endoscopically. Barium exam reduced as endoscopic unit developed Ct pneumocolon and virtual colonoscopy widely used. MRI-for local staging of colorectal carcinoma and imaging of SB. FDG/PET CT for secondaries from Ca GIT.
- 28. Different pathology and imaging investigation: Contrast study:if patient is stable and part of the investigation To see intestinal obstruction: start with plain film, if patient stable and suspect cancer rectal can do colonoscopy/barium enema. If not visualised can do CECT abdomen/pelvis. Ultrasound: as a preliminary investigation ie: stable aneurysm, suspect mass. To see the extension of the mass: CECT To stage the disease: CECT scan thorax, abdomen, pelvis
- 29. Different types of fluoro study Esophagus-barium swallow Stomach-barium meal Small bowel: small bowel follow through/small bowel enema Large bowel: Barium enema
- 30. Esophageal carcinoma on barium swallow
- 31. Pulsatile abdominal mass Plain radiography US CT/MRI Easily performed and shows calcification, if present. It does not accurately define an aneurysm. Definite screening modality and enables measurement of the aortic length and diameter. With helical CT, the branches of AA and extension aneurysm clearly visualized. Pre-operative angiography (as required by surgeon) Diagnosis Diagnosis
- 32. Abdominal aortic aneurysm on ultrasound CTA abdominal aorta
- 33. Barium enema showing apple core lesion-colorectal carcinoma
- 34. Colorectal carcinoma annular constricting carcinoma of the colon with overhanging edges on both the proximal and distal margins forming a so called "apple- core" lesion
- 35. Pathology on nuclear medicine Meckel’s diverticulum
- 36. Blunt abdominal trauma There is absolutely no indication for further imaging in a haemodynamically unstable patient. Active resuscitation and immediate surgery is the first line of management. In haemodynamically stable patients, futher imaging is indicated .
- 37. Blunt abdominal trauma Hemodynamically stable patient CT US Hemodynamically unstable patient Resuscitation and surgery Diagnosis Diagnosis CT- definitive imaging modality in the evaluation of abdominal and pelvic trauma. US-Initial rapid imaging technique to evaluate the abdomen and pelvis. much less accurate than CT in cases of abdominal trauma. Plain radiograph
- 38. Abdominal trauma Fluid in Morrison ’s pouch Liver laceration Splenic laceration
- 39. Any question?