1727261612120_Gastrointestinal Radiology.pptx MBChB FINAL!!.pptx

1727261612120_Gastrointestinal Radiology.pptx MBChB FINAL!!.pptx

1. Gastrointestinal Radiology Department of Radiology MAkCHS

2. Imaging modalities Plain X-Ray Contrast studies Ultrasound Computed Tomography Magnetic Resonance Imaging PTC, intra-op & T-tube cholangiogram , Radionuclide imaging – IDA, Meckel’s and GIT bleed.

3. Plain Abdominal X-ray-Indications Bowel obstruction Perforation Renal pathology Acute abdomen Foreign body localization Toxic megacolon Aortic aneurysm Control or preliminary films for contrast studies Detection of calcification or abnormal gas collection

4. Plain Abdominal X-ray Remember the five basic densities on x rays: Gas-> Black Fat-> Dark grey Soft tissue/fluid-> Light grey Bone/calcification->White Metal-> Intense white

5. Plain Abdominal X-ray-Anatomy

6. Interpretation Views: supine, erect, decubitus (usually left side down) Bowel gas pattern: normal gas : stomach and colon Normal air-fluid level : stomach and proximal duodenum Stomach – rugae ; Jejunum – feathery; Small bowel – valvulae conniventes ; Colon – haustrations .

7. Psoas outline: symmetrical and slightly concave lateral borders. Renal outline : 10-12cm / 3.5 vertebral height. Bladder outline, Liver and splenic outline. Intraperitoneal fluid / collections. Calculi / calcifications : GB, kidneys, pancreas, lymph nodes, vascular, phleboliths , tumoral . Soft tissue masses. Extra-luminal gasses.

8. Bowel gas pattern Where are the bowel loops located (central vs. peripheral)? Is there too much intraluminal gas? What is the distribution of the gas in the abdomen? What is the intraluminal caliber of the small and large bowel? Are there any dilatations of the small and/or large bowel? identify any air-fluid levels?

9. GASLESS ABDOMEN 1. Ascites. 2. Pancreatitis (acute) – due to excess vomiting. 3. Fluid-filled bowel – closed-loop obstruction, total active colitis, mesenteric infarction (early), bowel washout. 4. High obstruction – e.g. gastric outflow obstruction, congenital atresia. 5. Large abdominal mass – pushes bowel laterally. 6. Normal.

10. Small bowel Identified by: Central position in the abdomen, smaller calibre Valvulae conniventes - mucosal folds that cross the full width of the bowel Normal large bowel may be identified by: Peripheral position in the abdomen (the transverse and sigmoid colon occupy very variable positions) Haustra Contains faeces

11. Dilated Bowel Jejunum > 3.5 cm Mid small bowel > 3 cm Ileum > 2.5 cm Tranverse colon > 5.5 cm Caecum > 8 cm

12. Fecal impaction speckled low-density soft tissue mass within a distended large bowel, most commonly the rectum

13. Bowel obstruction: Mechanical obstruction of the small bowel: - small bowel dilatation with normal / reduced calibre of colon. Large bowel obstruction: - dilatation of large bowel +/- small bowel dilatation.

14. SMALL bowel obstruction Large bowel obstruction

15. Dilated small and large bowel Multiple air-fluid levels

16. Supine abdominal X-ray Dilated small bowel Central Valvulae coniventis

17. Extra-luminal gas Free intraperitoneal gas: Causes – Post-laparotomy (up to 7 days) Perforated peptic ulcer IBD / infarction. ERECT FILM! – air under diaphragm or lateral decubitus SUPINE – gas outlining the falciform ligament. - gas on both sides of the bowel ( Rigler’s sign)

18. CXR ABDOMINAL Air under the diaphragm

19. Lateral decubitus x-ray. Lateral decubitus view of an abdominal X-ray exhibiting free intra-abdominal air between the liver, right hemidiaphragm and lateral abdominal wall

20. Calcifications Phleboliths Vascular – Arteriosclerosis Solid organs: liver, spleen, pancreas, adrenals, kidneys. Tumors: fibroids, ovarian masses. Soft tissue Faecoliths .

21. Uterine fibroid Pancreatic Appendicolith

22. Abdominal x-ray showing oval white density to left of spine-- stone in left ureter.

23. CONTRAST STUDIES Administering a contrast agent modifies the image to give more information. Typical ones are barium , an inert particulate contrast used in GI tract evaluation and Iodine , a water soluble agent which can be injected into the vascular tree. Fluoroscopy is an imaging technique that uses X-rays to obtain real-time moving images of the internal structures of a patient

24. INDICATIONS Dysphagia or odynophagia (painful swallow) Motility disorders Globus sensation Assessment of tracheo-oesophageal fistulae Failed upper GI endoscopy Bowel obstruction GERD

25. CONTRAST STUDIES Barium swallow Barium meal Barium follow-through Barium enema

26. CONTRAST STUDIES Contrast material: BARIUM GASTROGRAFFIN (HOCM) Omnipaque (LOCM) Good opacification and coating BUT peritoneal leak (peritonitis) Safe if peritoneal leak BUT hypertonic, lung irritant if aspirated and less opaque Safe if aspirated or leak BUT expensive and poor opacification and coating

27. Description: - site of the abnormality - Is there a soft tissue mass? - what is its shape? - how long?

28. Barium swallow It is a medical imaging procedure used to examine upper gastrointestinal tract, which include the esophagus and to a lesser extent the stomach. The contrast used is barium sulfate.

29. Barium swallow Normal: full ---smooth outline Collapsed, 3-4 long straight parallel lines Indentation left: aorta and left bronchus anterior: (L) atrium and ventricle Peristalsis smooth

30. Full collapsed 3 ◦ contractions

31. There are three normal esophageal constrictions that should not be confused for pathological constrictions: cervical constriction: due to cricoid cartilage at the level of C5/6 thoracic constriction: due to aortic arch at the level of T4/5 abdominal constriction: at esophageal hiatus at T10/11

32. Normal sites of narrowing of Esophagus Superiorly: level of Cricoid cartilage, juncture with pharynx • Middle: crossed by aorta and left main bronchi • Inferiorly: diaphragmatic sphincter

33. Ca esophagus . Narrowing of the oesophagus . Irregular contour . prestenotic dilatation . Rat’s tail appearance

34. 70YR/F, 6months h/o dysphagia

35. Benign constriction Achalasia

36. Barium meal In a barium meal test, X-ray images are taken of the stomach and the duodenum. Method: - swallow barium then gas-producing agent, - iv smooth muscle relaxant -various positions

37. Barium meal anatomy

38. Conditions- Hiatus hernia (b) Rolling (a) Sliding

39. Ulcers

40. Carcinoma Multiple filling defects lesser curvature

41. Double-contrast barium meal study in a 54-year-old patient shows a mucosal mass  (arrows)  due to adenocarcinoma at the greater curvature.

42. Barium meal and follow through

43. Delayed film of the barium meal shows the dilated segment of the proximal duodenum retaining the contrast (arrow), and the abnormal position of the small bowel entirely occupying the right side of the abdomen. 

44. Barium enema SINGLE CONTRAST STUDY The colon is filled with barium, which outlines the intestine and reveals large abnormalities. DOUBLE CONTRAST with AIR. The colon is first filled with a thin layer of barium. The colon is then filled with air. This provides a detailed view of the inner surface of the colon, making it easier to see narrowed areas (strictures), diverticula, or inflammation.

45. Barium Enema Double contrasts

46. Diverticulosis

47. Carcinoma-- Apple core

48. On double contrast barium study; There is short segment stricture with shouldering appearance and  apple core sign  at proximal of transverse colon suggestive for tumoral infiltration. 

49. ULTRASOUND - Normal anatomy: solid organs + biliary tree + vessels + lymph nodes. - echogenicity: pancreas, liver, spleen, kidney. hyper………………………… hypo Appearances of various tissues: fat = hyper; fluid = hypo with posterior acoustic enhancement; Calculi/ bone = hyper with posterior accoustic shadowing; Gas- shadowing

50. INDICATIONS Abdominal pain Altered liver function tests Jaundice Gall stones Acute cholecystitis Abdominal aortic aneurysm Enlarged abdominal organ i.e hepatomegaly, splenomegaly

51. Computed Tomography Each pixel displayed on monitor has varying brightness The greater the attenuation, the brighter the pixel The less attenuation, the darker the pixel

52. INDICATIONS Abdominal pain Postoperative complications Bowel obstruction/perforation Trauma Aortic aneurysm Malignancy

53. Non contrasted CT scan CT of abdomen without contrast. Note the lack of distinction between abdominal organs.

54. CT scan of abdomen with intravenous contrast. Notice how much better you can see the kidneys and blood vessels.

55. CT anatomy

56. COMPUTED TOMOGRAPHY & MAGNETIC RESONANCE IMAGING General considerations Differences between CT and MRI Windowing in CT and sequences in MRI Various densities in CT and intensities in MRI

57. MRI

58. Hepatic cysts CT

59. Hepatic cysts MRI