Imaging modalities of intestinal obstruction Mithilesh Kumar Medical College kolkata

Mithilesh Kumar Medical College kolkata

1. IMAGING MODALITIES IN INTESTINAL OBSTRUCTION By – MITHLESH KUMAR Third Professional MBBS Part – II Medical College Kolkata

2. OVERVIEW Radiography Computed Tomography Magnetic Resonance Imaging Ultrasonography Nuclear Imaging Angiography

3. Radiography Plain upright abdominal X – Ray Conventional barium follow – through examination and enteroclysis Barium enema study

4. Radiological features of plain X - Ray Small bowel – straight segments generally central and lie transversely Jejunum – valvulae conniventes , spaced regularly, concertina or ladder effect Ileum – featureless Caecum – rounded gas shadow in right iliac fossa Large bowel except caecum – haustral folds, spaced irregularly

5. Some special points In intestinal obstruction fluid level appear later than gas shadow as it takes time for gas and fluid to separate In adults, two inconstant fluid levels – one at the duodenal cap and the other in the terminal ileum may be regarded as normal In infants fluid levels in small bowel may be physiological, in this age group it is difficult to distinguish large from small bowel in the presence of obstruction because the characteristic features seen in adults are not present or are unreliable In small bowel the number of fluid levels is directly proportional to the degree of obstruction and to its site, the number increasing the more distal the lesion Limited water soluble enema differentiates large bowel obstruction from pseudo-obstruction

6. Supine view of the abdomen in a patient with intestinal obstruction. Dilated loops of small bowel are visible(arrows)

7. Upright view of abdomen in a patient with intestinal obstruction, Showing multiple air fluid levels

8. Lateral decubitus view of abdomen, showing air fluid levels consistent with intestinal obstruction (arrows)

9. Plain abdominal radiograph shows dilated loops of small bowel associated with thickened edematous valvulae conniventes

10. Barium follow - through Following features may assist in diagnosis Delay in the transit time Snakehead appearance Beak sign Fixation and kinking

11. The contrast enhanced study shows dilated loops of small bowel with stretching of the mucosal folds and a narrowed segment ending in a beak (arrow)

12. Enteroclysis Divide small bowel obstruction into 3 groups Low – grade or incomplete obstruction High – grade obstruction Complete small – bowel obtruction

13. Barium enema study Useful in large bowel obstruction In children with intussusception it is diagnostic as well as therapeutic

14. Postevacuation image from part of a barium enema study, shows a coiled spring appearance at the hepatic flexure of the colon typical of an intussusception

15. Computed Tomography Recommended when initial clinical findings and plain radiographs are inconclusive When strangulation is suspected Clearly demonstrate abnormalities of bowel wall, mesentery, mesenteric vessels, peritoneum Should be performed with intravenous contrast enhancement

16. Axial computed tomography scan showing dilated, contrast filled loops of the bowel on the patient’s left( yellow arrows), with decompressed distal small bowel on the patient’s right(red arrows)

17. Magnetic Resonance Imaging Assessment of small – bowel obstruction with strangulation

18. Ultrasonography It is of particular value in looking at the dynamics of the small bowel Used to assess peristalsis

19. A sonogram of right iliac fossa shows a bowel mass

20. Nuclear Imaging White blood scanning for detection and localization of intra abdominal inflammatory disease

21. 99mTc HMPAO labeled white blood cell scan shows active uptake of the radionuclide in the terminal ileum and caecum /ascending colon indicative of an active inflammatory process

22. A ngiography Superior mesenteric angiography used in diagnosis of internal herniation , intussusception , volvulus , malrotation , and adhesions.

23. Imaging in Intussusception Plain abdominal X – Ray shows features of small and large bowel obstruction Barium follow through of ileocolic intussusception shows claw sign Abdominal ultrasonography demonstrate doughnut appearance

24. ‘Claw ‘sign of iliac intussusception , the barium in the intussusception is seen as a claw around a negative shadow of the intussusception

25. Postevacuation image from part of a barium enema study shows a coiled spring appearance in the region of caecum suggestive intussusception

26. Imaging in Volvulus Caecal volvulus – bird beak deformity in barium enema Sigmoid volvulus – dilated loop

27. Grossly dilated loop of bowel in the central abdomen with the ends of the loop pointing towards the right half of the pelvis

28. Shows a medially pointed end column of the barium (beak sign) in the mid ascending colon