imaging in tuberculosis

1. INTESTINAL TUBERCULOSIS
PRESENTOR : DR. MRUTHYUNJAYA R. P
MODERATOR: DR PRANEETHI K.

2. INTESTINAL TUBERCULOSIS
Tuberculosis of the GIT is the sixth most common site of
extrapulmonary tuberculosis.
• Intestinal tract
• Lymph nodes.
• Peritoneum.
• Solid viscera (Liver, Spleen, Adrenal, Pancreas)

3. Causative organisms,
• Mycobacterium tuberculosis hominis
• Mycobacterium bovis
• Atypical mycobacteria(MAC)

4. ROUTES OF INFECTION
• Ingestion of infected sputum
• Haematogenous route
• Local spread from surrounding organs
• 15% of patients with abdominal TB have evidence of
pulmonary disease.
• Chest radiograph may be normal in 50-65% of these
patients

5. PATHOLOGICAL FINDINGS
• Inflammation and fibrosis of the bowel wall and regional
lymph nodes, inflammation takes place in sub mucosal
lymphoid tissue resulting in wall thickening due to formation
of epitheloid tubercles.
• After 2-4 weeks caseous necrosis of the tubercle begins which
eventually leads to ulceration of overlying mucosa.
• Further extension within the bowel wall and regional lymph
nodes occurs by lymphatic spread.

6. • Granuloma formation, fibrosis and scarring develop in
the later stage.
• Regional lymphadenopathy may adhere to the diseased
bowel wall, forming an inflammatory mass.

7. TB manifestations divided into 3 categories
• Ulcerative form (60%)
Long axis of the ulcers is perpendicular to the long axis of
the bowel wall
• Hypertrophic form (10%)
Thickening of the bowel wall with scarring, fibrosis
and a rigid mass-like appearance that mimics that of
malignancies and
• Ulcero hypertrophic form (30%)

8. Clinical spectrum
• Predominantly a disease of young adults
• 2/3rds of patients are 21-40 yrs old
• In children peritoneal and lymph nodal involvement is more
common than gastro intestinal disease.
• Constitutional symptoms, diarrhea and malabsorption,
intestinal obstruction.

9. The most frequent region of involvement in descending
order of frequency
• Ileocecal junction
• Ileum
• Cecum,
• Ascending colon,
• Jejunum
• Rest of the colon, rectum,
• Duodenum and stomach.

10. IMAGING MODALITIES
• Barium meal follow through-evaluates motility and organic
lesions in the small intestine.
• Enteroclysis - ulcerations
• Barium enema- caecum and ileocaecal valve.
• Ultrasonography
• Computed tomography
10

11. TUBERCULOUS PERITONITIS
Modes of involvement
• Reactivation
• Secondary to tubercular salpingitis or discharge of
caseous material from diseased lymph nodes.

12. Traditionally tuberculous peritonitis is divided into three
types
• Wet type: Free or loculated ascites.
• Fixed-fibrotic type: Mesenteric and omental thickening
and masses, matted bowel loops, occasionally loculated
ascites
• “Dry” or “plastic” type is unusual
Characterized by caseous nodules, fibrous peritoneal
reaction and dense adhesions.

13. ASCITES
• Free or loculated ascites
• USG
Multiple fine complete or incomplete mobile fibrin strands
and debris in ascites.
• On CT
High density fluid ( 25-40 HU) due to high fibrin content and
cellular debris is characteristic of TB,
• Enhancement of ascites on MRI obtained 15-20 min after
gadolinium administration has been noted in TB peritonitis.

14. Ascites with septations

15. PERITONEUM
• Peritoneal thickening
• Nodules
• Smooth, slight peritoneal thickening and / or
pronounced enhancement are seen in presence of ascites
on CT.

17. OMENTUM
• Involvement of the omentum is classified as
• Nodular
• Smudged (Infiltration with ill-defined lesions) and
• Caked (Soft tissue replacement).
• CT reveals omental changes in most cases in up to 80%
of cases.
• The smudged type is the most common type
demonstrated by CT, while the caked type is uncommon.

18. Infiltration with small ill-defined
soft tissue densities interspersed within
the omental fat
Massive soft tissue omental cakes
(arrows), and soft tissue density masses
in the mesentery

19. • Omental caking seen in both TB peritonitis and
peritoneal carcinomatosis.
• Irregularly thickened outer contour of infiltrated
peritoneum favors malignancy.
• Fibrous wall covering the infiltrated omentum is
common in tuberculous peritonitis.

20. SMALL BOWEL MESENTERY
• Mesenteric thickening
• Nodular lesions
• Loss of normal mesenteric configuration
• Fixed loops of bowel and mesentery standing out as spokes
radiating out from the mesenteric root are described as USG
stellate sign.
“ Club sandwich sign” or “sliced bread appearance”
• Localized or focal ascites between radially oriented bowel
loops due to local exudation from inflamed bowel or ruptured
lymph nodes

21. Multiple discrete well-defined
mesenteric nodules
Diffused thickened soft tissue strands
with crowded vascular bundles in the
small bowel mesentery

22. MESOTHELIOMA
• Multifocal peritoneal
thickening of either sheet or
nodular types upto 3 cm
• Thick rigid septa between
peritoneal leaves and fixed
bowel loops
• Disproportionately small
amount of ascites to the degree
of tumour dissemination
TUBERCULOSIS
• Smooth, minimal peritoneal
thickening, (<5mm) with
pronounced smooth
enhancement
• Multiple, fine, complete or
incomplete mobile septa.

23. Abdominal Cocoon
• Sclerosing encapsulating
peritonitis.
USG
• Thick walled mass
containing bowel loops,
loculated ascites and
fibrous adhesions.
CT
• Small bowel loops
congregated to the center of
abdomen encased by a soft
tissue density mantle.

25. TUBERCULAR LYMPHADENITIS
• Commonest manifestation of abdominal tuberculosis
and may occur without any other evidence of abdominal
involvement.
• Tubercular adenitis, alone may be confused with
lymphoma and clinical and radiological differentiation
may be difficult.
• The nodes may vary from increased number of normal
sized nodes to massive conglomerates with matting.

26. ON USG
• Discrete or conglomerate masses.
• Enlarged lymph nodes contain central hypoechoic area with a
mixed heterogenous echotexture in contrast to homogenously
hypoechoic nodes in lymphoma.
• Lymph nodes may be adherent to intra abdominal
vasculature.
• Focal macrocalcifications can occur in the nodal, omental
masses, which may be clustered along the periphery or may be
central in location.
• Both caseation and calcifications are highly suggestive of
tubercular etiology, being uncommon in malignant
lymphoma.

28. ON CT
• Its multicompartmental localization with relative sparing of
the retroperitoneal compartment is the most characteristic
feature.
• On unenhanced scans, the nodes may display low attenuation
values <30 HU or soft tissue attenuation values similar to
muscle.
Four different forms of enhancement
• Peripheral enhancement
• Inhomogeneous enhancement
• Homogenous enhancement
• Non enhancing
• In the same group of lymph nodes, there may be variety of
patterns of enhancement, probably relating to the different
stages of pathologic process.

30. MR IMAGING
• Hypointense on T1 and hyperintense on T2 compared to
abdominal wall muscle.
• Few demonstrating rim, hypo on T1 and hyperintense on T2.
• Nodes when they are enlarged may show intranodal areas of high
signal intensity on T2 weighted images corresponding to non
enhancing portions on CT
• On contrast - may show different enhancement patterns.

32. TUBERCULOSIS LYMPHOMA
Distribution-
Mesenteric,lesser
omental,anterior pararenal or
upper para-aortic nodes.
Predominantly lower para-
aortic, retrocrural nodes.
Enhancement pattern-
Peripheral and multiloculated Homogenous enhancement
Others findings -
Mesenteric thickening,
I-C region and ascites present.
Absent

33. GASTRO INTESTINAL TUBERCULOSIS
• It can involve any segment but the ileocecal region is the most
commonly affected.
• Symptoms – diarrhea, abdominal pain and distension,
anorexia and weight loss
• Complications – obstruction, perforation, perianal fistula,
hemorrhage.

34. OESOPHAGUS TUBERCULOSIS
• Oesophageal TB is extremely rare
• Direct extension from adjacent mediastinal structures is
believed to be the main pathogenesis .
• The middle third of the oesophagus is usually involved.
• Primary oesophageal TB most commonly involves tracheal
bifurcation.
• Symptoms – dysphagia, odynophagia, chest pain or cough.
• The most common manifestation is a solitary ulcer with an
excavating base and rolled-up nodular edges .
• Other manifestations include external compression,
fistulous connections, traction diverticula .

35. Barium swallow :
• Will depict above features like extrinsic compression by
enlarged lymph nodes, smooth strictures, ulceration.
• Mucosal nodularity on barium examination can mimic
oesophageal malignancies.
• Mediastinal involvement and sinus tract formation are best
evaluated with CT.

37. GASTRIC TUBERCULOSIS
• Incidence-0.36-2.3%.
• Occurs with the secondary spread by adjacent nodes or
haematogenous.
• Clinical features
• The antrum and distal body are the sites usually involved.
Pathological types:-
• Ulcerative type (MC)-lesser curvature and pylorus.
• Hypertrophic type
• Miliary tubercles
Radiological features :
• Non-specific.
• Ulcers ( mimic benign ulcer in ulcerative type and malignant ulcer
in Hypertrophic type).
• Outlet obstruction.
37

39. DUODENAL TUBERCULOSIS
• Incidence-2% of GI TB.
• 3rd part more commonly involved.
• Affected by
▫ Extrinsic process (common)
 Due to lymphadenopathy or
adhesion
▫ Intrinsic process
 Ulcerative type or hyperplastic.
• Healing with fibrosis may lead to
duodenal obstruction
39

40. TUBERCULOUS ENTERITIS
• In India, TB is a common cause of small bowel obstruction.
• Presents with malabsorption syndrome.
• The radiographic features closely reflect pathological stages.
• Ulcerative form – stellate or linear shape, stricture
• Hypertrophic form

41. Plain x ray :
• Enterolith with features of
small intestinal obstruction
(dilated loops with multiple
air fluid levels).
• Perforation.
• Calcified lymph nodes.
41

43. Barium studies
• Barium meal follow through / enteroclysis followed by
barium enema if there is colonic involvement.
• Can establish diagnosis of intestinal tuberculosis in
75% of patients

44. BARIUM STUDY
First stage:- (superficial invasion of mucosa)
• Accelerated intestinal transit time.
• Disturbance in tone and peristalsis results in
hypersegmentation of barium column (chicken
intestine).
• Disturbance in secretion resulting in precipitation
,flocculation or dilution of barium suspension.
• Changes in contour- irregular or crenated.
• Changes in mucosal pattern- thickened folds.
44

46. Second stage:
• Ulcerations-barium flecks
surrounded by either a
thickened wall or converging
folds.
Third stage:- (fibrosis)
• Multiple stricture with
intervening dilatation.
• Fixity of loops and matting.
46

48. ILEO-CAECAL TUBERCULOSIS
• Most common site (80-90%) of GIT TB.
• Causes:
• Physiological stasis.
• Abundance of lymphatic follicles.
• Increased rate of absorption in the region.
• Closer contact of bacilli with the mucosa of the region.
• Types :
• Hyperplasic type-Long segment of narrowing with
rigidity and loss of distensibilty (Pipe stem colon).
• Ulcerative type.
• Ulcerohyperplastic type.
48

49. BARIUM STUDY
Fleischner sign
/inverted umbrella sign
• Thickening of the Ileo-caecal
valve lips and / or wide gaping
of the valve, with narrowing of
terminal ileum are considered
characteristic of tuberculosis.

50. • The caecum classically becomes conical, shrunken and
retracted out of iliac fossa due to contraction of the mesocolon.
• Loss of normal ileo-caecal angle with dilated terminal ileum
suspended from conical shrunken caecum- Goose neck
deformity
50

51. • Stierlin’s sign –
� Terminal ileum appears to
empty directly into the
stenotic ascending colon,
with non opacification of
the fibrotic, contracted
cecum.

52. • String sign
• Persistent narrow stream
of barium in the small
bowel –indicates stenosis

53. Purse string sign –
Localized stenosis opposite the ileocecal valve with a dilated
terminal ileum.

54. • In advanced ileo caecal
kochs there is symmetric
annular napkin stenosis.

56. USG
• Circumferential thickening of the
terminal ileum and caecum( Club
sign).
• Club sandwich” or “sliced bread”
sign is due to localized fluid
between radially oriented bowel
loops.
• Regional lymphadenopathy.
• Hyper peristalsis.
56

57. • Pseudokidney sign –
Involvement of the
ileocaecal region which is
pulled up to a subhepatic
position.

58. CT
• Commonest manifestation—
• Bowel wall thickening involving
the ileo-caecal region which can be
homogenous or hetrogenous in
appearance.
• Thickening and gaping of I-C
valve.
• Enlarged hypodense nodes in the
adjacent walls.
• Pericaeacal or mesenteric fat
haziness
• Distal small bowel obstruction
58

59. Tuberculosis Crohn ’s disease
Asymmetric wall thickening,
irregular
Circumferential bowel wall
thickening
Fleischner sign on barium studies Cobblestone appearance on
barium
No creeping fat Creeping fat (abnormal quantity
of mesenteric fat)
Positive chest film (50%) Negative chest film
Omental and peritoneal
thickening
Normal omentum and peritoneum
Enlarged lymph nodes with
low-density centers
Enlarged soft-tissue density
lymph nodes

60. APPENDICEAL TB
• Isolated appendicular involvement is rare and usually
presents as CHRONIC APPENDICITIS
• Due to -
• intrinsic disease of appendix
• Involvement by surrounding lymph nodes
• Occlusion of lumen by a caecal mass

61. COLONIC TUBERCULOSIS
• The large bowel is involved in 9% of cases without small bowel
involvement.
• They may present as different forms-
Segmental colitis , inflammatory polyps and hypertrophic
lesions resembling polyps and tumours.
• Rare form of diffuse type simulating ulcerative colitis
• Multiple sites of involvement with skip segments are common,
length of stricture is usually shorter than that of crohns disease.

63. DDS
• Crohns disease
• Ulcerative colitis
• Malignancy
• Ischaemic colitis
• Pseudomembranous colitis

64. • No specific CT findings that can distinguish tuberculosis from
crohns disease in terms of bowel wall involvement and
patterns except for distribution of disease.
• Ulceration in TB is circumferential while that in Crohns
disease is along the mesenteric border.
• Anal involvement and internal fistulae are more common in
Crohns while free perforation is more common in TB.
• Rare to see rectal involvement in tuberculosis and the
predominant left sided colonic involvement favors Crohns
disease.

65. VISCERAL TUBERCULOSIS
• LIVER AND SPLEEN:
• Hepatosplenic TB is common in miliary tuberculosis.
• Micronodular form is observed in miliary form of pulmonary
TB.
• On USG presents as diffuse hyper echogenicity.
• On CT, miliary nodules may not be appreciated but liver or
spleen can be enlarged and appear homogenous or
heterogeneous.

67. • Macro nodular form is rare manifestation of hepato-splenic
TB.
• Spreads via portal vein or hepatic artery from paraaortic or
portal lymph nodes.
• May be hypoechoic on USG and hypodense on CT.

69. Approach to abdominal tuberculosis

70. summary

71. THANK YOU