This document discusses various imaging techniques for the small intestine, including their indications, advantages, and disadvantages. Conventional radiography has limited ability to distinguish abnormalities due to overlying bowel loops. Barium studies like follow through and enteroclysis provide better distension but have low yield. Ultrasound is useful for detecting terminal ileitis but relies on operator skill. CT enteroclysis and CT enterography provide extraluminal detail but involve radiation. MR enteroclysis is preferable to CT in children due to lack of radiation, but images can be degraded by peristalsis. No single technique is considered the gold standard.

1. 1
Small intestine
imaging
dr sumer yadav

2. 2

3. 3
Indications for small bowel
investigations
• Investigation of non-specific symptoms such as
pain,distension,bloating,diarrhoea
• Suspected inflammatory bowel
disease,includingexclusion of small bowel disease in
Crohn’s colitis
• Partial small bowel obstruction
• Obscure G I bleeding,iron deficient anaemia or bleeding
per rectum with normal upper G I endoscopy and
colonoscopy
• Definition of anatomy,of fistulas or malrotation
• Exclusion of malignancy,for example,complicating
coeliac disease

4. 4
Difficulty in investigation
• Median lengthof 5.7m
• Difficult to visualise by location and anatomy
• Investigations must traverse proximal or distal
gut,and then negotiatea tortuous course
• Movement,with consequent artefact
• Radiation dose
• Patient acceptability of for example,NG
tubes,MRI scanners
• Low yield due to inappropiate referrals
• Interpretation of images

5. 5
KEY POINT 1
• The small bowel is difficult to image and
studies of all techniques are limited by the
lack of a gold standard reference and
agreed criteria for referral

6. 6
Techniques
• Conventional radiography
• Bariummeal follow through& enteroclysis
• Sonography
• CT-CT enteroclysis,CTenterography
• MRI-MRenteroclysis
• Capsule endoscopy
• Enteroscopy –push enteroscopy,push-pull
enteroscopy[also called double-balloon] and
intraoperative enteroscopy

7. 7
Conventional Xrays
• Preferred initial radiographic investigation
• Diagnostic in 50-60%
• Radiographs done are
1.Supine Abdomen-bladder should be emptied before the
film and film should include area from diaphragm to
hernial orifices
2.Chest Radiograph- superior to erect abdomen to detect
pneumoperitoneum
Chest disease may mimic SBO
3.Erect Abdomen-air fluid level are seen .normal two may
be seen at D-Jflexure and terminal ilenm

8. 8
Difference between large & small
intestine
• large bowel small bowel
• Haustra present absent
• Valvulae
conniventes absent present
loops pheripheral central

9. 9
SBO IN FPA

10. 10
FPA
Centrally placed small bowel loop
Valvulae conniventes

11. 11
Rigler’sign

12. 12
Barium meal follow through
• 500 ml of 42%w/v barium mixture is
ingested,fluroscopic and over head radiographs
at 15-30 minutes intervals,continue till
ileoceacal valve,when barium has reached
caecum,with targeted fluroscopy of special area
of interest.
• Manual palpation of the abdomen facilitates
movement of contrast and assesment of fixation
of bowel loops.

13. 13
Figure

14. 14
Figure
• X-ray image from a small bowel series showin

15. 15
Saddle bags

16. 16
Classic radiographic string sign

17. 17
Ca cecum invading terminal ileum

18. 18
Lymphoma mid ileum

19. 19
carcinoid

20. 20
• Radiograph from double-contrast upper GI
showing a normal duodenum.

21. 21
• Radiographic appearance of Crohn's
disease of the terminal ileum. Nodularity,
ulceration, narrowing, and irregularity ...

22. 22
Aphthoid ulceration of terminal ileum (small arrows)- Note also
"cobblestoning" (larger arrows).

23. 23
Typical features of Crohn's disease of the distal ileum
including fissure ulcers (small arrows), longitudinal ulcers
(arrowhead), "cobblestoning" (open arrows), aphthoid
ulcers (curved arrow) and stricturing. ic=ileocaecal valve

24. 24
Crohn 's disease of distal ileum with stricturing and sacculation on
the antimesenteric aspect (curved arrows), and fissure ulcers
(small arrows). Open arrow points to ileo-caecal valve

25. 25
Backwash ileitis" due to ulcerative colitis. Note features of chronic ulcerative
colitis in right colon, patulous ileocaecal valve, dilated distal ileum with
granular mucosa.

26. 26
Chronic ileocaecal tuberculosis. The caecum and ascending colon are
retracted craniad and are fibrotic. scarred and saccilated (curved
arrows). The terminal ileum in this patient is relatively patulous
(straight arrows) and probably nodular. v=ileocaecal valve.

27. 27
Nodular filling defects in small bowel of AIDS
patient (same of which are arrowed) are consistent
with the submucosal deposits of Kaposi sarcoma.
Disease was present elsewhere in the bowel.
Although unverified in this patient, the thickened
folds and pa or coating probably represent co-
existent opportunistic infection - most likely
cryptosporidium.

28. 28
Small bowel non-Hodgkin's lymphoma. Enteroclysis examination demonstrates a
segment of ileum in the right iliac fossa with wall thickening, destruction of the normal
fold pattern and aneurysmal ulceration (arrowed) and mass effect

29. 29
Benign lymphoid hyperplasia of distal ileum. Ileocaecal valve is arrowed.

30. 30
Jejunal diverticulosis on enteroclysis examination. Multiple
moderate-sized and large diverticula present.

31. 31
Meckel's diverticulum (arrowed) demonstrated on enteroclysis in a young
patient with recurrent melaena.

32. 32
Multiple band adhesions of small
bowel in left iliac fossa causing
retraction, tenting and fixation of
several adjacent loops.

33. 33
Acute small bowel ischaemia.
Small bowel barium study
shows partial functional
obstruction, proximal to diffuse
spastic narrowing of ileum with
thickened folds and thick walls.
There is a ''picket fence"
pattern in places (arrowed).
c=colon.

34. 34
Small bowel ischaemia.
Same patient as slide
33 CT after intravenous
contrast. Note "target"
sign in thickened ileal
loops in right iliac fossa
(arrowed), oedema in
adjacent mesentery and
fluid filled obstructed
bowel to left of midline.
Bowel had returned to
normal a few weeks
later on follow up
contrast study (patient
then asymptomatic).

35. 35
Advntages
• Relative ease of cocept and its
execution,the availability of equipment and
expertise,the acceptence to the
patient,and a relatively lower radiation
dose

36. 36
Disadvantage
• Limited ability to distinguish
abnormalit,given that there may be many
overlying loops of small intestine
• Length of examination
• Lack of complete distention of small bowel

37. 37
Small bowel enteroclysis
• The intubation and infusion of small bowel by
barium,challenges the distensibility of bowel
wall,exagerating the effects of mild or subclinical
obstruction,demonstrates mucosal detail more
readily
• Technique –infusion of 30-40%w/v at 60-
90mi/min after duodenal intubation.
• Double contrast enteroclysis infusion of 60-
95%w/v barium,followed by infusion of air/methyl
cellulose to distend lumen leaving a thin coating
of barium.

38. 38
Advantages
• Shorter examination time
• Better distension
• Greater positive and negative for a wide
range of S B pathology,including
strictures,adhesions and intrinsic SB
disease[eg sprue]

39. 39
Disadvantage
• Patient discomfort
• Higher radiation dose
• Gastroduodenal disease may not be seen
• More experienced radiologist required

40. 40
Key point 2
• Barium contrast studies are widely avilable
but yield is low

41. 41
Ulrtasonograpny
• Trans abdominal ultrasound
• Advantages
• 1.cheap
• 2.quick
• 3.acceptable to patient
• 4.no ionising radiation-important in Crohn’s
disease patient who may require many
investigations over a life time.due to this popular
wiyh paediatricians
• 5.extraluminal information
• 6.dynamic changes

42. 42
• Disadvantage
• 1.operator dependent modality
• 2.lack of standardisation
• 3.less useful in obese[images are better in
children] or in the presence of large
volumes of bowel gases

43. 43
Studies with of USG
• Studies concentrated for use in crohn’s disease
• It shows bowel wall thickening,presence of mesenteric fat wrapping.These
are used as marker of disease activity
• Other sign includes pattern of vascularisation,presence of free peritoneal
fluid and mesenteric lymphadenopathy
• Direct extra luminal information-presence of abscesseswhich may be
missed with small bowel contrast studies
• Compared with small bowel follow through of the ileum,ileal bowel wall
thickening of more than 2.5 mm gave comparative sensitivity of
75%,specificity of 92% and P P value of 88%
• Sup. Mesenteric artery doppler does not corelate with disease severity
• Small bowel follow through is more sensitiveand still indicated on strong
clinical grounds in spite of normal USG result
• There is lack of agreed definition of the bowel wall thickening that may be
considered abnormal
• Other disease processes, such as ileal TBand backwash ileitis of UC

44. 44
New development in USG
• Supplementation with oral contrast
• USG after distention of the small bowel
with PEG electrolyte balanced solution
• In this method greater length of diseased
bowel recognised and detection of jejunal
lesions other wise missed with plain USG
• By Calabrese et al
• cont.

45. 45
• Pareante et al used nonabsorbable
anechoic contrast to distend bowel with
proven crohn’s disease
• In this stricture was better seen
• Authors that USG with contrast may be
first-line investigation and comparable with
small bowel enema

46. 46
Doppler USG
• Evaluate changes seen in vasculature with
bowel inflamation
• Incresed vascularity is seen in the bowel
• Sup. Mesenteric artery images may
indicate disease activity
• But there are small no. of studies there
fore the role of Doppler USG is still to be
established

47. 47
• Ultrasound showing blood flowing
from intestines into liver. Image on
the left: routine. On the right with
power Doppler.

48. 48
Ultrasound of thickened bowel. Relatively hypoechoic thick walls (arrowed) with
echogenic lumen. Appearances are non-specific - in this case, Crohn's disease of
the ileum

49. 49
Ultrasound image demonstrates pelvic abscess and enterocutaneous
fistula complicating Crohn's disease. Abscess (arrows) contains
internal echoes. Hyperechoic foci (arrowhead) represent gas in bladder
(b) wall.

50. 50
Same patient as previous slide. CT of pelvis
demonstrates thickened loop of ileum (small arrows),
fistula to bladder (arrowhead) and gas in bladder wall
(curved arrow) and in non-dependent aspect of bladder
itself. More cranial image better showed associated
abscess.

51. 51
• An ultrasound miniprobe
(20 MHz) is placed in the
ascending part of the
partly water-filled jejunal
lumen in a patient with
CD. The layers of the wall
are seen and also an
erosion/superficial ulcer
(b) can be observed. The
edge of the lesion is
indicated

52. 52
Key point 3
• USG may be very useful and acceptable
in identifying terminal ileitis,particularly in
children ,but its use is very observer-
dependent and expertise in bowel USG is
not widely available.

53. 53
CT scan
C T has central role in imaging abdomen
CT can depict bowel
thickening,fistulas,abscesses and
lymphadenopathy
• Bowel wall assessment during different phases
of scanning with i.v. contrast allows assesment
of perfusion
• Intramural gas may be detected
• MDCT can reconstruct images in any angle

54. 54
C T SCAN
• Advantages
• 1.quick
• 2.acceptable to most of the patient
• 3. major advantage is –provide
extraluminal information over luminal
contrast studies

55. 55
Disadvantages
• Ionising radiation
• It is static rather than dynamic .This make
differentiation b/w skip lesionsand
peristalsis difficult
• Artefact which may arise from the lack of
physiological distension

56. 56
CT ENTEROCLYSIS
• Newer more specific technique for small
bowel
• Require same nasojejunal intubation and
small bowel distension with contrast as
barium enteroclysis
• More quick
• Ability to follow the progression of contrast
is lacking

57. 57
indicatinos
• Suspected malignancy
• Known inflamatory bowel disease
• Occult G I bleed
• Low grade small bowel obstruction
• Refractory coeliac sprue

58. 58
Studies with CT ENTEROCLYSIS
• It demonstrated fistula which was not shown by
other modality
• Aid in the diagnosis of ileoceacal TB by
demonstrating necrotic mesenteric lymph node
• In refractory coeliac sprueit demonstrated
ulceration,lymphoma,adenocarcinomaof jejunum
• Boudiaf et al
• cont.

59. 59
• Important-early crohn’s disease may be better
demonstrated on small bowel enema
• In patients with very high index of suspicion,use
of both tests may be appropiate
• More abnormality detected with CTenteroclysis
than small bowel enema,but principally with
extra luminal manifestation
• Minordi et al

60. 60
CT ENTEROGRAPHY
• Generic term for C T investigation where small bowel is distended
with orally ingested contrast as opposed to that delievered by
nasojejunal tube
• Primary reason for abandoning the naso jejunal tube is patient
acceptibility
• Enterography may prove itself as effective as enteroclysis
• Oral contrast agent used –water,methylcellulose,PEG,dilute barium
solution
• The advantage of oral hyperhydration to achieve small bowel
distensibility is that in future it could be added to the general
CTabd/pelvis for abdominal pain of uncertain etiology
• Mazzeo et al

61. 61
CT with free air and bowel loop

62. 62
• Enterovesical fistulas

63. 63

64. 64
Key point 4
• CT enteroclysis shold be at least as good
as small bowel enema,and will provide
extraluminal informatiom.
• Images are static and repeated studies
expose to ionising radiation

65. 65
M R Imaging
• Give extra luminal information and permit
multiplanar reformatting without ionising
radiation
• Preferable in children and reproductive age
group
• Distinguish active disease with fibrosis
• Definition of tissue planes is better than CT
• Real time functional information may be
obtained with MR fluroscopy and this is a distinct
advantage over CT

66. 66
• Contrast by physiological luminal content
• Purposeful distention by drinking or by
enteroclysis
• Positve gadolinium based or negative iron
based contrast used in MR entroclysis
• MR demonstrate In crohn’s disease –
muralulcer,fistulas,pseudopolyp,thickening
,stenosisand pre-stenotic dilatation

67. 67
Disadvantage
• Patient compliance-many patient fails to
complete the scan
• Long timeaffect image quality,as artefact
may be produced by peristalsis
• vomiting and rectal evacuation

68. 68
CT V/S MR
• CT in the absence of luminal distention is
not sensitive for excluding small bowel
pathology

69. 69
MR V/S CONVENTIONAL
RADIOGRAPHY
• No difference in finding of muralNo difference in finding of mural
ulceration,pseudopolyp,stenosis,pre stenoticulceration,pseudopolyp,stenosis,pre stenotic
dilatation or fistuladilatation or fistula
• More exrta luminal information with MRMore exrta luminal information with MR
enteroclysis in crohn’s disease asenteroclysis in crohn’s disease as
abscesses,lymphadenopathy,small bowelabscesses,lymphadenopathy,small bowel
separation and colonic lesionseparation and colonic lesion
• Studies say that MR enteroclysis may be inferiorStudies say that MR enteroclysis may be inferior
in detecting subtle lesionsin detecting subtle lesions
• EUR RADIOLOGY 2006EUR RADIOLOGY 2006

70. 70
KEY POINT 5
• MR enteroclysis may be equivalent to
other imaging modalities, but with the
advantage of dynamic imaging and no
ionising radiation

71. 71
Enteroscopy
• Imp. Both diagnostic and therapeutic
• Ileoscopy as part of colonoscopy
• Push enteroscopy-Enteroscope which traverse
the proximal jejunum. Max. distance covered
150 cm
• Push-pull or Double Balloon enteroscopy
visualise entire small bowel
• Good result in obscure GI bleed
• Mucosal visualisation better than capsule
endoscopy

72. 72
Disadvantages
• Invasive
• Risks of bleeding & perforation
• Lower patient acceptibility
• Limited expertise

73. 73
Key point 6
• Push enteroscopy permits therapeutic
intervention but has limited reach.Double
Balloon enteroscopy may overcome this
but is very invasiveand not widely
available

74. 74
Capsule endoscopy
• Direct luminal visualisation is aceived by the patient
swallowing a capsule containing a video
camera,microchip and transmitter,with images
transmitted to a receiver worn by the patient
• Important complication-impactation which may require
surgical removal.impactation rate 0.75%
• Contra indicated in stricturing Crohn’s disease,in
implanted pace maker,in swallowing disorder
• Patency capsule-capsules with a lactose body which
dissolves after 40 h to confirm the patency of the lumen
• Biopsy is not possible at present
• More small bowel pathology may be seen, leading to
further investigations, not all of which may be necessary

75. 75
• It is of note thay,in patients with suspected crohn’s disease,capsule
endoscopy did not give rise to a significantly greater yield over any
modality,whereas it did in the known Crohn’s disease patient.
• This is most likely to be due to the heterogeneity of patients labelled
as ‘suspected Crohn’s disease’
• There is lack of consensus as to what constitutes Crohn’s disease
on capsule endoscopy.
• It may be hard to distinguish b/w Crohn’s disease and NASID
induced enteropathy
• Overall impression is that capsule endoscopy produces a greater
yield.
• Take home message is- it may be powerful in promoting its uptake
in G I world

76. 76
Advantage
• Direct mucosal visualisation
• Patient acceptibility
• Lack of ionising radiation

77. 77
Disadvantages
• Cost
• Reporting time
• Impaction
• Difficult to localise the lesion
• High miss rate

78. 78
The capsule

79. 79
Inner workings of capsule

80. 80
Scanner

81. 81
Key point 7
• The evidence points towarss capsule
endoscopy being superior to other
imaging modalities in known Crohn’s
disease.however,it is not used in those
with stricturing Crohn’s disease patients
due to risk of capsule retention.Its
usefulness in the patient with suspected
Crohn’s disease is less clear.

82. 82
Implication for practice
• A department should be encoureged to ultrasound the terminal ileum of patient who
present with irritable bowel syndrome-type symptoms,in whom it is desiredto exclude
inflammatory bowel disease.
• Ultrasound should be performed by G I radoiologist expert in the field of bowel
sonography.
• Next tier of investigation should be CT enterography or enteroclysis,which should
replace barium enteroclysis,as result are similar but the latter is more comprehensive.
• Rigorous audit shold accompany the change in practice,to ensure standards remain
high and that results are as good as enteroclysis.
• For Crohn’s disease patient who may require repeated investigations over many
years,MR enteroclysis should be developed
• Finally ,capsule endoscopy should be available for investigation of lesions such as
angiodysplasia which are not seen on cross-sectional imaging.
• Recommendations for the investigation of obscure G I bleeding have been largely
established and are likely to comprise upper and GI endoscopy,followed by a repeat
UGI endoscopy as lesions are found at enteroscopy that would be within reach of the
initial study. This can be followed by capsule endoscopy, then enteroscopy

83. 83
Key point for clinical practice
• The small bowel is difficult to image and studies of all techniques are limited by the
lack of a gold standard reference and agreed criteria for referral.
• Barium contrast studies are widely available but yield is low.
• USG may be very helpful and accepyable in identifying terminal ileitis,particularly in
children,but its use is very observer-dependent and expertise in bowel ultrasound is
not widely available.
• CT enteroclysis should be at least as good as small bowel enema,and will provide
extraluminal information.images are static and repeatwd studies,such as Crohn’s
patient might expect during a life time,may result in considerable exposure to ionising
radiation.
• MR enteroclysis may be equivalentto other imaging modalities,but with the advantage
of dynamic imaging and no ionising radiation.
• Push enteroscopy permits therapeutic intervention but has limited reach.Double
balloon enteroscopy may overcome this but is very invasive and not widely available.
• The evidence points towards capsule endoscopy being superior to other imaging
modalities in known Crohn’s disease although it cannot be used in a large subsection
of Crohn’s disease patients due to stricturing with consequent risk of capsule
retention.Its usefulness in suspected Crohn’s disease is less clear.

84. •Thanks
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