Radiology ----Classical Signs in GIT Dr. Muhammad Bin Zulfiqar. It is very difficult to learn much in the sea of radiology. This presentation is the way to memorize classical signs in radiology.

1. CLASSICAL SIGNS IN GASTROINTESTINAL
RADIOLOGY(PART 1 & 2)
Dr. Muhammad Bin Zulfiqar
PGR IV FCPS SHL/SIMS
Alnoor Diagnostic Centre

2. INTRODUCTION
 Radiologists have established many classic imaging signs for
visual manifestations of pathophysiologic processes.
 The use of familiar objects to describe visual findings enables
radiologists both to arrive at a correct diagnosis and to
effectively convey such diagnostic findings to clinicians
 The goal of this article is to review an array of classic signs
associated with gastrointestinal tract pathologies whose
imaging manifestations resemble everyday objects e.g. The
“football” and “cobblestone” signs.

3. INTRODUCTION
 This article organizes the gastrointestinal signs from proximal
to distal within the gastrointestinal tract.

4. BIRD’S BEAK SIGN
 The “bird’s beak” sign is a classic finding on esophagrams; it
describes a dilated proximal esophagus with a smooth-
tapered, distal esophagus at the level of the esophageal
hiatus in the setting of achalasia.
 Achalasia is further characterized by esophageal aperistalsis
and failure of the lower esophageal sphincter to relax

5.  Radiograph of the distal esophagus after oral contrast
administration obtained in a patient with achalasia
demonstrates marked proximal esophageal dilatation with
tapering of the distal esophagus resembling a bird’s
beak. Note the debris in the dilated proximal esophagus.

6. ACHALASIA
 There are both primary and secondary forms of
achalasia.
 Primary achalasia, the more common etiology, is
idiopathic
 The lack of lower esophageal sphincter
relaxation is likely due to a loss of inhibitory
neurons in the esophageal myenteric plexus

7. ACHALASIA
 Proposed causes
1. Neuronal degeneration
2. Viral infection
3. Genetic inheritance
4. Autoimmune disease

8. ACHALASIA
 Secondary achalasia is much less common
 Caused by
1. Esophageal carcinoma
2. Chagas disease.

9. CORKSCREW SIGN
 The “corkscrew” sign is the visual manifestation of lumen-
obliterating, simultaneous, nonperistaltic contractions within
the esophagus
 These abnormal contractions of varying amplitude occur in
diffuse esophageal spasm, a rare esophageal motility disorder

10. Esophagram in a patient with diffuse esophageal spasm demonstrates non-
peristaltic contractions within the esophagus resulting in a corkscrew
appearance

11. DIFFUSE ESOPHAGEAL SPASM
 Characterized on manometry by periods of normal peristalsis
followed by simultaneous, repetitive, ineffective contractions.
 These abnormal contractions segment the normal esophageal
lumen, mimicking a corkscrew on barium studies of the
esophagus

12. DOUBLE-BARREL ESOPHAGUS
 The term “double-barrel esophagus” classically refers to the
radiographic appearance of a dissection between the
esophageal mucosa and submucosa without perforation.
 The double-barrel radiographic appearance of the esophagus
is due to the visualization of a barium-filled, intramural
dissecting channel separated from the true esophageal lumen
by a lucent line known as the mucosal stripe.

13. DOUBLE-BARREL ESOPHAGUS
 Intramural esophageal dissection is most commonly seen in
middle-aged or elderly women
 This entity can occur in the setting of a
1. Coagulopathy,
2. Emetogenic injury,
3. Trauma,
4. Instrumentation,
5. Ingestion of foreign bodies
6. Intramural esophageal abscess,
7. Intraluminal diverticulum
8. Esophageal duplication

14. Esophagram demonstrates dissection of oral contrast between the
esophageal mucosa and submucosa producing a double-barrel appearance

15. BULL’S EYE LESIONS
 Lesions within the stomach forming central collections of oral
contrast within ulcerated intramural masses can produce a
target or bull’s eye appearance on upper gastrointestinal
barium examinations
 Differential diagnosis is broad and includes
1. Gastric metastatic lesions from melanoma and lymphoma
2. Kaposi’s sarcoma
3. Carcinoid tumors
4. Gastric lipomas may also ulcerate and produce a bull’s eye
appearance

16. Radiograph from an upper gastrointestinal series of a patient with
metastatic melanoma demonstrates a bull’s eye lesion in the body of the
stomach

17. RAM’S HORN
 The unusual shape of the stomach resembling the horn of the
ram is due to combination of gastric deformity causing a
tubular shape, conical narrowing, and limited distensibility of
the stomach.
 Crohn’s disease is notable for this appearance
 Crohn’s disease affects the stomach and duodenum in 0.5%
to 4.0% of patients
 The antrum is the gastric region most frequently involved

18. Radiograph of the stomach following the oral administration of contrast in a
patient with HIV/AIDS demonstrates somewhat tubular, conical shape of the
distal stomach resembling a ram’s horn

19. LEATHER BOTTLE STOMACH
 The stiff, nondistensible wall gives the stomach a leather
bottle appearance, also known as linitis plastica
 Differential diagnoses for the appearance of a leather bottle
stomach include
1. Primary scirrhous adenocarcinoma of the stomach
2. Scirrhous metastases from lung, breast, colon
3. Pancreatic carcinomas
4. Lymphoma
5. Crohn’s disease
6. Sarcoidosis
7. Syphilis.

20. LEATHER BOTTLE STOMACH
 Primary scirrhous adenocarcinoma of the stomach spreads
predominantly in the submucosa and muscularis propria
 Scirrhous tumors constitute 5% to 15% of all gastric
carcinomas
 Scirrhous adenocarcinoma is thought to arise near the pylorus
and spread proximally diffusely involving the entire stomach

21. Radiograph of the stomach following oral barium administration
demonstrates a thickened, stiff wall of the stomach secondary to syphilis
creating a leather water bottle-like appearance

22. WINDSOCK SIGN
 The windsock appearance is formed by passive elongation of
the intraluminal diverticulum due to continual peristalsis of the
duodenum.
 The windsock appearance is most commonly located in the
second portion of the duodenum and consists of the barium-
filled diverticulum that lies entirely within the duodenum
 Appearance most commonly caused by Intraluminal Duodenal
Diverticulum

23. WINDSOCK SIGN
 Intraluminal duodenal diverticulum is a rare congenital cause
of duodenal obstruction
 These intraluminal diverticula are believed to arise from an
improper luminal recanalization of the foregut in the 7th week
of embryogenesis.
 A residual tissue diaphragm may span the entire
circumference of the duodenum and only allow passage of
enteric contents through fenestrations

24. Duodenal wind sock sign in a patient with duodenal diverticulum. Image
from an upper gastrointestinal series clearly demonstrates an
intraluminal duodenal diverticulum (arrows) surrounded by a narrow
radiolucent line (arrowheads). The diverticulum, arising in the second
portion of the duodenum and extending to the third portion, was
confirmed at surgery.

25. DOUBLE BUBBLE SIGN
 The “double bubble” sign represents the appearance of 2 gas-
filled structures in the upper abdomen of newborns and infants
on plain films of the abdomen
 The left-sided, proximal bubble is the distended gas and fluid-
filled stomach.
 The second, right-sided, more distal bubble is the distended
duodenum.
 The double bubble sign indicates the presence of duodenal
obstruction that can be caused by a number of intrinsic or
extrinsic etiologies

26. DOUBLE BUBBLE SIGN
 The intrinsic causes include
1. Duodenal webs
2. Duodenal atresia
3. Duodenal stenosis
 The extrinsic etiologies include
1. Preduodenal portal vein
2. Malrotation of the gut with a midgut volvulus
3. Ladd bands
4. Annular pancreas

27. DOUBLE BUBBLE SIGN
 Duodenal atresia is the causative entity most commonly linked
with a double bubble sign.
 Duodenal atresia is found in 1 in 10,000 newborns and is
typically associated with other congenital anomalies
 30% of children with duodenal atresia have Down’s syndrome

28. Plain radiograph of the abdomen in a patient with duodenal atresia creates
a double bubble appearance of the stomach and duodenum

29. WHIRLPOOL SIGN
 The “whirlpool” sign is found on both cross-sectional imaging
as well as abdominal ultrasound in the presence of midgut
volvulus
 The whirlpool appearance represents the swirling pattern of
the gut and the superior mesenteric vein as they wrap around
the superior mesenteric artery (SMA) in a clockwise rotation
 It is the clockwise rotation of the bowel loops that result in the
whirlpool sign on cross-sectional imaging

30. WHIRLPOOL SIGN
 Embryological explanation
 Normally, the midgut undergoes a 270-degree counterclockwise
rotation during embryologic development.
 Malrotation of the midgut represents a spectrum of developmental
anomalies that result in either an insufficient or total lack of
counterclockwise rotation of the midgut around the axis of the SMA.
 These anomalies all lead to a shortened mesenteric base.
 The shortened mesentery predisposes to volvulus that may result in
bowel obstruction.
 Midgut volvulus is the most common complication of malrotation
of the small bowel in adults.

31.  CT maximal intensity projection (MIP) demonstrates
the whirlpool appearance of the superior mesenteric
artery and vein wrapping around one another in a
patient with mid-gut volvulus.

33. STRING OF PEARLS
 The “string of pearls” sign indicates the presence of a small-
bowel obstruction. This sign is also commonly referred to as
the “string of beads” sign.
 It represents a row of small gas bubbles oriented in a
relatively linear fashion within the abdomen on plain films

34. STRING OF PEARLS
 The observed rows of gas bubbles represent gas trapped
between the valvulae conniventes of the nondependent wall of
small bowel.
 These loops of small bowel are dilated and filled with fluid in
the setting of a small-bowel obstruction, thus the meniscal
effect of the surrounding fluid gives these pockets of gas a
rounded or ovoid appearance.

35. String of pearls sign in a patient with small-bowel obstruction (SBO).
Left lateral decubitus radiograph of the abdomen demonstrates a row
of small air bubbles (arrows), which represents air trapped between
the valvulae conniventes.

36. STACK OF COINS
 The “stack of coins” sign typically indicates the presence of a
small-bowel hematoma
 This sign is seen on plain films or MDCT images and
represents adjacent, thickened folds with sharp demarcation
and crowding of the valvulae conniventes

37. STACK OF COINS
 Over-anticoagulation with warfarin is the most common
cause of spontaneous intramural small-bowel hematoma
 Other Causes include
1. Idiopathic thrombocytopenic purpura
2. Leukemia
3. Pancreatitis
4. Pancreatic cancer
5. Hemophilia
6. Lymphoma
7. Myeloma
8. Chemotherapy
9. Vasculidites

38. Plain radiograph of the abdomen following the oral administration of
barium to a patient with a small bowel hematoma demonstrates a stack of
coins sign.

39. STRING SIGN
 The string sign represents the marked narrowing of the
terminal ileum lumen secondary to symmetric, transmural
granulomatous inflammation and subsequent fibrotic
thickening of the bowel wall
 Bowel-wall thickening is the most common manifestation of
Crohn’s disease on MDCT scans, occurring in up to 82% of
patients

40. STRING SIGN
 In the setting of Crohn’s disease, the terminal ileum often
becomes markedly stenotic secondary to bowel-wall
inflammation and fibrosis.
 This results in the lumen of this portion of the small bowel
resembling a piece of string on plain radiographs after
ingestion of high-density oral contrast material

41. A thin line of barium is seen in the terminal ileum (long arrows), which
resembles a frayed cotton string (the gastrointestinal string sign). Small
mesenteric border ulceration is seen (small arrow).

42. RIBBON SIGN
 Fluoroscopic examinations performed with high-density oral
contrast material in patients with GVHD of the GI tract may
demonstrate marked fold thickening, luminal narrowing,
separation of folds, and ultimately complete effacement of
the valvulae conniventes. The latter causes the so-called
“ribbon sign”
 Donor lymphoid cells damage host tissues in graft-versus-host
disease (GVHD).
 The organs most commonly affected by GVHD include the
gastrointestinal tract, liver, and skin.
 Marked bowel-wall thickening can occur both in the small and
large bowel
GVHD: Graft versus host disease

43. RIBBON SIGN
 The ribbon bowel appearance can also occur with
multiple other clinical settings, such as
1. Infection
2. Irradiation
3. Allergy
4. Ischemia
5. Ingestion of corrosives or medications
6. Amyloid
7. Mastocytosis
8. Lymphoma
9. Crohn disease
10. Celiac disease

44. Plain radiograph of a small bowel follow through in a patient with
graft versus host disease illustrates marked luminal narrowing and
effacement of the valvulae conniventes producing a ribbon like
appearance of the small bowel

45. THANK YOU

46. COMB SIGN
 The “comb sign” is seen in the presence of Crohn’s
disease.
 This sign is observed on contrast-enhanced CT or
magnetic resonance imaging (MRI) scans.
 The teeth of the comb in this instance represent
engorged small arteries, the vasa recta, perfusing
the small bowel

47. COMB SIGN
 The vasa recta of the small bowel seen in Crohn’s disease
become tortuous and enlarged.
 They appear as prominent opacities on the mesenteric side of
the small bowel.
 These small arteries become engorged due to increased
blood flow to the inflamed small bowel and are accentuated
due to the fibrofatty proliferation in the mesentery.

48. Contrast-enhanced
CT image in a
patient with
Crohn’s disease
demonstrating
engorged vasa
recta secondary to
hyperemia of the
bowel producing
the comb sign.

49. TARGET SIGN
 The target sign is classically seen in patients with
Crohn’s disease.
 This pattern of bowel wall enhancement has been
observed in patients with
1. Radiation enteritis
2. GVHD
3. Ischemic bowel
4. Intramural hemorrhage
5. Vasculitides such as Henoch-Schonlein purpura, and
6. Pseudomembranous colitis

50. TARGET SIGN
 It represents an enhancement pattern of the bowel
wall seen in various disease processes on contrast-
enhanced CT or MRI scans.
 This appearance is formed when a thickened bowel
wall demonstrates alternating degrees of
attenuation, with an inner and outer layer of higher
attenuation and a middle layer of lower attenuation

51. TARGET SIGN
 The higher-attenuation inner and outer layers
represent the mucosa and muscularis propria,
respectively.
 The high attenuation of these layers is believed to
be secondary to contrast enhancement from
inflammation.
 The lower attenuation middle layer is thought to be
due to submucosal bowel wall edema.

52. Contrast-enhanced CT
image of the small
bowel in a patient with
Crohn’s disease reveals
rings of high attenuation
representing the
hyperemic mucosa and
muscularis propria of
the small bowel. The
hypodense ring
represents the
edematous submucosa.
This enhancement
pattern creates the
target sign.

53. COILED SPRING SIGN
 The “coiled spring” sign can be seen anywhere in
the bowel where an intussusception has occurred.
 These ring shadows represent contrast reflux within
the lumen between the walls of the intussusceptum
and intussuscipiens

54. COILED SPRING SIGN
 Classically, this sign describes the appearance of
the cecum in the presence of appendiceal
intussusception, a rare entity.
 It is thought that the coiled-spring appearance
results from intussusception of the cecal tip with the
invaginated appendix acting as the lead point for
variable amounts of cecocecal or cecocolic
intussusception

55. Plain radiograph of the abdomen following the administration
of contrast through a feeding tube in a patient who is status
postgastric bypass demonstrates a coiled-spring appearance
of the small bowel secondary to intussusception

56. ARROWHEAD SIGN
 This perceived arrowhead shape is secondary to
focal, symmetric thickening of the cecal wall
secondary to spreading inflammation from
appendicitis
 The cecal wall thickening causes funneling of oral
or rectal contrast material within the upper cecum,
which points to the obstructed appendiceal orifice

57. ARROWHEAD SIGN
 The arrowhead sign, which is obtained after the
administration of oral and/or rectal contrast
material, is seen on computed tomographic (CT)
images as an arrowhead-shaped collection of
contrast medium localized to the upper part of the
cecum near the orifice of the appendix

58. Contrast-enhanced CT image in a patient with right lower-
quadrant pain demonstrates arrowhead-shaped
inflammatory changes of the cecal base secondary to acute
appendicitis. Note the thickened appendix.

59. THUMBPRINT SIGN
 This sign is seen in roughly 75% of cases of
transient, nongangrenous ischemic colitis
 Other conditions that may also produce the
thumbprint sign include
1. Pseudomembranous colitis
2. Ulcerative colitis
3. Lymphoma
4. Leukemia
5. Coagulopathies

60. THUMBPRINT SIGN
 This sign describes smooth, rounded impressions
causing filling defects classically seen in barium
studies of ischemic colitis.
 These nodular densities represent edema and
hemorrhage into the wall of the colon most
commonly secondary to ischemia

61. Plain radiograph of the abdomen in a patient with ischemic colitis
demonstrates thickening of the haustra secondary to edema and
hemorrhage resulting in the appearance of multiple thumbprints in the
wall of the colon

62. COBBLESTONE SIGN
 The “cobblestone sign” is classically seen within the
small and large bowel on fluoroscopic studies in the
presence of active Crohn’s disease
 The cobblestone appearance of the bowel wall is
due to a combination of extensive, broad, linear
transverse and longitudinal ulcerations within an
inflamed mucosal surface. Only scattered islands of
normal mucosa remain in this setting

63. Radiograph of a small bowel follow-through in a patient with Crohn’s
disease demonstrates scattered islands of normal intestinal mucosa
adjacent to multiple ulcerations resulting in the cobblestone
appearance of the distal ileum

64. BOWLER HAT SIGN
 The “bowler-hat sign” represents the appearance of
a sessile colonic polyp on a double contrast barium
enema
 A colonic diverticulum can partially fill with barium
and also produce a bowler hat appearance

65. BOWLER HAT SIGN
 The bowler-hat sign is formed by a ring of barium
adjacent to the base of the polyp surrounding a
domed layer of barium coating the surface of the
polyp
 The orientation of the dome of the bowler hat sign
can help differentiate a polyp from a diverticulum.
 An intraluminal polyp will result in a bowler-hat sign
with its dome pointed inward toward the lumen,
while a diverticulum will produce a bowler hat sign
pointed outward

66. Magnified view of the sigmoid colon demonstrates " the
bowler hat sign" of the mid-sigmoid sessile polyp seen
obliquely (arrowhead) and diverticula en face (arrow).

67. MEXICAN HAT SIGN
 Pedunculated colonic polyps form the “Mexican hat
sign”
 The Mexican hat sign is formed by the appearance
of 2 concentric rings
 The outer ring represents the “en face” visualization
of barium coating the surface of the head of a
pedunculated polyp, while
 The inner ring represents a meniscus of barium
surrounding the stalk of the polyp visualized
through the head

68. Radiograph of an upper gastrointestinal series demonstrates a
pedunculated gastric polyp demonstrating a close resemblance to a
Mexican hat.

69. COLLAR BUTTON SIGN
 “Collar button ulcers” are manifestations of
inflammatory processes within the bowel.
 These deep ulcerations are classically seen in the
colon associated with active ulcerative colitis
 However they have also been observed in the
setting of other inflammatory bowel processes,
such as
1. Crohn’s disease
2. Ischemic colitis
3. Shigellosis

70. COLLAR BUTTON SIGN
 The collar button appearance is formed by mucosal
ulceration with associated undermining of the
ulcer’s edge by lateral submucosal extension
 Vertical penetration into the bowel wall is limited
due to the resistance of the underlying muscularis
mucosa, thus resulting in the discoid collar button
appearance of these ulcers

71. Radiograph from a single contrast barium enema in a patient with active
ulcerative colitis shows a deep ulcer within the descending colon that
demonstrates a collar button appearance

72. APPLE CORE SIGN
 The apple core sign is classically seen in cases of colon
carcinoma
 This appearance is most commonly located in the
sigmoid colon as well as in the ascending, transverse,
and descending colon.
 The apple core sign is not seen in the larger-caliber
cecum.

73. APPLE CORE SIGN
 The differential diagnosis of a lesion with an apple
core appearance is
1. Focal diverticulitis
2. Ischemic colitis
3. Ulcerative colitis
4. Endometriosis
5. Amebiasis
6. Serosal metastatic implants
7. Infectious colitis

74. APPLE CORE SIGN
 The apple core appearance is the visual manifestation of
an annular lesion of the bowel with irregular overhanging
edges and shouldered margins

75. Fluoroscopic image from a double contrast barium enema in
a patient with changing bowel habits reveals an annular
lesion with overhanging edges within the colon closely
resembling an apple core.

76. ACCORDION SIGN
 The “accordion sign” describes the appearance of
colonic wall thickening in the setting of colitis
 The accordion sign has also been observed with
1. colonic edema secondary to cirrhosis
2. Crohn’s disease
3. Ischemic colitis
4. Lupus vasculitis
5. Infectious colitis.

77. ACCORDION SIGN
 This sign describes the appearance of alternating,
edematous haustral folds that are due to transmural
edema and are separated by transverse mucosal
clefts filled with oral contrast .
 Oral contrast is trapped between thickened,
edematous colonic folds and pseudomembranes in
the setting of C. difficile-induced
pseudomembranous colitis

78. White oval highlights markedly thickened bowel wall with
oral contrast trapped between haustral folds in a patient
with known C difficle colitis. This is the "accordion sign."

79. LEAD PIPE SIGN
 The lead pipe appearance of the colon is classically
seen with chronic, smoldering ulcerative colitis.
 The differential diagnosis for a lead pipe
appearance of the colon includes
1. Crohn’s disease
2. Tuberculosis
3. Amebiasis

80. LEAD PIPE SIGN
 The lead pipe appearance likely represents the
visual manifestation of multiple pathophysiological
processes
 There is increased regeneration of the colonic
mucosa in ulcerative colitis.
 This mucosal regeneration may lead to hypertrophy
of the muscularis mucosae.
 Contraction of this hypertrophic muscle layer gives
the colon the lead pipe-like narrowed, ahaustral,
and foreshortened appearance

81. Radiograph from a double contrast barium enema in a
patient with chronic, smoldering ulcerative colitis
demonstrates an ahaustral, pipe-like appearance of the
colon

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