1) The pancreas develops from two buds, the dorsal and ventral buds, which arise from the duodenum and fuse during development. 2) CT is the preferred imaging modality for evaluating acute pancreatitis to confirm the diagnosis, assess severity and complications such as necrosis, pseudocysts and fluid collections. 3) Acute pancreatitis is classified on CT imaging as interstitial edematous pancreatitis or necrotizing pancreatitis depending on the presence of pancreatic or peripancreatic necrosis. CT also guides management by identifying complications.

1. EMBRYOLOGY OFEMBRYOLOGY OF
PANCREAS ANDPANCREAS AND
IMAGING OFIMAGING OF
PANCREATITISPANCREATITIS
Dr. Srikanth reddy VDr. Srikanth reddy V

3. DEVELOPMENT OFDEVELOPMENT OF
PANCREASPANCREAS
• The pancreas develops in two parts, both ofThe pancreas develops in two parts, both of
which arise from the endoderm of the primitivewhich arise from the endoderm of the primitive
duodenum.duodenum.
• The dorsal bud is the first to appear, as aThe dorsal bud is the first to appear, as a
diverticulum from the dorsal wall of thediverticulum from the dorsal wall of the
duodenum. This eventually forms the whole ofduodenum. This eventually forms the whole of
the neck, body and tail of the gland, togetherthe neck, body and tail of the gland, together
with part of the head.with part of the head.

4. • The ventral bud develops more caudally as aThe ventral bud develops more caudally as a
diverticulum from the developing bile duct atdiverticulum from the developing bile duct at
the point where the latter opens into thethe point where the latter opens into the
duodenum.duodenum.

6. • Soon after the appearance of the two parts, theSoon after the appearance of the two parts, the
duodenum undergoes partial rotation and theyduodenum undergoes partial rotation and they
approximate each other and fuse. Until this stageapproximate each other and fuse. Until this stage
the dorsal duct, the duct of Santorini, opens intothe dorsal duct, the duct of Santorini, opens into
the duodenum proximal to the major papillathe duodenum proximal to the major papilla
(ampulla of Vater) at the minor papilla, whereas(ampulla of Vater) at the minor papilla, whereas
the ventral duct, the duct of Wirsung, which isthe ventral duct, the duct of Wirsung, which is
joined with the lower common bile duct, opensjoined with the lower common bile duct, opens
into the major papilla.into the major papilla.

7. • In the majority of cases, fusion of the two ductsIn the majority of cases, fusion of the two ducts
occurs at the junction of the head and body ofoccurs at the junction of the head and body of
the gland Thus the main pancreatic duct opensthe gland Thus the main pancreatic duct opens
into the major papillainto the major papilla

8. CONGENITAL ANAMOLIESCONGENITAL ANAMOLIES
• Pancreatic divisum: Pancreas divisum is thePancreatic divisum: Pancreas divisum is the
most common congenital pancreatic ductalmost common congenital pancreatic ductal
anatomic variantanatomic variant
• The abnormality results from failure of theThe abnormality results from failure of the
dorsal and ventral pancreatic anlage to fusedorsal and ventral pancreatic anlage to fuse
during the sixth to eighth weeks of gestationduring the sixth to eighth weeks of gestation
• MRCP provides a noninvasive means ofMRCP provides a noninvasive means of
diagnosing pancreas divisum without the use ofdiagnosing pancreas divisum without the use of
contrast material and avoids the risk of ERCP-contrast material and avoids the risk of ERCP-
induced pancreatitis.induced pancreatitis.

9. MRCP pancreatic divisumMRCP pancreatic divisum

10. CT pancratic divisumCT pancratic divisum

11. • ANNULAR PANCREAS: 2ANNULAR PANCREAS: 2ndnd
most commonmost common
anamoly in which a band of pancreatic tissueanamoly in which a band of pancreatic tissue
surrounds the descending duodenum, eithersurrounds the descending duodenum, either
completely or incompletely, and is in continuitycompletely or incompletely, and is in continuity
with the head of the pancreaswith the head of the pancreas
• CT or MR images may show normal pancreaticCT or MR images may show normal pancreatic
tissue, with or without a small pancreatic duct,tissue, with or without a small pancreatic duct,
encircling the duodenumencircling the duodenum
•

12. MRCP annular pancreasMRCP annular pancreas

13. CT annular pancreasCT annular pancreas

14. • Agenesis/hypoplasia:Agenesis/hypoplasia:
complete agenesis is verycomplete agenesis is very
rare but hypoplasia may berare but hypoplasia may be
seenseen

15. • ECTOPIC PANCREATIC TISSUE:EctopicECTOPIC PANCREATIC TISSUE:Ectopic
rests of pancreatic tissue are usually located inrests of pancreatic tissue are usually located in
either the submucosa of the gastric antrum oreither the submucosa of the gastric antrum or
the proximal portion of the duodenumthe proximal portion of the duodenum
Variations of Pancreatic Ducts:A bifidVariations of Pancreatic Ducts:A bifid
pancreatic duct is an anomaly in which the mainpancreatic duct is an anomaly in which the main
pancreatic duct is bifurcated along its lengthpancreatic duct is bifurcated along its length

16. Imaging acuteImaging acute
pancreatitispancreatitis

17. INDICATIONS OF IMAGINGINDICATIONS OF IMAGING
The clinical signs of acute pancreatitis areThe clinical signs of acute pancreatitis are
nonspecific, with serum amylase and lipase levelsnonspecific, with serum amylase and lipase levels
correlating poorly with disease severity .correlating poorly with disease severity .
Elevated plasma serum amylase and lipase levelsElevated plasma serum amylase and lipase levels
are not specific to acute pancreatitis and may beare not specific to acute pancreatitis and may be
elevated by bowel obstruction, infarction,elevated by bowel obstruction, infarction,
cholecystitis, and perforated ulcer. Imaging ischolecystitis, and perforated ulcer. Imaging is
recommended to confirm the clinical diagnosis,recommended to confirm the clinical diagnosis,
diagnose its cause, exclude alternative causes ofdiagnose its cause, exclude alternative causes of
abdominal pain, and grade the extent andabdominal pain, and grade the extent and
severity of acute pancreatitisseverity of acute pancreatitis

18. Acute PancreatitisAcute Pancreatitis
PathophysiologyPathophysiology
• Blockage of the pancreatic duct leads to increasedBlockage of the pancreatic duct leads to increased
pressure in pancreatic duct and rupture.pressure in pancreatic duct and rupture.
• Pancreatic fluid (proteolytic and lipolytic enzymes)Pancreatic fluid (proteolytic and lipolytic enzymes)
ruptures into pancreas parenchyma and anteriorruptures into pancreas parenchyma and anterior
pararenal spacepararenal space
Gore and Levine,
Textbook of
Gastrointestinal Radiology

19. IMAGING MODALITIESIMAGING MODALITIES
Imaging of pancreasImaging of pancreas
• Radiograph– detect calcification (practically ofRadiograph– detect calcification (practically of
no help)no help)
• USG – differentiation of cystic and solid lesionsUSG – differentiation of cystic and solid lesions
(screening tool & for follow-up)(screening tool & for follow-up)
• CT scan – modality of choiceCT scan – modality of choice
• MRI and MRCP – complimentary to CTMRI and MRCP – complimentary to CT

20. Imaging Goals in PancreatitisImaging Goals in Pancreatitis
1.1. Exclude other abdominal disorders that canExclude other abdominal disorders that can
mimic acute pancreatitismimic acute pancreatitis
– DDx: acute cholecystitis, bowel obstruction orDDx: acute cholecystitis, bowel obstruction or
infarction, perforated viscus, renal colic, duodenalinfarction, perforated viscus, renal colic, duodenal
diverticulitis, aortic dissection, appendicitis, anddiverticulitis, aortic dissection, appendicitis, and
ruptured abdominal aortic aneurysmruptured abdominal aortic aneurysm
1.1. Confirm clinical diagnosis of acuteConfirm clinical diagnosis of acute
pancreatitispancreatitis
2.2. Staging the disease, by evaluation of theStaging the disease, by evaluation of the
extent and nature of pancreatic injury andextent and nature of pancreatic injury and
peripancreatic inflammationperipancreatic inflammation

21. TYPESTYPES
• The revised Atlanta classification (2012) ofThe revised Atlanta classification (2012) of
acute pancreatitis divides the condition intoacute pancreatitis divides the condition into
• interstitial oedematous pancreatitis andinterstitial oedematous pancreatitis and
necrotising pancreatitis, (formerly termed mildnecrotising pancreatitis, (formerly termed mild
and severe acute pancreatitis).Thisand severe acute pancreatitis).This
morphological classification system is based onmorphological classification system is based on
findings on contrast-enhanced CTfindings on contrast-enhanced CT

22. Interstitial OedematousInterstitial Oedematous
PancreatitisPancreatitis
• imaging findings in interstitial oedematousimaging findings in interstitial oedematous
pancreatitis include focal or diffuse enlargementpancreatitis include focal or diffuse enlargement
of the gland, with normal homogeneousof the gland, with normal homogeneous
enhancement or slightly heterogeneousenhancement or slightly heterogeneous
enhancement of the pancreatic parenchyma,enhancement of the pancreatic parenchyma,
which is attributable to oedema.which is attributable to oedema.

23. Necrotising PancreatitisNecrotising Pancreatitis
• This is the hallmark of severe acute pancreatitis.This is the hallmark of severe acute pancreatitis.
The revised Atlanta classification distinguishesThe revised Atlanta classification distinguishes
three forms of acute necrotising pancreatitis:three forms of acute necrotising pancreatitis:
pancreatic parenchymal necrosis alone,pancreatic parenchymal necrosis alone,
peripancreatic necrosis alone, and pancreaticperipancreatic necrosis alone, and pancreatic
necrosis with peripancreatic necrosis. All threenecrosis with peripancreatic necrosis. All three
types can be sterile or infectedtypes can be sterile or infected

24. Abdominal Plain FilmAbdominal Plain Film
Findings of AcuteFindings of Acute
Pancreatitis onPancreatitis on
Abdominal Plain FilmAbdominal Plain Film
– Duodenal ileusDuodenal ileus
– Colon cutoff (paucity ofColon cutoff (paucity of
gas distal to splenicgas distal to splenic
flexure due to spasm offlexure due to spasm of
colon affected by spreadcolon affected by spread
of pancreaticof pancreatic
inflammation)inflammation)
– Pancreatic abscess (gasPancreatic abscess (gas
bubbles)bubbles)
– Gasless abdomen due toGasless abdomen due to
excessive vomitting.excessive vomitting.
– Loss of psoas shadow.Loss of psoas shadow.

25. Plain Chest FilmPlain Chest Film
• Findings of Acute PancreatitisFindings of Acute Pancreatitis
on Plain Chest Film:on Plain Chest Film:
Left sided pleural effusions (seenLeft sided pleural effusions (seen
on 10% of chest films)on 10% of chest films)
– basal atelectasisbasal atelectasis
– pulmonary infiltratespulmonary infiltrates
– Splinting of left diaphragm andSplinting of left diaphragm and
basal parenchymabasal parenchyma

26. Colon cut-off signColon cut-off sign

27. UltrasoundUltrasound
• IndicationsIndications
– Good screening test in mild disease, suspected biliaryGood screening test in mild disease, suspected biliary
pancreatitispancreatitis
• UsesUses
– Detection of gallstonesDetection of gallstones
– Bile duct obstructionBile duct obstruction
– Follow up of pseudocystsFollow up of pseudocysts
– diagnosis of vascular complications, i.e. thrombosisdiagnosis of vascular complications, i.e. thrombosis
• Major LimitationsMajor Limitations
– Bowel gasBowel gas
– US cannot specifically reveal areas of necrosisUS cannot specifically reveal areas of necrosis

28. Ultrasound findingsUltrasound findings
• Enlargement of pancreas- Universal but notEnlargement of pancreas- Universal but not
specific , upper limit of normal pancreaticspecific , upper limit of normal pancreatic
thickness=22 mmthickness=22 mm
• Pancreatic echogenicty(subjective) decreases duePancreatic echogenicty(subjective) decreases due
to oedema but sometime rarely can be increasedto oedema but sometime rarely can be increased
due to haemorrhage, necrosis, fat saponification.due to haemorrhage, necrosis, fat saponification.
• ““pseudopancreatitis”- pacreatic echogencitypseudopancreatitis”- pacreatic echogencity
decreased due to fatty filtration.decreased due to fatty filtration.

29. • Pancreatic inflammation- hypoechoic/ anechoicPancreatic inflammation- hypoechoic/ anechoic
• Difficult to distinguish inflammaton from fluidDifficult to distinguish inflammaton from fluid
• Ventral and adjacent to pancreas in pre-Ventral and adjacent to pancreas in pre-
pancreatic retroperitoneum, rt and left antpancreatic retroperitoneum, rt and left ant
pararenal spaces, perinal spaces, transversepararenal spaces, perinal spaces, transverse
mesocolon.mesocolon.
• But fluid is more localised,thicker, causemassBut fluid is more localised,thicker, causemass
effecteffect

30. CT FINDINGSCT FINDINGS
• CT is the imaging modality of choice for theCT is the imaging modality of choice for the
diagnosis and staging of acute pancreatitis anddiagnosis and staging of acute pancreatitis and
its complications.its complications.

31. COMPLICATIONSCOMPLICATIONS
• Acute fluid collectionsAcute fluid collections
• PeudocystsPeudocysts
• Pancreatic abscessPancreatic abscess
• NecrosisNecrosis
• HaemorrhageHaemorrhage
• Venous thromboembolismVenous thromboembolism

32. Targets of Inflammatory spreadTargets of Inflammatory spread
in Acute Pancreatitisin Acute Pancreatitis
• 1= spread into the lesser1= spread into the lesser
sacsac
• 2 = spread into the2 = spread into the
transverse mesocolontransverse mesocolon
• 3 = spread into the root3 = spread into the root
of the bowel mesenteryof the bowel mesentery
• 4 = extension into the4 = extension into the
duodenumduodenum
• 5= inferior spread into5= inferior spread into
the remainder anteriorthe remainder anterior
pararenal spacepararenal space
• 6=RP fluid colecting6=RP fluid colecting
down to scrotum,or evendown to scrotum,or even
thighthigh
Gore and Levine, Textbook of Gastrointestinal Radiology

33. Differential diagnosisDifferential diagnosis
• Infiltrating pancreatic carcinomaInfiltrating pancreatic carcinoma
• Lymphoma and metsLymphoma and mets
• Chronic pancreatitisChronic pancreatitis
• Perforated duodenl ulcerPerforated duodenl ulcer

34. Computed TomographyComputed Tomography
““CT is the premier imaging test in the diagnosisCT is the premier imaging test in the diagnosis
and management of patients with acuteand management of patients with acute
pancreatitis. It visualizes the gland, thepancreatitis. It visualizes the gland, the
retroperitoneum, the abdominal ligaments, theretroperitoneum, the abdominal ligaments, the
mesenteries, and the omenta in their entirety.”mesenteries, and the omenta in their entirety.”

35. Bilateral fluid
accumulation
in dependent
lung regions
Chest CT: Pleural EffusionChest CT: Pleural Effusion
ROI: 5 HU
(simple fluid)

36. Acute Interstitial pancreatitisAcute Interstitial pancreatitis

37. Necrotizing pancreatitisNecrotizing pancreatitis

38. Necrotizing pancreatitisNecrotizing pancreatitis

39. Pseudocyst in Lesser Sac or Gastric WallPseudocyst in Lesser Sac or Gastric Wall
ROI:
•12 HU (simple
fluid)
•69mm x 36mm

40. Extensive pancreatic necrosisExtensive pancreatic necrosis

41. Normal Bowel
Wall Edematous,
Inflamed Bowel
Wall
Inflamed Fat
Normal Fat
Inflammation Spreads to the Transverse ColonInflammation Spreads to the Transverse Colon

42. Pancreatic AscitesPancreatic Ascites
Dependent fluid
collection
between liver
and diaphragm
ROI: 14 HU

44. Traditional CT severity indexTraditional CT severity index

45. Modified CT severity index-easierModified CT severity index-easier
wayway

46. • Total scoreTotal score
• Total points are given out of 10 to determineTotal points are given out of 10 to determine
the grade of pancreatitis and aid treatment:the grade of pancreatitis and aid treatment:
• 0-2: mild0-2: mild
• 4-6: moderate4-6: moderate
• 8-10: severe8-10: severe
•

47. Fluid collectns assc with acuteFluid collectns assc with acute
pancreatitispancreatitis
APFCAPFC
Acute Peripancreatic Fluid Collections containAcute Peripancreatic Fluid Collections contain
fluid only and are not or only partiallyfluid only and are not or only partially
encapsulated. They are seen within 4 weeks inencapsulated. They are seen within 4 weeks in
interstitial pancreatitisinterstitial pancreatitis
• ANCANC
Acute Necrotic Collections contain a mixture ofAcute Necrotic Collections contain a mixture of
fluid and necrotic material. They are not or onlyfluid and necrotic material. They are not or only
partially encapsulated. They are seen within 4partially encapsulated. They are seen within 4
weeks in necrotizing pancreatitis.weeks in necrotizing pancreatitis.

48. • PseudocystPseudocyst
After 4 weeks in interstitial pancreatitis. ThisAfter 4 weeks in interstitial pancreatitis. This
fluid collection is encapsulated. Most persistentfluid collection is encapsulated. Most persistent
fluid collections also contain some necroticfluid collections also contain some necrotic
material.material.
• WONWON
After 4 weeks most necrotic collections are fullyAfter 4 weeks most necrotic collections are fully
encapsulated, heterogenous non_liquefiedencapsulated, heterogenous non_liquefied
material and are called Walled-off Necrosismaterial and are called Walled-off Necrosis
(WON).(WON).

49. CHRONIC PANCREATITISCHRONIC PANCREATITIS
• Chronic pancreatitis occurs due to intermittentChronic pancreatitis occurs due to intermittent
pancreatic inflamation with progressivepancreatic inflamation with progressive
irreversible dilation to the glandirreversible dilation to the gland
• Alcholoism is the most common etiologyAlcholoism is the most common etiology
• HALL MARK imaging feature: ductal dilationHALL MARK imaging feature: ductal dilation
along with calcificationsalong with calcifications
• Other featurs areatrophic gland, focal necrosisOther featurs areatrophic gland, focal necrosis
ascites and pleural effusion formationascites and pleural effusion formation

50. • Pseudocysts are morePseudocysts are more
common in chroniccommon in chronic
thaan in acutethaan in acute
pancreatitis.pancreatitis.
• xray: calcifications canxray: calcifications can
be visualised in halfbe visualised in half
of the patients wthof the patients wth
alcohol etiologyalcohol etiology

51. Ultrasound picture shows calcificationsUltrasound picture shows calcifications
ulul

53. GROOVE PANCREATITISGROOVE PANCREATITIS
• Distinct form of chronic pancreatitis affectingDistinct form of chronic pancreatitis affecting
groove between pancreatic head, duodenum andgroove between pancreatic head, duodenum and
CBD.CBD.
• CT: plate like hypoattenuating lesion locatedCT: plate like hypoattenuating lesion located
between pancreatic head and decending part ofbetween pancreatic head and decending part of
duodenum.duodenum.
• MRCP: hypovascular lesion and pathognomicMRCP: hypovascular lesion and pathognomic
cystic changescystic changes

54. AUTO IMMUNEAUTO IMMUNE
• Another distinct form of chronic pancreatitisAnother distinct form of chronic pancreatitis
• Typically affects patients without a history ofTypically affects patients without a history of
alcohol abuse and biliary stone disease.alcohol abuse and biliary stone disease.
• Gland shows infiltration by CD4 T lymphocytesGland shows infiltration by CD4 T lymphocytes
and plasma cells.and plasma cells.
• CT/MRI: Diffuse/focal gland enlargementCT/MRI: Diffuse/focal gland enlargement
Narrowing of pancreaticNarrowing of pancreatic
ductduct
Delayed contrast enhancementDelayed contrast enhancement

55. THANK YOUTHANK YOU