the lecture explains the pathology of acute pancreatitis ,the different imaging findings and how to score the severity of disease.

1. Imaging acute
pancreatitis
Dr/Ahmed Bahnassy
MBCHB-MD-FRCR
Consultant Radiologist-RMH

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

3. Anterior Pararenal Space
• Kidney –like
pancreas-is
retroperitoneal
• Shares Anterior
pararenal
space with
duodenum,
ascending and
descending
colon
• Anterior to
Aorta, IVC, and
kidneys
Robbins and Cotran, Pathologic Basis of Disease

4. The long range inflammatory
missiles
• Peripancreatic fluid
can spread through
diaphragmatic
hiatuses ,peritoneal
recesses, or
retropritoneal fascial
planes to present in
remote sites.

5. Targets of Inflammatory spread
in Acute Pancreatitis
• 1= spread into the lesser
sac
• 2 = spread into the
transverse mesocolon
• 3 = spread into the root
of the bowel mesentery
• 4 = extension into the
duodenum
• 5= inferior spread into
the remainder anterior
pararenal space
• 6=RP fluid colecting
down to scrotum,or even
thigh
Gore and Levine, Textbook of Gastrointestinal Radiology

6. Imaging Goals in Pancreatitis
1. Exclude other abdominal disorders that can
mimic acute pancreatitis
– DDx: acute cholecystitis, bowel obstruction or
infarction, perforated viscus, renal colic, duodenal
diverticulitis, aortic dissection, appendicitis, and
ruptured abdominal aortic aneurysm
2. Confirm clinical diagnosis of acute
pancreatitis
3. Staging the disease, by evaluation of the
extent and nature of pancreatic injury and
peripancreatic inflammation

7. Abdominal Plain Film
Findings of Acute
Pancreatitis on
Abdominal Plain Film
– Duodenal ileus in 42% of
patients
– Colon cutoff (paucity of
gas distal to splenic
flexure due to spasm of
colon affected by spread
of pancreatic
inflammation)
– Pancreatic abscess (gas
bubbles)
– Abdominal fat necrosis
and saponification (effects
of activated lipase on fatty
tissues)

8. Plain Chest Film
• 1/3 of acute pancreatitis patients have pulmonary
changes secondary to superior spread of pancreatic
inflammation to diaphragm and lung bases
• Findings of Acute Pancreatitis
on Plain Chest Film:
– pleural effusions (seen on 10% of
chest films)
– basal atelectasis
– pulmonary infiltrates
– elevated diaphragm
– Acute Respiratory Distress
Syndrome
Gore and Levine, Textbook of Gastrointestinal Radiology

9. Colon cut-off sign

10. Ultrasound
• Indications
– Good screening test in mild disease, suspected biliary
pancreatitis, and thin patients lacking fat planes for good CT
evaluation
• Uses
– Exclude a diagnosis of gallstones
– Follow up of pseudocysts
– Doppler of cystic masses to rule out pseudoaneurysm
• Major Limitations
– Bowel gas
– US cannot specifically reveal areas of necrosis

11. Pictorial review

12. Color doppler role

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

16. Think stepwize

17. Lower chest CT: Consolidation
Patent
Airways
surrounded by
collapsed
alveolar air
spaces

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

19. Pancreas and Anterior Pararenal
Space

20. Bilateral renal halo sign
• The halo appears as ground-
glass attenuation on imaging,
due to enhancement of the
perirenal fat from the
retroperitoneal collection of
pancreatic exudates. Bilateral
perirenal fluid collections are
rare and suggest pancreatitis.

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

22. Evaluation for Pancreatic Necrosis
Focal areas of necrosis
show enhancement of
less than 30 HU in
early arterial phase
Due to high attenuation exudates,
presence of pancreatic necrosis
cannot be assessed unless the gland
is imaged during late arterial-early
portal venous phase of rapid bolus
intravenous injection of contrast
patchy areas of absence of
enhancement, fragmentation, and
liquefaction necrosis can be seen.

23. Extensive pancreatic necrosis

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

25. Splenic Vein thrombosis
Splenic vein thrombosis
occurs in 2% to 4% of
patients with chronic
pancreatitis. This event
leads to isolated gastric
varices with resulting
gastrointestinal
hemorrhage.

26. Fluid Collections
ROI: 16 HU
Course:
Superolateral to
(simple fluid)
the region of the
lesser sac,
becoming
contiguous with
the greater
curvature of the
stomach
Structure:
ill-defined, with
indistinct
margins
Image courtesy Dr. Anne Kim

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

29. Traditional CT severity index

30. Modified CT severity index-easier
way

31. Prognostic value of CTSI

33. I-Pancreatic cancer presenting as
acute pancreatitis

34. II-Hemorrhagic Pancreatitis
• Rare
• Noted clinically by ↓ in hematocrit

35. 70 year-old woman with hemorrhagic pancreatitis
CT scan demonstrates hemorrhagic pancreatitis as a heterogeneous mass in
the area of the pancreatic bed (*). Arrow indicates active extravasation
(hemorrhage).

36. III-Autoimmune pancreatitis
in 1995 researchers
described a form of
pancreatitis associated
with autoimmune
manifestations. Today
it's known that about 5-
6 percent of all cases of
chronic pancreatitis are
autoimmune in nature.
• Focal or diffuse
enlargement
• Delayed enhancement.
• Capsule like rim.