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Pancreas: Acute Pancreatitis Imaging Pearls - Learning Modules | CT Scanning | CT Imaging | CT Scan Protocols - CTisus
Imaging Pearls ❯ Pancreas ❯ Acute Pancreatitis
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  • Classification of acute pancreatitis—2012: revision of the Atlanta Classification and Definitions by International Consensus. 
Banks PA, Bollen TL, Dervenis C, et al. 
Gut 2013;62:102–11. 



    The New Revised Classification of Acute Pancreatitis 2012 
Sarr MG, Banks PA, Bollen TL et al.
Surg Clin N Am 93 (2013) 549–562
  • - The aim of this study is to update the original 1991 Atlanta Classification of acute pancreatitis to standardize the reporting of and terminology of the disease and its complications.
    - Important features of this classification have incorporated the new insights into the disease learned over the last 20 years, including the recognition that acute pancreatitis and its complications involve a dynamic process involving two phases, early and late. 

    - The accurate and consistent description of the two types of acute pancreatitis (interstitial edematous pancreatitis and necrotizing pancreatitis), its severity, and, possibly most importantly, the description of local complications based on characteristics of fluid and necrosis involving the peripancreatic collections, will help to improve the stratification and reporting of new methods of care of acute pancreatitis across different practices, geographic areas, and countries.
    - By using a common terminology, the advancement of the science of acute pancreatitis should be facilitated.
  • - The aim of this study is to update the original 1991 Atlanta Classification of acute pancreatitis to standardize the reporting of and terminology of the disease and its complications. 


    - Important features of this classification have incorporated the new insights into the disease learned over the last 20 years, including the recognition that acute pancreatitis and its complications involve a dynamic process involving two phases, early and late.
  • - The accurate and consistent description of the two types of acute pancreatitis (interstitial edematous pancreatitis and necrotizing pancreatitis), its severity, and, possibly most importantly, the description of local complications based on characteristics of fluid and necrosis involving the peripancreatic collections, will help to improve the stratification and reporting of new methods of care of acute pancreatitis across different practices, geographic areas, and countries.
• 
    - By using a common terminology, the advancement of the science of acute pancreatitis should be facilitated.
  • How do you make the diagnosis of acute pancreatitis?
    This classification requires 2 of the following 3 features:
    (1) central upper abdominal pain usually of acute onset often radiating through to the back
    (2) serum amylase or lipase activity greater than 3 times the upper limit of normal
    (3) characteristic features on cross-sectional abdominal imaging consistent with the diagnosis of acute pancreatitis
  • Acute Pancreatitis is divided into two groups
    - interstitial edematous pancreatitis
    - necrotizing pancreatitis.
  • Interstitial Edematous Pancreatitis
    The majority (80%–90%) of patients presenting with the clinical picture of acute pancreatitis will have this more mild form. The differentiating characteristic of acute interstitial edematous pancreatitis is the lack of pancreatic parenchymal necrosis or peripancreatic necrosis evident on imaging. The associated findings are usually diffuse (or, on occasion, localized) enlargement of the pancreas secondary to inflammatory edema; there may also be some peripancreatic fluid. The pancreatic parenchyma and surrounding tissues may have haziness and stranding secondary to inflammatory edema, but there is no necrosis evident on cross-sectional imaging. The clinical picture of this form of acute pancreatitis usually resolves quickly over the first week.
  • Necrotizing Pancreatitis
    The hallmark of this form of acute pancreatitis is the presence of tissue necrosis, either of the pancreatic parenchyma or the peripancreatic tissues. Necrotizing pancreatitis most commonly involves both the pancreatic parenchyma and the peripancreatic tissue or the peripancreatic tissue alone; rarely, the necrosis is limited only to the pancreatic parenchyma. Therefore, necrotizing pancreatitis is classified as pancreatic parenchymal necrosis alone, pancreatic parenchymal and peripancreatic necrosis, or peripancreatic necrosis alone. Involvement of the pancreatic parenchyma usually heralds a disease more severe than peripancreatic necrosis alone.
  • Necrotizing Pancreatitis
    Early in the illness (during the first week), the differentiation of “necrosis” can be difficult on CECT. For the pancreatic parenchyma, nonperfusion of the pancreatic gland is usually evident. For the peripancreatic region, obvious loss of “perfusion” of the retroperitoneal fat is not evident (this area has little radiographic “perfusion” even normally), and the diagnosis of necrosis is usually made based on the presence of local inflammatory changes and some element of associated fluid, but also a solid component.
  • Necrotizing Pancreatitis
    Early in the illness (during the first week), the differentiation of “necrosis” can be difficult on CECT. For the pancreatic parenchyma, nonperfusion of the pancreatic gland is usually evident. For the peripancreatic region, obvious loss of “perfusion” of the retroperitoneal fat is not evident (this area has little radiographic “perfusion” even normally), and the diagnosis of necrosis is usually made based on the presence of local inflammatory changes and some element of associated fluid, but also a solid component. Recognition of this peripancreatic necrosis is difficult during the first week of the disease, but thereafter the diagnosis on imaging becomes more apparent, with a more heterogeneous collection of both solid and liquid components.
  • Severity of Disease
    This classification of severity of acute pancreatitis defines 3 degrees of severity: mild acute pancreatitis, moderately severe acute pancreatitis, and severe acute pancreatitis. These levels of severity are based on the presence and/or absence of persistent organ failure and local and systemic complications. In general, mild acute pancreatitis resolves within several days to a week, moderately severe acute pancreatitis resolves slowly and may require interventions, and severe acute pancreatitis, in addition to longer hospital stay and interventions, is also associated with organ failure and death.

  • The New Revised Classification of Acute Pancreatitis 2012 
Sarr MG, Banks PA, Bollen TL et al.
Surg Clin N Am 93 (2013) 549–562
  • Definition of Key Terms in Pancreatitis
    - Interstitial edematous pancreatitis: Inflammation of pancreatic parenchyma and peripancreatic tissue, but without obvious tissue necrosis.
    - Necrotizing pancreatitis: Inflammation with pancreatic parenchymal necrosis and/or peripancreatic necrosis.
  • Definition of Key Terms in Pancreatitis
    APFC (acute peripancreatic fluid collection): Peripancreatic fluid with interstitial edematous pancreatitis and no peripancreatic necrosis. This term applies to peripancreatic fluid seen within the first 4 weeks after onset of interstitial edematous pancreatitis.
  • Definition of Key Terms in Pancreatitis
    - Pancreatic pseudocyst: Encapsulated fluid collection with minimal or no necrosis with a well- defined inflammatory wall usually outside the pancreas. This entity occurs more than 4 weeks after onset of interstitial edematous pancreatitis.
    - ANC (acute necrotic collection): A collection of both fluid and necrosis associated with necrotizing pancreatitis involving the pancreatic parenchyma and/or the peripancreatic tissues
  • Definition of Key Terms in Pancreatitis
    WON (walled-off necrosis): A mature, encapsulated collection of pancreatic and/or peripancreatic necrosis with a well-defined inflammatory wall occurring more than 4 weeks after onset of necrotizing pancreatitis.
  • “Acute peripancreatic fluid collections are nonencapsulated collections that typically arise less than 4 weeks after the onset of acute pancreatitis. They are peripancreatic, rarely become infected, and generally re- solve spontaneously. Five percent to 15% of acute peripancreatic fluid collections persist beyond 4 weeks and are likely to become pseudocysts.”

    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • Classification of Acute Pancreatitis
  • “Acute peripancreatic fluid collections have variable size and shape and may be numerous. They are predominantly adjacent to the pancreas, without extension within the pancreatic parenchyma, and commonly reside within the lesser sac or anterior pararenal space . They are not round, instead taking the contours of the peripancreatic fascial planes containing them. Uncommonly, the fluid may collect in more distant areas, including the pelvis, ligamentum venosum fissures, splenic hilum, and mediastinum.”


    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “Necrotizing pancreatitis presents in three configurations: combined pancreatic and peripancreatic necrosis (75%), peripancreatic necrosis alone (20%), and pancreatic necrosis alone (< 5%). Patients with peripancreatic necrosis alone have lower morbidity and mortality rates.”


    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “Pseudocysts are encapsulated cystic lesions filled with amylase-rich fluid that complicate 10–20% of cases of acute pancreatitis. They typically evolve from acute peripancreatic fluid collections by forming a capsule, a process that usually requires at least 4 weeks. Pseudocysts lack an epi- thelial lining and thus are not true cysts. About 50% of pseudocysts remain asymp- tomatic, and there are no reliable indicators, such as size or duration, to predict which will become symptomatic and require treatment. Approximately 40% of pseudocysts will spontaneously resolve.”


    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “Many pseudocyst-associated complications and symptoms, such as gastric obstruction leading to early satiety and nausea, are secondary to local mass effect. Pseudocysts can also erode into adjacent vessels and cause pseudoaneurysms (discussed below). Hemorrhage within a pseudocyst shortly after an acute attack of pancreatitis is generally not due to pseudoaneurysm rupture but is rather the result of bleeding from intramural capillaries within the pseudocyst or retroperitoneum.”


    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “Walled-off necroses are well-circumscribed encapsulated cavities containing necrotic pancreatic and peripancreatic tissue that complicate about 1–9% of cases of acute pancreatitis. Walled-off necroses develop when necrotic tissues and acute necrotic collections mature and form a capsule. This process usually requires at least 4 weeks, similar to the process seen in pseudocyst formation.”

    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “Secondary infection of necrotizing pancreatitis is associated with increased mortality and is usually diagnosed at least 2–3 weeks after disease onset. Infected pancreatic necrosis is associated with poor outcomes (mortality rate of 32%) and frequently requires intervention, whereas sterile pancreatic necrosis has a mortality rate of about 12% . The risk of infection is increased in prolonged disease with persistent  bacteremia. Prophylactic antibiotics are usually ineffective, likely because of poor penetration into necrotic tissue.”


    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “Any collection complicating acute pancreatitis can become secondarily infected. The diagnosis of infection can be difficult on imaging. Gas within a collection is the most sensitive imaging finding for infection but is visible in only 12–18% of cases. Although MRI can reveal large amounts of gas, CT is more sensitive for small quantities. However, gas is not pathognomonic and can alternatively indicate fistulization into an adjacent hollow viscus.”


    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “Venous thrombosis is the most common vascular complication of pancreatitis, usually involving the splenic vein, but possibly also the portal and superior mesenteric veins. Thrombosed vessels are nonenhancing tubular structures on imaging.”


    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “Pseudocysts and walled-off necroses can erode into adjacent vasculature, resulting in pseudoaneurysms. The splenic, gastroduodenal, and pancreaticoduodenal are the most commonly affected vessels . Pseudoaneurysm formation takes time and therefore does not occur early in the disease. Pseudoaneurysms tend to gradually en- large and may rupture. They are associated with high mortality rates: 12.5% when detected and treated and more than 90% if untreated. The hemorrhage is most often within the gastrointestinal tract but can be intraperitoneal or, rarely, even within the pancreatic ductal system.”


    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “A major pitfall of percutaneous and surgical procedures is the subsequent development of pancreaticocutaneous fistulas, either to the surgical incision or in the path of the drain. These are not rare, developing in 25– 45% of patients who receive percutaneous or surgical intervention, and may be associated with severe electrolyte disturbances and sepsis. The presence of gas is a common imaging finding after invasive procedures. Therefore, finding gas after intervention is not as indicative of infection and should be interpreted with caution.”


    Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging 
 Zhao K et al.
AJR 2015; 205:W32–W41
  • “In conclusion, in up to 27% of patients, the small (2 cm) asymptomatic pancreatic cysts grew during follow-up imaging, and 11% exhibited growth after 1 year of initial stability. While the majority of cysts remained stable or did not evolve into a life-threatening neoplasm over a mean follow-up period of almost 3 years, the fate of pancreatic cysts exhibiting delayed growth is unknown and deserves further investigation. Nevertheless, the cessation of follow-up imaging studies after only 1 year of documented stability could have undesirable consequences in younger patients, in whom a longer life span provides time for the cyst to evolve into an invasive neoplasm.”

    Delayed growth in incidental Pancreatic cysts: Are the Current American College of Radiology Recommendations for Follow-up Appropriate?
Brook OR et al.
Radiology 2016; 000:1–10 
  • “Thus, the current recommendations of the American College of Radiology Incidental Findings Committee for follow-up of small (2 cm) pancreatic cysts may need to be revised, with particular emphasis on providing guidelines regarding the interval between imaging studies and recommendations for the duration of the follow-up period. These should take into consideration other comorbidities and the lifetime risk of developing pancreatic cancer.”

    Delayed growth in incidental Pancreatic cysts: Are the Current American College of Radiology Recommendations for Follow-up Appropriate?
Brook OR et al.
Radiology 2016; 000:1–10
  • “ Acute necrotizing pancreatitis is a severe form of acute pancreatitis characterized by necrosis in and around the pancreas and is associated with high rates of morbidity and mortality.”
    Necrotizing Pancreatitis: Diagnosis, Imaging and Intervention
    Shyu JY et al.
    RadioGraphics 2014;34:1218-1239
  • Acute Pancreatitis: Facts
    - 300,000 admissions in the US each year
    - Hospital cost is approximately 2.2 billion dollars a year
    - Disease is divided into two forms; interstitial edematous pancreatitis and necrotizing pancreatitis
    - Necrotizing pancreatitis occurs as a complication in 20-30% of patients with acute pancreatitis
  • Necrotizing Pancreatitis: facts
    - Associated with high rates of morbidity (34-95%) and mortality (2-39%)
    - Revised Atlanta classification system was introduced in 2012 to help with management and triage
  • Acute Pancreatitis: Clinical Dx
    - In early pancreatitis (<1 week) imaging is not usually needed
    - Diagnosis of acute pancreatitis is made by clinical findings;
    - Abdominal pain typically epigastric in location and radiating to the back
    - Serum amylase or lipase levels more than 3x higher than normal
  • Acute Pancreatitis (<1 week): Role of Imaging
    - Confirm dx of pancreatitis if symptoms are atypical or serum lipase or amylase levels are less than 3x normal
    - When cause of pancreatitis uncertain and neoplasm suspected
    - Patient doing poorly and concern is for necrosis early in disease process
  • Acute Pancreatitis (>1 week): Role of Imaging
    - Diagnosing pancreatitic necrosis
    - Diagnosing other complications of pancreatitis
    - Help in management decision making (IR vs surgery vs endoscopic management)
    - Monitoring treatment response
  • Pancreatic Necrosis: Three Categories
    - Parenchymal necrosis only (<5% of cases)
    - Peripancreatic necrosis only (<20%)
    - Combined pancreatic and peripancreatic necrosis (75-80% of cases)
    - Patients with peripancreatic necrosis only have a better prognosis
  • Pancreatic Necrosis: Pearls
    - Extent of involvement is considered <30%, 30%-50%, and >50%
    - Usually best seen at 40 seconds post injection in parenchymal phase
    - May be difficult to dx externally
  • Complications of Necrotizing Pancreatitis: Pseudoaneurysm
    - Typically late complication
    - Splenic artery most common in pancreatitis followed by GDA, pancreaticoduodenal, hepatic and left gastric artery
    - Pseudoanueysm can rupture into the necrotic collection, GI tract or pancreas
  • Complications of Necrotizing Pancreatitis: Infection
    - Infection (20%) usually occurs 2-4 weeks after initial presentation
    - Less than 20% of infected collections contain air so bx may be necessary
    - Infected necrosis has a 25-70% mortality rate
  • Complications of Necrotizing Pancreatitis: inflammation of adjacent organs
    - Mass effect or obstruction of the stomach or small bowel is not uncommon
    - Small bowel inflammation or mesenteric inflammation not uncommon
  • Complications of Necrotizing Pancreatitis: Miss. Findings
    - Common duct obstruction
    - Pancreatic duct stricture
    - Disconnected pancreatic duct
    - Pseudoaneurysm
    - Hemorrhage
    - Venous thrombosis
  • Complications of Necrotizing Pancreatitis: Venous Thrombosis
    - May be acute or chronic
    - Splenic vein is most common vessel involved (23%)
    - SMV and portal veins are less commonly involved
    - May result in splenomegaly
  • Necrotizing Pancreatitis: Management
    - Imaging guided percutaneous techniques
    - Endoscopic drainage
    - Laparoscopic necrosectomy
    - Open surgical necrosectomy
    - Decisions are often based on local expertiece
  • Necrotizing Pancreatitis
    - 20 - 30% of cases
    - Diffuse or focal areas of pancreatic non-enhancement
    - Contrast-enhanced study is required
    - Atlanta Classification:
    - >30% parenchymal necrosis
    - (<30%, 30-50%, > 50%)
    - Thrombosis of the pancreatic microcirculation
  • Necrotizing Pancreatitis
    - Usually not visible <48 hours after onset of symptoms, but should be evident by 96 hours
    - You may need to reimage!
    - Most develop at least single organ failure
    - Mortality 12-30%
  • Extra-Pancreatic Necrosis (EXPN)
    - Peripancreatic tissue necrosis without pancreatic necrosis
    - Pancreas enhances normally
    - Less severe course than pancreatic necrosis
    - Thickening of paracolic gutters and base of mesentery
    - Stranding and density in anterior pararenal spaces
  • Complications
    - Infected Pancreatic Necrosis
    - Central Gland Necrosis
    - Fluid Collections
    - Acute Peripancreatic Fluid Collection
    - Pseudocyst
    - Post-necrotic fluid collection
    - Walled-off Pancreatic Necrosis
    - Pancreatic Abscess
    - Vascular Complications
  • Infected Pancreatic Necrosis
    - 20-30% of patients with necrotizing pancreatitis
    - Significantly higher mortality rate than sterile necrosis
    - May approach 100% if untreated
    - Usually 2-3 weeks after clinical onset
  • Infected Pancreatic Necrosis
    - Extraluminal gas should be considered as equivalent to infection!
    - Gas is not typical for sterile necrosis
    - Treatment is surgical debridement
    - Drainage usually doesn’t work
    - If clinically suspected, biopsy may be necessary
  • Central Gland Necrosis
    - “Disconnected duct syndrome”
    - Necrosis of the neck and/or body
    - Sparing of head and tail
    - Disrupted pancreatic duct
    - Persistent secretions
    - Treatment:  Distal pancreatectomy or internal drainage
  • Acute Peripancreatic Fluid Collection
    - Peripancreatic fluid collection
    - Without an appreciable wall
    - 1st 4 weeks after symptom onset
    - Rich in pancreatic enzymes
    - Conform to shape of the retroperitoneum
    - Conservative treatment if sterile
    - Only rarely infected
  • Revised Atlanta Classification

    CT Findings:
    Normal Pancreas Score: 0
    Pancreatic/Peripancreatic Inflammation Score: 2
    Greater than or equal to 1 fluid collection or peripancreatic fat necrosis Scroe: 4

    Pancreatic Necrosis
    -None Score: 0
    -less than 30% Score: 2
    - greater than or equal to 30% Score: 4
    Extrapancreatic Complications Score: 2
  • Acute Interstitial Edematous Pancreatitis
    - 70-80% of cases
    - Enlargement of the pancreas
    - Loss of normal lobulations
    - Peripancreatic fat stranding and inflamation
    - Fluid in the lesser sac
    - Thickening of Gerota’s fascia
    - In mild cases, pancreas and adjacent tissues can look normal (up to ¼ of cases)
  • Acute Interstitial Edematous Pancreatitis
    Complications can occur even in mild cases of pancreatitis.
    - 5.3% of patients with mild acute pancreatitis
    - Routine follow-up only necessary to follow fluid collections
  • Mimics of Acute Pancreatitis
    Pancreas lies in anterior pararenal space
    1. Other constituents:
    - Duodenum
    - Ascending colon
    - Descending colon
    2. Other pathology
    - Duodenal ulcers
    - Colitis
    - Diverticulitis
  • Autoimmune Pancreatitis
    - Chronic pancreatitis – mixed inflammatory infiltrate
    - Rare (~2% of cases of pancreatitis)
    - Minimal abdominal pain
    - Weight loss, recent-onset diabetes
    - Elevated IgG4
    - Responds to steroids
  • Necrotizing Pancreatitis
    1. 20 - 30% of cases
    2. Diffuse or focal areas of pancreatic non-enhancement
    3. Contrast-enhanced study is required
    4. Atlanta Classification:
    - >30% parenchymal necrosis
    - (<30%, 30-50%, > 50%)
    5. Thrombosis of the pancreatic microcirculation
  • Necrotizing Pancreatitis
    - Usually not visible <48 hours after onset of symptoms, but should be evident by 96 hours
    - You may need to reimage!
    - 6-20% of patients
    - Most develop at least single organ failure
    - Mortality 12-30%
  • Infected Pancreatic Necrosis
    1. 20-30% of patients with necrotizing pancreatitis
    2. Significantly higher mortality rate than sterile necrosis
    - May approach 100% if untreated
    3. Usually 2-3 weeks after clinical onset
  • Infected Pancreatic Necrosis
    1. Extraluminal gas should be considered as equivalent to infection!
    - Gas is not typical for sterile necrosis
    2. Treatment is surgical debridement
    - Drainage usually doesn’t work
    3. If clinically suspected, biopsy may be necessary
  • Central Gland Necrosis
    1. “Disconnected duct syndrome”
    2. Necrosis of the neck and/or body
    - Sparing of head and tail
    3. Disrupted pancreatic duct
    4. Persistent secretions
    5. Treatment:  Distal pancreatectomy or internal drainage
  • Extra-Pancreatic Necrosis (EXPN)
    - Peripancreatic tissue necrosis without pancreatic necrosis
    - Pancreas enhances normally
    - Less severe course than pancreatic necrosis
    - Thickening of paracolic gutters and base of mesentery
    - Stranding and density in anterior pararenal spaces
  • Complications
    - Acute Peripancreatic Fluid Collection
    - Pseudocyst
    - Post-necrotic fluid collection
    - Walled-off Pancreatic Necrosis
    - Pancreatic Abscess
    - Vascular Complications
  • Pancreatitis May Mimic a Pancreatic Adenocarcinoma
    - Chronic pancreatitis (focal)
    - Groove pancreatitis
    - Autoimmune pancreatitis
  • Autoimmune Pancreatitis: Extrapancreatic CT Findings

    Retroperitoneal Involvement
    - Retroperitoneal fibrosis is seen in 10% of cases  

    Salivary Gland Involvement
    - Salivary gland enlargement can be seen in 15% of patients

    Pulmonary Involvement
    - Reticular nodules or ground glass opacities

  • Autoimmune Pancreatitis: Extrapancreatic CT Findings
    - Renal involvement is seen in about 35% of patients with renal parenchymal involvement in 30% and renal sinus or pelvis in 10% of cases
    - Renal parenchymal lesions are often bilateral and multiple and involve the cortex either as discrete lesions or diffuse patchy involvement
  • Autoimmune Pancreatitis:Extrapancreatic CT Findings

    Biliary Involvement in 80% of patients
    - Multifocal intrahepatic or extrahepatic duct strictures or thickening with enhancement
    - Diffuse thickening of the gallbladder wall
    - Soft tissue mass may be seen in port  

    Renal involvement is seen in about 35% of patients with renal parenchymal involvement in 30% and renal sinus or pelvis in 10% of cases
  • Autoimmune Pancreatitis: CT Findings
    - Diffuse parenchymal enlargement is seen I 40-60% of patients, focal enlargement in 30-40% of patients
    - Decreased attenuation during arterial phase and delayed enhancement during late phase imaging
    - capsule like rim with halo around gland in 12-40% of cases
    - Diffuse or segmental narrowing of the pancreatic duct
  • Autoimmune Pancreatitis: Facts
    - Autoimmune systemic disease witjh elevated IgG4 as a serologic marker
    - Involves pancreas and other organ systems including bile ducts, the kidneys, the retroperitoneum, and the salivary glands
    - Can simulate pancreatic cancer and is the actual pathology in 2-6% of patients who undergo resection for suspected pancreatic cancer 31-437
  • "It is important for radiologists to understand both the pancreatic and extrapancreatic imaging findings of autoimmune pancreatitis to make accurate and timely diagnoses."

    Autoimmune Pancreatitis: Pancreatic and Extrapancreatic Imaging Findings Bodily
    KD et al.
    AJR 2009; 192:431-437

  • "Autoimmune pancreatitis is a systemic disease with a wide range of pancreatic and extrapancreatic imaging findings. These findings can mimic those of other diseases in the pancreas or other organs and therefore are commonly misdiagnosed and mistreated. It is important for radiologists to understand both the pancreatic and extrapancreatic imaging findings of autoimmune pancreatitis to make accurate and timely diagnoses."

    Autoimmune Pancreatitis: Pancreatic and Extrapancreatic Imaging Findings Bodily
    KD et al.
    AJR 2009; 192:431-437

  • "In patients with milder interstitial forms of pancreatitis, routine follow-up CT examinations are indicated only in patients with fluid collections to document resolution of fluid or the development of complications."

    MDCT of Acute Mild (Nonnecrotizing) Pancreatitis: Abdominal Complications and Fate of Fluid Collections
    Lenhart DK, Balthazar EJ
    AJR 2008; 190:643-649

  • "A small number of acute, life threatening abdominal complications and chronic complications are expected to occur in patients with milder forms of acute non-necrotizing pancreatitis presenting with fluid collections."

    MDCT of Acute Mild (Nonnecrotizing) Pancreatitis: Abdominal Complications and Fate of Fluid Collections
    Lenhart DK, Balthazar EJ
    AJR 2008; 190:643-649

  • CT Grading of Pancreatitis(Balthazar Grading System)

    Grade

    CT Finding

    A

    Normal pancreas

    B

    Enlarged edematous pancreas

    CPancreatic and peripancreatic inflammation (peripancreatic stranding)
    D

    Single small peripancreatic fluid collection

    E

    Large or several fluid collections or retroperitoneal air

  • Acute Pancreatitis: Classification
    Mild acute pancreatitis
    - 80% of cases
    - No CT evidence of necrosis
    - Rapid recovery w/o complications

    Severe acute pancreatitis
    - 20% of cases
    - AKA necrotizing pancreatitis
    - CT evidence of necrosis
    - Increased incidence of morbidity and mortality  
  • " In the focal form of autoimmune pancreatitis enhancement of the mass was progressive, whereas pancreatic carcinoma was of low attenuation in both the pancreatic and hepatic phases."

    Autoimmune Pancreatitis:Differentiation From Pancreatic Carcinoma and Normal Pancreas on the Basis of Enhancement Characteristics at Dual-Phase CT
    Takahasni N et al.
    AJR 2009; 193:479-484

  • "The pancreas in autoimmune pancreatitis exhibited decreased enhancement in the pancreatic phase with nearly normal enhancement in the hepatic phase of imaging (35 and 60 sec)."

    Autoimmune Pancreatitis:Differentiation From Pancreatic Carcinoma and Normal Pancreas on the Basis of Enhancement Characteristics at Dual-Phase CT
    Takahasni N et al.
    AJR 2009; 193:479-484

  • "At dual phase CT, the enhancement patterns of the pancreas and pancreatic masses inpatients with autoimmune pancreatitis are different from those of pancreatic carcinoma and normal pancreas."

    Autoimmune Pancreatitis:Differentiation From Pancreatic Carcinoma and Normal Pancreas on the Basis of Enhancement Characteristics at Dual-Phase CT
    Takahasni N et al.
    AJR 2009; 193:479-484

  • Groove Pancreatitis
    - Soft tissue within pancreaticoduodenal groove with or without delayed enhancement, small cystic lesions along the medial duodenal wall
    - A Clinical and Radiologic Review of Uncommon Types and Causes of Pancreatitis Shanbhogue AK et al. RadioGraphics 2009; 29:1003-1026
  • Autoimmune Pancreatitis: CT Findings
    - Diffuse glandular enlargement with loss of lobular texture (“featureless gland)
    - Homogeneously iso- or hypoattenuating parenchyma with a nondilated or diffusely narrowed pancreatic duct
    - “halo” around gland is not uncommon
  • Autoimmune Pancreatitis can be confused with Pancreatic Cancer
    - Hx of weight loss
    - No good hx of pancreatitis
    - CEA 19-9 may be elevated
    - CT appearance often mass like and looks like pancreatic cancer
  • Autoimmune Pancreatitis: Facts
    - Age range 14-77 but most patients over 50
    - Male affected 2x compared to woman
    - Signs and symptoms at presentation include jaundice (63%), abdominal pain (35%), weight loss (35%), and diabetes mellitus (42-76%)
    - Extra-pancreatic processes include sclerosing cholangitis and PBC (68-88%) of cases, IBD (usually ulcerative colitis), Sjogren syndrome, renal involvement, retroperitoneal fibrosis
  • Autoimmune Pancreatitis
    - Type of chronic pancreatitis that is characterized by an autoimmune inflammatory process with lymphoplasmacytic infiltration associated with fibrosis of the pancreas
    - Key findings absence of classic hx of prior pancreatitis, elevated immunoglobulin G4, dramatic response to steroid therapy, and difficulty distinguishing from pancreatic cancer
  • Autoimmune Pancreatitis is also known as
    - Lymphoplasmacytic sclerosing pancreatitis
    - Chronic sclerosing pancreatitis
    - Pseudotumorous pancreatitis
    - Nonalcoholic duct destructive chronic pancreatitis
  • Autoimmune Pancreatitis
    - Diffusely enlarged gland with loss of lobular architecture, a "sausage"shape, and a peripheral rind of hypoattenuation; nondilated or diffusely narrowed pancreatic duct,extrapancreatic autoimmune manifestations
    - A Clinical and Radiologic Review of Uncommon Types and Causes of Pancreatitis Shanbhogue AK et al. RadioGraphics 2009; 29:1003-1026
  • Uncommon Types of Pancreatitis
    - Autoimmune pancreatitis
    - Groove pancreatitis
    - Hereditary pancreatitis
    - Pancreatitis in cystic fibrosis
    - Pancreatic divisum associated with pancreatitis
    - Tropical pancreatitis
    - Ascaris induced pancreatitis
  • "Acute pancreatitis is one of the most common conditions for which emergent imaging is indicated. Alcohol consumption and cholelithiasis are the most common causes of acute pancreatitis in adults, whereas the majority of cases in children are idiopathic or secondary to trauma."

    A Clinical and Radiologic Review of Uncommon Types and Causes of Pancreatitis
    Shanbhogue AK et al.
    RadioGraphics 2009; 29:1003-1026

  • Pancreatic Pseudocysts:Complications

    - Infection
    - Hemorrhage
    - Rupture
    - Obstruction of other organs
  • Cystic Pancreatic Mass: Differential Diagnosis

    - Pseudocyst
    - Serous cystadenoma
    - Mucinous cystic tumor
    - IMPN (intraductal mucinous tumor)
    - SPEN (solid and papillary neoplasm)
    - Cystic islet cell tumor
© 1999-2017 Elliot K. Fishman, MD, FACR. All rights reserved.