Gi -- Pancreas

Front 1

What are features of an unresectable pancreatic CA?

Back 1

- Size >3 cm
- Arterial invasion: usually the SMA or celiac axis.
- Venous invasion: limited involvement of the SMV or jxn of SMV and portal vein is considered resectable and reconstructable. More extensive venous involvement may not be resectable.
- Regional adenopathy with mets
- Distant mets (liver, peritoneum, and lungs)

Front 2

What are the complications of acute pancreatitits?

Back 2

1. Parenchymal necrosis (lack of enhancement) with superimposed infection (gas is only present in 20% of cases of infected pancreatic necrosis/abscess) is the most severe complication.
- Pancreatic hemorrhage (inflammatory changes can cause erosion of the pancreatic vessels) resulting in hemorrhage.
- Splenic artery pseudoaneurysm
- Splenic and portal vein thrombosis
- Biliary obstruction

Front 3

What are the causes of acute pancreatitis?

Back 3

Alcohol
Gallstones
Pancreatic divisum
CF
Drugs
Hypercalcemia (HPTH),
Hyperlipidemia
Viral infections
Endotoxins
Trauma
Familial
Autoimmune

Front 4

1. What are the imaging features of autoimmune pancreatitis?
2. What lab test is sensitive and specific for autoimmune pancreatitis?
3. What other conditions are associated autoimmune pancreatitis?

Back 4

1.
- Diffusely or focally enlarged pancreas with "halo" of low density (intensity)
- Sausage-like, loss of fatty lobulation
- Minimal peripancreatic stranding
- Stricture of common bile duct ± intrahepatic ducts.
2. IgG4
3. PSC, Graves disease

Front 5

1. Focal pancreatitis can be confused with what?
2. What is the most common location of the focal pancreatitis?
3. How do you differentiate focal pancreatitis from pancreatic adenoCA?

Back 5

1. Focal pancreatitis can be confused with pancreatic adenocarcinoma.
2. Focal pancreatitis usually involves the head of the pancreas.
3. Look for associated signs of acute pancreatitis: loss of discrete planes and peripancreatic fat stranding.

Front 6

1. At what time period do you say that a peripancreatic fluid collection is a pseudocyst?
2. Above what size are pseudocysts drained?
3. Why is ultrasound helpful in evaluation of peripancreatic fluid collections?

Back 6

1. 6 weeks after episode of acute pancreatitis. Before 6 weeks, you say peripancreatic fluid collections. Fluid collections that last more than 6 weeks are referred to as pseudocysts and usually have a thick fibrous wall. Persistence of the fluid collection indicates a communication with the pancreatic duct.
2. >4cm or if causing sx.
3. Most peripancreatic fluid collections appear homogeneous on CT. US can show the complexity of the psuedocyst suggesting infection/hemorrhage.

Front 7

What are the plain film findings of acute pancreatitis?

Back 7

"COLON CUTOFF SIGN"
- Pancreatic inflammatory fluid preferentially occupies the left anterior pararenal space --> inflammatory fluid bathes the colon and causes colonic spasm --> persistent spasm causes partial colonic obstruction with gaseous dilatation of the colon proximal to the splenic flexure

Front 8

What are the UGI findings of acute pancreatitis?

Back 8

1. Widening of the C-loop of the duodenum (non-specific = can be seen with any mass lesion in the pancreatic head)
2. Tethering of mucosal folds
3. Narrowing of the duodenal lumen due to severe spasm which can result in gastric outlet obstruction. Long-standing inflammation can result in duodenal stricture.
- If pancreatic effusion is large, it can spread beyond the lesser sac into the small bowel mesentery resulting in small bowel fold thickening.

Front 9

1. What are the imaging findings of chronic pancreatitis?
2. Where are the calcifications located in chronic pancreatitis?
3. What finding is specific for pancreatitis?
4. What can chronic pancreatitis be confused with?
5. What is a common sequelae of chronic pancreatitis?

Back 9

1. Pancreatic ductal calcifications, dilated main and side branch ducts, pancreatic parenchymal atrophy.
2. The calcifications in chronic pancreatitis are ductal in origin.
3. Intraductal stone
4. Chronic pancreatitis can be confused with IPMN. In general, ductal dilatation is the predominant finding in IPMN, whereas parenchymal atrophy is the predominant finding in chronic pancreatitis.
5. Biliary strictures leading to intrahepatic and extrahepatic ductal dilatation. Also, pts w/ chronic pancreatitis are at increased risk of developing pancreatic adenoCA.

Front 10

1. What disorders result in fatty replacement of the pancreas?
2. What are the clinical findings of pancreatic insufficiency?

Back 10

1. CF, chronic pancreatitis, diabetes, obesity
2. Diabetes and malabsorption.

Front 11

1. What feature is most suggestive of pancreatic adenoCA vs. other solid neoplasms of the pancreas?
2. In pts with suspected pancreatic adenoCA, how should you protocol the CT?

Back 11

1. Upstream ductal dilatation. Ductal dilatation is less common in other solid pancreatic masses -- islet cell tumor, mets, lymphoma, focal pancreatitis.
2. Dual phase imaging (pancreatic and portal venous phase). Pancreatic phase is important for detection of hypovascular mass in the pancreas. Portal venous phase is best for liver mets.

Front 12

1. What is the normal anatomy of the uncinate process?
2. What findings suggest adenoCA of the uncinate process?
3. Does the SMV have a cuff of fat between it and the pancreatic neck?

Back 12

1. The uncinate process is triangular in configuration. The SMA and SMV pass between the pancreatic head (anterior) and uncinate process (posterior). These vessels can become compressed during pathologic disease of the pancreas.
2. Rounding of the uncinate process, change in attenuation, loss of fat plane b/w the mass and SMA.
3. No, there is no cuff of fat b/w the SMV and pancreatic neck.

Front 13

1. What are the imaging features of islet cell tumors?
2. What are the two broad categories of islet cell tumors?
3. What is the most common islet cell tumor?

Back 13

1. Hypervascularity, propensity to calcify, and lack of vascular encasement.
2. Hyperfunctioning and non-hyperfxning
3. Insulinoma

Front 14

1. What is the gastrinoma triangle?
2. What syndrome is associated with gastrinoma?
3. What symptoms are associated with a gastrinoma?
4. Are most gastrinomas benign or malignant?

Back 14

1. Gastrinomas can be extrapancreatic but are usually found in the gastrinoma triangle which is limited by the ampulla of Vater, junction of the neck and body of the pancreas, junction of the cystic duct and common bile duct. Most commonly located w/n the gastric antrum and proximal duodenum.
2. MEN I (tumors associated with this syndrome tend to be multiple and small).
3. Gastrinomas are responsible for Zollinger-Ellison syndrome in which pts have overproduction of gastrin and excess stomach acid.
4. Most are malignant (75%).

Front 15

1. What are the imaging features of intraductal papillary mucinous neoplasm of the pancreas?
2. What benign entity can have similar imaging features? How can you tell them apart?
3. When can IPMN be confused with pancreatic carcinoma?

Back 15

1. IPMN can be main duct type, side branch type (most common in the pancreatic head), and combined. Main duct type presents as gross dilation of the pancreatic duct with associated atrophy of the pancreatic parenchyma.
2. Chronic pancreatitis can present as an irregularly dilated pancreatic duct with calcification of the atrophic pancreas. IPMN may show a mass within the duct.
3. When tumor has broken through the walls of the ducts, it may behave like other pancreatic malignancies with invasion and obstruction of bile ducts, vessels, etc.

Front 16

What is the differential diagnosis of dilated pancreatic duct?

Back 16

1. Pancreatic Ductal Carcinoma:
- Abrupt transition from dilated to narrowed duct.
- Hypoenhancing & hypoechoic mass at point of obstruction.
- Commonly associated with vascular invasion, nodes, liver metastases
2. Chronic Pancreatitis:
- Calcifications & atrophy of parenchyma.
- May cause fibrotic mass in pancreatic head that may obstruct bile duct; hard to distinguish from carcinoma.
3. Senescent Change:
- Elderly patients often have atrophy of gland, mild dilation of pancreatic duct
4. IPMT:
- Duct is often markedly dilated with mucous, causing bulging of papilla of Vater into duodenum.
- Main duct involvement, especially with polypoid lesions, indicates aggressive, often malignant lesion
5. Ampullary Carcinoma:
- Often indistinguishable from pancreatic carcinoma except for smaller size & better prognosis.
- Associated with Gardner syndrome.
6. Duodenal Carcinoma:
- Tumor that occludes ampulla of Vater may simulate all imaging features of pancreatic head carcinoma
- Look for mass within lumen of duodenum (carcinoma, villous adenoma, carcinoid, etc.)
7. Choledocholithiasis:
- Stone lodged in distal common channel can obstruct pancreatic & bile duct
- Usually no mass, but may cause "gallstone pancreatitis" with swelling of pancreatic head
- Correlate with history of sudden onset of pain; elevated pancreatic enzymes

Front 17

What features can be used to differentiate among pancreatic cystic tumors?

Back 17

1. Age & gender
- young woman: SPEN or mucinous cystic
- older man: Serous
2. Location of lesion:
- head/neck: serous & side branch IPMT
- body/tail: mucinous cystic neoplasm
3. Calcification within lesion:
- peripheral = mucinous
- central = serous cystadenoma
4. Mural nodularity:
- enhancement = neoplastic
5. Duct communication:
- favors IPMT

Front 18

What are the imaging features of mucinous cystic tumor of the pancreas?

Back 18

- Circumscribed cystic tumor with septations.
- Most common cystic neoplasm
- Usually in middle-aged women, in body-tail segment
- May have peripheral calcification

Front 19

What are the imaging features of the serous cystadenoma of pancreas?

Back 19

- Innumerable "microcysts" in spherical pancreatic mass giving a honeycomb appearance.
- Innumerable thin septa, may coalesce and calcify in center of mass
- Unilocular oligocystic variant with thin wall, usually in pancreatic head may be difficult to distinguish from mucinous cystic neoplasm
- associated with VHL.

Front 20

What entities can mimic a pancreatic neoplasm?

Back 20

Mesenteric hematoma:
- Can mimic a mass arising from the pancreas. The hematoma is located at the base of the mesentery immediately anterior to the pancreatic neck.
- Look for history of trauma or anticoagulation.
- High attenuation mass (45-65HU) that does not enhance.
Splenosis:
- Usually located in the tail of the pancreas.
- Follows attenuation and signal intensity of the spleen on all imaging.
Duodenal diverticulum:
- Can mimic a cystic pancreatic neoplasm.
- Look for air or opacification with oral contrast.

Front 21

DDX of pancreatic head mass

Back 21

- Pancreatic AdenoCa
- Groove pancreatitis
- Lymphoma

Front 22

Grading of pancreatic injury

Back 22

Grade A: less than 50% thickness or focal pancreatitis.
Grade B: greater than 50% laceration of the body or tail (B1) or transection of the body (B2).
Grade C: >50% laceration of the head (C1) or transection of the head (C2).

Front 23

Fatty replacement of the pancreas

Back 23

- CF
- Schwachman-Diamond syndrome: associated with short stature.
- Steroid therapy/Cushing's syndrome

Other manifestations of CF:
- Lungs: recurrent infection, bronchiectasis, mucus plugging, hyperexpansion of the lungs.
- GI tract: Biliary cirrhosis/portal HTN, fatty atrophy of the pancreas, meconium ileus.