Chapter 12 Flashcards
Where does the pancreas lie?
Deep in the epigastrium and left hypochondrium, behind the lesser sac
How is the pancreas divided?
Head- Most inferior portion, anterior to IVC, to right of portal-splenic confluence, inferior to MPV and caudate lobe, medial to duodenum
Uncinate process- Small curved tip at the end of the head of the panc.
Neck- Anterior to the confluence or SMV
Body- Largest section, anterior to the SMA, the splenic a. is the superior border of the gland, splenic v. is posteriomedial border
Tail- Anterior to the left kidney, posterior to the left colic flexure and transverse colon (making it difficult to image), splenic v. is posterior border
What is the primary duct?
Duct of Wirsung is the primary duct extending the length of the pancreas, enters duodenum with the CBD at the ampulla of Vater (they join)
Duct of Wirsung- easier to visualize, should measure less than 2 mm
What is the secondary duct?
Duct of Santorini- secondary duct, drains the upper anterior head, enters the duodenum at the minor papilla 2 cm proximal to the ampulla of Vater
Where does the CBD open into?
Opens into the duodenum after forming a common trunk with the pancreatic duct
What is the ms for pancreas? Head, neck, body and tail ms?
Length- 15 cm, range 12-18 cm Head- thickest part 2-3 cm AP Neck- 1.5-2.5 cm Body- 2-2.5 cm Tail- 1-2 cm
What should sonographers evaluate?
Sonographers should evaluate the size, contour, and texture
True or false: The gland appears larger in children than in adults.
True
True or False: The gland stays the same even with age.
False.
The gland decreases in size with age
What is the vascular supply to the pancreas?
Splenic artery Pancreaticoduodenal arteries (many branches)
What is the vascular drainage from the pancreas?
Venous drainage is through tributaries of the splenic and superior mesenteric veins
What are the branches of the celiac axis?
Celiac axis- superior to pancreas
Left gastric artery
Common hepatic artery
Splenic artery
What is the superior border of the pancreas body and tail?
splenic artery
What does the CHA divide into?
Common Hepatic Artery- divides into the proper hepatic artery and gastroduodenal artery (GDA)
What is the anterolateral border of the pancreas?
GDA
From where does the SMA rise from?
SMA- rises from the aorta inferior to the celiac axis, posterior to the lower portion of the pancreatic body
Where is the MPV formed?
MPV is formed posterior to the neck by the junction of the SMV and splenic vein.
Where does the CBD join the pancreatic duct?
Ampulla of Vater
Define agenesis of the pancreas
Agenesis- agenesis of the body and tail, hypertrophy of the pancreatic head. Congenital defect
Define pancreatic divisum
Pancreas divisum- Rare, lack of fusion of the dorsal and ventral pancreatic buds, difficult to diagnosis with sonography
Define ectopic pancreatic tissue
Ectopic pancreatic tissue- most common pancreatic anomaly, in the form of intramural nodules, frequent sites—stomach, duodenum, small bowel, and large bowel
define annular pancreas
Annular pancreas- rare, head of the pancreas surrounds the 2nd portion of the duodenum, more common in males than females
What is the function of the pancreas?
Pancreas is a digestive (exocrine) and hormonal (endocrine) gland
What is the function of the exocrine gland?
Primary exocrine function- produce pancreatic juice, which enters duodenum together with bile—these are essential for normal digestion and absorption of food
What is the function of the endocrine gland?
Endocrine function (located in islets of Langerhans)- controls secretion of glucagon and insulin, failure of the pancreas to produce sufficient insulin leads to diabetes mellitus
What are the three lab values associated with pancreas?
Amylase
Lipase
Glucose
Why is the pancreas difficult to visualize?
Pancreas is the most difficult abdominal organ to evaluate because it lies posterior to the stomach and sometimes transverse colon
What does the pancreatic tissue texture depend on?
Pancreatic tissue texture depends on the amount of fat between the lobules
What are the patient positions for examining the pancreas?
Patient is examined in supine, oblique and sometimes upright positions
What is the transducer selection for pancreas?
Curved and 3-5MHz
What can provide an acoustic window?
Giving the patient 32 oz. of water through a straw can help with visualization along with having the patient in an upright position
Define pancreatitis
Inflammation of the pancreas
Why does pancreatitis occur?
Occurs when the pancreas becomes damaged and malfunctions as a result of increased secretion and blockage of ducts
Pancreatic tissue may be digested by its own enzymes
What is associated with acute pancreatitis that makes it difficult to visualize the pancreas?
In acute pancreatitis it may be difficult to visualize the pancreas because ileus is often associated with this condition
What are the categories of pancreatitis?
Acute
Hemorrhagic
Phlegmonous
Chronic
What is acute pancreatitis caused by?
Caused by inflamed acini releasing pancreatic enzymes into pancreatic tissue
The enzymes usually do not become active until they reach the duodenum to breakdown food
What is the most common cause of acute pancreatitis?
Gallstones
What is the second most common cause of acute pancreatitis?
Alcohol abuse
What are the symptoms of acute pancreatitis?
Severe pain, usually after a large meal or alcohol binge
With damage to the tissue and ductal system the pancreatic juices can leak into what?
With damage to the tissue and ductal system the pancreatic juices can leak into the pancreatic tissue as well as peripancreatic tissue
With acute pancreatitis, what are the lab values that are elevated?
Amylase increases within 24 hours
Lipase increases within 72-96 hours and stays elevated longer than amylase
What are the possible complications of acute pancreatitis?
Pseudocyst (10%) Phlegmon (18%) Abscess (1-9%) Hemorrhage (5%) Duodenal obstruction
What are ultrasound findings of acute pancreatitis?
May appear normal-early
Hypoechoic with swelling
Enlarged
Pancreatic duct may become obstructed
What is the most common complication of acute pancreatitis?
fluid collections and pseudocyst
When do fluid collections occur?
Fluid collections occur within 4 weeks- may resolve spontaneously
When is not considered a pseudocyst?
When well-defined walls are visable
What can pseudocyst occur from?
Pseudocyst can occur from trauma or acute/chronic pancreatitis
What is the primary and secondary common locations for pseudocysts?
Pseudocyst most common location- lesser sac (anterior to panc. Posterior to stomach)
2nd most common location- pararenal space, most often left
What are patient symptoms of spontaneous rupture of a pseudocyst?
Spontaneous rupture occurs in 5% of these patients
Symptoms- sudden shock and peritonitis
Mortality rate- 50%
What are the ultrasound findings of a pseudocyst?
Usually well-defined mass—echo-free
Debris may be seen within- infection and hemorrhage
Borders are echogenic
Calcifications may develop within the wall
Define Hemorrhagic Pancreatitis
Rapid progression of acute with rupture of vessels resulting in hemorrhage
Diffuse enzyme destruction of pancreas
Cause focal areas of fat necrosis
In nearly half of these patients this occurs after a large binge or excessively large meal
What are the ultrasound findings of hemorrhagic pancreatitis?
Depends on the age of the hemorrhage
May be homogeneous and echogenic with fresh blood
Areas of fat necrosis seen
At 1 week may appear cystic
Define phlegmonous pancreatitis
Phlegmon is an inflammatory process that spreads along fascial pathways
Causes areas of diffuse inflammatory edema of soft tissue
May proceed to necrosis
Extension outside the gland occurs in 18-20% of patients
What are ultrasound findings of phlegmonous pancreatitis?
Phlegmonous tissue appears hypoechoic with good through-transmission
Usually involves the lesser sac, left anterior pararenal space, and transverse mesocolon
Define pancreatic abcess
Low incidence, but serious complication—related to tissue necrosis
Majority of patients develop an abscess secondary to pancreatitis that develops from postoperative procedures
High mortality rate if left untreated
Ultrasound findings of pancreatic abcess
Poorly defined hypoechoic mass
Smooth or irregular walls
Few internal echoes seen, may be echo-free
Air bubbles may be seen within, with shadowing posterior
When it forms secondary to chronic pancreatitis and develops calcification within its walls typically doesn’t resolve on its own
Define chronic pancreatitis
Results from recurrent attacks of acute and causes continuing destruction of pancreas
What is chronic pancreatitis associated with?
Generally associated with chronic alcoholism or biliary disease
What can occur b/c of chronic pancreatitis?
Fibrous connective tissue and scarring occur
What can become obstructed b/c of chronic pancreatitis?
Pancreatic duct becomes obstructed because of protein plugs with resultant calcifications
What do patients with chronic pancreatitis have a chance of developing?
Patients have an increased risk in developing pancreatic cancer
Ultrasound findings of chronic pancreatitis
Mixed pattern Increased overall echogenicity with hypoechoic and hyperechoic foci Decreased size Irregular borders Possibly dilated duct
Name some cystic lesions of the pancreas
Autosomal dominant polycystic disease
Congenital cystic lesions of the pancreas
Cystic fibrosis
Fibrocystic disease of the pancreas
Von Hippel-Lindau syndrome
Solitary pancreatic cysts
What is the most common primary neoplasm of the pancreas?
adenocarcinoma
Accounts for greater than 90% of all malignant pancreatic tumors
Fourth most common cause of cancer related mortality after lung, breast, and colon cancer
What does adenocarcinoma involve?
Involves the exocrine portion of the gland–Fatal tumor
What is the survival rate for adenocarcinoma is poorly diagnosed?
Poor prognosis– survival time of 2-3 months and 1 year survival rate of 8%
True or false: Majority of patients over 60 years old get adenocarcinoma
true
What are the clinical symptoms of adenocarcinoma?
Depends on the location
Tumors in the head present symptoms early, causing obstruction of the CBD with jaundice and hydrops of the GB (Courvoisier’s sign)
Palpable, nontender GB with jaundice seen in 25% of patients with pancreatic ca
Tumors in the body and tail—less specific symptoms
Most commonly- weight loss, pain, jaundice, and vomiting (as GI tract has been invaded by tumor)
Tumors in the body and tail more frequently larger
What is the most common location for pancreatic adenocarcinoma?
head followed by body, then tail
Ultrasound findings of adenocarcinoma
Poorly defined mass in the region of the pancreas
Hypoechoic or isoechoic
Rarely, necrosis will be seen as a cystic area within the mass
May have secondary enlargement of the duct from edema or tumor in the panc head
If tumor is within the head look for biliary dilation
Sonographer should look for mets in the liver, para-aortic nodes, displacement of vessels
What are the two types of cystic pancreatic neoplasms?
Microcystic (serous adenoma)
Macrocystic (mucinous adenoma)
What accounts for 10-15% of all pancreatic cysts?
Cystic neoplasms of the pancreas account for 10-15% of all pancreatic cyst
Define microcystic adenoma
Rare, benign disease is found more often in older women.
Tumor is well circumscribed and usually consists of a large mass with multiple tiny cysts.
Define Macrocystic Adenoma
Benign with malignant potential
More often in the tail followed by body then head
Ultrasound findings of macrocystic adenoma
Well-defined Thin or thick walled Usually larger than 2 cm 4 types Hypoechoic Echogenic with debris Cyst with solid mural vegetations Completely filled or solid looking cyst
Define Intraductal Papillary Mucinous Tumor
Form of mucinous cystic neoplasm
Slow growing occurs in patients in their 60’s & 70’s
Benign to malignant
Where does intraductal papillary mucinous tumor originates from?
Originates from main pancreatic duct or its branches
What are the clinical symptoms of intraductal papillary mucinous tumor?
Clinical symptoms- abdomen pain, elevated amylase, so pancreatitis is a differential
Define Endocrine Pancreatic Neoplasms
Rise from the islet cells of the pancreas
Several types of islet cell tumors; may be functional or nonfunctional
Benign or malignant
Growth rate is slow
Usually do not spread beyond regional lymph nodes and liver
What is the most common functioning islet cell tumor or endocrine pancreatic neoplasm? What is the second most common?
Most common functioning islet cell tumor- Insulinoma
2nd most common functioning islet cell tumor-Gastrinoma
Define insulinoma (B-Cell)
Most common functioning islet cell tumor
Usually benign
Most- small, well encapsulated, and hypervascular
What are the clinical symptoms of insulinoma?
Palpitations, headache, confusion, pallor, sweating, slurred speech and coma
Clinical triad:
Patients in their 40’s-60’s
Hypoglycemic symptoms with immediate relief after IV glucose
Define gastrinoma (G-Cell)
2nd most common functioning islet cell tumor
Produces Zollinger-Ellison syndrome
Caused by non-insulin secreting pancreatic tumors that secrete excessive amounts of gastrin
Frequently multiple, extrapancreatic, difficult to locate and 60% are malignant
What does the gastrinoma stimulate?
Stimulates the stomach to produce great amounts of hydrochloric acid and pepsin
What does gastinoma lesion affect?
These lesions usually affect young patients with peptic ulcer disease
What does Rare Islet-Cell Tumors include?
Rare functioning islet-cell tumors include:
Glucagonoma, lipoma, somatostatinoma and carcinoid and multihormonal tumor
Most commonly malignant- glucagonomas and vipomas
Define vipomas
Vipomas- associated with GB dilation, fluid-filled distended bowel loops, and excessive secretion of fluid and electrolytes
What can be present with rare islet-cell tumors?
Thickening of the gastric wall may be present
What are ultrasound findings of nonfunctioning islet-cell tumors?
Typically small
Best seen when in the head
May be multiple and usually occur in the body and tail—greater concentration of Langerhans islets in that area
Define nonfunctioning islet-cell tumor?
33% of all islet-cell neoplasms
Tendency to present as large tumors in the head of the pancreas with a high incidence of malignancy
Primary tumors that can metastasize to the pancreas?
Primary tumors that can metastasize to the pancreas are: Melanomas Breast Gastrointestinal Lung tumors
Define lymphoma
Most common parapancreatic neoplasm
Arise from lymphoid tissue
May be difficult to separate from primary lesion
How can intra-abdominal lymphomas appear?
Intra-abdominal lymphoma may appear as a hypoechoic mass or with necrosis, a cystic mass in the pancreas
With lymphoma, how can the SMV be displaced?
Superior mesenteric vessels may be displaced anterior instead of posterior, as seen with a primary pancreatic mass
Where can multiple nodules be seen with lymphoma?
Multiple nodes are seen along the pancreas, duodenum, porta hepatis, and superior mesenteric vessels.
What can Phlegmonous Pancreatitis cause?
Causes areas of diffuse inflammatory edema of soft tissue
What can phlegmonous pancreatitis proceed to?
necrosis
When does hemorrhagic pancreatitis occur?
In nearly half of these patients this occurs after a large binge or excessively large meal
What does hemorrhagic pancreatitis cause?
Cause focal areas of fat necrosis
What does majority of patients develop secondary to pancreatitis?
Majority of patients develop an abscess secondary to pancreatitis that develops from postoperative procedures
