Mod 6-1 Chole

Question 1

How many people are affected by cholelithiasis in the U.S. every year?

Answer 1

20 million people

Question 2

The ______ population are more commonly affected by cholelithiasis.

Answer 2

female

Question 3

Cholelithiasis is another term for __________.

Answer 3

gallstones

Question 4

What are the two types of gallstones?

Answer 4

• Cholesterol stones
• Pigment stones

Question 5

Which type of gallstones are predominant in the US? And which occurs more frequently in the tropics and Asian countries?

Answer 5

• U.S. - 75% are cholesterol stones
• Tropics/Asia - Pigment stones

Question 6

What do genetic predispositions associated with higher incidence include?

Answer 6

• Family history of the disorder
• Age older than 40
• Excess weight
• Female sex

Question 7

When can gallstones develop?

Answer 7

• Whenever bile contains insufficient bile salts and lecithin in proportion to cholesterol to maintin the cholesterol in solution.
• Increased hepatic synthesis of cholesterol

Question 8

What can cause a decrease in the amount of bile salts present?

Answer 8

Decreased reabsorption in the terminal ileum as a result of inflammatory disease or surgical resection

Question 9

Cholesterol is radio______.

Answer 9

lucent.

*Most gallstones are radiolucent

Question 10

How can we visualize cholesterol stones?

Answer 10

Contrast examinations or ultrasound

Question 11

What percentage of patients are gallstones detectable on plain abdominal radiographs and why?

Answer 11

20% because the gallstones contain sufficient calcium to be detectable.

Question 12

What three ways can a gallstone appear?

Answer 12

• A central nidus (focus) of calcification
• A laminated appearance (with alternating opaque and lucent rings)
• Calcification around the periphery

*Occasionally a nonopaque stone may contain gas-fllled fissures that produce the mercendes-benz sign (triradiate pattern)

Question 13

What method was once used to visualize gallstones?

Answer 13

Oral cholecystography (OCG) now replaced with ultrasound

Question 14

Solitary gallstones are usually ______; multiple stones are generally ______.

Answer 14

rounded; faceted (many sides)

Question 15

Describe characteristics of large number of stones

Answer 15

• Sandlike or gravel-like consistency
• Visible only when they layer out on radiographs obtained using a horizontal bean with the patient in an erect or lateral decub position.
• Infrequently coated with tenacious mucus and adheres to the gallbladder wall

Question 16

What range of sizes do gallstones range?

Answer 16

From grain of sand to those 1-2 stones large enough to fill the entire gallbladder.

Question 17

Why is sonography the method of choice for demonstrating gallstones?

Answer 17

Because it does not depend upon patient compliance in taking the contrast material and can effectively demonstrate the biliary tree as well as the gallbladder.

Question 18

What causes acute cholecystitis?

Answer 18

Usually caused by an obstructing stone in the cystic duct leading to the gallbladder.

Question 19

What does the obstruction that leads to acute cholecytitis cause?

Answer 19

Irritation of the wall of the duct and the signs of inflammation become apparent.

Question 20

What can be used to diagnose cholecystitis?

Answer 20

Sonography and nuclear medicine

*Radiographic methods ar enot useful at all.

Question 21

What is the radiographic technique for the gallbladder?

Answer 21

• With a kVp that is less than that used for routine abdominal radiograph.
• To improve contrast, use 70 kVp or less

Question 22

What is acute cholecystitis?

Answer 22

Inflammation of the gallbladder

Question 23

What causes most cases of acute cholecystitis? What percentage?

Answer 23

95% occurs after obstruction of the cystic duct by an impacted gallstone.

*Gallstones may injure hte mucosal wall allowing bacteria to enter.

Question 24

How can large number of stones be visible on a radiograph?

Answer 24

When they layer out using a horizontal beam with the patient erect or lateral decubitus position.

Question 25

How often are gallstones coated with tenacious mucus and adhere to gallbladder wall?

Answer 25

infrequently

Question 26

What can lead to nonvisualization of the gall bladder in OCG?

Answer 26

• Malabsorption of the radiopaque contrast material (hepatocellular dysfunction)
• Intrinsic disease of the gallbladder

If these can be excluded, evidence of gallbladder disease

Question 27

When using ultrasound to visualize the gallbladder, what else can be evaluated?

Answer 27

Billiary tree and hepatic parenchyma

Question 28

Ultrasound diagnossi of acute cholecystits requries the demonstration of…..

Answer 28

distended gallbladder containing gallstones.

*Also edema of wall and focal tenderness

Question 29

What modality is used with cholecystitis when ultrasound findings are inconclusive?

Answer 29

MRI