GI Tests/Imaging (Pass NPLEX)

Question 1

If ALP is elevated out of proportion to AST and ALT, what condition should you consider?

Answer 1

Cholestasis or a bone disorder marked with an increase in osteoclastic activity

Note: cholestasis typically presents with elevated ALP & GGT much higher than ALT and AST. AST and ALT may be slightly elevated though.

ALP can also be fractioned into the various isotypes to determine whether the ALP is from a bone condition (AP2)

Question 2

In gram staining what colour are gram negative bacteria? What colour are gram positive bacteria?

Answer 2

Gram Negative = Pink

Gram Positive = Blue (because the cell wall retains the blue dye)

Question 3

What is the gold standard method for diagnosis of Crohn’s Disease?

Answer 3

Ileum biopsy

Question 4

Fistulas are best seen with what form of radiographic imaging? What IBD condition is a likely cause of the fistula?

Answer 4

Barium enema is best used to identify a fistula

Crohn’s disease is a common cause of fistulae

Question 5

What lab tests will be abnormal in pancreatitis?

Answer 5

1. ) Elevated Amylase & Lipase
2. ) Glucose may be elevated in severe cases
3. ) GGT is likely to be elevated if related to alcoholism
4. ) TG are usually elevated

Question 6

What does a sentinel loop in plain film imaging typically designate?

Answer 6

Local ileus (obstruction) from nearby inflammation. It is the dilation of a segment of the large or small intestine

Question 7

How do you investigate for vibrio cholera?

Answer 7

Darkfield microscopy

Question 8

Describe what each of the following tests indicate:

1. ) HBsAg
2. ) HBcAg
3. ) HBeAg

Answer 8

1. ) HBsAg (Hep B surface antigen)
   i. ) indicates the presence of hepatitis B virus.
   ii. ) To differentiate chronic and acute hepatitis B = IgM Anti-HBc (Acute) & IgG Anti-HBc (Chronic)
2. ) HBcAg (Hepatitis B core antigen)
   i. ) it is an indicator of active viral replication in the hepatocyte
   ii. ) Requires hepatic biopsy, it cannot be identified through serological investigation.
3. ) HBeAg (Hepatitis B extracellular antigen)
   i. ) The test is an indicator of active viral replication found in the blood.
   ii. ) it is the equivalent to HBcAg but found extracellularly (in the serum).

Question 9

What evaluation test is used to identify Hepatitis C?

Answer 9

Biopsy

Question 10

What is the gold standard diagnostic test for H.pylori?

Answer 10

Culture from biopsy obtained during endoscopy of the stomach

Question 11

Gull Wing Organisms (like a bird in flight) found on gram staining is associated with what cause of bacterial diarrhea?

Answer 11

Campylobacter jejuni

Question 12

What are mallory bodies?

Answer 12

Mallory bodies are inclusion bodies bound in the liver’s cells’ cytosol

Present in alcholic hepatitis, wilson’s dx, cirrhosis, hepatocarcinoma

Question 13

In plain film imaging, how can a clinician differentiate a gastric ulcer from malignancy?

Answer 13

Non-malignant ulcerations have hampton’s line. Hampton’s line is the radiolucent (dark) line (typically 1mm) along the rim of the gastric ulcer

Question 14

How do you diagnose Zenker’s Diverticulum?

Answer 14

Zenker’s Diverticulum is typically diagnosed using a barium swallow on plain film, however an upper GI endoscope may also reveal the diverticulum.

Question 15

What percent of abdominal aneurysms are calcified, and therefore visible on plain film imaging?

Answer 15

50%

a diameter > 3.5cm is problematic

Question 16

Gastrointestinal String Sign is a medical term for a radiographic finding that represents:

Answer 16

Severe narrowing of the intestinal lumen.

It is commonly seen in crohn’s disease, colon cancer, and hypertrophic pyloric stenosis

Question 17

Increased ALP and GGT are suggestive of what condition?

Answer 17

Cholestasis

Question 18

What is hampton’s line?

Answer 18

it is a radiolucent (dark) line along the rim of a peptic ulceration

it is not present in a carcinomatous ulcer and is therefore a typical differentiation between the two aforementioned pathologies

Question 19

If you have isolated elevation of ALP, what should you rule out and how?

Answer 19

Bone disease should be ruled out by fractioning ALP into the various isozymes. (AP2 is a byproduct of osteoblastic activity).

Note: if cholestasis is the cause of elevated ALP then GGT will also be elevated

Question 20

A bulge in the wall of the esophagus (that is non-mobile) on plain film imagining is most likely to be:

Answer 20

Zenker’s diverticulum

Question 21

What condition presents with a stacked coin appearance on plain film imaging of the abdomen?

Answer 21

Generalized ileus

Question 22

A rise in serum O and H agglutinin titers 3-4 weeks post-infection suggests what microorganism?

Answer 22

Salmonellosis

Question 23

What liver enzyme is more specific to liver damage: AST or ALT?

Answer 23

ALT

Question 24

What lab marker is indicative of an active Hepatitis A viral infection?

Answer 24

IgM HAV

Question 25

A lead pipe colon displayed on plain film imaging is likely related to what condition?

Answer 25

Ulcerative Colitis.

A lead pipe colon is present with the loss of haustra

Question 26

What would diverticulosis look like with a barium enema?

Answer 26

Multiple small white masses

Question 27

What are Schistocytes and in what conditions would you find them?

Answer 27

Schistocytes are fragmented RBCs found on microscopy

When the endothelial layer of small vessels becomes damaged fibrin deposits and platelets aggregate. Then as RBCs travel through the damaged blood vessels they are fragmented (into schistocytes) resulting in intravascular hemolysis. This is known as MAHA (microangiopathic hemolytic anemia).

MAHA and the corresponding schistocytes occur in the following conditions:

1. ) Disseminated Intravascular Coagulation (DIC)
2. ) Hemolytic Uremic Syndrome (caused by Shiga-like toxin from EHEC)
3. ) Aortic Stenosis (most common cause of schistocytes)
4. ) Artificial Heart Valves

Question 28

The prognosis for Hepatitis B is worse if HBsAg, HBeAg, HBcAg persist for greater than how long?

Answer 28

3 months

Question 29

Kidney Stones vs. Gall Stones: Which are more radiopaque on imaging?

Answer 29

Kidney stones are very radiopaque because of a high calcium content. Gall stones are typically radiolucent (more black)

Question 30

What would the AST:ALT ratio look like in viral hepatitis or fatty liver?

Answer 30

<1:1

ALT will be higher than AST.

Note: in alcoholic hepatitis AST is significantly higher than ALT

Question 31

What is the most common cause of elevated ALT?

Answer 31

Fatty Liver

Question 32

What condition will present with Mickey Mouse ears on abdominal radiographic imaging?

Answer 32

Ascites (CHF, liver disease, or renal failure)

Question 33

How do you evaluate for esophageal spasms?

Answer 33

Esophageal monometry (measuring the pressure in the lower part of the esophagus)

Question 34

What testing method is regularly performed in the evaluation of Ulcerative Colitis?

Answer 34

Sigmoidoscopy with mucosal biopsy (to exclude self-limited colitis)

Question 35

What lab test can you run to screen for hepatocellular carcinoma in cases of liver cirrhosis?

Answer 35

Alpha-fetoprotein (AFP)

Question 36

What liver enzyme is elevated in alcoholics?

Answer 36

GGT