GI Tests/Imaging (Pass NPLEX) Flashcards
If ALP is elevated out of proportion to AST and ALT, what condition should you consider?
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)
In gram staining what colour are gram negative bacteria? What colour are gram positive bacteria?
Gram Negative = Pink
Gram Positive = Blue (because the cell wall retains the blue dye)
What is the gold standard method for diagnosis of Crohn’s Disease?
Ileum biopsy
Fistulas are best seen with what form of radiographic imaging? What IBD condition is a likely cause of the fistula?
Barium enema is best used to identify a fistula
Crohn’s disease is a common cause of fistulae
What lab tests will be abnormal in pancreatitis?
- ) Elevated Amylase & Lipase
- ) Glucose may be elevated in severe cases
- ) GGT is likely to be elevated if related to alcoholism
- ) TG are usually elevated
What does a sentinel loop in plain film imaging typically designate?
Local ileus (obstruction) from nearby inflammation. It is the dilation of a segment of the large or small intestine
How do you investigate for vibrio cholera?
Darkfield microscopy
Describe what each of the following tests indicate:
- ) HBsAg
- ) HBcAg
- ) HBeAg
- ) 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) - ) 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. - ) 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).
What evaluation test is used to identify Hepatitis C?
Biopsy
What is the gold standard diagnostic test for H.pylori?
Culture from biopsy obtained during endoscopy of the stomach
Gull Wing Organisms (like a bird in flight) found on gram staining is associated with what cause of bacterial diarrhea?
Campylobacter jejuni
What are mallory bodies?
Mallory bodies are inclusion bodies bound in the liver’s cells’ cytosol
Present in alcholic hepatitis, wilson’s dx, cirrhosis, hepatocarcinoma
In plain film imaging, how can a clinician differentiate a gastric ulcer from malignancy?
Non-malignant ulcerations have hampton’s line. Hampton’s line is the radiolucent (dark) line (typically 1mm) along the rim of the gastric ulcer
How do you diagnose Zenker’s Diverticulum?
Zenker’s Diverticulum is typically diagnosed using a barium swallow on plain film, however an upper GI endoscope may also reveal the diverticulum.
What percent of abdominal aneurysms are calcified, and therefore visible on plain film imaging?
50%
a diameter > 3.5cm is problematic