GI pathology Flashcards
what structures must be seen on an abdo x-ray?
lumbar spine and its transverse processes, liver, kidneys, psoas muscles
what kVp is used for adequate penetration of dense barium in GI studies?
120kVp
what kVp is used for penetration of double-contrast GI studies?
90-100kVp
what is achalasia?
obstruction if the distal section of the esophagus with proximal dilation caused by incomplete relaxation of the lower esophageal sphincter.
what is anemia?
decrease in the amount of oxygen-carrying hemoglobin in peripheral blood
what does anemia do to respiration and heart beats?
- increased respiratory rate (to meet body’s need for oxygen)
- heart beats more rapidly
what is ascites?
Ascites develops because of a combination of albumin deficiency and increased pressure within obstructed veins, which permits fluid to leak into the abdominal cavity.
how does ascites appear on x ray?
Large amounts of ascitic fluid are easily detectable on plain abdominal radiographs
as a general abdominal haziness (ground-glass appearance)
does ascites call for a raise or decrease in technical factors?
increase
does bowel obstruction call for an increase or decrease in technical factors?
decrease
what is the reason for 75% of all small bowel obstructions?
fibrous adhesions caused by previous surgery or peritonitis
would a hernia of the inguinal, femoral, umbilical, or incisional areas result in a small bowel obstruction?
yee, this is the 2nd most common cause of small bowel obstructions
how does a small bowel obstruction look in xray?
on upright xray or decub = interface between gas and fluid forms a straight horizontal margin.
if there is a point of dilated bowel, where would the obstruction be seen?
below the point of dilation
what procedure can be performed if abdomen xrays are insufficient to distinguish between small and large bowel obstruction?
barium enema can be performed for ruling out LARGE BOWEL OBSTRUCTION.
how can barium be administered to visualize a small bowel obstruction?
retrograde: barium enema
antegrade: mouth
what is the best contrast to use for demonstrating the site of a small bowel obstruction ?
barium
what is the image appearance of cancer of the stomach?
stimulates intense fibrosis which begins near the pylorus and progresses slowly upward.
large polypoid mass. if there is irregularities and ulcers in this mass, it is a sign of malignancy
what is the area that is least involved in cancer of the stomach?
fundus.
how does gastric carcinoma look on CT?
thickening of gastric wall or intraluminal mass
what can be determined in gastric carcinoma on CT?
- staging
- planning treatment
- assessing response of therapy
- detecting tumor recurrence
what is cholelithiasis?
gallstones
are cholesterol stones radiopaque?
no, radiolucent. this is why most gallstones are only visible on contrast exams.
what is the mercedez sign in gallstones? how is it formed?
its when the gallstones are nonopaque, they sometimes contain gas-filled fissures that produce the mercedez sign.
what is cholecystitis?
inflammation of the gallbladder
what is cirrhosis of the liver?
chronic destruction of the liver cells and structure, fibrosis, end-stage liver disease.
what is the major cause of cirrhosis of liver?
alcoholism
what happens to the liver during cirrhosis?
fibrous connective tissue replaces the destroyed liver cells with cells that have no liver cell function.
does the liver get bigger or smaller with cirrhosis?
it actually increases in size initially because of regeneration, but eventually becomes smaller as the fibrous connective tissue contracts
does alcoholic cirrhosis cause a large amount of fat accumulation in the liver?
yes
which modality will show the fatty liver the best? how will it appear in comparison to the spleen?
CT
will be darker than the spleen because of the fat build up. it is usually brighter than the spleen.
how will the portal veins be seen on a CT of a fatty liver?
high density in comparison to the fatty liver. usually they are low density.
what is the most characteristic symptom of cirrhosis?
ascites
what is the xray sign of ascites?
ground glass appearance.
where do half of colon cancers occur?
rectum and sigmoid. can be felt by rectal exam or seen with sigmoidoscope.
are peduncled polyps usually malignant?
no, sessile (no stalk) usually are.
what is the radiographic appearance of annular cancer of the sigmoid colon?
apple-core lesion.
what is the modality of choice for staging colon cancer and assessing tumor recurrence?
CT virtual colonoscopy.
what does 70% of large bowel obstruction result from?
primary colonic carcinoma.
what is the major danger of colonic obstruction?
perforation
what is crohns disease and where is it found?
regional enteritis in small bowel. in terminal area of ileum usually but can affect any part of the GI tract.
what are skip areas in crohns disease?
inflammatory process is discontinuous, diseased segments of bowel separated by healthy portions
what is the radiographic appearance of crohns disease?
rough cobble stone appearance caused by ulcerations
rigid segment of small bowel where mucosal pattern is lost shows a string sign.
hallmark of chronic crohns disease?
fistula formation
what is esophageal atresia?
discontinuation in the esophagus
when a person that is older than 40 years old has dysphagia, what must be assumed until proven otherwise?
that it is caused by cancer
where does esophageal cancer mostly occur?
at esophagogastric junction
what are esophageal varices?
dilated veins in the wall of the esophagus that are most commonly the result of increased pressure in the portal venous system
what is the radiographic appearance of esophageal varices?
rosary beads. because of the filling defects
what causes esophageal varices?
portal hypertension
what is intussusception?
telescoping of one part of the intestinal tract into another because of peristalsis.
