Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

GI part II questions, Assignments of Biology

Gastrointestinal system questions

Typology: Assignments

2023/2024

Uploaded on 11/08/2024

ranch-2
ranch-2 🇺🇸

5 documents

1 / 3

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Gastrointestinal System Lab Assignment 2 Answer Key
REFERENCE: Textbook unless otherwise stated
GASTROINTESTINAL BLEEDING AND DETECTION AND LOCALIZATION
1. List the reasons that an acute GI Bleed scan is performed. (Page 538)
a. Evaluate presence of a bleed and localize site of bleeding prior to treatment
2. What are the labeling efficiencies for in-vivo and in-vivo/in-vitro techniques? What is the advantage
of these techniques? (Page 539)
a. In-vivo: 60-90% labelling efficiency
b. In-vivo/in-vitro method: approaches 95% labelling efficiency
c. Absence of blood manipulation or risk of contamination
3. When there is an abundance of free pertechnetate secreted by the gastric mucosa and the kidneys,
what areas of the anatomy might be affected? (Page 539)
a. Interfere with ability to detect bleeding site in the stomach, proximal small bowel, colon
4. What is the advantage of using 99mTc-Sulfur Colloid for gastrointestinal bleeding? (Page 539)
a. 99mTc-sulfur colloid minimizes background activity and promotes high contrast ratios
5. What is the advantage of using 99mTc-RBC for gastrointestinal bleeding? (Page 539)
a. 99mTc-Tagged RBCs have prolonged retention in intravascular pool, which is better for
intermittent, slow GI bleeding; allow repetitive imaging up to 36 hours, lower radiation dose
to the liver and spleen, better detection of bleeding in the upper abdominal region
6. List the body structures that are normally seen during gastrointestinal bleeding imaging using both
radiopharmaceuticals. (Page 539 and Page 540)
a. 99mTc-Sulfur Colloid: early: intravascular space; later: liver, spleen, bone marrow, genitals
b. 99mTc-Tagged RBCs: great vessels of abdomen, kidneys, spleen, large/small bowel, genitals
7. List the instances that may lead to a false-positive result occurring when using both
radiopharmaceuticals. (Page 540)
a. 99mTc-Sulfur Colloid: renal transplants with rejection; asymmetrical bone marrow
accumulation of tracer (Paget’s, post-radiation therapy, tumor, etc.)
b. 99mTc-Tagged RBCs: anatomic variants of vascular structure
ECTOPIC GASTRIC MUCOSA
8. Most Meckel’s diverticula are asymptomatic, however ¾ of all symptoms that occur in children are
presented in what form? What other symptoms may be present? (Page 540)
a. Bleeding is ¾ of all symptoms in children; other symptoms include inflammation,
obstruction, intussusception, perforation of the bowel
9. What is the “Rules of 2” for Meckel’s diverticulum? (GI Lecture)
a. 2% of population; under the age of 2 years; within 2 feet of ileocecal valve; 2 inches in
length; 2 types of heterotrophic mucosa (pancreatic/gastric); and 2:1 male: female ratio
10. List the pharmacological agent that may be used during patient preparation to enhance the
probability of observing the ectopic gastric mucosa in a Meckel’s diverticulum. (Page 180)
a. Cimetidine/ Tagamet 20 mg/kg orally, 24 hours up to 1 hour before study
LIVER AND SPLEEN IMAGING
11. Liver and spleen imaging should be performed before administration of what contrast
agent? Why? (Page 542)
a. Iodinated or barium contrast- can result in artifactual defects of spleen or liver
pf3

Partial preview of the text

Download GI part II questions and more Assignments Biology in PDF only on Docsity!

Gastrointestinal System Lab Assignment 2 Answer Key REFERENCE: Textbook unless otherwise stated GASTROINTESTINAL BLEEDING AND DETECTION AND LOCALIZATION

  1. List the reasons that an acute GI Bleed scan is performed. (Page 538) a. Evaluate presence of a bleed and localize site of bleeding prior to treatment
  2. What are the labeling efficiencies for in-vivo and in-vivo/in-vitro techniques? What is the advantage of these techniques? (Page 539) a. In-vivo: 60-90% labelling efficiency b. In-vivo/in-vitro method: approaches 95% labelling efficiency c. Absence of blood manipulation or risk of contamination
  3. When there is an abundance of free pertechnetate secreted by the gastric mucosa and the kidneys, what areas of the anatomy might be affected? (Page 539) a. Interfere with ability to detect bleeding site in the stomach, proximal small bowel, colon
  4. What is the advantage of using 99mTc-Sulfur Colloid for gastrointestinal bleeding? (Page 539) a. 99mTc-sulfur colloid minimizes background activity and promotes high contrast ratios
  5. What is the advantage of using 99mTc-RBC for gastrointestinal bleeding? (Page 539) a. 99mTc-Tagged RBCs have prolonged retention in intravascular pool, which is better for intermittent, slow GI bleeding; allow repetitive imaging up to 36 hours, lower radiation dose to the liver and spleen, better detection of bleeding in the upper abdominal region
  6. List the body structures that are normally seen during gastrointestinal bleeding imaging using both radiopharmaceuticals. (Page 539 and Page 540) a. 99mTc-Sulfur Colloid: early: intravascular space; later: liver, spleen, bone marrow, genitals b. 99mTc-Tagged RBCs: great vessels of abdomen, kidneys, spleen, large/small bowel, genitals
  7. List the instances that may lead to a false-positive result occurring when using both radiopharmaceuticals. (Page 540) a. 99mTc-Sulfur Colloid: renal transplants with rejection; asymmetrical bone marrow accumulation of tracer (Paget’s, post-radiation therapy, tumor, etc.) b. 99mTc-Tagged RBCs: anatomic variants of vascular structure ECTOPIC GASTRIC MUCOSA
  8. Most Meckel’s diverticula are asymptomatic, however ¾ of all symptoms that occur in children are presented in what form? What other symptoms may be present? (Page 540) a. Bleeding is ¾ of all symptoms in children; other symptoms include inflammation, obstruction, intussusception, perforation of the bowel
  9. What is the “Rules of 2” for Meckel’s diverticulum? (GI Lecture) a. 2% of population; under the age of 2 years; within 2 feet of ileocecal valve; 2 inches in length; 2 types of heterotrophic mucosa (pancreatic/gastric); and 2:1 male: female ratio
  10. List the pharmacological agent that may be used during patient preparation to enhance the probability of observing the ectopic gastric mucosa in a Meckel’s diverticulum. (Page 180) a. Cimetidine/ Tagamet 20 mg/kg orally, 24 hours up to 1 hour before study LIVER AND SPLEEN IMAGING
  11. Liver and spleen imaging should be performed before administration of what contrast agent? Why? (Page 542) a. Iodinated or barium contrast- can result in artifactual defects of spleen or liver
  1. What information can be ascertained from planar images of the liver and spleen? (Page 543 and Page
    a. Identification of defects caused by compression of the liver by the ribs b. Size, shape of liver, spleen; relative concentration/distribution of RP, defects and displacements
  2. Name two artifacts that are seen in liver and spleen imaging? What can be done to clarify the problem? (Page 544) a. Stomach artifact- outline stomach by ingesting small loral does of SC or albumin colloid mixed with water b. Breast attenuation- mimic intrahepatic lesion: crescent shape makes it more identifiable as breast other overlying structures/organs: obtain supine and upright images LIVER HEMANIGIOMA DETECTION
  3. Are hemangiomas benign or malignant tumors? (Page 545) a. Benign
  4. How should the patient be positioned if the lesion is located anteriorly in the right or left lobe of the liver? If the lesion is posteriorly in the right lobe? (Page 545) a. Anterior right/left lobe: supine (image anterior) b. Posterior right lobe: prone (image posterior)
  5. What are the characteristics features of a hemangioma? How long do hemangiomas retain red cells, in contrast to other types of lesions? (Page 545) a. Characteristics: i. Little or no blood flow to the lesion in early angiographic images; early uptake may occur in late angiographic images ii. Early accretion of tagged cells at periphery of lesion inwards on blood-flow images iii. Accretion of tagged cells equal to/greater than surrounding liver parenchyma on delayed planar/SPECT images b. Hemangiomas retain RBCs up to two hours HEPATOBILIARY IMAGING
  6. List the time frame and pain medications which should be discontinued before HIDA imaging. Why? (Page 546) a. Opium/morphine derivatives 2-6 hours before study, can prevent transit of radiotracer through biliary system
  7. What should the technologist do if the gallbladder or biliary ducts fail to visualize by 1 hr of imaging? Why? (Page 546) a. Continue study for up to 4 hours for delayed imaging due to chronic cholecystitis, or administer morphine to contract sphincter of Oddi and force radiotracer into gallbladder
  8. In acute cholecystitis, what is anatomically seen and at what time frames? In chronic cholecystitis? (Page 547) a. Acute: liver, common bile duct, GI tract 60 minutes PI, no gallbladder after 60 minutes/ 4 hours b. Chronic: liver common bile duct, GI tract by 60 minutes, delayed gallbladder after 60 minutes (2-4 hours)
  9. Absence of the excretion of the radiotracer into the gastrointestinal tract is evidence of what condition? (Page 548) a. Common bile duct obstruction (functional or anatomic)
  10. In pediatric and congenital abnormalities, 99mTc-IDA derivatives are helpful in the detection of what pathologies? In what condition is extraction of the 99mTc-IDA compounds by the hepatocytes severely reduced? (Page 548 and Page 549)