Questions | Answers |
1. What type of meal is used for radionuclide esophageal transit scintigraphy? | 1. a liquid bolus |
2. What is the critical organ for oral 99mTc–sulfur colloid? | 2. the large intestine |
3. How are patients prepared for radionuclide esophageal transit scintigraphy? | 3. by an overnight fast |
4. How is a radionuclide esophageal transit scintigraphy performed? | 4. The patient lies supine and practices swallowing nonradioactive boluses. Then the patient swallows a radioactive bolus, dry swallows at 30 seconds, and thereafter swallows a radioactive bolus every 30 seconds for two minutes. |
5. Why are multiple swallows required for a radionuclide esophageal transit scintigraphy? | 5. There is a 25% incidence of aberrant swallows; multiple swallows give a more representative result. |
6. What is the definition of an “aber-rant” swallow? | 6. a swallow followed by a dry swallow that inhibits the initial swallow and causes delayed transit |
7. How does one calculate esophageal transit time? | 7. the time from the initial entry of the bolus into the esophagus until all but 10% of the initial activity remains |
8. Which esophageal abnormality can radionuclide esophageal scintigraphy detect most sensitively? | 8. achalasia |
9. How are patients prepared for gastroesophageal reflux scintigraphy? | 9. by an overnight fast |
10. What are the radiopharmaceutical dose and meal used for gastroesophageal reflux scintography in adults? | 10. 300 µCi (11.1 MBq) of 99mTc–sulfur colloid in 150 mL of orange juice |
11. What images are obtained for gastroesophageal reflux scintigraphy in children? | 11. 5- to 10-second dynamic images of the anterior abdomen and chest for 60 minutes and a 2- to 4-hour delayed image of the chest to look for aspiration |
12. Why is abdominal compression not used for gastroesophageal reflux scintigraphy in children? | 12. It is nonphysiologic and does not increase the detection rate of reflux in children. |
13. What three features of reflux should be described in gastroesophageal re-flux scintigraphy in children? | 13. the height of the reflux in the esophagus, the duration of the reflux, and the time from the meal |
14. What other radionuclide technique can be used for accurately detecting pulmonary aspiration? | 14. a radionuclide salivagram, where the tracer is placed on the tongue and dynamic images are obtained |
15. What are the two functionally distinct areas of the stomach involved in gastric emptying? | 15. the fundus and the antrum |
16. What are the common symptoms of delayed gastric emptying? | 16. early satiety, bloating, nausea, vomiting |
17. What are the symptoms of rapid gastric emptying? | 17. palpitations, diaphoresis, weakness, diarrhea |
18. What is the most common cause of chronic gastroparesis? | 18. diabetes |
19. What drugs are used to treat chronic gastroparesis? | 19. metoclopramide, domperidone, cisapride, erythromycin |
20. What tracer is used to measure liquid gastric emptying in single-isotope studies? | 20. 99m Tc–sulfur colloid |
21. What tracer is used to measure liquid gastric emptying in a dual-isotope study, simultaneous with solid-phase emptying? | 21. 111In-diethylene triamine pentacetic acid (DTPA) |
22. What characteristics of a meal affect its rate of gastric emptying? | 22. liquidity, texture, volume, weight, particle size, caloric density, nutrient composition |
23. What is the standard scintigraphic meal for the evaluation of gastric emptying? | 23. An egg-white meal (Egg Beaters or generic equivalent) radiolabeled with 0.5 mCi of 99mTc–sulfur colloid and toast and jam |
24. What is the advantage of dual-isotope gastric emptying studies over solid-phase gastric emptying studies? | 24. 20% to 30% of adults with normal solid gastric emptying have abnormal liquid emptying. |
25. What are the relative sensitivities of solid- and liquid-phase gastric emptying studies? | 25. The solid phase is more sensitive than the liquid phase (80% vs. 60%) to detect gastroparesis. |
26. When should liquid-phase gastric emptying studies be performed? | 26. when the patient cannot tolerate solids or when gastric emptying was normal |
27. True or false: Decay and attenuation corrections are utilized for calculation of gastric emptying half-time. | 27. true |
28. Why is attenuation correction helpful in performing gastric emptying studies? | 28. Movement of the meal from the posterior fundus to the anterior antrum can cause an increase in counts due to attenuation effects alone. |
29. How is attenuation accounted for in gastric emptying studies? | 29. Obtain anterior and posterior counts and calculate the geometric mean. |
30. What is the current consensus on the imaging time periods for the evaluation of solid gastric empting? | 30. Imaging should at least be performed at the ingestion and one, two, and four hours after the ingestion of the radiolabeled meal |
31. When does emptying of a liquid meal begin? | 31. immediately |
32. How does a coexisting solid meal affect the emptying of a liquid meal? | 32. It slows the emptying of the liquid meal. |
33. What is the half-life of a liquid meal in the stomach? | 33. approximately 10 to 20 minutes |
34. When does emptying of a solid meal begin? | 34. after an initial lag phase |
35. What are the normal retention values at one, two, and four hours? | 35. one hour, 37% to 90%; two hours, 30% to 60%; four hours, 0% to 10% |
36. What disease can cause an increased lag phase of gastric emptying? | 36. diabetes |
37. How are patients prepared for a gastric emptying study? | 37. by an overnight fast |
38. How does the urea breath test work? | 38. The patient is given 13C- or 14C-labeled urea orally; the presence of 13C- or 14C-labeled CO2 in the breath indicates urea-splitting bacteria in the stomach, such as Helicobacter pylori. |
39. How is gastrointestinal bleeding diagnosed by scintigraphy with 99mTc–sulfur colloid? | 39. A focal area of tracer accumulation is seen that increases in intensity with time and moves within the gastrointestinal tract. |
40. What are the causes of false-positive gastrointestinal bleeding scintigraphy with 99mTc–sulfur colloid? | 40. ectopic spleen, renal transplant up-take, asymmetric marrow uptake |
41. It is difficult to diagnose gastrointestinal bleeding with 99mTc–sulfur colloid in what areas of the gastrointestinal tract? | 41. splenic flexure and transverse colon, due to overlap of the liver and spleen |
42. How is a gastrointestinal bleeding scintigraphy performed with 99mTc–sulfur colloid? | 42. The patient is injected with 10 mCi (370 MBq) of 99mTc–sulfur colloid; 1-second flow images are obtained for 60 seconds, followed by 1- to 2-minute dynamic images for 20 minutes. |
43. How is a gastrointestinal bleeding scintigraphy performed with 99mTc–red blood cells (RBCs)? | 43. The patient is injected with 25 mCi (925 MBq) of 99mTc-RBCs; 1- to 2-minute dynamic images are obtained for 60 to 90 minutes. |
44. How is gastrointestinal bleeding diagnosed by scintigraphy with 99mTcRBCs? | 44. A focal area of tracer accumulation is seen that increases in intensity with time and moves within the gastrointestinal tract. |
45. What is the main advantage of 99mTcRBCs over 99mTc–sulfur colloid for the detection of gastrointestinal bleeding? | 45. The bleeding does not have to be active at the time of tracer injection, resulting in greater sensitivity. |
46. What are the methods of labeling 99mTc with RBCs for gastrointestinal bleeding scintigraphy? | 46. in vivo, in vitro, and in-vivtro |
47. Which method of labeling has the highest labeling efficiency? | 47. in vitro (greater than 97%) |
48. What drug can be given to enhance the sensitivity of gastrointestinal bleeding scintigraphy for small bowel bleeding? | 48. glucagon |
49. What is the significance of large bowel activity on 24-hour images in gastrointestinal bleeding scintigraphy with 99mTc-RBCs? | 49. It indicates gastrointestinal bleeding but does not localize the site; the site could have been anywhere in the gastrointestinal tract with pooling in the large intestine. |
50. A false-positive interpretation on a 99mTc-RBC-tagged study can result from: A. free 99mTc-pertechnetate secreted by the gastric mucosa B. pelvic structures such as ectopic kidneys, fibroids, uterus, and genitalia C. renal pelvic retention of activity D. abdominal aortic aneurysm E. hepatic hemangioma, accessory spleen, varicies F. all of the above | 50. F, all of the above |
51. What rate of bleeding can be detected with gastrointestinal bleeding scintigraphy? | 51. as low as 0.05 to 0.1 mL/minute |
52. What rate of bleeding can be detected with contrast mesenteric angiography? | 52. 1 mL/minute or more |
53. What is the reported rate of bleeding that can be detected on a contrast-enhanced MDCT, given that the patient is actively bleeding during the scan period? | 53. 0.3 mL/minute or more |
54. What volume of blood can be detected with gastrointestinal bleeding scintigraphy? | 54. as little as 3 mL |
55. What is the whole-body radiation dose of gastrointestinal bleeding scintigraphy with 99mTc–sulfur colloid? | 55. 0.190 rad (1.9 mGy) |
56. What is the whole body radiation dose of gastrointestinal bleeding scintigraphy with 99mTc-RBCs? | 56. 0.4 rad (4 mGy) |
57. the spleen, with 2.1 rads (21 mGy) | |
58. What are the critical organ and its radiation dose for gastrointestinal bleeding scintigraphy with 99mTcRBCs? | 58. the heart, with 1.4 rads (14 mGy) |
59. What are the two main advantages of 99mTc–sulfur colloid over 99mTcRBCs for the detection of gastrointestinal bleeding? | 59. There are fewer false positives, and the test is easier to interpret. |
60. What is the target organ for 99mTcpertechnetate? | 60. the stomach |
61. What cell type in the stomach takes up 99mTc-pertechnetate? | 61. the mucin-producing parietal cells |
62. What patient preparation is required for a Meckel scan? | 62. four to six hours of fasting and no barium studies in the past three or four days |
63. 99mTc-pertechnetate abdominal imaging may be used to detect: A. Barrett esophagus B. Meckel diverticulum C. retained gastric antrum D. all of the above E. none of the above | 63. D, all of the above |
64. All of the following have been proposed as pharmacologic interventions to enhance Meckel diverticulum imaging except: A. cholestyramine B. pentagastrin C. glucagons D. cimetidine E. all of the above | 64. A, cholestyramine |
65. What are the mechanisms of action of glucagon, pentagastrin, and cimetidine for gastrointestinal (GI) scintigraphy? | 65. Glucagon, antiperistaltic effect; pentagastrin, increased pertechnetate uptake and secretion, similar to gastrin; cimetidine, histamine H2-receptor blocker that inhibits pertechnetate secretion by mucin cells |
66. What are the sensitivity and specificity of a Meckel scan for ectopic gastric mucosa? | 66. both approximately 80% |
67. True or false: In jaundiced patients, there is enhanced renal excretion. | 67. Related posts: Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
Get Clinical Tree app for offline access
|
