PET/CT > Post Test


Post Test

All of the material covered in this test can be found on the previous pages. Answers are provided at the end of the test.


1) What is the cellular characteristic that most contributes to FDG accumulation in cancer cells?

High mitotic rate
 Up regulation of glucose transporters and glycolytic enzymes
 Increased cell membrane permeability
 Over expression of high affinity cell surface receptors
 None of the above

2) While FDG PET targets neoplasms, increased uptake can also been seen in all the following processes except?

Inflammation
 Infection
 Post radiation therapy
 Necrosis
 Surgical scar

3) In comparing PET/CT to PET which on of the following is incorrect?

CT attenuation correction is superior to positron transmission scan attenuation correction.
 PET/CT improves anatomic localization of metabolic FDG activity.
 A PET/CT scan requires more time than a PET - only scan.
 PET/CT improves temporal correlation between PET and CT data.

4) In regard to FDG PET imaging in 2007, the Center for Medicare and Medicaid Services provides reimbursement for all of the following indications except?

Head and neck cancer (non-thyroid, non-CNS): diagnosis, staging, and restaging
 Brain tumor: diagnosis, staging, and restaging
 Myocardial viability: primary or initial diagnosis
 Refractory seizures (brain): pre-surgical evaluation
 Oncological indications not approved by CMS can be submitted through the National Oncologic PET Registration (NOPR) for Medicare reimbursement.

5) Which one of the following statements is not true regarding PET attenuation artifacts?

Non attenuation corrected PET data, attenuation corrected, as well as co-registered PET CT data should all be viewed to improve interpretation and problem solve.
 Orthopedic prosthesis can generate “hot spots” in adjacent tissues on non attenuation corrected data.
 Non attenuation corrected data sets have low counts with in the central body structures like the spine.
 The lungs and skin appear darker on non attenuation corrected images compared to attenuation corrected data sets.
 PET attenuation artifacts occur with PET-CT and not PET-only.

6) All of the following are true regarding Standard Uptake Values (SUVs) except?

SUVs are semiquantitative measurements based FDG activity, administered dose, and body weight.
 SUVs above 2.5 are diagnostic of malignancy.
 SUVs can only be calculated on attenuation corrected images.
 SUVs may be calculated using body surface area instead of weight.

7) Which of the following statements is false regarding FDG activity in the brain?

FDG PET of the brain is clinically limited due to high background glucose metabolism.
 FDG PET of the brain can identify seizure foci.
 FDG PET of the brain can identify metabolism patterns associated with Alzheimer’s disease.
 FDG PET of the brain can identify brain tumors.

8) Which of the following tissues would be expected to have the lowest background FDG activity?

Liver
 Testicles
 Mediastinal lymph nodes
 Salivary glands
 Heart

9) Which of the following is true regarding FDG PET and endogenous glucose?

In whole body scans, the patient fasts for 4 hours in part to reduce myocardium uptake.
 In whole body scans, the patient glucose loads to increase tumor uptake.
 Hyperglycemic states, found in diabetics, do not significantly alter FDG PET scans.
 Injection of insulin to hyperglycemic patients optimizes FDG PET scan.

10) To avoid false negative FDG PET results, what is the target range for serum glucose?

0 - 50 mg/dl
 50 - 100 mg/dl
 100 to 150 mg/dl
 150 to 200 mg/dl
 FDG PET results are not significantly affected by serum glucose level

11) All of the following are potential artifacts which can mimic a malignancy on FDG PET-CT scan except?

Metallic prosthesis
 Dense barium in bowel
 Chest ports
 Motion misregistration at the diaphragm
 FDG uptake in the larynx

12) In regards to brown fat, which statement is true?

Brown Fat is adipose tissue with high glucose metabolism associated with heat generation.
 Brown fat activity can be reduced by premedicating with a benzodiazepine.
 Insuring adequate warmth in the patient before and during FDG PET scan can reduce brown fat activity.
 Brown fat can be confidently identified by characteristic locations.
 All of the above.

13) A breast cancer patient isundergoing restaging FDG PET/CT 6 months after completion of neoadjuvant chemotherapy, radiotherapy and lumpectomy. New increased uptake is evident within several non adjacent vertebral bodies of the lumbar spine. Which of the following is the most likely explanation?

Marrow response to chemotherapy
 Marrow response to granulocyte-colony stimulating factor (G-CSF)
 Marrow response to radiation therapy
 Tumor recurrence in vertebral bodies
 None of the above

14) Patient with papillary thyroid cancer status post total thyroidectomy and two previous I-131 therapies returns for followup which reveals an elevated serum thyroglobulin level. I-131 diagnostic scan reveals no abnormal I-131 uptake. Which of the following would be the most appropriate next step?

FDG PET/CT scan
 I 131 ablation
 Contrast enhanced neck CT
 Contrast enhanced neck MRI
 Advise surgeon to re-excise neck

15) Patient with history of sigmoid colon adenocarcinoma status partial resection and chemotherapy receives a restaging PET/CT. There is a segment of high FDG activity within the lumen of the caecum. Which best characterizes the finding?

Activity within stool
 Recurrent cancer
 Artifact from barium
 Colitis
 Indeterminate. Need additional clinical information or another study.

16) Patient with fever and history of smoking has a LUL density on chest x-ray. CT thorax demonstrates a nodular focus of LUL air space disease and no mediastinal adenopathy. What is the best next course?

PET/CT
 Repeat chest x-ray or CT thorax in one month after antibiotics
 Biopsy
 Wedge resection
 MRI

Your score is out of 16.

Answers