اختبار: الأشعة البوزيتورنية

The term “partial volume effect” is caused by the limited resolution of PET scanners and refers to phenomenon that make intensity values in images differ from what they ideally should be. The “hot” spot smaller than twice the resolution of the scanner will have total counts preserved and will appear:

F-18 FDG uptake in tumors correlates with tumor:

The time from F-18 fluorodeoxyglucose (FDG) administration to the time of data acquisition has been shown to have a marked effect on FDG uptake. An increased interval between the injection and imaging uptake time will DECREASE radiotracer concentration in:

The elevated serum glucose level at the time of fluorodeoxyglucose (FDG) administration may decrease the sensitivity of the FDG-PET study. Althoguh intravenous bolus of insulin may effectively lower the serum glucose level, however induced hyperinsulinemia will:

Localizing metastatic disease in thyroid cancer patients with F-18 fluorodeoxyglucose (FDG) PET imaging is the primary clinical indication if:

All of the following cellular mechanisms are responsible for malignant cells increased F-18 fluorodeoxyglucose accumulation EXCEPT:

Before FDG administration, the patient relaxes in a waiting room to minimize muscular activity, and in so doing minimizes any physiological uptake of FDG in the muscles. Hyperventilation may cause increased uptake in the:

All of the following scintigraphic methods are often used in the diagnosis of fever of unknown origin (FUO) EXCEPT:

The concentration of glucose-6-phosphatase, an enzyme mediating dephosphorylation of FDG-6-phosphate, is low in most tumors EXCEPT:

The majority of radiation exposure to personnel performing PET/CT procedures comes from the: