FRCR FRCR Nuclear Medicine

Question 1

In a bone scan, which radiopharmaceutical is most commonly used?

Accepted Answer

Technetium-99m methylene diphosphonate (MDP)

Answer

Tc-99m MDP localizes in bone through chemisorption onto hydroxyapatite crystals at sites of increased osteoblastic activity, making it ideal for detecting bone metastases and fractures.

Question 2

FDG-PET exploits which metabolic characteristic of tumor cells?

Accepted Answer

Increased glucose uptake and glycolysis (Warburg effect)

Answer

Most tumors overexpress GLUT transporters and hexokinase, trapping FDG (fluorodeoxyglucose) intracellularly after phosphorylation — this is the basis of FDG-PET oncologic imaging.

Question 3

Which nuclear medicine study is used to evaluate renal tubular function and obstruction?

Accepted Answer

Tc-99m MAG3 renogram

Answer

MAG3 (mercaptoacetylglycine) is actively secreted by renal tubules and provides superior renal function and drainage assessment compared to DTPA in patients with reduced GFR.

Question 4

In a ventilation-perfusion (V/Q) scan, a high-probability result for pulmonary embolism requires:

Accepted Answer

Two or more large segmental perfusion defects with normal ventilation

Answer

PIOPED criteria define high-probability V/Q as two or more large segmental mismatched perfusion defects (perfusion defect with normal ventilation), indicating high likelihood of pulmonary embolism.

Question 5

Sentinel lymph node mapping in breast cancer most commonly uses which combination?

Accepted Answer

Tc-99m sulfur colloid + blue dye

Answer

Combined Tc-99m sulfur colloid lymphoscintigraphy and intraoperative blue dye injection maximizes sentinel node identification accuracy in breast cancer staging.

FRCR - Fellow of the Royal College of Radiologists Practice Test

FRCR - Fellow of the Royal College of Radiologists Practice Test

FRCR FRCR Nuclear Medicine