FRCR FRCR Nuclear Medicine 2

Question 1

SPECT-CT combines which two imaging modalities?

Accepted Answer

Single-photon emission CT and anatomic CT

Answer

SPECT-CT fuses functional nuclear medicine (gamma camera tomography) with anatomic CT on the same device, improving lesion localization and attenuation correction.

Question 2

The 'flip-flop' phenomenon on bone scan refers to:

Accepted Answer

Areas of initially increased uptake appearing photopenic on follow-up due to healing or flare response

Answer

In patients responding to cancer therapy, previously photopenic lytic metastases may show increased uptake (healing response) — and vice versa — leading to the flip-flop appearance.

Question 3

Gallium-68 DOTATATE PET-CT is the preferred imaging modality for:

Accepted Answer

Gastroenteropancreatic neuroendocrine tumors (NETs)

Answer

Ga-68 DOTATATE binds somatostatin receptors overexpressed in most gastroenteropancreatic NETs, providing superior sensitivity and resolution compared to In-111 OctreoScan.

Question 4

In myocardial perfusion imaging, which finding indicates a fixed defect rather than ischemia?

Accepted Answer

Perfusion defect present on both stress and rest images

Answer

A fixed defect (present on both stress and rest) indicates scar tissue (prior infarction) with no viable myocardium, whereas a reversible defect (stress only) indicates ischemia.

Question 5

Which radiopharmaceutical is used to image pheochromocytoma and paraganglioma in nuclear medicine?

Accepted Answer

I-123 or I-131 MIBG (metaiodobenzylguanidine)

Answer

MIBG is a norepinephrine analogue taken up by catecholamine-secreting tumors via the norepinephrine transporter, making it highly specific for pheochromocytoma imaging.

FRCR - Fellow of the Royal College of Radiologists Practice Test

FRCR - Fellow of the Royal College of Radiologists Practice Test

FRCR FRCR Nuclear Medicine 2