Q-1. PET stands for (NEET Based)
a) Positive electron tomography
b) Proton-electron therapy
c) Positron emission tomography
d) Photon emitting tomography
Answer: Positron emission tomography
Explanation:
Positron emission tomography (PET) is a radio-nucleotide scan which uses FDG (2-Fluoro-deoxy-glucose) tracer for anatomical and functional assessment of tissue. FDG is analogue of glucose. FDG-PET scan shows increased uptake and metabolism by malignant cells.
It can be used to detect distance metastasis, tumor recurrence after surgery or radio-therapy, treatment response and staging of various tumors.
It is also helpful in pre-operative localization of temporal lobe lesion in refractory epilepsy.
Important points:
Anatomical assessment by PET is inferior to CT with low spatial resolution.
Q-2. PET scan uses (NEET Based)
a) 2-Fluoro-deoxy-glucose
b) Technetium
c) Chromium
d) Cobalt
Answer: 2-Fluoro-deoxy-glucose
Explanation:
See above explanation.
Q-3. True about FDG-PET scan: (PGI 13)
a) FDG is analogue of glucose
b) Malignant cells shows high uptake due to increased metabolism
c) It cannot be used to detect brain metastasis
d) Used to detect tumor recurrence in patients who have undergone surgery for brain tumors
e) Helpful in investigating lesion
Answer: a, b, d and e
Explanation:
See above explanation.
Q-4. All are true regarding PET scan except: (PGI 14)
a) Help in assessment of both anatomical and functional status of tissue
b) Do not pose any radiation exposure to patient
c) Superior to CT for anatomical detail
d) FDG is used
Answer: b and c
Explanation:
See above explanation.
Q-5. Gamma camera in Nuclear Medicine is used for: (Al 05)
a) Organ imaging
b) Measuring the radioactivity
c) Monitoring the surface contamination
d) RIA
Answer: Measuring the radioactivity
Explanation:
The decay of radio-tracer leads to emission of gamma rays which are measured by gamma camera with help of scintillation crystal.
Important point:
Gamma camera in nuclear medicine is used for measuring radio-activity.
Neurology
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Q-6. A patient presented with a 4 cm tumour in the left parietal lobe for which he underwent surgery and radiotherapy. After 2 months, he presented with headache and vomiting. Which of the following would best characterize the lesion in this patient? (A112)
a) Gd-enhanced MRI
b) 99T-HMPAO SPECT brain
c) Digital subtraction angiography with dual source CT scan
d) 18-FDG PET scan
Answer: 18-FDG PET scan
Explanation:
Positron emission tomography (PET) can be used to detect distance metastasis, tumor recurrence after surgery or radio-therapy, treatment response and staging of various tumors.
Important point:
It is also helpful in pre-operative localization of temporal lobe lesion in refractory epilepsy.
Q-7. Radiation induced necrosis can be diagnosed by (AIIMS NOV 209)
a) PET
b) CT
c) MRI
d) Biopsy
Answer: PET
Explanation:
PET and SPECT have ancillary roles in the imaging of the brain tumors, primarily in distinguishing tumor recurrence from tissue necrosis that can occur after radiation.
Biopsy is frequently required to establish the correct diagnosis.
Important points:
PET and SPECT may demonstrate that glucose metabolism is increased in tumor but decreased in radiation necrosis.
Q-8. Which of the following techniques in best for differentiating recurrence of brain tumor from radiation therapy induced necrosis? (AIIMS MAY 2005, 09)
a) MRI
b) Contrast enhanced MRI
c) PET scan
d) CT scan
Answer: PET scan
Explanation:
See above explanation.
Q-9. Which one of the following is the most preferred route to perform cerebral angiography? (AI 05)
a) Trans-femoral route
b) Trans-medullary route
c) Direct carotid puncture
d) Trans-brachial route
Answer: Trans-femoral route
Explanation:
Most preferred route to perform cerebral angiography is trans-femoral route.
Important point:
Puncture of the axillary artery or direct puncture of the carotid artery are rarely performed.
Gastroenterology
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Q-10. In Pancreatic scanning radio isotope used (DNB 06, AIIMS 04)
a) Cr 51
b) Se 75
c) Tc 99
d) I-131
Answer: Se 75
Explanation:
Uses of Nucleotides in scanning:
Tc labelled RBC: Splenic disease
Selenium 75 methionine: Pancreatic disease
Q-11. Tc labelled RBCs are used for (A1 05, DNB 07)
a) Biliary tree
b) Renal disease
c) Pulmonary embolism
d) Splenic disease
Answer: Splenic disease
Explanation:
Uses of Tc-99 labelled RBCs:
GI Bleeding
Splenic disease
Cardiac ventriculography
Hemangioma detection
Q-12. Protein losing enteropathy diagnosis, all used except? (AIIMS MAY 2011)
a) Tc Albumin
b) Tc dextran
c) In transferrin
d) Tc seclosumab
Answer: Tc seclosumab
Explanation:
For diagnosis of protein losing enteropathy, following chemicals have been used:
Indium III chloride
Indium III transferrin
Tc dextran
Tc albumin
Tc immunoglobulin
Q-13. Gold standard investigation for recurrent gastrointestinal stromal tumor is (AIIMS NOV 2008)
a) MRI
b) MIBG
c) USG
d) PET CT
Answer: PET CT
Explanation:
CT and 18F-FDG PET have comparable sensitivity and positive predictive values in staging malignant recurrent GISTs. However, 18F-FDG PET is superior in predicting early response to therapy.
Endocrine System
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Q-14. All isotopes are used for thyroid except: (PGI 02)
a) I-131
b) I-123
c) I-122
d) I-125
e) I-129
Answer: c, d and e
Explanation:
Thyroid scan:
I-123: Radiotracer of choice for functional evaluation of thyroid
I-131: Most favored for therapeutic purpose
Important point:
99Tc Pertechnetate most commonly used for imaging
Q-15. Isotope for thyroid scanning: (PGI 00, DNB 01)
a) I-129
b) I-131
c) Technetium
d) Selenium
Answer: b and c
Explanation:
See above explanation.
Q-16. Amount of I-131 used for thyroid scan is (AIIMS 02, DNB 06)
a) 5 Micro-curies
b) 50 Micro-curies
c) 50 Mili-curies
d) 500 Mili-curies
Answer: 50 Micro-curies
Explanation:
Dose of radio-agents in thyroid scan:
I-131: 50-100 microcurie
I-123: 100-300 microcurie
Tc 99 m: 2-10 m curie
Q-17. Sestamibi Scan is used in (DNB 01, PGI 03)
a) Ectopic thyroid
b) Ectopic parathyroid
c) Parathyroid adenoma
d) Extra adrenal pheochromocytoma
e) Adrenal pheochromocytoma
Answer: Parathyroid adenoma
Explanation:
Parathyroid scan:
MIBI (Tc99m Sestamibi) – Preferred
Tc Thallium substraction scan
Q-18. Investigation of choice for locating Parathyroid gland: (AIIMS 01, DNB 05)
a) Tc Thallium substraction scan
b) CAT scan
c) USG
d) Angiography
Answer: Tc Thallium substraction scan
Explanation:
See above explanation.
Q-19. Neuro-endocrinal tumors can be best detected by (AIIMS Nov 2001)
a) PET scan
b) HRCT Scan
c) MRI
d) Radio-nucleotide Scan
Answer: Radio-nucleotide Scan
Explanation:
The diagnosis of neuro-endocrine tumors is based on histopathology, imaging, and circulating biomarkers.
The histopathology should contain specific neuro-endocrine markers such as chromogranin A, synaptophysin, and neuron-specific enolase.
Somatostatin receptor scintigraphy is now the imaging modality of choice for localizing both primary and metastatic NET tumor.
Important point:
68Ga-DOTA-octreotate scans will in the future replace somatostatin receptor scintigraphy because they have higher specificity and sensitivity.
Heart Scan
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Q-20. Isotope used in ventriculography is (AIIMS 04)
a) Gallium
b) Lipoidate
c) Technetium
d) Dia-trizoate
Answer: Technetium
Explanation:
Ventriculography:
Tc-99m albumin
Tc-99m pyrophosphate
Tc-99m pertechnate
Q-21. Hot spot in acute MI is seen in: (DNB 09, AI 03)
a) Thallium
b) Strontium
c) Tc99 Strontium Pyrophosphate
d) Gallium Citrate
Answer: Tc99 Strontium Pyrophosphate
Explanation:
Myocardium perfusion:
Thallium scan
Myocardial infarction:
Cold spot/ Non-avid infarct imaging- Thallium (Tl)-201 (< 12-48 hours post infarct)
Hot spot/Avid infarct imaging-Tc-99m pyrophosphate (> 10-12 hours post infarct)
It shows doughnut pattern- Central cold effect due to necrosis in large infarct
Important point:
Only tumor producing hot nodules: Wertheim’s tumor/Adeno-lymphoma
Q-22. Hot spot in MI is seen in (AIIMS 06)
a) Th-201
b) Gallium
c) Pyrophosphate Tc99
d) Albumin
Answer: Pyrophosphate Tc99
Explanation:
See above explanation.
Q-23. Which test is performed to detect reversible myocardial ischemia? (NEET Based)
a) Coronary angiography
b) MUGA Scan
c) Thallium Scan
d) Resting echocardiography
Answer: Thallium Scan
Explanation:
See above explanation.
PET is generally regarded as the gold standard for the assessment of myocardium viability. PET identifies ischemic or hibernating myocardium in 10-20 % of the regions that would be classified as fibrotic or infracted by thallium and technetium labeled compounds.
Important point:
Viable myocardium is myocardium which due to ischemia does not contract normally at rest but has the potential to recover its function, either by itself over time or after revascularization.
Q-24. Best non-invasive test for myocardial viability (AIIMS May 2015)
a) Echo cardiograph
b) PET
c) MRI
d) Thallium 201 Scan
Answer: PET
Explanation:
See above explanation.
Bone Scan
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Q-25. Bone scan in multiple myeloma shows-: (AIIMS 06)
a) Hot spot
b) Cold spot
c) Diffusely increased uptake
d) Diffusely decreased uptake
Answer: Cold spot
Explanation:
Bone scans are the most sensitive routine imaging modality to try and identify both sclerotic and lytic lesions.
In most cases they demonstrate increased uptake (hot spot) although occasionally (in very aggressive purely lytic lesions) a photopaenic defect (cold spot) may be visible.
Myeloma is a disease that results in over-activity of osteoclasts, with resultant liberation of bone and suppression of osteoblasts.
Important point:
Nuclear medicine bone scans rely on osteoblastic activity (bone formation) for diagnosis.
99mTc-MDP (Technetium-99m linked to Methylene dis-phosphonate) bone Scan has highest affinity for Osteogenic bone site.
Q-26. On 3 phase 99mTc-MDP bone Scan, which of the following bone lesions will show least osteoblastic activity? (NEET Based)
a) Paget’s disease
b) Osteoid Osteoma
c) Fibrous Dysplasia
d) Fibrous cortical defect
Answer: Fibrous cortical defect
Explanation:
Hot spot in bone scan (Increased uptake of tracer): Seen in primary bone tumors
Paget’s disease
Osteoid osteoma
Osteomyelitis
Fibrosis dysplasia
Cold spot on bone scan: Decreased uptake of tracer
Multiple myeloma
Fibrous cortical defect
Q-27. Increased Radioisotope uptake is seen in A/E (AI 03)
a) Primary bone tumor
b) Osteomyelitis
c) Paget’s disease
d) Pseudo-arthrosis
Answer: Pseudo-arthrosis
Explanation:
See above explanation.
Q-28. Radionuclide imaging the most useful radio pharmaceutical for skeletal imaging is: (NEET Based)
a) Gallium 67
b) Technetium-sulphur-colloid
c) Technetium-99m
d) Technetium-99m linked to Methylene dis-phosphonate
Answer: Technetium-99m linked to Methylene dis-phosphonate
Explanation:
See above explanation.
Q-29. Best investigation for bone metastasis is: (NEET Based)
a) MRI
b) CT
c) Bone scan
d) X-ray El
Answer: Bone scan
Explanation:
Bone scan (Radio-nucleotide bone scintigraphy):
It is highly sensitive and most common investigation for evaluation of cancer patients for bone metastasis.
Important point:
It is proffered because it examines entire skeleton and more sensitive than CT scan in detecting small and early metastatic lesions.